Platelet Derivatives in Regenerative Medicine: An Update

Transfusion Medicine Reviews 29 (2015) 52–61

Contents lists available at ScienceDirect

Transfusion Medicine Reviews journal homepage: www.tmreviews.com

Platelet Derivatives in Regenerative Medicine: An Update Maria Rosaria De Pascale a,1, Linda Sommese a,1, Amelia Casamassimi b,⁎, Claudio Napoli a,c a UOC Immunohematology, Transfusion Medicine and Transplant Immunology (SIMT), Regional Reference Laboratory of Transplant Immunology (LIT), Azienda Ospedaliera Universitaria (AOU), Second University of Naples, Naples, Italy b Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy c Institute of Diagnostic and Nuclear Development, IRCCS, Naples, Italy

a r t i c l e

i n f o

a b s t r a c t Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n N 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed. © 2015 Elsevier Inc. All rights reserved.

Available online 18 November 2014 Keywords: Platelet derivatives Regenerative medicine Clinical trials Growth factors

Contents Introduction . . . . . . . . . . . . . . . Literature Search Strategy . . . . . . Collection and Preparation . . . . . . . . Clinical Applications . . . . . . . . . . . Treatment of Chronic Wounds . . . . Treatment of Bone and Tendon Defects Ophthalmology . . . . . . . . . . . Conclusions and Future Perspectives . . . . References . . . . . . . . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

Introduction Tissue integrity and blood vessel repair are essential after a destructive event as surgery, trauma, and during degenerative diseases. Numerous cell types are involved in wound repair [1,2]. Endothelial cells, white

Declaration of interest: The authors declare no conflict of interest. ⁎ Corresponding author. Amelia Casamassimi, BiolD, Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Via Luigi de Crecchio, 7, 80138 Naples, Italy. E-mail address: [email protected] (A. Casamassimi). 1 These authors equally contributed to this work. http://dx.doi.org/10.1016/j.tmrv.2014.11.001 0887-7963/© 2015 Elsevier Inc. All rights reserved.

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

52 54 54 55 55 56 57 58 58

blood cells, and especially platelets play a pivotal role, first in the coagulation phase and then in the possible tissue regeneration, by releasing growth factors (GFs) and cytokines [2,3]. Platelet-derived factors have been extensively used for clinical and surgical applications requiring tissue regeneration [4–7]. The rationale for the widespread use of platelet derivatives in the healing process is due to the abundance and accessibility of critical GF and other signaling molecules in platelets [2,3,6]. Under normal conditions, GF and bioactive peptides contribute to a well-orchestrated tissue-healing response to injury, which proceeds sequentially through the inflammatory, reparative, and remodeling phase [1]. Generally, platelets are in a resting state and require a trigger before becoming active players in hemostasis and wound healing [5].

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61 Table 1 Summary of main PGFs GFs

Actions and functions

References

TGF-β

It acts as GF both in an autocrine and paracrine fashion with long-term healing; it inhibits macrophage and lymphocyte proliferation; it stimulates mesenchymal stem cells proliferation; it regulates endothelial, fibroblastic, and osteoblastic cell mitogenesis as well as collagen synthesis and collagenase secretion. It is the first GF in a wound and is responsible for connective tissue healing; it promotes chemotaxis of macrophages and neutrophils, chemotaxis and mitogenesis of mesenchymal stem cells, fibroblastic, and osteoblastic cells; it regulates collagen synthesis and collagenase secretion. It is a multifunctional protein with mitogenic effect and with regulatory, morphologic, and endocrine role; it regulates endothelial cells, mesenchymal stem cells, osteoblastic cells, and fibroblastic cells; promotes mitogenesis of chondrocytes; it promotes angiogenesis and formation of new blood vessels from the preexisting vasculature. It is a potent mitogen that increases the expression of several genes leading to DNA synthesis and cell proliferation; it regulates mesenchymal stem cells and epithelial cells mitogenesis; it promotes chemotaxis of endothelial cells and angiogenesis; it regulates collagenase secretion. It stimulates the proliferation and migration of endothelial cells to form immature vasculature; it regulates collagenase secretion. It is a protein of extracellular matrix that is contained in platelets in a concentration 20-fold higher than any other PGFs; it promotes platelet adhesion; it stimulates white blood cell migration; it promotes angiogenesis; it regulates osteoblastic cell activity; it regulates collagen synthesis.

[21,22,26,53,106]

PDGF

bFGF

EGF

VEGF

CTGF

[15,17–19]

[20,109]

[12,26,123]

[24,55]

[25,124]

CTGF, connective tissue growth factor.

During tissue repair, activated platelets release 2 types of granules known as dense granules with ADP, ATP, serotonin, and calcium and α-granules with clotting factors and platelet growth factors (PGFs) that are critical to normal platelet activity [6,8]. Platelet growth factors have specific cellular targets and promote cell proliferation, differentiation, and chemotaxis by inducing the migration of the cells with morphometric and mitogenic effects (Table 1). Furthermore, PGFs allow the differentiation

53

of immature cells by promoting expansion of mesenchymal stem cells from bone marrow, adipose tissue, or cord blood [9–11], and increasing the number of effective proliferating cells, thereby enhancing the healing process [12]. Once PGFs are released, they bind to tyrosine kinase receptors [13], thus propagating the signal from the plasma membrane to the nucleus through explicit pathways and signaling cascades [14,15], finally activating the expression of target genes [16]. Platelet growth factors modulate the cellular response to injury as shown in Figure. Platelet-derived growth factor (PDGF) [17–19] and fibroblast growth factor (FGF) [20] are the first GFs that are produced by platelets in relevant quantity to improve the recruitment and the activation of cells (macrophages, neutrophils, endothelial cells, etc), which are involved in tissue repair. In addition, transforming growth factor β (TGF-β) appears critical in the start of the wound healing process [21,22], stimulating chemotaxis and mitogenesis on neutrophils, monocytes, and macrophages [23]. During the healing process, an essential contribution is provided by vascular endothelial growth factor (VEGF) [24], which increases vessel permeability and neoangiogenesis. Moreover, Kubota et al [25] demonstrated that connective tissue growth factor enhances angiogenetic activity, cartilage regeneration, and fibrosis. Epithelialization, wound contraction, and remodeling occur via the epidermal growth factor (EGF) [26]. These collective biological properties underline the clinical use of platelet derivatives [2] not only to prevent hemorrhage but also to support the healing process especially during wound complications [27,28]. Furthermore, compared with the application of single recombinant GF in high concentrations, the use of platelet-derived products has the potential advantage of offering multiple synergistic GFs at the wound site [29]. These products include platelet-rich plasma (PRP), platelet gel (PG), platelet-rich fibrin (PRF), serum eye drops (E-S), and PRP eye drops (E-PRP). In particular, PRP and PG can be applied alone or in combination with substitutes to promote cell migration and tissue regeneration [30]. In this context, the use of platelet derivatives with scaffolds and with bone marrow or mesenchymal stem cells represents an opportunity to increase the effectiveness of treatments in clinical applications [31,32]. Here, we describe the methodological difference concerning the variety of platelet derivatives stressing the lack of standardization during the steps of their preparation. Moreover, we report the main clinical application focusing on different areas of regenerative medicine. We summarize reported findings given the lack of consistent therapeutic effects and the absence of data from studies with a large number of patients.

Figure. Schematic illustration of the role of platelet derivatives GFs during the different stages of wound healing process. CTGF, connective tissue growth factor.

54

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61

Literature Search Strategy We performed a computerized literature search on studies and trials by using the following search terms (also combining them): platelet derivatives, platelet growth factors, platelet-rich plasma, plateletrich fibrin, platelet gel, serum eyedrop, and plasma rich platelet eyedrop. This search was achieved without any time and language restrictions in the following databases: PubMed, controlled-trials.com, clinicaltrialsregister.eu, eudract.ema.europa.eu, and clinicaltrials.gov. The complete reference list of the most relevant studies was analyzed for the methodology of platelet derivative collection and preparation as well as for their main clinical applications. Published clinical trials were selected from studies published in the last 5 years (2010-2014). Because clinical trials in the field of dermatology and orthopedics are numerous and in a more advanced stage, we have considered for National Institutes of Health registered trials only those studies in phases 3 and 4 with more than 100 patients.

