Abstract

Novel triblock copolymers of poly(L-lactide)-poly(ethylene glycol)-sebacate-poly(ethylene glycol)-poly(L-lactide) were synthesized by Ring-Opening Polymerization (ROP) of different ratios of L-lactide with three pre-prepared poly(ethylene glycol)-sebacate-poly(ethylene glycol) polymers A, B and C have different poly(ethylene glycol) molecular weight (2000, 4000, and 10000 g/mole). The triblock copolymers were used to produce nine triblock copolymers having new different lactide chain length (n=10, 25 and 50), coded AL10, AL25, AL50, BL10, BL25, BL50, CL10, CL25, and CL50, respectively. Nine networks were prepared from triblock copolymers with cross-linked sodium alginate, S1-S9. All those polymer networks were loaded with 50 IU of insulin. Each component of the polymer network groups was mixed with cross-linked hydroxyl ethyl cellulose to form SH1-SH9 from S1-S9 fiber IPN’s. These samples were coated with gelatin cross-linked with two different ratios of gluteraldehyde, 20% and 40% w/w by one layer and two layers. Insulin release study at pH 1.2 and 8.4 for 24 hours was performed. Hydrolytic degradation studies were followed at three different pH, 1.2, 7 and 8.4 for 7 weeks with 40% as maximum degradation.