Abstract
Use biodegradable and amphiphilic copolymer as drug delivery carrier has been researched widely, most of them are made in micelle form. Recently, there is another method developed. Photo-cross-linked reaction is used to prepare nano-hydrogel particles as drug carriers. This is an easy and low residual toxicity hydrogel preparation. Hydrogel has been widely applied because its unique behaviors, it can swell but not dissolve in water, and have different responses depend on the environment. This research synthesized mPEG and L-lactide by ring-opening polymerization without solvent, after analysis mPEG-PLLA by GPC, 1H-NMR, FT-IR, then modified as mPEG-PLLA-AC carried C=C double bond at the hydrophobic chain end. By the UV reaction we formulated nano-size photo-cross-linked hydrogel particles. The UV photo-cross-linking irradiation added photo-initiator（DMPA） and different concentration of photo-crosslinker（EGDMA）to form nano-hydrogel particles. Without cross-linked micelle particle sizes are 150 nm, and cross-linked nano-hydrogel particles are 125 ~ 195 nm, the size range depends crosslinker concentration. MTT assay appears that 20% EGDMA nano-hydrogel has little influence on cell growth, after 72 hr cell culture viability is 36.85 ± 1.18 %. After nano-hydrogel particles were prepared, Paclitaxel is encapsulated by dialysis method. Particle sizes are increased 10 ~ 40 nm, and 20% EGDMA nano-hydrogel encapsulation efficiency (EE) is the best. During 30 days accumulative drug release, 0% EGDMA has the most amount of release ratio 73.1 ± 2.2 %, and the most stable release is 20% EGDMA hydrogel, 35.1 ± 0.7 %. In HeLa cell cytotoxicity test, after incubate 72 hr all of Paclitaxel-loaded particles have cell inhibition effect. In this research we obtain an amphiphilic copolymer to prepare hydrogel particles, which have smaller than 200 nm particle size, no serious cytotoxicity and stable drug release results. Provide an optimistic choice as drug delivery carrier.