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Synthesis and characterisation of nanobioactive glass for biomedical applications
Materials Letters 65 (2011) 31–34
Contents lists available at ScienceDirect
Materials Letters j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / m a t l e t
Synthesis and characterisation of nanobioactive glass for biomedical applications B. Saravanakumar, M. Rajkumar, V. Rajendran ⁎ Centre for Nano Science and Technology, K.S. Rangasamy College of Technology, Tiruchengode-637 215, Tamil Nadu, India
a r t i c l e
i n f o
Article history: Received 6 August 2010 Accepted 20 September 2010 Available online 24 September 2010 Keywords: Bioactive glass Sonochemical Hydrothermal Sol–gel preparation Nanomaterials
a b s t r a c t In recent years, bioactive materials have become important in applications such as implantation, bone regeneration, scaffold, oral implantation and antioxidant materials because of their excellent bioactivity, biocompatibility, osteoconductivity and osteoinductive properties. When exposed to simulated body fluid, bioactive glasses have the ability to bond with both hard and soft tissues through the formation of a hydroxyapatite layer. Nowadays, nanotechnology is emerging as a nascent technology in all disciplines because of its high surface-to-volume ratio and unique properties at nanoscale length. The impact of nanotechnology in biomaterials is of interest because of the enhancement in their biocompatibility and bioactivity. In this investigation, the preparation of nanobioactive glasses by using different methods (such as sol–gel, hydrothermal and sonochemical) is discussed in detail. The structural and morphological characterisation of the prepared samples was made. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Understanding a biomaterial's interaction with the surrounding environments such as tissues and fluids is essential to tailor the properties of biomaterials. Bioactive glasses show potential applications in non-load-bearing applications such as middle ear implants and alveolar ridge augmentation because of the high degree of affinity of calcium phosphate in in vitro and in vivo conditions [1]. They have the ability to form a hydroxyapatite (HAp) layer on the surface when exposed to biological fluids. The HAp, in turn, has the capacity to bond with the collagen generated by the surrounding tissues [2]. HAp nucleation is induced because of the presence of hydrated silica on the glass surface [3–5] and it matches more with the natural bone apatite than with the synthetic apatite [3,6]. The bioresorbable nature of bioactive glasses enhances tissue regeneration [7] and stimulates bone growth by releasing the critical concentration of ions from the surface [8]. The low processing temperature of bioactive glasses facilitates loading of the drugs, that is, biologically active agents [9]. Recently, much attention has been paid on the fabrication of nanostructured biomaterials to improve their biological activity and biocompatibility. Among the biomaterials, nanobioactive glasses (NBGs) have become an essential biomaterial in view of their bonebonding ability and load-bearing applications. Even though different methods are available, the sol–gel method has unique advantages such as low processing temperature, higher purity and better homogeneity, microporosity, and higher surface area [10]. The sonochemical method is the formation, growth and collapse of ⁎ Corresponding author. Tel.: +91 4288 274741 4, 274880; fax: +91 4288 274880 (direct), 274860. E-mail address: [email protected] (V. Rajendran). 0167-577X/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2010.09.053
