Cyclodextrin dimer with porphyrin core for target transport and combined therapy

Cyclodextrin dimer with porphyrin core for target transport and combined therapy

Abstracts / Journal of Controlled Release 132 (2008) e19–e36 e27 Conclusion Nanofibrous networks formed by gelators 1 and 2 are compatible with the ...

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Abstracts / Journal of Controlled Release 132 (2008) e19–e36

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Conclusion Nanofibrous networks formed by gelators 1 and 2 are compatible with the encapsulation of proteins and cells. The highly open architecture of these gels allows for rapid transport of solutes and initial results for their use as scaffold materials for three dimensional tissue culture are promising. References [1] A. Heeres, C. van der Pol, M. Stuart, A. Friggeri, B.L. Feringa, J. van Esch, J. Am. Chem. Soc. 125 (2003) 14252–14253. [2] K.J.C. van Bommel, C. Pol, I. van der Muizebelt, A. Friggeri, A. Heeres, A. Meetsma, B.L. Feringa, J. van Esch, Angew. Chem. Int. Ed. 43 (2004) 1663–1667. [3] K.J.C. van Bommel, M.C.A. Stuart, B.L. Feringa, J. van Esch, Org. Biomol. Chem. 3 (2005) 2917–2920. [4] M. Montalti, L.S. Dolci, L. Prodi, N. Zaccheroni, M.C.A. Stuart, K.J.C. van Bommel, A. Friggeri, Langmuir 22 (2006) 2299–2303; A. Friggeri, B.L. Feringa, J. Van Esch, J. Control. Release 97 (2004) 241–248. [5] A. Brizard, M. Stuart, K. van Bommel, A. Friggeri, M. de Jong, J. van Esch, Angew. Chem. Int. Ed. 47 (2008) 2063–2067.

doi:10.1016/j.jconrel.2008.09.015

Cyclodextrin dimer with porphyrin core for target transport and combined therapy

Z. Kejíka,b,⁎, T. Břízaa,b, P. Poučkováb, J. Kralovác, V. Krála,d, P. Martásekb a Institute of Chemical Technology in Prague, Technická 5, Praha 6, 16628. Czech Republic b First Medical Faculty of Charles University in Prague, Kateřinská 32, Praha 2, 12108. Czech Republic c Institut of Molecular Genetics, Academy of Sciences in Prague, Flemingovo nám. 2, 1663. Czech Republic d Zentiva R & D, U Kabelovny 130, 10237 Prague 10, Czech Republic E-mail: [email protected] Abstract We tested beta- and gamma-cyclodextrin dimer with porphyrin core as a linker for target transport drugs (taxol and doxorubicin) and for combined therapy on nunu mice with skin cancer. Introduction At present, a lot of anticancer drugs are in use. The main problems of these drugs are high toxicity for healthy tissues and low solubility in water. These problems can be solved by targeted transport using drug delivery systems (DDS), for example cyclodextrins or cyclodextrin systems [1]. Convenient DDS, for example polymers combined with hormones [2,3] can also have a therapeutic effect. Advantage of a DDS with its own therapeutic effect is that it enables enhanced targeted therapy, the therapeutic effect of the DDS being combined with the effect of the transported drug, which causes high efficiency of treatment. Toxicity of this therapy for the body is low. This way of treatment is called the combined therapy [3]. Cyclodextrins consist of a cyclo-oligo-glucose unit with a hydrophobic cavity and a hydrophilic surface. The cavity can be used for complexation of hydrophobic molecules, such as an anticancer drug [4]. However, the binding constants are not high enough to enable optimal using of simple cyclodextrins. This problem can be solved by developing cyclodextrin dimers [5]. We designed some porphyrins as linkers of cyclodextrin units. Porphyrins and porphyrin systems can be used for photodynamic therapy, because they have high selectivity for cancer cells, and their strong fluorescence can be used for recognition of cancer cells and for observation of transport selectivity [6]. In addition, the porphyrin core can bind the hydrophobic part of the transported drug. The porphyrin core improves the stability constant of the complex. In our latest study [7], the selectivity of cyclodextrin-porphyrins was tested for cancer cells. A higher level of porphyrins was observed in cancer cells than in healthy ones. After this successful study we decided to test the anticancer effect of cyclodextrinporphyrin using the combined therapy.

