温敏性脯氨酸系列多肽材料的制备与性能

发布时间：2018-01-15 00:24

本文关键词：温敏性脯氨酸系列多肽材料的制备与性能　出处：《河北大学》2017年硕士论文　论文类型：学位论文

【摘要】：温敏性聚合物是指能够对外界温度变化作出可逆响应的一类智能材料。近年来,温敏性聚合物已应用于药物释放、生物分离、酶的固定等研究领域。温敏性聚合物的重要参数是最低临界溶液温度(LCST)或最高临界溶液温度(UCST),而良好的生物可降解性和生物相容性则是其实际应用的重要保证。在本文中,以几种天然的氨基酸为原料,合成其相应的氨基酸-N-羧基-环内酸酐(NCA)单体,通过开环聚合反应,直接制备出没有任何修饰并且兼具良好生物相容性和优异温敏特性的多肽生物材料。论文主要分四个部分:一、在文献综述部分,简单介绍了温敏性聚合物研究现状,主要包括多肽概述、分类及其实际应用。二、以天然的L-脯氨酸和肌氨酸为原料,合成了L-脯氨酸-N-羧基环内酸酐(LP-NCA)和肌氨酸-N-羧基环内酸酐(SA-NCA)单体,经开环共聚合制备出温敏性聚(L-脯氨酸-co-肌氨酸)多肽生物材料(PPS)。通过FTIR、1H NMR、UV、XRD和CD等方法系统地表征单体与多肽生物材料的结构与性能。不同于传统的温敏性聚合物,PPS水溶液在升温与降温过程中,显示了复杂的相转变行为,即PPS在水中具有最低临界溶解温度(LCST=37℃)和最高临界溶解温度(UCST=30℃)双重特性。CD结果表明:在升温和降温过程中,多肽链上肌氨酸结构单元的引入有效地改变了原有的二级结构,即PPS出现第一次相变后,随着温度继续变化以及H键相互作用减弱或升高,PPS再次出现第二次相变。此外,在PPS溶液中HeLa细胞的存活率在24 h和48 h后仍达到70%左右,表明其优异的生物相容性。总之,具有温度响应性和低细胞毒性的多肽生物材料PPS在生物医学领域具有潜在的应用价值。三、以天然的L-脯氨酸和L-丙氨酸为原料,利用L-脯氨酸-N-羧基环内酸酐(LP-NCA)和L-丙氨酸-N-羧基环内酸酐(LA-NCA)两种单体开环共聚,成功的制备出温敏性生物多肽材料,即聚(L-脯氨酸-co-L-丙氨酸)(PPA)。依据多肽PPA(脯氨酸结构单元含量56%-78%)水溶液透光率与温度变化曲线可知,升温时其LCST为75℃,降温时其LCST为42℃,显示出很宽的滞后现象。CD结果表明,在不同温度下,PPA溶液吸收没有明显的变化,可见,其二级结构具有较强的热稳定性。此外,在PPA溶液经过24 h和48 h培养,HeLa细胞存活率仍达到90%以上,表明PPA无明显的细胞毒性。综上,温度响应性多肽生物材料PPA有望应用于药物释放、生物分离等生物医学领域。四、以L-苯丙氨酸和L-脯氨酸为原料,通过合环反应制备出氨基酸-N-羧基环内酸酐(NCA)单体,通过两种NCA单体的开环共聚合,成功制备出既有温敏特性又有良好生物相容性的多肽生物材料。实验表明,在L-苯丙氨酸-N-羧基环内酸酐(LPh-NCA)与L-脯氨酸-N-羧基环内酸酐(LP-NCA)单体投料比为1:4时,所得聚(L-脯氨酸-co-L-苯丙氨酸)(PPPh)才具有温敏特性,其升温时最低临界溶解温度(LCST)为71℃,且存在明显的滞后现象。同时,在PPPh多肽水溶液经过24 h、48 h和72 h培养,HeLa细胞的存活率已超过100%,表明PPPh多肽材料具有非常优异的生物相容性。总之,温度响应性多肽生物材料PPPh有望应用于药物释放、生物分离等生物医学领域。
[Abstract]:Temperature sensitive polymer is a kind of smart material can make reversible response to external temperature changes. In recent years, Wen Min has been applied to polymer drug release, biological separation, etc. in the research field of fixed enzyme. The important parameters of temperature sensitive polymer is lower critical solution temperature (LCST) or UCST (the highest critical solution temperature), and the biodegradability and excellent biocompatibility is the important guarantee for the practical application. In this paper, using several kinds of natural amino acids as raw materials, the synthesis of the corresponding amino acid carboxyl -N- - ring anhydride (NCA) monomer through ring opening polymerization and direct preparation of polypeptide biological material without any modification and good biocompatibility and excellent Wen Min characteristics. The paper is divided into four parts: first, in the part of literature review, a brief introduction of Wen Min polymer research, mainly including the overview and classification of polypeptide. The practical application. Two, with natural L- proline and sarcosine as raw materials, L- proline -N- carboxyl ring anhydride synthesis (LP-NCA) and sarcosine -N- carboxyl ring anhydride (SA-NCA) monomer by ring opening copolymerization prepared temperature sensitive poly (L- proline -co- sarcosine) polypeptide biological materials (PPS). Through FTIR, 1H NMR, UV, structure and properties of XRD and CD methods systematically represent material monomer and peptide biological. Temperature sensitive polymer which is different from the