Photoresponsive Hydrogels

Andreopoulos, F.M. Persaud, I. 2006, Delivery of basic fibroblast growth factor (bFGF) from photoresponsive hydrogel scaffolds . Biomaterials, vol. 27, no. 11, pp. 2468-2476. 

PPR hydrogels were obtained for the first time by Harada and coworkers with PEG chains threading a-CD units. Photoresponsive hydrogels were also created from PEG-a-CD systems by addition of l- p-(phenylazo) benzyljpyridinium bromide as competive guest for a-CD. Photoreversible control of sol-gel transition was achieved through trans-cis photoisomerization. (Fig. 17). A light controlled fluorescent PPR... 

Harada and coworkers reported forming a photoresponsive hydrogel system by combination of a-cyclodextrin, dodecyl-modified poly(acrylic acid), and a photoresponsive competitive guest, 4,4 -azodibenzoic acid. An aqueous solution of dodecyl-modified poly(acrylic acid) exhibits a gel-like behavior, because polymer chains form a network structure via hydrophobic associations of Ci2 side chains. When a-cyclodextrin is added to the gel-like aqueous solution, the gel is converted to a sol mixture because hydrophobic interactions of Ci2 side chains are dissociated by the formation of inclusion complexes of a-cyclodextrin with the C12 side chains. Upon addition of 4,4 -azodibenzoic acid to the binary sol mixture of the modified poly(acrylic acid) and a-cyclodextrin, the cyclodextrin interacts predominantly with 4,4 -azodibenzoic acid ... 

Watanabe, T., Akiyama, M., Totani, K., et al. (2002) Photoresponsive hydrogel microstructure fabricated by two-photon initiated polymerization, Adv. Functional Mat., 12, 611-4. 

SzUagyi, A., Sumaru, K., Sugiura, S., Takagi, T, Shinbo, T, Zrinyi, M. and Kanamori, T. (2007). Rewritable microrehef formation on photoresponsive hydrogel layers. Chemistry of Materials, 19,2730-2732. 

Tomatsu, L, Peng, K. and Kros, A. (2011). Photoresponsive hydrogels for biomedical apphcations. Advanced Drug Delivery Reviews, 63,1257-1266. 

Dextran-based bioeompatible and photoresponsive hydrogels for light-eontrolled protein release applications have been reported by Peng et al. based on inelusion complex of trans azobenzene and cyclodextrin as a photo-switehable eross-linker (Peng et al. 2010). 

Tomatsu, 1., Hashidzume, A., and Harada, A. (2005) Photoresponsive hydrogel system using molecular recognition of alpha[Pg.242]

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