Collection and Preparation Before receiving platelet-derived products, patients have to undergo a laboratory evaluation. Contraindications to the use of platelet-derived products are: platelet count less than 105/μL, hemoglobin level less than 10 g/dL, presence of active infections, or presence of tumor or metastasis in the wound [33]. In clinical practice, an important issue is the choice between the use of autologous and allogeneic platelet derivatives. In the absence of pathogen inactivation treatment, the use of autologous platelet derivatives avoids the ethical and legal implications of exposing the patient to the viral risks of allogenic blood components [34], especially in countries with high infectious rates and with limited donor screenings and donation tests [35]. In contrast, autologous products carry only the risk of infection related to contamination during collection and handling [36]. Furthermore, autologous products may be more acceptable to patients. Disadvantages of autologous products include a larger individual variability in the quality of platelet derivatives compared with allogenic products that are prepared from healthy blood through standardized working procedures of blood transfusion services [37]. In routine practice, platelet derivatives are frequently used in the absence of robust and controlled clinical trials, which could serve to establish precise clinical protocols for product preparation [30]. To date, there is no universally accepted protocol [38–40]. It is clear that different procedures of platelet preparation may differentially affect the PGFs release and cell growth [40–44]. Production parameters include the absolute number and concentration of platelets over baseline, centrifugation conditions, the possible exogenous preactivation of platelets, the delay between injections or applications, and the number of treatments to be performed [40]. An important variable that can have a critical impact on the quality of platelet-derived products is the centrifugation protocol [45], which, as shown in Table 2, has been highly variable with respect to the force and time. High centrifugation forces can lead to the activation of platelets during preparation thus impairing the platelet function and their activity on the wound [4]. Moreover, some authors show as that the use of higher centrifugation forces with higher platelet concentrations does not necessarily lead to better clinical results [46]. There is also controversy regarding the ideal platelet concentrations in platelet derivatives [44]. Protocols with platelet concentration of 1- to 3-fold showed better results in wound healing compared with products containing higher concentrations [47]. Indeed, comparison of different platelet concentrations in PRP showed in vitro that rates of 2.5-fold gave better results on fibroblast and osteoblast proliferation and functionality [46]. In contrast, a recent in vitro study aimed to evaluate the effects of different platelet concentrations in PRP on the biological features of normal human tenocytes, which are usually required during tendon healing, suggests the need for a compromise between extremely

Table 2 Different centrifugation protocols for platelet derivatives Platelet derivatives

Centrifugation speed

Time (min)

References

PRP/PG

350g 959g 3000g 180g 1500 rpm 1000 rpm 3000 rpm 3000 rpm 1500 rpm 1000g 3000g 3000g 3000g 460g

15 11 15 10 15 10 10 10 10 15 15 15 15 8

[58] [7] [91] [38] [78] [125] [57] [58] [113] [114] [134] [60] [135] [114]

PRF E-S

E-PRP

high and low platelet concentrations to obtain an optimal global effect when inducing in vivo tendon healing [48]. Current PRP procedures share some points in common. The final PRP product typically has a platelet count of about 1 × 10 6/μL (4-5 times higher than baseline), and whole blood can be collected both through standard blood banking techniques and through devices including blood cell savers/separators (Table 3) or table top devices (Table 4). Nevertheless, the choice of each system is mainly dependent on the required product for the surgical or clinical procedures and on the size of the lesion to be treated. To produce PRP, whole blood is collected in acid/citrate/dextrose and centrifuged. Platelet-rich plasma undergoes a second higher centrifugation step to obtain a pellet of platelets and a supernatant of platelet-poor plasma (PPP) [32,38]. The release of GFs from PRP is due to the action of thrombin—the most potent platelet activator [49,50]. In clinical practice, the use of bovine thrombin has been occasionally associated with the development of antibodies to clotting factor V, factor XI, and human thrombin with the consequent risk of severe coagulopathies [51,52]. To avoid this concern, autologous thrombin can be prepared by mixing PPP with calcium gluconate [38]. Platelet gel is obtained by mixing PRP with thrombin and calcium gluconate, thus obtaining the gelation of the platelet concentrate. Previous studies, using different PRP production devices, showed that PDGF-αβ and TGF-β1 concentrations in platelet derivatives ranged from 100 to 200 ng/mL [53,54]. Platelet-derived growth factor β was about 10 ng/mL; EGF and VEGF, 1 to 5 ng/mL; TGF-β2, about 0.5 ng/mL; and IGF-1, about 100 ng/mL [54]. Thus, to achieve wound healing, a physiological mixture of PGFs may be more clinically advantageous than a single recombinant GF as PDGF-BB [29,55]. Normally, a volume of 0.2 to 0.5 mL calcium chloride to antagonize the anticoagulant effect of ACD-A, and 0.2 to 0.5 mL thrombin in 1 mL PRP can be used to obtain a functional solid PG. Platelet-rich fibrin is an alternative to PRP [44]. It can be considered a second-generation of platelet concentrate, which has been shown to have several advantages over traditionally PRP [56]. Some authors assert that PRF has a physiologic architecture that is very favorable to the healing process, and it is obtained through slow polymerization process [56]. The preparation of PRF results in a physiologic degree of platelet degranulation [57] without the stimulation of thrombin, thus allowing the establishment of a flexible fibrin network mostly capable of supporting cytokine release and cellular migration. Indeed, as demonstrated by Passaretti et al [58], the release of bFGF, VEGF, and some cytokines are significantly increased in PRF-conditioned medium compared with PRP-conditioned medium, whereas the procedure of PRP preparation leads to a larger release of PDGF as a possible result of the platelet degranulation [58]. This study shows that different procedures lead to quantitative differences in the content of GFs and cytokines of relevance for different clinical settings. The protocol for the preparation of PRF requires blood collection in tubes without

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61

55

Table 3 Overview of currently available cell saver/separator devices Device name

Manufacturer

Characteristic

Bowl size (mL)

Flow

Brat 2 Compact A Electa Haemonetics CS5-Plus Sequestra 1000 Fresenius Cats

Cobe Cardiovascular Inc, Arvada, CO Sorin Group, Mirandola, Italy Haemonetics Corporation, Braintree, MS Medtronic Inc, Minneapolis, MN Fresenius Kabi AG, Bad Homburg, Germany

Baylor bowl Latham bowl Latham bowl Latham bowl Separation chamber

55, 125, 175, 225, 240 55, 125, 175, 225 70, 125, 225 125, 225 n/a

Discontinuous Discontinuous Discontinuous Discontinuous Continuous

n/a, not applicable.

anticoagulant and an immediate centrifugation for the formation of a fibrin clot, which includes platelets and leukocytes (L-PRF). In contrast, E-S derives from a spontaneous coagulation of whole blood at room temperature with the subsequent release of PGFs [59]. The centrifugation after the clotting phase of 2 to 72 hours permits a good separation between serum and the clot [60,61]. The obtained serum is diluted with variable concentrations of sodium chloride 0.9% (NaCl) or/and antibiotics [62]. In the last 2 decades, E-S has been most used in ophthalmology for severe dry eye treatment because GFs and proteins may help the proliferation, migration, and adhesion of epithelial corneal cells [63,64]. As reported by Geerling et al [60], E-S is nonallergic by nature and its biomechanical and biochemical properties are similar to normal tears. However, compared with tears, serum contains TGF-β, vitamin A, lysozime, and fibronectin in major quantity [60,64]. When compared with E-S, E-PRP contains higher concentrations of essential GFs and cell adhesion molecules in a small volume of plasma that is diluted with saline, thus making the product more suitable for the ocular instillation [59]. The preparation of platelet derivatives, in these 2 available formulations, is inexpensive and easy, although it requires strict sterility conditions by operating inside a laminar flow hood. An important practical aspect on the use of platelet derivatives is their production, which can be adapted in a clinical setting with minimal costs allowing large number of patients to potentially benefit from this biological therapy.

