Study On Modified Technology Environment Sensitive Interpenetrating Polymer Networ Hygrogel

Hydrogels are three-dimensional hydrophilic polymers, which swell butdo not dissolve. Over the past decades, environment sensitive hydrogels canundergo a volume change in response to small changes in environmentalfactors. However, the main limitations of the conventional hydrogel used inbiomedical fields are the poor mechanical strength and the slow rate ofresponse. To solve these problems, interpenetrating polymer network (IPN)technology was introduced in this study to modify the conventional hydrogels.The modified hydrogels were used in the controlled drug release systems.A series of Polyaspartic acid/polyvinyl alcohol (PASP/PVA) IPNhydrogels were synthesized and the results showed that: the PASP/PVA IPNhydrogels had a more compact structure and exhibit a transformation trendfrom amorphousness to crystalloid compared with PASP hydrogel. All thePASP/PVA IPN hydrogels enjoyed a good pH-sensitivity, however, the swollenequilibrium of the IPN hydrogels decreased in function of the content of PVAhydrogel. The results of in vitro Naproxen Sodium (NS) release indicated that:in simulated gastric fluid, there was hardly any drug was released from thePASP/PVA IPN hydrogels which contend PVA above5%. In the simulated intestinal fluid there was40%drug released from the IPN hydrogel whichcontend PVA10%, whereas there was almost90%drug released from the PASPhydrogel.The PASP/PVA IPN hydrogels synthesized in the last part were used ascores to make a series of novel core-shell sodium alginate (SA) microspheres.The controlled drug release properties of the microspheres were evaluated inthis study. The results showed that through introducing IPN hydrogel into SAmicrospheres, the drug release was prolonged.Various Poly (N-isopropylacrylamide) PNIPAAm/PASP IPN hydrogelwith sensitivity to temperature and pH were prepared. The results ofexperiment showed that: Through introducing PASP hydrogel, IPN hydrogelsexhibited enhanced thermal sensitivity and much faster shrinking andre-swelling in function of the composition ratio of the two network components.In the test of de-swelling, the PNIPAAm/PASP IPN contends20%PASP lost90%water in10min, whereas PNIPAAm hydrogel only lost30%water. Thesefast responsive hydrogels foster potential applications in biomedical andbiotechnology fields.IPN technology was used in this study to modify eniromental hydrogels.The modified hydrogels were used in drug deliver systems successfully.