Construction And Process Optimization Of Reverse NM Of PEG-PLA-SA Ttiblock Copolymer

Because of its special properties,amphiphilic block copolymers have potential application value in the fields of medical materials and drug carriers,and have become one of the research hotspots in the field of medicine.In this paper,polyethylene glycol(PEG)was used as the initiator to synthesize a PEG-PLA-SA triblock copolymer by ring-opening polymerization and esterification.The structure was characterized by Fourier Transform Infrared Spectroscopy(FT-IR),Nuclear Magnetic Resonance(1H NMR)and Gel Permeation Chromatography(GPC).The preparation process of PEGPLA-SA was optimized by single factor experiment and response surface analysis.Selfassembly of PEG-PLA-SA triblock copolymer in toluene/ethanol/water to obtain PEGPLA-SA triblock copolymer reverse micelles.The drug release performance and biocompatibility of PEG-PLA-SA triblock copolymer reverse micelles were observed using aspirin as a model drug.The research results show that the PEG-PLA-SA triblock copolymer reverse micelles are spherical,with a particle size of less than 70 nm,and the encapsulation efficiency and drug loading are 60 % and 23 %,respectively.The best preparation process is that the reaction temperature is 30.6 ℃,the reaction time is 36.8 h,the mass of lactide is 11.6 g,and the molar weight of stearic acid is 0.036 mol.The release rate of the triblock polymer PEG-PLA-SA was faster in the first 8 h,and the cumulative drug release reached 50 %.After 8 h,the release rate tended to be flat,and the cumulative drug release at 24 h reached 70 %.MTT and agar diffusion experiments confirmed that PEG-PLA-SA reverse micelles have good cell compatibility.The hemolysis rate and dynamic clotting time confirmed that PEG-PLA-SA reverse micelles have good blood compatibility.Toxicity experiments confirmed that PEG-PLA-SA reverse micelles have good histocompatibility,indicating that the triblock polymer PEG-PLA-SA has good biocompatibility.This laid a working foundation for the clinical practical application of PEG-PLA-SA triblock copolymer reverse micelles.