Clinical Applications Since 1998 [44,65], platelet-derived products have been used as a resource in regenerative medicine for patients who have a poor response to standard treatments [66]. An increasing number of physicians have tried to use platelet-derived products in various medical settings to improve all stages of tissue repair [30,67]. Unfortunately, multicenter randomized trials with large sample sizes have not been done to validate this therapy [68] (see also Table 5). In surgery and during postoperative management, platelet-derived products have been used with standard treatment in attempt to prevent infection [69–74]. Antibacterial activity from platelet-derived products is felt result from increased local concentration of neutrophils, lymphocytes, and monocytes and the effect of platelet antibacterial proteins [69–74]. However, very little is known about the antibacterial effects of these products [75]. Indeed, other authors reported no statistically

significant difference in wound complications like infection or necrosis between patients treated with PRP and those not given PRP in 9 randomized controlled trials with a total of 325 participants [76]. Thus, the largest trial published to date suggests that platelet-derived products offer no substantial antibacterial effects. In nonrandomized trials, some authors observed a reduction in pain among patients treated with platelet derivatives [77,78]. Reduction in pain was attributed to release of serotonin by platelet-dense granules [79] or the activity of recruited leukocytes [80]. Nonrandomized favorable results have been reported in the treatment of osteoarthritis [81,82] and sports medicine [83–85]. Platelet-released factors could not directly reduce pain, but they might trigger the events that lead to the elimination of neuropathic pain [84]. However, a systemic review of the use of PRP injections in patients with chronic lateral epicondylar tendinopathy found no evidence of benefit [86]. Recently, a rigorously conducted randomized double-blind clinical study in patients with chronic Achilles tendinopathy found that PRP injection was no more effective in reducing pain and improving return to activity than placebo [87]. Thus, the current best evidence suggests no significant benefit from the use of platelet derivatives in the treatment of musculoskeletal pain syndromes. Of course, the reduction of pain produces important psychological and social implications leading to a less need for medications with a more rapid recovery of function. To date, there is no evidence of systemic effects that might limit the use of platelet derivatives if we exclude the possible risk of infections [35,36]; indeed, few randomized controlled trials reported adverse events, although without a proven causal relation with the application of these derivatives [68]. Most of the side effects are local and related to venipuncture required for blood collection or rarely bad scarring or calcification in the application sites [88]. The application of platelet derivatives has become commonplace in several fields of regenerative medicine as dentistry, maxillofacial, orthopedic, and ophthalmology, although their therapeutic effects have achieved conflicting results (Table 5). Of course, many ongoing studies suggest great interest of the scientific community on this topic (Tables 6 and 7) [7,89–97].

Treatment of Chronic Wounds Chronic nonhealing diabetic ulcers of lower extremity occur in association with peripheral neuropathy, ischemia, and trauma [98]. The goal

Table 4 Overview of currently available table top devices Device name

Manufacturer

Characteristics

Components

PRP (mL)

rpm

Angel Magellan Secquire GPS II Sympony II Genesis CS

Sorin Group Medtronic Inc PPAI Medical, Fort Myers, FL Biomet, Warsaw, IN DePuy Inc, Raynham, MS Emcyte Corporation, Ft Myers, FL

RBCs, PPP, PRP RBCs, PPP, PRP RBCs, PPP, PRP PPP, PRP PPP, PRP BMC, PPP, PRP

5-18 1-8 7 5-6 7 4-10

4000 4000 3500 3200 Fixed 2 steps 2400

Vivostat

Vivolution A/S, Birkeroed, Denmark

Variable chamber disk Chamber Container Container and buoy Two chambers Concave Aspiration Disc Preparation chamber

PRF, FS

5-7

n/a

RBCs, red blood cells; BMC, bone marrow concentrate; FS, fibrin sealant; n/a, not applicable.

56

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61

Table 5 Published interventional clinical studies on platelet derivatives (years 2010-2014) Medical fields

Trial registration no.

Study type

Patient no.

Outcome

References

Dentistry Dentistry Dentistry Orthopedics Orthopedics

Unregistered Unregistered Unregistered Unregistered Unregistered

Cooperative trial Comparative study Clinical investigation Randomized controlled study Cohort study

133 25 22 40 42

[93] [125] [126] [78] [127]

Orthopedics

Unregistered

Cohort study

58

Orthopedics

Unregistered

Clinical trial

27

Orthopedics Orthopedics Orthopedics Orthopedics

Unregistered Unregistered NCT01200875 NCT00758641

Orthopedics

NCT00761423

54

PRP does not improve patients in pain and activity.

[87]

Dermatology Dermatology Dermatology

Unregistered Unregistered Unregistered

Randomized controlled study Pilot open study Descriptive laboratory study Randomized controlled multicenter trial Randomized double-blind interventional study Prospective pilot trial Pilot open study Uncontrolled study

PG improves the quality and quantity of newly formed bone tissue. PRP improves bone density, decrease in probing depth. PRF improves the regeneration of bone after third molar surgery. PRP has significant effect in preventing blood loss, postoperative pain. PRP has not clearly demonstrated an accelerated recovery except for an improvement in internal rotation. PG improves healing preventing the risk of infections and of wound dehiscence. PG improves healing and pain in joint degeneration, after the first infiltration. PRP reduces pain. PRP heals muscle lesions and improves pain and muscle function. PRP supports a possible ergogenic effect. PRP induces a healing rate

8 12 21

[130] [91] [89]

Dermatology

NCT00931567

PG improves complete healing PG reduces ulcer wound size and improves quality of patient life. Homologous PG improves wound healing in diabetic lower extremity wounds. Platelet concentrates improve healing of postoperative hand wounds.

Dermatology Ophthalmology Ophthalmology

NCT00956020 Unregistered NCT01075347

PRFM stimulates histological changes in human skin. E-Ss improve dry eye. Autologous serum improves epithelial healing.

[132] [113] [133]

Prospective, randomized, controlled clinical trial Interventional study Clinical trial Prospective interventional study

40 53 25 120

68 4 16 165

[7] [108] [94] [128] [109] [129]

[131]

PRFM, platelet-rich fibrin matrix. NCT from ClinicalTrials.gov.

of treatment is to obtain complete and fast healing. The currently used standard treatments include adequate debridement, control of infection, revascularization of ischemic tissue, and avoidance of inappropriate pressure on the wound. In this context, human fibroblasts are believed to be the most important cells for the production and remodeling of the extracellular matrix, whereas the proteolytic enzyme matrix metalloproteinase1 plays a key role in collagen deposition and scarring [99]. Because they enable remodeling and wound contraction, PRP and PG are potential therapeutic agents for skin wound healing [67,100] and can be used in addition to skin equivalents that show short shelf-life and are expensive [101]. Indeed, PRP and PG increase the expression of type I collagen and matrix metalloproteinase-1 in human dermal fibroblasts promoting the differentiation of human dermal fibroblasts into myofibroblasts [99]. Particularly, positive outcomes have been reported in neuropathic diabetic ulcers and in pressure sores [7,89,90]. Results of clinical studies using these products are encouraging [37,102]. In the most common size of diabetic foot ulcers (b7.0 cm2 in area and b 2.0 cm 3 in volume) PG-treated wounds appear to be more likely to heal than control wounds [103]. A prospective, randomized controlled trial of autologous PG showed that 68.4% (13/19 patients) treated with PG healed in 12 weeks [103]. In this context, PG was also found to enhance the take of skin graft [104]. In 8 of the 9 skin grafts, time to healing ranged from 2 to 3 weeks without major loss, and patients achieved durable wound healing in the follow-up in 10 to 19 months [104]. Current evidence suggests that PRP and skin graft combination enhances the efficacy of treating chronic diabetic wounds by enhancing healing rate and decreasing recurrence rate [104]. Although the clinical safety and effectiveness data are derived from pilot studies rather than from randomized controlled trials, they provide a preliminary indication of the potential advantage of platelet products as an adjunct to standard treatment of nonhealing ulcers [67]. However, a meta-analysis, analyzing chronic skin ulcers in 6 randomized controlled studies with a total of 227 patients, showed no significant difference between experimental and control groups for the endpoint of complete epithelialization of skin ulcers. In addition, 2 studies with a total of 38 patients with surgical wounds found no difference between treatment groups [68]. Thus, there is a lack of strong evidence in favor of the use of PG in the treatment of severe and large ulcers, and

further studies are needed to determine whether any subset of patients might benefit.