cavitations. During the formation of cavitations, it produces a temperature of roughly 5273 K and a pressure of about 500 atm with heating/cooling rates greater than 109 K s− 1. In view of the unique chemical reactions in liquids, nanometal oxide particles are prepared by using the sonochemical method [11]. The hydrothermal method provides better control on particle size, shape and uniform distribution of particles [12]. In this investigation, an attempt has been made to prepare NBGs by sonochemical, hydrothermal and sol–gel methods. The as prepared and incubated glasses in simulated body fluid (SBF) solution are characterised to explore the biological responses. 2. Experimental 2.1. Materials The silica-based NBGs with a composition of 48SiO2–40CaO– 12P2O5 were prepared by three different methods, namely sol–gel, hydrothermal and sonochemical. AR-grade (Merck) chemicals (99.999% purity), namely tetraethyl orthosilicate (TEOS, Si (OC2H5)4), triethyl phosphate (TEP, (C2H5)3PO4), calcium carbonate (CaCO3), ethanol, nitric acid, ammonia solution (Merck, min. 25% GR) and ultrapure water (Arium 611UF; Sartorius AG, Germany) were used for the preparation of NBG. 2.2. Preparation of nanobioactive glass 2.2.1. Sonochemical method Initially, TEOS (7.792 ml) was mixed with 20 ml ethanol and 50 ml HNO3 solution (2 N). Then, the mixed solution was sonicated for 25 min using a sonochemical reactor operated at a frequency of
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B. Saravanakumar et al. / Materials Letters 65 (2011) 31–34
2.2.2. Hydrothermal method TEOS, TEP and CaCO3 were mixed in water/ethanol in a correct proportion. The solution that was prepared was hydrothermally treated at 393 K for 1 h with continuous stirring (100 rpm). The resultant slurry was filtered and washed with deionised water. The product that was obtained was dried in a hot-air oven at 353 K for 12 h and then calcined at 573 K for 3 h. The powder that was obtained after calcination was named as SCP-2. 2.2.3. Sol–gel method TEOS, TEP and CaCO3 were mixed in water/ethanol to a clear solution by using the sol–gel method. The solution was condensed by adding an ammonia solution. The sol–gel method was used to prepare the NBG as discussed elsewhere [13]. The gel was dried in a hot-air oven at 353 K for 6 h and then calcined at 573 K for 3 h in a muffle furnace to get the NBG powder, which was termed as SCP-3. 2.3. Characterisation techniques 2.3.1. Structural and morphological characterisation The amorphous nature of the NBG powder has been studied through X-ray diffraction (XRD) studies using an X-ray diffractometer (D500; Siemens, USA) with CuKα as a radiation (λ = 1.5418 Å) source. The diffractometer was operated at 40 kV with the 2θ value varying from 0 to 80° with an increase of 0.05°. The particle size and shape of the prepared NBG powders were determined using transmission electron microscopy (TEM, CM 200; Philips; USA). The presence of functional groups was confirmed through Fourier transform infrared (FTIR) spectrometer in the range of 4000–400 cm− 1 using KBr as a reference.
Fig. 1. XRD pattern of SCP-1, SCP-2 and SCP-3 NBG glasses (a) as prepared and (b) after incubation in the SBF solution.
22 kHz (VC 505; Sonics, USA). TEP (2.92 ml) was added to the sonicated solution. After adding TEP, sonication was continued for another 25 min. Subsequently, a small quantity of CaCO3 (2.930 g) was added to the sonicated solution and then sonication was continued until gelation. The white gel that was obtained was dried in a hot-air oven at 353 K for 12 h. The dried gel was calcined at 573 K for 3 h in a furnace. The calcinated NBG powder was named as SCP-1.
2.3.2. Incubation in SBF solution The SBF solution was prepared by using the standard procedure as described by Kokubo et al. [14]. The pH value of the prepared SBF solution was equal to human blood plasma. A powder sample of 250 mg was pressed in a hydraulic pressure pellet maker (10 tonnes) to obtain the sample in the form of a pellet. The incubation of all the prepared samples was carried out after immersing them in the SBF solution (35 ml) for 21 days, which was kept in a water bath shaker at a constant temperature of 340 K. The change in the pH value was measured every day using a pH meter (Orion 5-Star; Thermo Scientific, USA). 3. Results and discussion The XRD patterns of the as prepared samples namely SCP-1, SCP-2 and SCP-3 employing the three methods are shown in Fig. 1(a), while
Fig. 2. TEM images of (a) SCP-1, (b) SCP-2 and (c) SCP-3 NBG glasses. The insert represent the electron diffraction pattern of the respective glasses.