Fig. 1. Influence of the combined therapy on the tumor volume after treatment with bis-cyclodextrin-porphyrin and taxol.

Experimental methods Medicinal studies were done using the nunu mice mouse model with human skin cancer. Doses of the drug were 5 mg/kg. All aspects of the animal experiment and husbandry were carried out in compliance with national and European regulations and were approved by the institutional committee. Results and discussion We studied applications of bis-cyclodextrin-porphyrins for target transport of anticancer drugs and for combined therapy. We used bis-βcylodextrin-porphyrin for the transport of taxol and bis-γ-cyclodextrinporphyrin for the transport of doxorubicin. In our systems, we tested the target transport and the photodynamic therapy both separately and in combination. A high synergic effect was observed. Volume of tumor — the thirtieth day of treatment. Reduction of tumor (treated group / control group) in % System

PDT

Drug delivery

PDT+ Drug delivery

β-CD2 γ-CD2

32% 19%

55% 90%

7% 4%

Conclusion Porphyrin-cyclodextrins have a high potential for the target transport of anticancer drugs and for the combined therapy. Acknowledgements This work was funded by grant from the Ministry of Education of the Czech Republic (project MSM021620806, project MSM6046137307, project LC 512 and project KAN200200651).

References [1] F. Uekama, H. Hirayama, H. Arima, Recent aspect of cyclodextrin-based drug delivery Systém, J. Incl. Phenom. Macrocycl. Chem. 56 (1–2) (2006) 3–8. [2] B. Říhova, J. Strohalm, J. Prausova, K. Kubackova, M. Jelínkova, L. Rozprimova, M. Sırova, D. Plocova, T. Etrych, V. Subr, T. Mrkvan, M. Kovar, K. Ulbrich, Cytostatic and immunomobilizing activities of polymer-bound drugs: experimental and first clinical data, J. Control. Release 91 (1–2) (2003) 1–16. [3] J.V. Marie, F. Greco, R.I. Nicholson, A. Paul, P.C. Griffiths, R. Duncan, Polymer therapeutics designed for a combination therapy of hormone-dependent cancer, Angew. Chem. Int. Ed. 44 (26) (2005) 4061–4066. [4] T. Loftsson, M. MassonM, Cyclodextrins in topical drug formulations: theory and practice, Int. J. Pharm. 225 (1–2) (2001) 15–30.

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[5] Y. Liu, Y. Chen, Cooperative binding and multiple recognition by bridged bis(,-cyclodextrin)s with functional linkers, Acc. Chem. Res. 39 (10) (2006) 681–693. [6] V. Kral, J. Kralova, R. Kaplanek, T. Briza, P. Martasek, Quo vadis porphyrin chemistry? Physiol. Res. 55 (2) (2006) S3–S26. [7] J. Kralova, A. Synytsya, P. Pouckova, M. Koc, M. Dvorak, V. Kral, Novel porphyrin conjugates with a potent photodynamic antitumor effect: differential efficacy of mono- and bis-β-cyclodextrin derivatives in vitro and in vivo, Photochem. Photobiol. 82 (2) (2006) 432–438 82.