Treatment of Bone and Tendon Defects Both bone morphogenetic proteins (BMPs) and cytokines signals influence osteoblast differentiation and bone formation [105,106]. Platelet derivatives were found to improve bone maturation, bone regeneration and bone density perhaps in response to the presence of BMPs, as BMP-2, 4, BMP-6, or BMP-7, belonging to the TGF family [106]. Genetic disruption of BMPs results in various skeletal and extraskeletal abnormalities during development [105]. Their most important role is the induction of fibroblast chemotaxis, the production of collagen and fibronectin and the inhibition of collagen degradation by decreasing proteases and increasing protease inhibitors. Specifically, TGF-β1 has been shown to increase osteoblast and osteoclast activity [106]. As suggested by several studies, PRP and PG are used to improve autologous and allogenic bone grafts and implant placement for dental rehabilitation during alveolar ridge atrophy, periodontal diseases, and during loss of bone volume [93]. The addition of platelet derivatives to bone appears to give better grafting results than bone alone, with enhancement of osseointegration of dental implants optimizing the expansion of new bone cells. The osteoinductive and collagen synthetic properties have led to use of platelet derivatives in combination with standard medical and orthopedic treatment of tendon and ligament ruptures [107,108]. Tendon repair is felt to be due to VEGF release that stimulates angiogenesis [24] leading to an improved blood supply. A recent study has shown that VEGF could be the most sensitive molecular marker to detect recently PRP treated patients, although after PRP injection, serum IGF-1 and bFGF levels were significantly elevated [109]. Furthermore, a critical factor for the proliferation of tendon cells is the production of hepatocyte growth factor, a potent antifibrotic agent that reduces scar formation and fibrosis in newly reconstructed tendon tissues [110]. Under the assumption of reduced inflammation and pain in the damaged structures [77,78,85], PRP has been used to treat acute and chronic tendon, ligament, and muscle injuries in more than 86 000 athletes in the United States annually [109].

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61

57

Table 6 Ongoing clinical studies on platelet derivatives from ClinicalTrials.gov Field

Trial registration no.

Study type

Patient no.

Platelet derivatives

Delivery route

Condition

End point

Phase

Dentistry

NCT01793389

22

PRF

Topical

Gingival recession

Reduction in gingival recession

Not provided

Dentistry Dentistry

NCT02190409 NCT02198001

20 100

PRF PRF

Topical Topical

NCT01530126

180

PG

Topical

Dental implant Bisphosphonate-Associated osteonecrosis of the jaw Periodontitis

Implant stability Prevention of jaw osteonecrosis after tooth extraction Reduction in gingival recession

Not provided Not provided

Dentistry Orthopedics

NCT01670578

192

PRP vs HA

NCT01923909

100

PRP vs Steroid

Knee chondropathy, osteoarthritis Knee osteoarthritis

Orthopedics

NCT01765712

100

PRP vs placebo

Pain relief and recovery of knee function Improvement in WOMAC and Oxford Knee score Anterior knee pain

Orthopedics

NCT01926327

Randomized, double blind

150

PRP vs placebo

Intra-articular injections Intra-articular injections Intra-articular injections Injection

Phase 4

Orthopedics

Randomized single blind Open label Randomized single blind Randomized double blind Randomized double blind Randomized single blind Randomized

Phase 3

Orthopedics

NCT00758641

120

Plantar fasciitis

NCT01270412

100

PRP vs corticosteroid PRP vs HA

Injection

Orthopedics

Injection

Knee osteoarthritis

NCT02211521

110

PRP vs HA

Injection

Knee osteoarthritis

Pain, function, quality of life, activity level Pain reduction

Phase 2/3

Orthopedics Dermatology

NCT02213952

150

PRP vs standard care

Topical

Ulcer

NCT01816633

380

PG

Topical

Diabetic foot ulcers

Dermatology

NCT01816672

280

PG vs standard care

Topical

Dermatology

NCT01819142

400

PG vs standard care

Topical

Non healing diabetic foot ulcers Pressure ulcer

Ulcer size change, quality of life Time to heal, ulcer recurrence, incidence of amputation, quality of life, proportion of completely healed ulcers Time to complete wound closure

Phase 3

Dermatology

Randomized, double blind Randomized, double blind Randomized, double blind Randomized, single blind Open label

Pain, physical activity, cartilage repair, quality of life, joint replacement Pain reduction

Time to complete wound healing

Phase 4

Dermatology

NCT01817543

385

PG vs standard care

Topical

Venous leg ulcer

Time to wound closure

Phase 4

Ophthalmology

NCT01089985

10

ASE vs tears

Instillation

Xerophthalmia

Phase 1

Ophthalmology

NCT01972438

44

AS therapy

Instillation

GVHD

Grading of punctate corneal staining in the worse eye A greater than or equal to 50% reduction in the combined score of the modified Oxford punctate keratopathy grading and the NIH/NEI visual analog scale in the study eye from baseline to month 3

Randomized single blind Multicenter, prospective Multicenter, prospective, cohort Open label Randomized, double blind

Postoperative pain Osteoarthritis

Not provided

Phase 4 Phase 4

Phase 4

Phase 3

Phase 4

Phase 4

Phase 1/2

HA, hyaluronic acid; WOMAC, Western Ontario and McMaster Universities Arthritis Index; VAS, visual analog scale; ASE, Autologous serum eye drops; GVHD, graft vs host disease; NIH, National Institutes of Health; NEI, National Eye Institute.

Nevertheless, we should consider that despite the encouraging results in painful tendon disorders, some authors evidenced an absence of efficacy of PRP in chronic lateral epicondylar tendinopathy [86]. Relevantly, a meta-analysis on 6 studies strongly proved that PRP injections are not successful in the management of tendinopathy [86]. Ophthalmology Platelet-derived products have shown an important role in the treatment of dry eye syndrome, dormant ulcers (epithelial defects of the cornea that fail to heal), ocular surface syndrome after Laser In Situ Keratomileusis, and for surface reconstruction after corneal perforation associated also with amniotic membrane transplantation [61,111–114]. Furthermore, platelet derivatives appear to show therapeutic effects in some diseases such as diabetic keratitis, keratocongiuntivite sicca, traumatic postinfectious, and vernal ulcers that lead to a condition known as persistent epithelial defects [115]. Several groups have focused their attention to understand the different processes related to wound healing of the ocular surface. Firstly, fibroblast recruitment repopulates injured sites [116]. In this context, GFs such as EGF, FGF, and TGF-β1, play a primary role [117]. Above all, TGF-β can induce the fibroblast differentiation into myofibroblasts [117], which is a critical

passage for the development of scarring tissue [118]. Unfortunately, the presence of fibrotic tissue at the anterior surface of the eye after an injury or a surgery may induce corneal opacification (corneal haze) [119] and may lead to surgical failure. Different approaches to regenerate the ocular surface and to treat the scar formation have been attempted [120]. Results demonstrated that different blood formulations (whole plasma and PRP) showed similar biological effects on proliferation and migration of keratocytes and conjunctival fibroblast cells and on the inhibition of myofibroblastic phenotype to reduce scarring [110]. Human serum has a lubricating and mechanical-refractive action but above all a tropic effect for the epithelial cells. It contains a variety of GFs, vitamins, and immunoglobulins, even in higher concentrations compared with natural tears [60]. This property may be of value in some conditions where reduction of lachrymation can seriously alter the integrity of ocular surface leading to delayed healing of existing lesions. To date, surgical attempts aimed at restoring the integrity of the ocular surface in dry eye syndrome have not proved effective nor have the use of the artificial lubricants and the currently available pharmaceutical products [59]. Indeed, all the pharmaceutical substances support only the mechanical function of tears, and their biological substances (fibronectin, vitamins, and GFs) are subjected to a loss of stability [121]. In contrast, platelet-derived eye drops contain components not

58

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61

Table 7 Ongoing clinical studies on platelet derivatives from clinicaltrialsregister.eu Field

Trial registration no.

Study type

Patient no.

Platelet derivatives

Delivery route

Condition

End point

Phase

Orthopedics

EudraCT 2013-001303-36 EudraCT 2012-001056-19

Controlled randomized double blind Controlled randomized single blind

50

PRP vs HA

Knee osteoarthritis

Pain reduction

Phase 3

84

PRGF vs corticosteroids

Intra-articular injections Intra-articular injections

Rotator cuff tendinopathy

Phase 3

EudraCT 2006-002198-32 EudraCT 2013-000478-32 EudraCT 2006-005391-40 EudraCT 2010-023977-21 EudraCT 2009-011755-47 EudraCT 2012-002247-20

Controlled randomized double blind Controlled randomized single blind Controlled randomized single blind Controlled randomized, double-blinded parallel group Pilot study

230

PRP vs lidocaine and corticoids PRP vs lidocaine

Intra-articular injections Intra-articular injections Intra-articular injections Intra-articular injections Topical

Tennis elbow (lateral epicondylitis) Chronic epicondylitis

Improvement in the reference tests (UCLA and quick DASH) of more than 15% Pain reduction The percentage of patients that improves DASH scale Reduction of rheumatoid erosions Pain reduction

Phase 3

Phase 2

EudraCT 2012-001556-19 EudraCT 2012-004605-27

Proportion of completely healed ulcers after 12 wk % of patients with only 1 core per week CIVIQ score ulcer area Tear film and ocular surface changes Improvement of at least 2 degrees of the scale of Oxford