B. Saravanakumar et al. / Materials Letters 65 (2011) 31–34
33
Table 1 FTIR vibrational bands of nanobioactive glass before and after incubation in the SBF solution. Assignments
Before incubation
After incubation
SCP-1 SCP-2 SCP-3 SCP-1 SCP-2 SCP-3 H–O–H stretching [15] 3434 OH stretching in O=P–OH group [15] – O–H bending (molecular water) [16] 1635 C–O stretching vibration band [17] – Asymmetric Si–O–Si stretching in 1078 SiO4 tetrahedron [16] C–O Stretching vibration band [15,17] 863 Symmetric Si–O–Si stretching [16] – Si–O–Si bending [16] – – –P=O bending band [18], Phosphate vibration mode [16] PO−3 4 Phosphate PO3−2 vibration mode [16] 563 Si–O–Si stretching [16] 468
3457 – 1642 – 1094
3448 – 1635 – 1094
3457 – 1633 1420 1081
3457 – 1633 1420 1072
3457 2856 1633 1428 1072
871 – – –
863 – – –
876 796 710 599
876 796 710 599
876 796 710 599
545 468
563 477
560 465
560 465
567 473
confirms the particle size as being less than 50 nm. It is inferred from Fig. 2(c) that SCP-3 glass shows non-agglomerated NBG particles prepared by the sol–gel method when compared with SCP-1 (Fig. 2(a)) and SCP-2 (Fig. 2(b)). However, the electron diffraction patterns (insert in Fig. 2(a), (b) and (c)) confirm the amorphous nature of all the NBG glasses. The FTIR spectra of all three samples in the as prepared and after incubation in the SBF solution are shown respectively in Fig. 3(a) and (b). The characteristic infrared bands under the above conditions are shown in Table 1.The formation of the HAp layer was shown by using the FTIR spectrum, as shown in Fig. 3(b). The presence of vibrational bands at 567 and 599 cm− 1 confirms the existence of the HAp in the sample after incubation in the SBF solution. The double band (567 and 599 cm− 1) of the vibrational bands obtained at 600 cm− 1 corresponds to the crystalline phase of phosphate. The formation of the crystalline phosphate is evident from the formation of HAp on the surface of the NBG [16]. Bone mineral formation on the glass surface was identified through XRD (Fig. 1(b)). The sharp peaks at (210), (212), (301), (113) and (220) confirm the crystalline HAp (JCPDS No. 09-0432) [18]. Owing to the higher content of the NBG, the resolution of HAp in the XRD pattern was poor after incubation in the SBF solution. pH variation has been measured in the SBF as a function of soaking time (Fig. 3(c)), which indicates variation in ionic exchange for different methods. A higher magnitude in ionic exchange is obtained in SCP-3 than SCP-1 and SCP-2 (Fig. 3(c)). However, the variation that was obtained was small when compared with SCP-3. The exchange of Ca2+ and OH− ions between the glass and the SBF and vice versa leads to an increase in the pH value. The results that are obtained further support the formation of silanol (Si–OH) on the glass surface after the saturation of Ca2+ ions. The formation of the Si–OH layer is more essential for the formation of crystalline HAp. pH variation was higher in SCP-3 when compared with SCP-1 and SCP-2, which leads to the speeding up of the formation of HAp on the surface [19]. Fig. 3. SCP-1, SCP-2 and SCP-3 NBG glasses. (a) FTIR spectra in the as prepared, (b) FTIR spectra after incubation in SBF solution and (c) pH variation in different soaking periods.
4. Conclusions
after incubation of all three samples in the SBF solution for 21 days are shown in Fig. 1(b). The XRD patterns show only one broad peak at 2θ values in the range of 20–30° (JCPDS No. 79-1711), which indicates the absence of crystalline peaks. The size and shape of the NBG were confirmed through TEM analysis, as shown in Fig. 2. The TEM image
The NBG with a composition of 48SiO2–40CaO–12P2O5 was prepared using three different methods (sonochemical, hydrothermal and sol–gel). The different characterisation studies on NBGs reveal a higher bioactivity in SCP-3 than other glasses such as SCP-1 and SCP-2. The higher bone-bonding ability of the NBG that is observed indicates that the sol–gel method is more suitable for the preparation of bioactive glass for implant applications.