conventional PPS solution during heating and cooling process, shows the phase transition behavior of complex, i.e. PPS has the lowest critical temperature in water (LCST=37 C) and the highest critical solution temperature (UCST=30 C).CD results showed that the dual characteristics in the heating and cooling process, the polypeptide chain into sarcosine structural unit effectively changed the two level structure of the original PPS, which appeared for the first time after transformation, with the the temperature continues to change And the H bond interaction decreased or increased, PPS phase appears second times again. In addition, in PPS solution, the survival rate of HeLa cells in 24 h and 48 h is reached about 70%, showed its excellent biocompatibility. In short, with the temperature response of biological materials and PPS polypeptide with low cytotoxicity potential applications in biomedical field. In three, the natural L- proline and L- alanine as raw material, the use of L- -N- ring proline carboxyl anhydride (LP-NCA) and L- alanine -N- carboxyl ring anhydride (LA-NCA) two monomer ring opening polymerization prepared temperature sensitive peptide material, i.e. poly (L- proline alanine -co-L- (PPA)). On the basis of the peptide PPA (56%-78% proline content unit) water solution transmittance and temperature change curve, the LCST temperature is 75 DEG C, cooling the LCST 42 degrees, showing a wide hysteresis.CD results show that, At different temperatures, PPA visible absorption did not change obviously, and the secondary structure has good thermal stability. In addition, in the solution of PPA after 24 h and 48 h culture, HeLa cell survival rate was more than 90%, PPA showed no significant cytotoxicity. In conclusion, the temperature response of biological materials is expected to PPA polypeptide applied to the field of drug release, biological separation and other biomedical. Four, L- and L- with phenylalanine proline as raw material, through the loop reaction preparation of amino acid -N- carboxyl ring anhydride (NCA) monomer, two kinds of NCA through ring opening copolymerization, prepared both temperature sensitivity and the compatibility of good biological polypeptide biological materials. Experimental results show that the anhydride in L- phenylalanine -N- carboxyl ring (LPh-NCA) and L- -N- proline carboxyl anhydride ring (LP-NCA) monomer feed ratio is 1:4, the poly (L- -co-L- phenyl alanine proline (PPPh) with temperature) The temperature sensitive characteristic, when the lower critical solution temperature (LCST) of 71 DEG C, and there is an obvious lag phenomenon. At the same time, the PPPh peptide aqueous solution after 24 h, 48 h and 72 h medium, the survival rate of HeLa cells is more than 100%, showed that the PPPh polypeptide material with excellent biocompatibility. In short, temperature responsive polypeptide biological material PPPh is expected to be applied to the field of drug release, biological separation and biomedical.

【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O636;TB381

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