Orthopedics

Orthopedics Orthopedics Orthopedics Orthopedics Dermatology Dermatology

Ophthalmology Ophthalmology

72 60 64

Autologous PG vs biological drugs PRP vs corticoids

60

PRF

Controlled randomized open-parallel group

42

Autologous PRP vs standard care

Topical

Diabetic nonischemic foot ulcers Vascular venous ulcers

Controlled randomized, double blinded Controlled randomized, double-blinded parallel group

123

AS, ES, umbilical cord serum AS vs tear substitute

Instillation

Dry eye syndrome

Instillation

Dry eye syndrome

100

Rheumatoid arthritis Knee osteoarthritis

Phase 4

Phase 3 Phase 3

Phase 2

Phase 2 Phase 4

HA, hyaluronic acid; PRGF, plasma rich in GFs; UCLA, University of California, Los Angeles; DASH, Disabilities of Arm Shoulder and Harm; CIVIQ, Chronic Venous Insufficiency Quality of Life Questionnaire; NMR, nuclear magnetic resonance; AS, autologous serum; ES, heterologous serum.

found in artificial tears including a variety of GFs, vitamins, and immunoglobulins. In vitro experiments showed that corneal epithelial cell morphology and biological functions are better maintained by human E-S drops than by pharmaceutical tear substitutes [121]. However, the highest-quality randomized controlled trials data seem to show opposite findings. Indeed, a recent meta-analysis has considered four randomized controlled trials where 20% AS was compared with artificial tears in 72 patients with a large variety of dry etiologies. The authors concluded that 20% AS may provide some benefit in reported symptoms only in a short period (2 weeks) but not in longer period of follow-up. Therefore, current data on adverse effects do not provide consistent information about safety of 20% AS as well as on adverse outcomes like complications, infections, and tolerance of AS [122]. Thus, well-planned, large-scale, high-quality randomized controlled trials are needed to achieve a final conclusion on the efficacy of AS in eye disorders. Conclusions and Future Perspectives Overall, platelet derivatives could be a promising therapeutic tool for periodontal, oral, maxillofacial, orthopedic, and dermatologic procedures. Platelets are a well-known source of cytokines and GFs, which amplify wound healing and tissue repair. Because of encouraging results from several clinical studies, the number of patients that use platelet derivatives is continuously increasing and includes patients with important restrictions in quality of life, as reported in Tables 5–7. Several published studies have reported the absolute safety of platelet derivatives, suggesting that they can improve clinical outcomes compared with standard treatments in these patients. In contrast, in other studies, no improvement has been observed with their use. Generally, the absence of accepted standards for the production of PRP/PG, PRF, and eye drops significantly undermines the consistency of platelet derivatives. In addition, the lack of a universal terminology contributes to the confusion in the data interpretation, thus making the comparison of results more difficult [44]. The widespread application of this technology in the absence of well-conducted, blinded, multicenter randomized controlled trials with large sample sizes makes interpretation of the existing literature uncertain. Despite numerous studies

conducted over the last years in several medical fields, important questions remain still unresolved, particularly with regard to the timing of the therapy and to the actual impact of the use of platelet derivatives on wound rehabilitation, pain reduction [13,85,97], functional recovery [107], antibacterial activity [70,71,73,74], and cancer development [33]. To date, there is no available information about therapeutic dosages as well as PGFs half-life and possible interference of drugs (eg, antiaggregants) on PGFs release. A feature of the PGFs that could limit the effectiveness of treatment is the rapid and disorderly release of PGFs at the sites of application. The lack of long-term activity of PGFs may require repeated applications over time to maintain their therapeutic effect. Overall, more research is needed to establish the therapeutic efficacy of topical platelet therapy. The road ahead can be achieved through the ongoing clinical trials. Indeed, as shown in Tables 6 and 7, many trials are currently investigating the efficacy of platelet derivatives in regenerative medicine through randomized trials with large cohorts. Noteworthy, numerous phase 3 and phase 4 studies are exploring the efficacy of these treatments in the fields of orthopedics and dermatology. Indeed, as reported in Tables 6 and 7, at least 14 ongoing studies in advanced phase have been designed with large groups of treated patients (n N 100). Nevertheless, currently no ongoing clinical trials are aimed to establish standard protocols for platelet derivative collection to use in therapy. Further investigation is needed to understand the potential therapeutic role of platelet derivatives and to increase a most rational use among physicians. References [1] Velnar T, Bailey T, Smrkolj V. The wound healing process: an overview of the cellular and molecular mechanisms. J Int Med Res 2009;37:1528–42. [2] Barrientos S, Stojadinovic O, Golinko MS, Brem H, Tomic-Canic M. Growth factors and cytokines in wound healing. Wound Repair Regen 2008;16:585–601. [3] Suzuki S, Morimoto N, Ikada Y. Gelatin gel as a carrier of platelet-derived growth factors. J Biomater Appl 2013;28:595–606. [4] Eppley BL, Pietrzak WS, Blanton M. Platelet-rich plasma: a review of biology and applications in plastic surgery. Plast Reconstr Surg 2006;118:147–59. [5] Nurden AT, Nurden P, Sanchez M, Andia I, Anitua E. Platelets and wound healing. Front Biosci 2008;13:3532–48. [6] Blair P, Flaumenhaft R. Platelet alpha-granules: basic biology and clinical correlates. Blood Rev 2009;23:177–89.