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B. Saravanakumar et al. / Materials Letters 65 (2011) 31–34
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Hall SR, Walsh D, Green D, Oreffo R, Mann S. J Mater Chem 2003;13:186–90. Hench LL, West JK. Life Chem Rep 1996;13:187–241. Hench LL. Ann NY Acad Sci 1988;523:54–71. Karlsson KH, Froberg K, Ringbom T. J Non-Cryst Solids 1989;12:69–72. Ohtsuki C, Kokubo T, Yamamuro T. J Non-Cryst Solids 1992;143:84–92. Fujiu T, Ogino M. J Biomed Mater Res 1984;18:845–59. Cerruti M, Magnacca G, Bolis V, Morterra C. J Mater Chem 2003;13:1279–86. Hench LL, Polak JM. Science 2002;295:1014–7. Carta D, Knowles JC, Guerry P, Smith ME, Newport RJ. J Mater Chem 2009;19:150–8. Vallet-Reg M, Salinas AJ, Roman J, Gil M. J Mater Chem 1999;9:515--8. Kis-Csitári J, Kónya Z, Kiricsi I. Functionalized Nanoscale Materials, Devices and Systems. Netherlands: Springer; 2008. p. 369–72.
[12] Ashok M, Narayana Kalkura S, Meenakshi Sundaram N, Arivuoli D. J Mater Sci Mater Med 2007;18:895–8. [13] Xia W, Chang J. Mater Lett 2007;61:3251–3. [14] Kokubo T, Kushitani H, Sakka S, Kitsugi T, Yamamuro T. J Biomed Mater Res 1990;24:721–34. [15] Zhang Y, Wang M. Mater Sci Eng B 1999;67:99–101. [16] Costa HS, Rocha MF, Andrade GI, Barbosa-Stancioli EF, Pereira MM, Orefice RL, et al. J Mater Sci 2008;43:494–502. [17] Yan X, Huang X, Yu C, Deng H, Wang Y, Zhang Z, et al. Biomaterials 2006;27: 3396–403. [18] Lin KSK, Tseng Yao-Hung, Mou Y, Hsu Yu-Chuan, Yang China-Min, Chan JCC. Chem Mater 2005;17:4493–501. [19] Arcos D, Pena J, Vallet-Regi M. Chem Mater 2003;15:4132–8.
Contents lists available at ScienceDirect
Materials Letters j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / m a t l e t
Synthesis and characterisation of nanobioactive glass for biomedical applications B. Saravanakumar, M. Rajkumar, V. Rajendran ⁎ Centre for Nano Science and Technology, K.S. Rangasamy College of Technology, Tiruchengode-637 215, Tamil Nadu, India
a r t i c l e
i n f o
Article history: Received 6 August 2010 Accepted 20 September 2010 Available online 24 September 2010 Keywords: Bioactive glass Sonochemical Hydrothermal Sol–gel preparation Nanomaterials
a b s t r a c t In recent years, bioactive materials have become important in applications such as implantation, bone regeneration, scaffold, oral implantation and antioxidant materials because of their excellent bioactivity, biocompatibility, osteoconductivity and osteoinductive properties. When exposed to simulated body fluid, bioactive glasses have the ability to bond with both hard and soft tissues through the formation of a hydroxyapatite layer. Nowadays, nanotechnology is emerging as a nascent technology in all disciplines because of its high surface-to-volume ratio and unique properties at nanoscale length. The impact of nanotechnology in biomaterials is of interest because of the enhancement in their biocompatibility and bioactivity. In this investigation, the preparation of nanobioactive glasses by using different methods (such as sol–gel, hydrothermal and sonochemical) is discussed in detail. The structural and morphological characterisation of the prepared samples was made. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Understanding a biomaterial's interaction with the surrounding environments such as tissues and fluids is essential to tailor the properties of biomaterials. Bioactive glasses show potential applications in non-load-bearing applications such as middle ear implants and alveolar ridge augmentation because of the high degree of affinity of calcium phosphate in in vitro and in vivo conditions [1]. They have the ability to form a hydroxyapatite (HAp) layer on the surface when exposed to biological fluids. The HAp, in turn, has the capacity to bond with the collagen generated by the surrounding tissues [2]. HAp nucleation is induced because of the presence of hydrated silica on the glass surface [3–5] and it matches more with the natural bone apatite than with the synthetic apatite [3,6]. The bioresorbable nature of bioactive glasses enhances tissue