Biodegradability and biocompatibility of a pH- and thermo-sensitive hydrogel formed from a sulfonamide-modified poly(ε-caprolactone-co-lactide)–poly(ethylene glycol)–poly(ε-caprolactone-co-lactide) block copolymer

摘要: A pH- and thermo-sensitive block copolymer was synthesized by adding pH-sensitive sulfamethazine oligomers (SMOs) to either end of a poly(epsilon-caprolactone-co-lactide)-poly(ethylene glycol)-poly(epsilon-caprolactone-co-lactide) (PCLA-PEG-PCLA) copolymer. The resulting SMO-PCLA-PEG-PCLA-SMO solution did not form gel at high pH (pH 8.0) or increased temperatures (ca. 70 degrees C), but stable under physiological conditions 7.4 37 C). degradation rate the decreased substantially compared with control PCLA-PEG-PCLA, due buffering effect sulfonamide groups on acidic monomer-induced rapid PCLA-PEG-PCLA. This suitable sol-gel transition sustained biodegradability resolves two major drawbacks associated copolymers, namely premature gelation degradation. Interestingly, showed no evidence cytotoxicity in vitro. However, subcutaneous injection (20wt% PBS into Sprague-Dawley (SD) rats resulted rapid, formation, injected hydrogel being completely degraded vivo just 6 weeks. presented typical acute inflammation within 2 weeks, although chronic observed during first 6-week period. As such, is candidate for use drug delivery systems cell therapy.