Synthesis And Drug Release Behaviors Of Thermo-sensitive Poly(n-(methyl) Acryloyl Animo Acid Ester)

In this study, we synthesized and characterized a series of thermo-sensitive polymers, mainly discussed their thermo-sensitivity and application in drug release. This study can be devided into three sections, and the main contents are listed as follows:Chapter I: The kinds of intelligent materials, the properties and development of thermo-sensitive polymers were presented in detail. Also, the advance in the synthesis of thermo-sensitive hydrogels and its applications in biological engineering field are depicted.Chapter II: The novel thermo-sensitive poly(N-acryloylglycine methyl ester) (PNAGME), poly(N-acryloylglycine ethyl ester) (PNAGEE) and poly(N-methacryloylglycine methyl ester) (PNMAME) was synthesized by a three-step reaction. The chemical structures of the corresponding monomers and polymers were characterized by 1H NMR and IR measurements. The lower critical solution temperature (LCST) was investigated systematically as a function of polymer concentration, inorganic salt solution and pH value. To obtain a thermo-sensitive hydrogel with the phase transition temperature close to human body temperature, the copolymerization was conducted between NAGME and NAGEE. The swelling behavior of co-polymeric hydrogels was evaluated at different temperatures, inorganic salt solution and pH value. The application in drug release of thermo-sensitive co-polymeric hydrogels was also investigated.Chapter III, A monomer, acryloyl alanine methyl ester (NAAME) was synthesized from L-alanine and acryloyl chloride. The radical bulk polymerization was performed to prepare the thermo-responsive PNAAME. The molecular structures of the corresponding monomer and polymer have been confirmed by 1H NMR and IR measurements. The thermo-sensitivity of the polymer was investigated by measuring their LCST in pure water, inorganic salt solutions and in different pH solution. To get the responsive hydrogel with LCST in the physiological temperature range, the caffeine-loaded hydrogel was prepared with NAAME and NAGEE. The effects of temperature and contents of cross-linkers [N, N-methylenebis (acrylamide) (NMBA)] on drug release were discussed.