Biological character of Dex-PCL-HEMA/PNIPAAm as a kind of heat sensitivity hydrogel

Objective:To study the process of syntyesis and degradation in vitro of Dex-PCL-HEMA/PNIPAAm as a kind of heat sensitivity hydrogel,and to research its biological character.Methods:To synthesize Dex-PCL-HEMA/PNIPAAm through free radical polymerization,to detect lower critical solution temperature(LCST),to observe internal structure through scanning electron microscope(SEM);to make degradation test in vitro and to controllc release bovine serum albumin in vitro.Results:LCST of Dex-PCL-HEMA/PNIPAAm was 33.2～34.2 °C;the pore diameter of Dex-PCL-HEMA/PNIPAAm decreased when the contents of Dex-PCL-HEMA increased;DN hydrogel degraded quickly in the first three days,sequences of degradation rate were DN1DN2DN3DN4 in 4～16 d,its weight kept stable state and stopped degradation after 16 d;BSA curve showed Dex-PCL-HEMA/PNIPAAm release quickly in the first 5 h and then stepped down gradually.Conclusion:Dex-PCL-HEMA/PNIPAAm possesses satisfactory temperature sensitivity and biocompatibility in vitro,so Dex-PCL-HEMA/PNIPAAm is a good material in animal studies.