Controlled release of paclitaxel from biodegradable unsaturated poly(ester amide)s/poly(ethylene glycol) diacrylate hydrogels

Biodegradable hydrogels (FPBe-G) were synthesized by the photopolymerization of two precursors: FPBe, a fumurate-based unsaturated poly(ester amide) (UPEA), and poly(ethylene glycol) diacrylate (PEG-DA). Depending on the feed ratio of these two precursors, the resultant FPBe-G hydrogels showed different crosslinking levels of network structure, mesh sizes (xi) and matrix morphology. When a lipophilic drug, paclitaxel, was preloaded into FPBe-G hydrogels, the two-month drug-release kinetics from FPBe-G hydrogels in both pure PBS buffer and alpha-chymotrypsin media were measured. The paclitaxel-preloaded FPBe-G hydrogels in a alpha-chymotrypsin solution had significantly faster drug release rate than the corresponding hydrogels in a pure PBS buffer due to an enzyme catalyzed biodegradation of FPBe-G hydrogels. Sustained paclitaxel releases over a two-month period without initial burst release were also achieved by using hydrogels having certain feed ratios of hydrogel precursors. These paclitaxel release data correlated well with the molecular mesh size (xi), molecular weight between cross-links (M-c) and matrix morphological structure of FPBe-G hydrogels.