Preparation And Characterization Of Thermosensitive In Situ Gel Based On Poly (ether-ester Anhydride) Nanoparticles

In order to obtain the hydrogel which is more suitable for biomedical application, wesynthesized and characterized a novel thermosensitive in situ gel based onpoly(ether-ester anhydride) nanoparticles.We synthesized and characterized an amphiphilic multiblock copolymerpoly(ether-ester anhydride)(PES) by esterification and polycondensation. Both FT-IRand1H-NMR can confirm that PES is consistent with the designed copolymer. PESnanoparicles (NPs) were prepared by nanoprecipitation technology. PES NPs were ofa well-defined spherical shape and lower than200nm in diameter. Hydrophobicpaclitaxel can be incorporated into PES NPs. With increasing Mnof PEG, the size ofNPs was decreased and the drug-load amount was increased. During the in vitrorelease process, the initial burst release was not observed and paclitaxel wassustainably released from the drug-loaded NPs. Using L929and a cancerous cell lineMCF-7as model cell, MTT cell proliferation assay was employed to assess the cellviability after the incubation with NPs. The results indicate that PES NPs pose nothreat on the cells.Then, the thermogelling behaviors of PES NPs, in vitro erosion, in vitro drugrelease and in vivo evaluation of biocompatibility of hydrogel were highlightened.The aqueous dispersions of PES NPs underwent a sol-gel-sol phase transition as thetemperature was increased from4to70°C. With increasing the concentration of PESNPs aqueous dispersion, the temperature of sol-gel phase transition was decreased andthe temperature of gel-sol was increased. During the in vitro erosion process, the innerpore size of hydrogel was enlarged gradually and the hydrogel released particles in theerosion liquid. During the in vitro release processes,5-FU, BSA, paclitaxel anddexamethasone were controlled release in24h,7d,36d and35d. Histopathologicalstudies confirmed that PES-NP hydrogel have well biocompatibility.