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61 [7] Serra R, Buffone G, Dominijianni A, Molinari V, Montemurro R, de Franciscis S. Application of platelet-rich gel to enhance healing of transmetatarsal amputations in diabetic dysvascular patients. Int Wound J 2013;10:612–5. [8] Anitua E, Zalduendo MM, Alkhraisat MH, Orive G. Release kinetics of plateletderived and plasma derived growth Factors from autologous plasma rich in growth factors. Ann Anat 2013;195:461–6. [9] Doucet C, Ernou I, Zhang Y, Liense JR, Bergot L, Holy X. Platelet lisates promote mesenchimal stem cell expansion: a safety substitute for animal serum in cellbased therapy applications. J Cell Physiol 2005;205:228–36. [10] Salvadè A, Della Mina P, Gaddi D, Gatto F, Villa A, Bigoni M, et al. Characterization of platelet lysate cultured mesenchimal stromal cells and their potential use in tissueengineered osteogenic devices for the treatment of bone defects. Tissue Eng Part C Methods 2010;16:201–14. [11] Gentile P, Orlandi A, Scioli MG, Di Pasquali C, Bocchini I, Curcio CB, et al. A comparative translational study: the combined use of enhanced stromal vascular fraction and platelet rich plasma improves fat grafting maintenance in breast reconstruction. Stem Cell Transl Med 2012;1:341–51. [12] You DH, Nam MJ. Effects of human epidermal growth factor gene-transfected mesenchymal stem cells on fibroblast migration and proliferation. Cell Prolif 2013;46:408–15. [13] Hubbard SR, Till JH. Protein tyrosine kinase structure and function. Annu Rev Biochem 2000;69:373–98. [14] Pawson T. Protein modules and signalling networks. Nature 1995;373:573–80. [15] Montmayeur JP, Valius M, Vandenheede J, Kazlauskas A. The platelet-derived growth factor beta receptor triggers multiple cytoplasmic signaling cascades that arrive at the nucleus as distinguishable inputs. J Biol Chem 1997;272:32670–8. [16] Wrana JL. Regulation of Smad activity. Cell 2000;100:189–92. [17] Andrae J, Gallini R, Betsholts C. Role of platelet-derived growth factors in physiology and medicine. Genes Dev 2008;22:1276–312. [18] Graham S, Leonidou A, Lester M, Heliotis M, Mantalaris A, Tsiridis E. Investigating the role of PDGF as a potential drug therapy in bone formation and fracture healing. Expert Opin Investig Drugs 2009;18:1633–54. [19] Ghosh D, Lili L, McGrail DJ, Matyunina LV, McDonald JF, Dawson MR. Integral role of platelet derived growth factor in mediating transforming growth factor-β1 dependent mesenchymal stem cell stiffening. Stem Cells Dev 2014;23:245–61. [20] Sonmez AB, Castelnuovo J. Applications of basic fibroblastic growth factor (FGF-2, bFGF) in dentistry. Dent Traumatol 2014;30:107–11. [21] Ito J, Harada N, Nagashima O, Makino F, Usui Y, Yagita H, et al. Wound-induced TGF-β1 and TGF-β2 enhance airway epithelial repair via HB-EGF and TGF-α. Biochem Biophys Res Commun 2011;412:109–14. [22] McNary SM, Athanasiou KA, Reddi AH. Transforming growth factor β-induced superficial zone protein accumulation in the surface zone of articular cartilage is dependent on the cytoskeleton. Tissue Eng Part A 2014;20:921–9. [23] El-Sharkawy H, Kantarci A, Deady J, Hasturk H, Liu H, Alshahat M, et al. Platelet-rich plasma: growth factors and pro- and anti-inflammatory properties. J Periodontol 2007;78:661–9. [24] Bao P, Kodra A, Tomic-Canic M, Golinko MS, Ehrlich HP, Brem H. The role of vascular endothelial growth factor in wound healing. J Surg Res 2009;153:347–58. [25] Kubota S, Kawata K, Yanagita T, Doi H, Kitoh T, Takigawa M. Abundant retention and release of connective tissue growth factor (CTGF/CCN2) by platelets. J Biochem 2004;136:279–82. [26] Brown GL, Curtsinger LJ, White M, Mitchell RO, Pietsch J, Nordquist R, et al. Acceleration of tensile strength of incisions treated with EGF and TGF-β. Ann Surg 1988;208: 788–94. [27] Akingboye AA, Giddings S, Gamston P, Tucker A, Navsaria H, Kyriakides C. Application of autologous derived-platelet rich plasma gel in the treatment of chronic wound ulcer: diabetic foot ulcer. J Extra Corpor Technol 2010;42:20–9. [28] Villela DL, Santos VL. Evidence on the use of platelet-rich plasma for diabetic ulcer: a systematic review. Growth Factors 2010;28:111–6. [29] Steed DL. Clinical evaluation of recombinant human platelet-derived growth factor for the treatment of lower extremity ulcers. Plast Reconstr Surg 2006;117(7 Suppl.):143S–9S [discussion 150-1S]. [30] Marques LF, Stessuk T, Camargo IC, Sabeh Junior N, Santos LD, Ribeiro-Paes JT. Platelet-rich plasma (PRP): methodological aspects and clinical applications. Platelets 2014. http://dx.doi.org/10.3109/09537104.2014.881991. [31] Dallari D, Savarino L, Stagni C, Cenni E, Cenacchi A, Fornasari PM. Enhanced tibial osteotomy healing with use of bone grafts supplemented with platelet gel or platelet gel and bone marrow stromal cells. J Bone Joint Surg Am 2007; 89:2413–20. [32] Pallotta I, Kluge JA, Moreau J, Calabrese R, Kaplan DL, Balduini A. Characteristics of platelet gels combined with silk. Biomaterials 2014;35:3678–87. [33] Dauendorffer JN, Fraitag S, Dupuy A. Basal cell carcinoma following platelet-rich plasma injection for skin rejuvenation. Ann Dermatol Venereol 2013;140:723–4. [34] Allain JP, Bianco C, Blajchman MA, Brecher ME, Brusch M, Leiby D, et al. Protecting the blood supply from emerging pathogens: the role of pathogen inactivation. Transfus Med Rev 2005;19:110–26. [35] Burnouf T, Radosevich M. Reducing the risk of infection from plasma products: specific preventative strategies. Blood Rev 2000;14:94–110. [36] Thanathanee O, Phanphruk W, Anutarapongpan O, Romphruk A, Suwan-Apichon O. Contamination risk of 100% autologous serum eye drops in management of ocular surface diseases. Cornea 2013;32:1116–9. [37] Greppi N, Mazzucco L, Galetti G, Bona F, Petrillo E, Smacchia C, et al. Treatment of recalcitrant ulcers with allogeneic platelet gel from pooled platelets in aged hypomobile patients. Biologicals 2011;39:73–80. [38] Mazzucco L, Balbo V, Cattana E, Borzini P. Platelet rich plasma and platelet gel preparation using platelet. Vox Sang 2008;94:202–8.

59

[39] Mazzucco L, Balbo V, Cattana E, Guaschino R, Borzini P. Not every PRP-gel is born equal. Evaluation of growth factor avaibility for tissues trought four PRP-gel preparations: Fibrinet, Regen PRP-kit, Platelex and one manual procedure. Vox Sang 2009;97:110–8. [40] Amable PR, Carias RB, Teixeira MV, da Cruz Pacheco I, Corrêa do Amaral RJ, Granjeiro JM, et al. Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors. Stem Cell Res Ther 2013;4:67. [41] Staudenmaier R, Froelich K, Birner M, Kindermann J, The Hoang N, Pueschel RC, et al. Optimization of platelet isolation and extraction of autogenous TGF-beta in cartilage tissue engineering. Artif Cells Blood Substit Immobil Biotechnol 2009; 37:265–72. [42] Everts PA, Hoffmann J, Weibrich G, Mahoney CB, Schönberger JP, van Zundert A, et al. Differences in platelet growth factor release and leucocyte kinetics during autologous platelet gel formation. Transfus Med 2006;16:363–8. [43] Anitua E, Sánchez M, Zalduendo MM, de la Fuente M, Prado R, Orive G, et al. Fibroblastic response to treatment with different preparations rich in growth factors. Cell Prolif 2009;42:162–70. [44] Dohan Ehrenfest DM, Andia I, Zumstein MA, Zhang CQ, Pinto NR, Bielecki T. Classification of platelet concentrates (platelet-rich plasma—PRP, plateletrich fibrin—PRF) for topical and infiltrative use in orthopedic and sports medicine: current consensus, clinical implications and perspectives. Muscles Ligaments Tendons J 2014;4:3–9. [45] Jo CH, Roh YH, Kim JE, Shin S, Yoon KS. Optimizing platelet-rich plasma gel formation by varying time and gravitational forces during centrifugation. J Oral Implantol 2013;39:525–32. [46] Graziani F, Ivanovski S, Cei S, Ducci F, Tonetti M, Gabriele M. The in vitro effect of different PRP concentrations on osteoblasts and fibroblasts. Clin Oral Implants Res 2006;17:212–9. [47] Rappl LM. Effect of platelet rich plasma gel in a physiologically relevant platelet concentration on wounds in persons with spinal cord injury. Int Wound J 2011; 8:187–95. [48] Giusti I, D'Ascenzo S, Mancò A, Di Stefano G, Di Francesco M, Rughetti A, et al. Platelet concentration in platelet-rich plasma affects tenocyte behavior in vitro. Biomed Res Int 2014;2014:630870. http://dx.doi.org/10.1155/2014/630870. [49] Lacoste E, Martineau I, Gagnon G. Platelet concentrates: effects of calcium and thrombin on endothelial cell proliferation and growth factor release. J Periodontol 2003;74:1498–507. [50] Su CY, Chiang CC, Lai WF, Lin KW, Burnouf T. Platelet-derived growth factor-AB and transforming growth factor-beta 1 in platelet gels activated by single-donor human thrombin. Transfusion 2004;44:945. [51] Rodgers GM. Immune-mediated coagulophaty associated with topical bovine thrombin: a review of the pediatric literature. J Pediatr Hematol Oncol 2011;33: 86–8. [52] Clark J, Crean S, Reynolds MW. Topical bovine thrombin and adverse events: a review of the literature. Curr Med Res Opin 2008;24:2071–87. [53] Su CY, Kuo YP, Nieh HL, Tseng YH, Burnouf T. Assessment of the kinetics of growth factors release from platelet gel. Transfusion 2008;48:2414–20. [54] Weibrich G, Kleis WK, Hafner G, Hitzler WE. Growth factor levels in platelet-rich plasma and correlations with donor age, sex, and platelet count. J Craniomaxillofac Surg 2002;30:97–102. [55] Galiano RD, Tepper OM, Pelo CR, Bhatt KA, Callaghan M, Bastidas N, et al. Topical vascular endothelial growth factor accelerates diabetic wound healing through increased angiogenesis and by mobilizing and recruiting bone marrow–derived cells. Am J Pathol 2004;164:1935–47. [56] Choukroun J, Diss A, Simonpieri A, Girard MO, Schoeffler C, Dohan SL, et al. Plateletrich fibrin (PRF): a second-generation platelet concentrate. Part IV: clinical effects on tissue healing. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101: 56–60. [57] Dohan Ehrenfest DM, Rasmusson L, Albrektsson T. Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF). Trends Biotechnol 2009;27:158–67. [58] Passaretti F, Tia M, D’Esposito V, De Pascale M, Del Corso MD, Sepulveres R, et al. Growth-promoting action and growth factor release by different platelet derivatives. Platelets 2014;25:252–6. [59] Geremicca W, Fonte C, Vecchio S. Blood components for topical use in tissue regeneration: evaluation of corneal lesions treated with platelet lysate and considerations on repair mechanisms. Blood Transfus 2010;8:107–12. [60] Geerling G, Maclennan S, Hartwig D. Autologous serum eye drops for ocular surface disorders. Br J Ophthalmol 2004;88:1467–74. [61] López-García JS, Rivas L, García-Lozano I, Murube J. Autologous serum eyedrops in the treatment of aniridic keratopathy. Ophthalmology 2008;115:262–7. [62] Cho YK, Huang W, Kim GY, Lim BS. Comparison of autologous serum eye drops with different diluents. Curr Eye Res 2013;38:9–17. [63] Yamada C, King KE, Ness PM. Autologous serum eyedrops: literature review and implications for transfusion medicine specialists. Transfusion 2008;48:1245–55. [64] Quinto GG, Campos M, Behrens A. Autologous serum for ocular surface diseases. Arq Bras Oftalmol 2008;71:47–54. [65] Marx RE, Carlson ER, Eichstaedt RM, Schimmele SR, Strauss JE, Georgeff KR. Platelet-rich plasma: growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:638–46. [66] Burnouf T, Goubran HA, Chen TM, Ou KL, El-Ekiaby M, Radosevic M. Blood-derived biomaterials and platelet growth factors in regenerative medicine. Blood Rev 2013; 27:77–89. [67] Carter MJ, Fylling CP, Parnell LK. Use of platelet rich plasma gel on wound healing: a systematic review and meta-analysis. Eplasty 2011;11:e38.