doi:10.1016/j.jconrel.2008.09.016

Hydrosomes, novel thermosensitive gel-containing polymersomes J.S. Leea, W. Zhoua, D. Zhangb, C. Ottob, J. Feijena a Institute for Biomedical Technology (BMTI), Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands b MESA+ Institute for Nanotechnology, Biophysical Engineering Group, University of Twente, Enschede, The Netherlands Abstract Novel thermosensitive gel-containing polymersomes (hydrosomes) were prepared by incorporating poly(N-isopropylacrylamide), PNIPAAm, into polymersomes based on poly(ethylene glycol)-b-poly(d,l-lactide). These hydrosomes are potential novel carriers for anticancer drugs and proteins. Hydrosomes with a size of 100–200 nm as determined with high resolution SEM, were prepared by injecting a solution of the polymer and PNIPAAm in THF into water. Giant hydrosomes containing fluorescein labeled PNIPAAm were prepared using CHCl3 as the organic phase. The presence of the gel inside the polymersomes was shown by confocal laser scanning microscopy. Release of fluorescein isothiocyanate tagged dextran (FD, FITC-dextran, Mw 4000 g/mol) reveals that hydrosomes have acquired a more sustained release profile in comparison with empty polymersomes at 37 °C for 30 days, with low initial burst effect. Introduction Polymersomes (PS), vesicles with membranes consisting of amphiphilic block copolymers are more stable than liposomes and can be surface modified by targeting molecules [1]. The release rate of drugs from PS can only be varied to a limited extent due to constraints imposed by amphiphilic block copolymers with a rather narrow range of hydrophobic/hydrophilic balances and a suitable glass transition temperature (Tg) to form the membrane. In principle, release rates of drugs can be further tuned by introducing a temperature sensitive gel inside the PS. Nanogels, a new family of nanoscale materials based on dispersed submicron polymer networks, have become an important research area for intravenous and targeted drug delivery. [2]. However, currently used nanogels or nanoparticles have substantial shortcomings due to complicated preparative procedures, which require the presence of the drug during synthesis, which often leads to drug inactivation. In this study, we selected poly(ethylene glycol)-b-poly(d,llactide) (PEG-PDLLA) for the formation of PS and PNIPAAm as a temperature-

Fig. 1. Schematic 2D-cross sectional illustration of hydromes undergoing a phase transition at 32 °C.

Fig. 2. DLS measurements as a function of temperature: empty PS ( , and gray bars); hydrosome (●, ▲ and black bars); Size distribution (gray and black bars), kilo count per second (kcps) ( and ●) and polydispersity index (PDI) ( and ▲) are represented.

responsive model hydrogel, respectively. This combination could lead to hydrosomes, which can be loaded with drugs in a simple way and of which the release behavior can be regulated by the presence of the temperature sensitive nanogel. In this contribution, we will address the formation of a nanogel inside the PS. A schematic presentation of the hydrosome system is presented in Fig. 1. Experimental methods D,l-lactide (DLLA, Purac), N-isopropylacrylamide (NIPAAm, Aldrich), and 2,2'-azobisisobutyronitrile (AIBN, Fluka) were recrystallized from toluene, hexane, and methanol, respectively. Monomethoxy poly(ethylene glycol) with a molecular weight of 5000 g/mol (mPEG, Fluka) was dried by dissolution in anhydrous toluene followed by azeotropic distillation under N2. Stannous octoate (SnOct), FITC-dextran (Mw 4000 g/mol) and Sepharose® 6B (6B) (6% Beaded Agarose, pore size 10–1000 KDa) were obtained from Sigma. Fluorescein isothiocyanate (FITC), 2-aminoethanethiol (ATE), N,N'dicyclohexylcarbodiimide (DCC), and 4-di(methylamino)pyridine (DMAP) were purchased from Fluka and used as received. Amphiphilic block copolymers were synthesized by ring-opening polymerization of DLLA using SnOct and mPEG as a catalyst and an initiator, respectively. PNIPAAm was prepared by free radical polymerization using a chain transfer agent [3] and this polymer was labeled using FITC by amine/ isothiocyanate coupling chemistry. Nano-sized hydrosomes with encapsulated FITC-dextran (FD-hydrosomes) were prepared by the solvent injection method using THF [4]. Free PNIPAAm was removed by ultra-filtration for 5 h and free FITC-dextran was separated by 6B column filtration. Size distribution measurements as a function of temperature were carried out by dynamic light scattering (DLS, Zetasizer Nano, Malvern, UK).

Fig. 3. Single molecule fluorescence confocal microscopy at 25 °C: (a) FITC-PNIPAAmPS (hydrosome bound FITC), (b) FITC-PNIPAAm (100 nM, water).