regeneration [7] and stimulates bone growth by releasing the critical concentration of ions from the surface [8]. The low processing temperature of bioactive glasses facilitates loading of the drugs, that is, biologically active agents [9]. Recently, much attention has been paid on the fabrication of nanostructured biomaterials to improve their biological activity and biocompatibility. Among the biomaterials, nanobioactive glasses (NBGs) have become an essential biomaterial in view of their bonebonding ability and load-bearing applications. Even though different methods are available, the sol–gel method has unique advantages such as low processing temperature, higher purity and better homogeneity, microporosity, and higher surface area [10]. The sonochemical method is the formation, growth and collapse of ⁎ Corresponding author. Tel.: +91 4288 274741 4, 274880; fax: +91 4288 274880 (direct), 274860. E-mail address: [email protected] (V. Rajendran). 0167-577X/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2010.09.053
cavitations. During the formation of cavitations, it produces a temperature of roughly 5273 K and a pressure of about 500 atm with heating/cooling rates greater than 109 K s− 1. In view of the unique chemical reactions in liquids, nanometal oxide particles are prepared by using the sonochemical method [11]. The hydrothermal method provides better control on particle size, shape and uniform distribution of particles [12]. In this investigation, an attempt has been made to prepare NBGs by sonochemical, hydrothermal and sol–gel methods. The as prepared and incubated glasses in simulated body fluid (SBF) solution are characterised to explore the biological responses. 2. Experimental 2.1. Materials The silica-based NBGs with a composition of 48SiO2–40CaO– 12P2O5 were prepared by three different methods, namely sol–gel, hydrothermal and sonochemical. AR-grade (Merck) chemicals (99.999% purity), namely tetraethyl orthosilicate (TEOS, Si (OC2H5)4), triethyl phosphate (TEP, (C2H5)3PO4), calcium carbonate (CaCO3), ethanol, nitric acid, ammonia solution (Merck, min. 25% GR) and ultrapure water (Arium 611UF; Sartorius AG, Germany) were used for the preparation of NBG. 2.2. Preparation of nanobioactive glass 2.2.1. Sonochemical method Initially, TEOS (7.792 ml) was mixed with 20 ml ethanol and 50 ml HNO3 solution (2 N). Then, the mixed solution was sonicated for 25 min using a sonochemical reactor operated at a frequency of
32
B. Saravanakumar et al. / Materials Letters 65 (2011) 31–34
2.2.2. Hydrothermal method TEOS, TEP and CaCO3 were mixed in water/ethanol in a correct proportion. The solution that was prepared was hydrothermally treated at 393 K for 1 h with continuous stirring (100 rpm). The resultant slurry was filtered and washed with deionised water. The product that was obtained was dried in a hot-air oven at 353 K for 12 h and then calcined at 573 K for 3 h. The powder that was obtained after calcination was named as SCP-2. 2.2.3. Sol–gel method TEOS, TEP and CaCO3 were mixed in water/ethanol to a clear solution by using the sol–gel method. The solution was condensed by adding an ammonia solution. The sol–gel method was used to prepare the NBG as discussed elsewhere [13]. The gel was dried in a hot-air oven at 353 K for 6 h and then calcined at 573 K for 3 h in a muffle furnace to get the NBG powder, which was termed as SCP-3. 2.3. Characterisation techniques 2.3.1. Structural and morphological characterisation The amorphous nature of the NBG powder has been studied through X-ray diffraction (XRD) studies using an X-ray diffractometer (D500; Siemens, USA) with CuKα as a radiation (λ = 1.5418 Å) source. The diffractometer was operated at 40 kV with the 2θ value varying from 0 to 80° with an increase of 0.05°. The particle size and shape of the prepared NBG powders were determined using transmission electron microscopy (TEM, CM 200; Philips; USA). The presence of functional groups was confirmed through Fourier transform infrared (FTIR) spectrometer in the range of 4000–400 cm− 1 using KBr as a reference.
