Preparation And Properties Of Thermo-sensitive Poly(tartaric Acid) Materials

Temperature-sensitive polymer materials can make reversible response withsubtle changes in ambient temperature, so that it can be widely used in many fields.For example, it has a wide range of application in drug controlled release,bio-separation and enzyme immobilization. In addition, good biocompatibility is afundamental starting point in temperature sensitive materials research and it’s theobjective requirement for the material. There are three main parts in this paper:The first part is the literature review and it includes the introduction of intelligentpolymer materials, synthesis and characterization of temperature responsive polymerand application of thermo-sensitive polymer.Second, the nontoxicity or good biocompatibility is an inevitable requirement forthe thermosensitive polymers because of its extensive biomedical applications. In thisinvestigation, we first developed a facile and efficient strategy for the syntheses of thethermosensitive polymeric material. A family of thermosensitive poly (lysine ester/diacetoxy tartaric acid)s (PLEDT) with excellent biocompatibility were thensuccessfully prepared on the base of natural lysine and tartaric acid units. Thestructure of the monomers and polymers were sufficiently confirmed by FTIR,1HNMR, elemental analysis and GPC measurements. The temperature-dependentcharacteristics from UV data have revealed that PLEDT showed an adjustable lowercritical solution temperature (LCST) of about25-35°C depending on molecularweight, concentration and solvents. Additionally, the high viability of Hela cells byMTT assays demonstrated no detectable cytotoxicity of PLEDT at all testconcentrations up to1mg/mL. The experimental results suggested that the novelbiocompatible PLEDT with adjustable temperature sensitivity could be a promisingmaterial in the biomedical fields.Third, we used L-aspartic acid, tartaric acid dimethyl ester, propionic acidanhydride and oxalyl chloride as raw material to prepare N-propy-L-aspartic acid, N-propy-L-aspartic acid acyl chloride and the thermo-sensitive poly (N-propy-L-aspartic acid/tartaric acid dimethyl ester)(PPAT). The chemical structures of the intermediates, monomer and polymer have been confirmed by FTIR, and1H NMRmeasurements. UV spectrum data showed the thermo-sensitivity of PPAT and itsUCST is tunable via changing the ratio of methanol and water. It is consistent with thephenomenon of reentrant phase seperation. Besides, we found that PPAT has goodbio-compatibility with cytotoxicity assay. The survival rate of Hela cells was morethan80%in all cases. The results suggested that poly (N-propy-L-aspartic acid/tartaric acid dimethyl ester) is a new promising material with good biocompatibilityand themosensitivty.