Abstract
The objective of our research is to prepare environmental responsibility bio-hydrogel with good biocompatibility based on interpenetrating polymer networks constructed with polyoxazoline、poly(acrylic acid) and polylactide. The prepared hydrogel swell to release the drug at high pH such as the neutral pH of intestine, and shrink to protect the drug at low pH such as the pH of stomach. The characterization of swelling dependence on environmental responsibility can be applied in drug delivery systems (DDS), and effectively controlled release drug to reach the purpose of therapy.In our study, POx/PAA IPN and PEG-b-PLA/PAA SIPN are synthesized, respectively. The response of these prepared hydrogel by environmental stimuli especially in pH stimuli is obvious and fast. Hence, these prepared hydrogel belong to fast responsibility hydrogel. According to the result of swelling test, no mater POx/PAA IPN or PEG-b-PLA /PAA SIPN swell at physiology environment (pH 7-7.4, 37℃) and shrink at low temperature/pH, which form reversibly swelling/shrinking. According to the confirmation of drug controlled release experiment, these prepared hydrogel can effectively controlled release drug, no mater small molecule drug like theophylline or large molecule drug like bovine serum albumin (BSA) can be released from that, and form the intelligential “On-Off “ drug release profile. The biocompatibility of these hydrogel is evaluated by in vitro cytotoxicity test. According to the result of cytotoxicity test, the survival ratio of cultured cell can reach above 80%. In addition PEG-b-PLA/PAA SIPN have the characterization of degradable, which degrade upon hydrolysis of the polylactide regions into PEG、the lactic acid and PAA at physiology environment in one month .