環境敏感型磁性奈米顆粒之研製與藥物釋放性質研究I.以無乳化劑乳化聚合法合成中空磁性奈米顆粒II.以活性聚合法合成自組裝奈米顆粒

Abstract

In this study, stimuli responsive latex nanoparticles composed of copolymers of N-isoprylacrylamide(NIPAAm) and acrylic acid(AA) derivatives were synthesized by two methods. Because of the thermo-sensitivity of polyNIPAAm and the pH-sensitivity of polyAA derivatives, these nanoparticles which is sensitive to both temperature and pH can be used in drug release system as a drug carrier. In the first method, emulsifier-free emulsion polymerization were used to synthesize magnetic hollow particles composed of random copolymer of NIPAAm and methacrylic acid(MAA) . Particle morphology. drug loading and release behavior were discussed. The magnetic hollow particles which can respond to temperature and pH were synthesized successful. The largest drug release percentage was found in the condition of room temperature and basic system. The drug bust phenomena occurred when particles were put into acidic solution. In the second method, well-defined living block copolymer of PNIPAAm and PAA was synthesized by Reversible Addition-Fragmentation Ttransfer (RAFT) to achieve self-assembly behavior at high temperature. When the poly(NIPAAm-b-AA) aqueous solution was heated, various morphologies in different ratios of PNIPAAm and PAA were observed due to the hydrophobic nature of PNIPAAm above its LCST. Sensitivities of temperature and pH were also confirmed in the lowest critical solution temperature experiment.