Study of PNIPAAm-PEG thermo-sensitive copolymer micelle and Application as drug carrier for icariin

A series of thermally responsive copolymers PNIPAAm-PEG were prepared through RAFT polymerization. Their molecular structures were verified by ¹H NMR spectroscopy and GPC. The temperature-dependent characteristics study has revealed that PNIP AAm-PEG exhibits a lower critical solution temperature (LCST) of about 34~42°C with the PNIPAAm:PEG molecular weight ratio of 1:1 to 10:1. When PNIPAAm:PEG=I.8:1, the polymer has a LCST of 37.8°C, which is very close to body temperature. The micelles also showed nearly 85% encapsulation efficiency for icariin with temperature dependent release. These results indicate that PNIPAAm-PEG is a promising drug carrier for icariin, and icariin-PNIPAAm-PEG has great potential in bone defect and disease treatment.