Fig. 1. XRD pattern of SCP-1, SCP-2 and SCP-3 NBG glasses (a) as prepared and (b) after incubation in the SBF solution.
22 kHz (VC 505; Sonics, USA). TEP (2.92 ml) was added to the sonicated solution. After adding TEP, sonication was continued for another 25 min. Subsequently, a small quantity of CaCO3 (2.930 g) was added to the sonicated solution and then sonication was continued until gelation. The white gel that was obtained was dried in a hot-air oven at 353 K for 12 h. The dried gel was calcined at 573 K for 3 h in a furnace. The calcinated NBG powder was named as SCP-1.
2.3.2. Incubation in SBF solution The SBF solution was prepared by using the standard procedure as described by Kokubo et al. [14]. The pH value of the prepared SBF solution was equal to human blood plasma. A powder sample of 250 mg was pressed in a hydraulic pressure pellet maker (10 tonnes) to obtain the sample in the form of a pellet. The incubation of all the prepared samples was carried out after immersing them in the SBF solution (35 ml) for 21 days, which was kept in a water bath shaker at a constant temperature of 340 K. The change in the pH value was measured every day using a pH meter (Orion 5-Star; Thermo Scientific, USA). 3. Results and discussion The XRD patterns of the as prepared samples namely SCP-1, SCP-2 and SCP-3 employing the three methods are shown in Fig. 1(a), while
Fig. 2. TEM images of (a) SCP-1, (b) SCP-2 and (c) SCP-3 NBG glasses. The insert represent the electron diffraction pattern of the respective glasses.
B. Saravanakumar et al. / Materials Letters 65 (2011) 31–34
33
Table 1 FTIR vibrational bands of nanobioactive glass before and after incubation in the SBF solution. Assignments
Before incubation
After incubation
SCP-1 SCP-2 SCP-3 SCP-1 SCP-2 SCP-3 H–O–H stretching [15] 3434 OH stretching in O=P–OH group [15] – O–H bending (molecular water) [16] 1635 C–O stretching vibration band [17] – Asymmetric Si–O–Si stretching in 1078 SiO4 tetrahedron [16] C–O Stretching vibration band [15,17] 863 Symmetric Si–O–Si stretching [16] – Si–O–Si bending [16] – – –P=O bending band [18], Phosphate vibration mode [16] PO−3 4 Phosphate PO3−2 vibration mode [16] 563 Si–O–Si stretching [16] 468
3457 – 1642 – 1094
3448 – 1635 – 1094
3457 – 1633 1420 1081
3457 – 1633 1420 1072
3457 2856 1633 1428 1072
871 – – –
863 – – –
876 796 710 599
876 796 710 599
876 796 710 599
545 468
563 477
560 465
560 465
567 473
confirms the particle size as being less than 50 nm. It is inferred from Fig. 2(c) that SCP-3 glass shows non-agglomerated NBG particles prepared by the sol–gel method when compared with SCP-1 (Fig. 2(a)) and SCP-2 (Fig. 2(b)). However, the electron diffraction patterns (insert in Fig. 2(a), (b) and (c)) confirm the amorphous nature of all the NBG glasses. The FTIR spectra of all three samples in the as prepared and after incubation in the SBF solution are shown respectively in Fig. 3(a) and (b). The characteristic infrared bands under the above conditions are shown in Table 1.The formation of the HAp layer was shown by using the FTIR spectrum, as shown in Fig. 3(b). The presence of vibrational bands at 567 and 599 cm− 1 confirms the existence of the HAp in the sample after incubation in the SBF solution. The double band (567 and 599 cm− 1) of the vibrational bands obtained at 600 cm− 1 corresponds to the crystalline phase of phosphate. The formation of the crystalline phosphate is evident from the formation of HAp on the surface of the NBG [16]. Bone mineral formation on the glass surface was identified through XRD (Fig. 1(b)). The sharp peaks at (210), (212), (301), (113) and (220) confirm the crystalline HAp (JCPDS No. 09-0432) [18]. Owing to the higher content of the NBG, the resolution of HAp in the XRD pattern was poor after incubation in the SBF solution. pH variation has been measured in the SBF as a function of soaking time (Fig. 3(c)), which indicates variation in ionic exchange for different methods. A higher magnitude in ionic exchange is obtained in SCP-3 than SCP-1 and SCP-2 (Fig. 3(c)). However, the variation that was obtained was small when compared with SCP-3. The exchange of Ca2+ and OH− ions between the glass and the SBF and vice versa leads to an increase in the pH value. The results that are obtained further support the formation of silanol (Si–OH) on the glass surface after the saturation of Ca2+ ions. The formation of the Si–OH layer is more essential for the formation of crystalline HAp. pH variation was higher in SCP-3 when compared with SCP-1 and SCP-2, which leads to the speeding up of the formation of HAp on the surface [19]. Fig. 3. SCP-1, SCP-2 and SCP-3 NBG glasses. (a) FTIR spectra in the as prepared, (b) FTIR spectra after incubation in SBF solution and (c) pH variation in different soaking periods.