60

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61

[68] Martínez-Zapata MJ, Martí-Carvajal A, Solà I, Bolibar I, Angel Expósito J, Rodriguez L, et al. Efficacy and safety of the use of autologous plasma rich in platelets for tissue regeneration: a systematic review. Transfusion 2009;49:44–56. [69] Tang YQ, Yeaman MR, Selsted ME. Antimicrobial peptides from human platelets. Infect Immun 2002;70:6524–33. [70] Li H, Li B. PRP as a new approach to prevent infection: preparation and in vitro antimicrobial properties of PRP. J Vis Exp 2013;74. http://dx.doi.org/10.3791/50351. [71] Chen L, Wang C, Liu H, Liu G, Ran X. Antibacterial effect of autologous platelet-rich gel derived from subjects with diabetic dermal ulcers in vitro. J Diabetes Res 2013; 2013:269527. [72] Różalski MI, Micota B, Sadowska B, Paszkiewicz M, Więckowska-Szakiel M, Różalska B. Antimicrobial/anti-biofilm activity of expired blood platelets and their released products. Postepy Hig Med Dosw 2013;22:321–5. [73] Burnouf T, Chou ML, Wu YW, Su CY, Lee LW. Antimicrobial activity of platelet (PLT)-poor plasma, PLT-rich plasma, PLT gel, and solvent/detergent-treated PLT lysate biomaterials against wound bacteria. Transfusion 2013;53:138–46. [74] Edelblute CM, Donate AL, Hargrave BY, Heller LC. Human platelet gel supernatant inactivates opportunistic wound pathogens on skin. Platelets 2014. http://dx.doi. org/10.3109/09537104.2013.863859. [75] Cieslik-Bielecka A, Dohan Ehrenfest DM, Lubkowska A, Bielecki T. Microbicidal properties of leukocyte- and platelet-rich plasma/fibrin (L-PRP/L-PRF): new perspectives. J Biol Regul Homeost Agents 2012;26:43S–52S. [76] Martinez-Zapata MJ, Martí-Carvajal AJ, Solà I, Expósito JA, Bolíbar I, Rodríguez L, et al. Autologous platelet-rich plasma for treating chronic wounds. Cochrane Database Syst Rev 2012;10:CD006899. [77] Zavadil DP, Satterlee CC, Costigan JM, Holt DW, Shostrom VK. Autologous platelet gel and platelet poor plasma reduce pain with total shoulder arthroplasty. J Extra Corpor Technol 2007;39:177–82. [78] Aggarwal AK, Shashikanth VS, Marwaha N. Platelet-rich plasma prevents blood loss and pain and enhances early functional outcome after total knee arthroplasty: a prospective randomised controlled study. Int Orthop 2014;38:387–95. [79] Valhondo M, Marco I, Martín-Fontecha M, Vázquez-Villa H, Ramos JA, Berkels R, et al. New serotonin 5-HT1A receptor agonists endowed with antinociceptive activity in vivo. J Med Chem 2013;56:7851–61. [80] Hackel D, Pflücke D, Neumann A, Viebahn J, Mousa S, Wischmeyer E, et al. The connection of monocytes and reactive oxygen species in pain. PLoS One 2013;8: e63564. [81] Sanchez M, Guadilla J, Fiz N, Andia I. Ultrasound-guided platelet-rich plasma injections for the treatment of osteoarthritis of the hip. Rheumatology 2012; 51:144–50. [82] Mei-Dan O, Carmont MR, Laver L, Mann G, Maffulli N, Nyska M. Platelet-rich plasma or hyaluronate in the management of osteochondral lesions of the talus. Am J Sports Med 2012;40:534–41. [83] Andia I, Sánchez M, Maffulli N. Platelet rich plasma therapies for sports muscle injuries: any evidence behind clinical practice? Expert Opin Biol Ther 2011;11: 509–18. [84] Kuffler DP. Platelet-rich plasma and the elimination of neuropathic pain. Mol Neurobiol 2013;48:315–32. [85] Hechtman KS, Uribe JW, Botto-vanDemden A, Kiebzak GM. Platelet-rich plasma injection reduces pain in patients with recalcitrant epicondylitis. Orthopedics 2011;34:92. [86] de Vos RJ, Windt J, Weir A. Strong evidence against platelet-rich plasma injections for chronic lateral epicondylar tendinopathy: a systematic review. Br J Sports Med 2014;48:952–6. [87] de Vos RJ, Weir A, van Schie HT, Bierma-Zeinstra SM, Verhaar JA, Weinans H, et al. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. JAMA 2010;303:144–9. [88] Sampson S, Gerhardt M, Mandelbaum B. Platelet rich plasma injection grafts for muscoloskeletal injures: a review. Curr Rev Musculoskelet Med 2008;1:165–74. [89] Shan CQ, Zhang YN, Ma J, Li YH, Zuo DM, Qiu JL, et al. Evaluation of the effects of homologous platelet gel on healing lower extremity wounds in patients with diabetes. Int J Low Extrem Wounds 2013;12:22–9. [90] Scevola S, Nicoletti G, Brenta F, Isernia P, Maestri M, Faga A. Allogenic platelet gel in the treatment of pressure sores: a pilot study. Int Wound J 2010;7:184–90. [91] Giuggioli D, Colaci M, Manfredi A, Mariano M, Ferri C. Platelet gel in the treatment of severe scleroderma skin ulcers. Rheumatol Int 2012;32:2929–32. [92] Del Fabbro M, Boggian C, Taschieri S. Immediate implant placament into fresh extraction sites with chronic periapical pathologic features combined with plasma rich in growth factors: preliminary results of single-cohort study. J Oral Maxillofac Surg 2009;67:2476–84. [93] Forni F, Marzagalli M, Tesei P, Grassi A. Platelet gel: applications in dental regenerative surgery. Blood Transfus 2013;11:102–7. [94] Cervellin M, de Girolamo L, Bait C, Denti M, Volpi P. Autologous platelet-rich plasma gel to reduce donor-site morbidity after patellar tendon graft harvesting for anterior cruciate ligament reconstruction: a randomized, controlled clinical study. Knee Surg Sports Traumatol Arthrosc 2012;20:114–20. [95] Virchenko O, Grenegàrd M, Aspenberg P. Indipendent and additive stimulation of tendon repair by thrombin and platelets. Acta Orthop 2006;77:960–6. [96] Vogrin M, Rupreht M, Dinevski D, Hašpl M, Kuhta M, Jevsek M, et al. Effects of a platelet gel on early graft revascularization after anterior cruciate ligament reconstruction: a prospective, randomized, double-blind, clinical trial. Eur Surg Res 2010;45:77–85. [97] Gardner MJ, Demetrakopoulos D, Klepchick PR, Mooar PA. The efficacy of autologous platelet gel in pain control and blood loss in total knee arthroplasty. An analysis of the haemoglobin, narcotic requirement and range of motion. Int Orthop 2007;31:309–13.

