Design And Synthesis Of A Thermo-sensitive PGAL And Drug Release Properties Of PIGA

Intelligent polymer materials can respond to the external stimuli, such as temperature, pressure, p H and so on, when the external condition is changed, the properties of the polymer also change. Temperature-sensitive polymer is a kind of material which can occur fast phase transition with temperature changes. Currently, temperature-sensitive polymers have been widely used in the biomedical field such as drug delivery, bio-separation and tissue engineering. So, the biodegradable and biocompatible polymer with temperature sensitivity has become an important issue in this field. The paper is divided into the following three parts :First, the literature review section briefly describes the research status of the temperature-sensitive polymer, the applications in the biomedical field and survey of poly(amino acid)s.Second, non-cytotoxicity or good biocompatibility is an essential requisite for the thermo-sensitive polymeric materials used in the biomedical fields. In this study, a new poly(N-acetyl-L-glutamic acid-co-lysine ester)(PGAL) with excellent thermo-sensitivity and biocompatibility is synthesized from natural lysine and glutamic acid. The chemical structures of the monomers and polymers are determined by 1H NMR, FTIR spectrum and GPC. PGAL shows a reversible lower critical solution temperature(LCST) of 17.3-31.7 ℃, and the thermo-sensitivity is affected by its molecular weight, structure and concentration. The viability of He La cells in 0.01-100 μg/m L PGAL solution is found to be in a range of 98-110% after 24 h, 48 h and 72 h of incubation. To sum up, this new thermo-sensitive PGAL has excellent biocompatibility that makes it a promising material in the biomedical fields.Third, the monomer, BLG was first synthesized from L-glutamic acid and ibuprofen. Three kinds of polymers including PIGB, PIGH and PIGA which their pendant group was ibuprofen, were prepared from BLG and 1,4-butanediol, 1,6-hexanedio, 6-amino-1-hexanol by melting polycondensation. The chemical structures of the monomers and polymers are determined by 1H NMR, FTIR spectrum and GPC. At the same time, the viability of He La cells in 0.01-100μg/m L polymer solution is found to be upon 100% after 24 h of incubation, indication no cytotoxicity. Drug release behavior of ibuprofen from three polymers was measured by using ultraviolet spectrophotometer. The results showed that ibuprofen-controlled release properties provided a strategy for enhancing drug effect ang decrease by-function of drug in the future.