4. Conclusions
after incubation of all three samples in the SBF solution for 21 days are shown in Fig. 1(b). The XRD patterns show only one broad peak at 2θ values in the range of 20–30° (JCPDS No. 79-1711), which indicates the absence of crystalline peaks. The size and shape of the NBG were confirmed through TEM analysis, as shown in Fig. 2. The TEM image
The NBG with a composition of 48SiO2–40CaO–12P2O5 was prepared using three different methods (sonochemical, hydrothermal and sol–gel). The different characterisation studies on NBGs reveal a higher bioactivity in SCP-3 than other glasses such as SCP-1 and SCP-2. The higher bone-bonding ability of the NBG that is observed indicates that the sol–gel method is more suitable for the preparation of bioactive glass for implant applications.
34
B. Saravanakumar et al. / Materials Letters 65 (2011) 31–34
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Hall SR, Walsh D, Green D, Oreffo R, Mann S. J Mater Chem 2003;13:186–90. Hench LL, West JK. Life Chem Rep 1996;13:187–241. Hench LL. Ann NY Acad Sci 1988;523:54–71. Karlsson KH, Froberg K, Ringbom T. J Non-Cryst Solids 1989;12:69–72. Ohtsuki C, Kokubo T, Yamamuro T. J Non-Cryst Solids 1992;143:84–92. Fujiu T, Ogino M. J Biomed Mater Res 1984;18:845–59. Cerruti M, Magnacca G, Bolis V, Morterra C. J Mater Chem 2003;13:1279–86. Hench LL, Polak JM. Science 2002;295:1014–7. Carta D, Knowles JC, Guerry P, Smith ME, Newport RJ. J Mater Chem 2009;19:150–8. Vallet-Reg M, Salinas AJ, Roman J, Gil M. J Mater Chem 1999;9:515--8. Kis-Csitári J, Kónya Z, Kiricsi I. Functionalized Nanoscale Materials, Devices and Systems. Netherlands: Springer; 2008. p. 369–72.
[12] Ashok M, Narayana Kalkura S, Meenakshi Sundaram N, Arivuoli D. J Mater Sci Mater Med 2007;18:895–8. [13] Xia W, Chang J. Mater Lett 2007;61:3251–3. [14] Kokubo T, Kushitani H, Sakka S, Kitsugi T, Yamamuro T. J Biomed Mater Res 1990;24:721–34. [15] Zhang Y, Wang M. Mater Sci Eng B 1999;67:99–101. [16] Costa HS, Rocha MF, Andrade GI, Barbosa-Stancioli EF, Pereira MM, Orefice RL, et al. J Mater Sci 2008;43:494–502. [17] Yan X, Huang X, Yu C, Deng H, Wang Y, Zhang Z, et al. Biomaterials 2006;27: 3396–403. [18] Lin KSK, Tseng Yao-Hung, Mou Y, Hsu Yu-Chuan, Yang China-Min, Chan JCC. Chem Mater 2005;17:4493–501. [19] Arcos D, Pena J, Vallet-Regi M. Chem Mater 2003;15:4132–8.