發(fā)布時間：2018-07-01 16:40

  本文選題：聚乳酸 + 膠原蛋白��； 參考：《山東輕工業(yè)學(xué)院》2012年碩士論文

【摘要】：聚乳酸由于具有良好的生物相容性、生物可降解性以及良好的力學(xué)性能和加工性能，已成為生物降解醫(yī)用材料領(lǐng)域中最受重視的材料之一。但是單純的PLA材料存在以下性質(zhì)缺陷：PLA表面的疏水性強，降低了它的生物相容性；在人體內(nèi)的降解時間長，降解周期難以控制；易出現(xiàn)局部酸度過大導(dǎo)致非感染性炎癥等。為克服聚乳酸的上述缺陷，人們對PLA進行了大量的改性研究工作。利用蛋白質(zhì)或多肽對聚乳酸進行共價修飾改性，可以改善聚乳酸的性能缺陷。本文利用膠原蛋白對聚乳酸進行了改性研究，并研究了改性聚乳酸的主要性能，為聚乳酸的改性研究和應(yīng)用研究作出探索。 本文以DL-乳酸為原料，以氯化亞錫為催化劑，采用直接縮聚法合成得到聚乳酸，采用紅外光譜、核磁共振等方法證明了其結(jié)構(gòu)，經(jīng)過測定其粘均分子量為1萬左右。以自制聚乳酸為原料，選用二環(huán)己基碳二亞胺（DCC）為縮合劑，用膠原蛋白對聚乳酸進行改性，在聚乳酸鏈中引入膠原蛋白，得到改性聚乳酸（CPLA），采用FT-IR、熒光光譜、茚三酮顯色以及DSC測定等方法對改性聚乳酸進行了表征，證明了膠原蛋白與聚乳酸發(fā)生作用并且已成功接入到聚乳酸中。DSC分析表明，PLA的玻璃化轉(zhuǎn)變溫度為56.0℃，而CPLA的玻璃化轉(zhuǎn)變溫度只有一個為41.7℃，從而證明CPLA中成功接入了膠原蛋白，且已完全純化。 研究發(fā)現(xiàn)，CPLA的水接觸角小于PLA而其吸水率大于PLA，表明CPLA的親水性要明顯高于未改性的PLA。降解性研究表明，CPLA在降解的前兩周降解速率較高，然后降解速率比較均勻，沒有酸催化的自加速降解過程，而PLA在降解過程中存在明顯的酸催化的自加速降解現(xiàn)象。細胞相容性研究結(jié)果顯示，3T3纖維原細胞在CPLA材料表面上的粘附、鋪展以及生長情況都要好于未改性的PLA，表明采用膠原蛋白改性聚乳酸后，可以明顯提高其細胞相容性。 本文采用O/W型溶劑揮發(fā)法，通過優(yōu)化制備工藝條件，制備得到膠原改性聚乳酸微球。SEM和粒度分析表明，微球的表面光滑、成球圓整、分散性好、大小均勻，平均粒徑為3.10μm，跨度為0.6548。紅外分析結(jié)果表明，微球的制備過程沒有改變CPLA的化學(xué)結(jié)構(gòu)，只是改變了其形態(tài)。利用差熱分析對微球的熱穩(wěn)定性進行了研究，，結(jié)果顯示PLA接枝上膠原蛋白后其玻璃化溫度下降了10.06℃，冷結(jié)晶溫度下降了12.45℃。
[Abstract]:Polylactic acid (PLA) has become one of the most important biomaterials in the field of biodegradable medical materials due to its good biocompatibility, biodegradability, good mechanical properties and processability. However, the simple PLA material has the following properties: the hydrophobicity of the surface of the PLA is strong, which reduces its biocompatibility; the degradation time in human body is long, the degradation cycle is difficult to control, and the local acidity is too large to lead to non-infectious inflammation and so on. In order to overcome the above defects of PLA, a lot of research work has been done on the modification of PLA. The performance defects of polylactic acid can be improved by covalent modification of polylactic acid with protein or polypeptide. In this paper, the modification of polylactic acid by collagen was studied, and the main properties of modified PLA were studied. Poly (lactic acid) was synthesized by direct Polycondensation with DL-lactic acid as raw material and stannous chloride as catalyst. Its structure was proved by IR and NMR. Its viscosity average molecular weight was about 10,000. Polylactic acid (CPLA) was prepared by using self-made polylactic acid (PLA) as raw material and dicyclohexyl carbodiimide (DCC) as shrinkage agent. Collagen was introduced into the chain of polylactic acid to obtain modified polylactic acid (CPLA). The modified polylactic acid was characterized by indenhydrin color development and DSC measurement. It was proved that collagen acted with polylactic acid and was successfully inserted into polylactic acid. DSC analysis showed that the glass transition temperature of PLA was 56.0 鈩

本文編號：2088405