[98] Crawford F, Inkster M, Kleijnen J, Fahey T. Predicting foot ulcers in patients with diabetes: a systematic review and meta-analysis. QJM 2007;100:65–86. [99] Shin MK, Lee JW, Kim YI, Kim YO, Seok H, Kim NI. The effects of platelet-rich clot releasate on the expression of MMP-1 and type I collagen in human adult dermal fibroblasts: PRP is a stronger MMP-1 stimulator. Mol Biol Rep 2014;41:3–8. [100] Kushida S, Kakudo N, Suzuki K, Kusumoto K. Effects of platelet-rich plasma on proliferation and myofibroblastic differentiation in human dermal fibroblasts. Ann Plast Surg 2013;71:219–24. [101] Gentzkow GD, Iwasaki SD, Hershon KS, Mengel M, Prendergast JJ, Ricotta JJ, et al. Use of dermagraft, a cultured human dermis, to treat diabetic foot ulcers. Diabetes Care 1996;19:350–4. [102] Crovetti G, Martinelli G, Issi M, Barone M, Guizzardi M, Campanati B, et al. Platelet gel for healing cutaneous chronic wounds. Transfus Apher Sci 2004;30: 145–51. [103] Driver VR, Hanft J, Fylling CP, Beriou JM. Autologel Diabetic Foot Ulcer Study Group. A prospective, randomized, controlled trial of autologous platelet-rich plasma gel for the treatment of diabetic foot ulcers. Ostomy Wound Manage 2006;52:68–70. [104] Mahmoud SM, Mohamed AA, Mahdi SE, Ahmed ME. Split-skin graft in the management of diabetic foot ulcers. J Wound Care 2008;17:303–6. [105] Zhao GQ. Consequences of knocking out BMP signaling in the mouse. Genesis 2003;35:43–56. [106] Maeda H, Wada N, Tomokiyo A, Monnouchi S, Akamine A. Prospective potency of TGF-β1 on maintenance and regeneration of periodontal tissue. Int Rev Cell Mol Biol 2013;304:283–367. [107] Alsousou J, Thompson M, Hulley P, Noble A, Willett K. The biology of platelet-rich plasma and its application in trauma and orthopaedic surgery: a review of the literature. J Bone Joint Surg (Br) 2009;91:987–96. [108] Napolitano M, Matera S, Bossio M, Crescimbene A, Costabile E, Almolla J, et al. Autologous platelet gel for tissue regeneration in degenerative disorders of the knee. Blood Transfus 2012;10:72–7. [109] Wasterlain AS, Braun HJ, Harris AH, Kim HJ, Dragoo JL. The systemic effects of platelet-rich plasma injection. Am J Sports Med 2013;41:186–93. [110] Anitua E, Sanchez M, Merayo-Lloves J, De la Fuente M, Muruzabal F, Orive G. Plasma rich in growth factors (PRGF-Endoret) stimulates proliferation and migration of primary keratocytes and conjunctival fibroblasts and inhibits and reverts TGF-beta1–induced myodifferentiation. Invest Ophthalmol Vis Sci 2011;52:6066–73. [111] Kojima T, Higuchi A, Goto E, Matsumoto Y, Dogru M, Tsubota K. Autologous serum eye drops for the treatment of dry eyes disease. Cornea 2008;27:25–30. [112] Dalmon CA, Chandra NS, Jeng BH. Use of autologous serum eyedrops for the treatment of ocular surface disease: first US experience in a large population as an insurance-covered benefit. Arch Ophthalmol 2012;130:1612–3. [113] Na KS, Kim MS. Allogeneic serum eye drops for the treatment of dry eye patients with chronic graft-versus-host disease. J Ocul Pharmacol Ther 2012; 28:479–83. [114] Freire V, Andollo N, Etxebarria J, Duràn JA, Morales MC. In vitro effects of three blood derivatives on human corneal epithelial cells. Invest Ophthalmol Vis Sci 2012;53:5571–8. [115] Jeng BH, Dupps Jr WJ. Autologous serum 50% eyedrops in the treatment of persistent epithelial defects. Cornea 2009;28:1104–8. [116] Fini ME, Stramer BM. How the cornea heals: cornea-specific repair mechanisms affecting surgical outcomes. Cornea 2005;24:S2–S11. [117] Saika S. TGFbeta pathobiology in the eye. Lab Invest 2006;86:106–15. [118] Maltseva O, Folger P, Zekaria D, Petridou S, Masur SK. Fibroblast growth factor reversal of the corneal myofibroblast phenotype. Invest Ophthalmol Vis Sci 2001; 42:2490–5. [119] Sakimoto T, Rosenblatt MI, Azar DT. Laser eye surgery for refractive errors. Lancet 2006;29(367):1432–47. [120] Kesavan K, Balasubramaniam J, Kant S, Singh PN, Pandit JK. Newer approaches for optimal bioavailability of ocularly delivered drugs: review. Curr Drug Deliv 2011;8: 172–93. [121] Urzua CA, Vasquez DH, Huidobro A, Hernandez H, Alfaro J. Randomized doubleblind clinical trial of autologous serum versus artificial tears in dry eye syndrome. Curr Eye Res 2012;37:684–8. [122] Pan Q, Angelina A, Zambrano A, Marrone M, Stark WJ, Heflin T, et al. Autologous serum eye drops for dry eye. Cochrane Database Syst Rev 2013;8:CD009327. [123] Bertrand-Duchesne MP, Grenier D, Gagnon G. Epidermal growth factor released from platelet-rich plasma promotes endothelial cell proliferation in vitro. J Periodontal Res 2010;45:87–93. [124] Cicha I, Garlichs CD, Daniel WG, Goppelt-Struebe M. Activated human platelets release connective tissue growth factor. Thromb Haemost 2004;91:755–60. [125] Kaul RP, Godhi SS, Singh A. Autologous platelet rich plasma after third molar surgery: a comparative study. J Maxillofac Oral Surg 2012;11:200–5. [126] Girish Rao S, Bhat P, Nagesh KS, Rao GH, Mirle B, Kharbhari L, et al. Bone regeneration in extraction sockets with autologous platelet rich fibrin gel. J Maxillofac Oral Surg 2013;12:11–6. [127] Jo CH, Kim JE, Yoon KS, Lee JH, Kang SB, Lee JH, et al. Does platelet-rich plasma accelerate recovery after rotator cuff repair? A prospective cohort study. Am J Sports Med 2011;39:2082–90. [128] Bernuzzi G, Petraglia F, Pedrini MF, De Filippo M, Pogliacomi F, Verdano MA, et al. Use of platelet-rich plasma in the care of sports injuries: our experience with ultrasound-guided injection. Blood Transfus 2014;12:229–34. [129] Peerbooms JC, van Laar W, Faber F, Schuller HM, van der Hoeven H, Gosens T. Use of platelet rich plasma to treat plantar fasciitis: design of a multi centre randomized controlled trial. BMC Musculoskelet Disord 2010;11:69.

M.R. De Pascale et al. / Transfusion Medicine Reviews 29 (2015) 52–61 [130] Tzeng YS, Deng SC, Wang CH, Tsai JC, Chen TM, Burnouf T. Treatment of nonhealing diabetic lower extremity ulcers with skin graft and autologous platelet gel: a case series. Biomed Res Int 2013;2013:837620. [131] Chignon-Sicard B, Georgiou CA, Fontas E, David S, Dumas P, Ihrai T, et al. Efficacy of leukocyte- and platelet-rich fibrin in wound healing: a randomized controlled clinical trial. Plast Reconstr Surg 2012;130:819e–29e. [132] Sclafani AP, McCormick SA. Induction of dermal collagenesis, angiogenesis, and adipogenesis in human skin by injection of platelet-rich fibrin matrix. Arch Facial Plast Surg 2012;14:132–6.

61

[133] Chen YM, Hu FR, Huang JY, Shen EP, Tsai TY, Chen WL. The effect of topical autologous serum on graft re-epithelialization after penetrating keratoplasty. Am J Ophthalmol 2010;150:352–9. [134] Liu L, Hartwig D, Harloff S, Herminghaus P, Wedel T, Kasper K, et al. Corneal epitheliotrophic capacity of three different blood-derived preparations. Invest Ophthalmol Vis Sci 2006;47:2438–44. [135] Lekhanont K, Jongkhajornpong P, Choubtum L, Chuckpaiwong V. Topical 100% serum eye drops for treating corneal epithelial defect after ocular surgery. Biomed Res Int 2013;2013:521315.