Dual Cross-Linking Systems of Functionally Photo-Cross-Linkable and Thermoresponsive Polyphosphazene Hydrogels for Biomedical Applications

• Published in: Biomacromolecules 2010-07, Vol.11 (7), p.1741-1753
• Main Authors: Potta, Thrimoorthy, Chun, ChangJu, Song, Soo-Chang
• Format: Article
• Language: English
• Subjects: Applied sciences; Biological and medical sciences; Chemical modifications; Cross-Linking Reagents - chemistry; Cross-Linking Reagents - radiation effects; Exact sciences and technology; General pharmacology; Hot Temperature; Hydrogels - chemistry; Hydrogels - therapeutic use; Inorganic and organomineral polymers; Mechanical Phenomena; Medical sciences; Methacrylates; Organophosphorus Compounds - chemical synthesis; Organophosphorus Compounds - chemistry; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Photochemical Processes; Physicochemistry of polymers; Polymers - chemical synthesis; Polymers - chemistry; Transition Temperature
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm100197y

Photo-cross-linkable, functionalized, and thermosensitive polyphosphazenes were synthesized to develop a dual cross-linking system with properties of mechanically suitable strength and controllable biodegradation for injectable biomedical applications. The aqueous solutions of the polymers exhibited sol−gel transition behaviors against temperature. The incorporated methacrylate groups were photo-cross-linked upon UV light under mild conditions, which resulted in the formation of compact three-dimensional networks. The thermoresponsive hydrophobic interactions at body temperature facilitated the rapid dual cross-linking accomplishment of the photo-cross-linking even under mild conditions. The characteristics of the polymers such as pore size and density showed that the inner three-dimensional networks depended on the degree of cross-linking of methacrylate units. Mechanical properties of the gel were also improved several folds after developing the photo-cross-linking in the network from the in vivo degradation studies. The results demonstrate that the photo-cross-linkable and thermoresponsive polyphosphazenes have great potential as injectable, biodegradable, and controllable carriers for various biomedical applications by tuning the mechanical gel property and the degradation rate.