A Studv On The Solution Assembly Of Micelles And Drug Loading Of PH-resnonsive Polymer

Surfactant molecules and micelle solutions are playing a more and more important role in biochemistry and pharmaceutical applications. A good understanding of the micellization of surfactant and the determination of the critical micelle concentration (CMC) of surfactants are of fundamental importance. Furthermore, micelles of amphiphilic polymer have great potential applications in anti-cancer drug delivery. Physical stimuli-responsive polymeric micelles develop quickly based on the differences between the tumor and normal tissues. In particular, pH-responsive micelles have been widely concerned.Firstly, a novel fluorescence method for probing the assembling/disassembling of amphiphilic molecules was constructed based on the aggregation-induced emission (AIE) of a1,2-Diphenyl-1,2-di(p-tolyl)ethene (TPE). Based on a comparison of the CMC values obtained by the TPE probe method with those obtained by conventional pyrene-based method and other methods in the literature, the TPE method was useful for determining the CMC of various surfactants, including cationic, anionic, and amphiphilic neutral molecules. While the conventional fluorescence based method might have problems to study the CMC of those colored surfactants due to its ACQ disturbed by colored surfactants, the AIE based method can study it since TPE fluorescence signal mainly come from the aqueous phase. The AIE based method provided an alternative method to investigate the assembling/disassembling of amphiphilic moleculesSecondly, a kind of amphiphilic polymer (PEG-PEI/amide) with PEG as hydrophilic segment and amide as hydrophobic segment was synthesized by graft poly(ethylene glycol)(PEG) and amide to polyethyleneimine(PEI) and self-assembled into pH responsive polymeric micelles in aqueous solution. Blank micelles and the drug-loaded micelles were prepared by the dialysis method. In vitro, it show that the drug released faster at pH6.0than pH7.4The polymeric micelles may be used for pH targeting of drug delivery. Cell cytotoxicity tests indicated that the material showed excellent biocompatibility, and drug-loaded micelles had obvious cell inhibition effects. Cell experiments also indicated that the release of drugs in the drug-loaded micelles spread in the cell matrix. The high biocompatibility and responsive amphiphilic polymer micelles would have potential applications in the anti-cancer drug carrier.