| In the cause of human death,cancer located in the first place which has been attracted lots of attentions.The purpose of this study: biodegradable nanoparticles drug carrier was synthesized and loaded antitumor drugs in vitro;temperature/pH stimuli responsive of drug carrier was synthesized and study stimuli responsive,drug delivery.Specific experiments are as follows:Using Novozyme-435 as the catalyst,di-tert-butyl dicarbonate-protected ethanolamine initiated the caprolactone ring-opening polymerization.After deprotected the tert-butoxycarbonyl protecting group,the copolymer initiated γ-2-chloroethyl-L-glutamic acid(CELG-NCA)through ring-opening polymerization.Through atom transfer radical polymerization(ATRP),the pH stimuli responsive polymer PCL-b-PCELG-g-OEG was synthesized that polyethylene glycol monomethyl ether(OEG)was introduced into PCL-b-PCELG.The micelles,made by the PCL-b-PCELG-g-OEG,confirmed to be nano-scale by electron transmission electron microscopy(TEM)and dynamic light scattering(DLS).Doxorubicin(DOX)which was loaded by drug carrier released in different simulated physiological environment,experiments show that drug delivery system in the pH 6.4 phosphate buffer solution(PBS)drug release rate higher than 7.4 pH of the PBS solution.In addition,using the ATRP method,the N-isopropylacrylamide(NIPAM)and OEG were initiated by the polymer PCELG which prepared by triethylamine initiated CELG-NCA to obtain a random polymer P(PCELG-g-(PNIPAM-co-POEG)).The synthesized drug carrier has a temperature-sensitive property,the critical phase transition temperature is closed to human body temperature.The materials formed micelles in solution,the size and morphology of the micelles were tested.Drug-loaded materials P(PCELG-g-(PNIPAM-co-POEG))loaded DOX released drug in vitro.In acidic environment,the drug delivery system showed a higher drug release rate. |
