化学处理对蚕丝降解性质及生物相容性的影响

发布时间：2018-05-21 16:22

本文选题：蚕丝 + 降解　；参考：《西南大学》2017年硕士论文

【摘要】：蚕丝是由桑蚕(俗称家蚕)或柞蚕幼虫分泌产生的天然丝纤维,分别称为桑蚕丝和柞蚕丝,本文中的蚕丝是指家蚕丝。在蚕丝的形成过程中,家蚕幼虫的后部丝腺分泌产生丝素蛋白(简称丝素),中部丝腺分泌产生丝胶蛋白(简称丝胶),丝素由经中部丝腺时与丝胶混合,排出体外形成茧丝。未经脱丝胶处理的蚕丝称为生丝,经脱丝胶处理的蚕丝称为熟丝。蚕丝是一种具有良好生物相容性的天然材料,已经被广泛应用于生物医药领域研究和实践中。手术缝合线(丝线)是蚕丝在生物医药领域应用的典型例子。根据降解性质的不同,可以将生物组织工程材料分为两类,其一是要求在动物体内不发生降解作用的材料,如聚四氟乙烯制备的人工血管、骨科固定用途的金属材料和牙科用途的一些材料等。另一类是希望在动物体内发生完全降解作用的材料,在使用这类材料的过程中,人们希望随着组织的再生,这些材料逐步降解,最终完全代谢,这就要求这类材料的降解速率要和组织再生的速率匹配。现有研究表明,蚕丝在体内的降解速率极为缓慢,这就限制了蚕丝在组织工程中的应用,为此,本研究试图探讨在体外对蚕丝化学处理能否促进其在体内的降解。组织工程材料需要一定的力学性能,用途不同,对力学性能的要求就不同。人工血管需要较好的韧性和弹性,骨科固定材料需要较好的硬度,人工神经对力学性能的要求较低,能够耐受神经移植手术操作即可。本研究希望在体外化学处理过程中,蚕丝部分降解的同时,能保持其纤维状态和一定的力学性能。有研究表明,蚕丝纤维在体内的降解是随机的,当蚕丝移植到动物体内后,蚕丝纤维的数量会减少,但是有些蚕丝纤维的形态和直径无显著变化,我们猜想这是由于炎症反应介导的细胞吞噬作用在起作用,在细胞吞噬作用进行的同时,一般都伴随组织纤维化,因此本研究拟考察蚕丝在大鼠皮下埋植过程中炎症因子和胶原的表达的情况。本文以家蚕丝为主要材料,在1%的碳酸钠溶液中煮沸30 min脱丝胶获得熟丝,然后分别用0.05 moL/L、0.1 moL/L、0.5 moL/L的NaOH、NaHCO3、HCl、H3PO4、CH3COOH、CaCl2溶液和饱和石灰水处理熟丝,分别在第1、2、3和4周取材,检测力学性质,称重计算失重率,检测上述溶液中粗蛋白含量和pH值;扫描电镜观察其表面形貌;在大鼠皮下埋植,取材进行石蜡切片,H.E染色观察,冰冻切片免疫荧光染色观察;RT-PCR检测炎症和胶原相关基因的表达情况。7种化学物质对蚕丝进行体外降解的过程,体现出了浓度效应。化学物质对蚕丝的体外降解作用由强到弱的顺序依次为氢氧化钠饱和石灰水盐酸醋酸碳酸氢钠磷酸溶液氯化钙。扫描电镜结果显示,与处理前单丝直径相比,各实验组单丝直径都有所减小,但减小程度不同,纤维直径缩小的程度由大到小的顺序依次为饱和石灰水氢氧化钠醋酸盐酸碳酸氢钠和氯化钙。力学测试结果表明随着化学处理浓度的增大,时间的延长,蚕丝纤维的机械强度会显著降低。降低程度由大到小依次为醋酸碳酸氢钠氯化钙氢氧化钠盐酸磷酸饱和石灰水。随化学处理时间的延长,蚕丝纤维的硬度增大,由大到小的顺序为氯化钙醋酸碳酸氢钠盐酸磷酸饱和石灰水氢氧化钠。蚕丝弹性随处理时间的变化幅度不大,蚕丝弹性由大到小的顺序为醋酸碳酸氢钠氯化钙盐酸磷酸饱和石灰水氢氧化钠。皮下埋植化学处理后的蚕丝,取出包块进行组织切片H.E染色,结果显示,各组中蚕丝均有程度不同的降解。根据单位面积中残留的蚕丝数量,可知细胞对蚕丝的吞噬作用由弱至强依次为对照组、磷酸处理组、盐酸处理组、醋酸处理组、石灰水处理组、氢氧化钠处理组、氯化钙处理组、碳酸氢钠处理组。根据残留蚕丝横截面平均面积,可知组织液对蚕丝降解程度由强至弱依次为盐酸处理组、磷酸处理组、醋酸处理组、碳酸氢钠处理组、氯化钙处理组、氢氧化钠处理组、石灰水处理组、对照组。RT-PCR检测显示,不同的化学处理对蚕丝材料的生物相容性的影响有差异。蚕丝生物相容性由强到弱依次为,磷酸处理组、盐酸处理组、醋酸处理组、石灰水处理组、氢氧化钠处理组、氯化钙处理组、碳酸氢钠处理组。因此,7种化学物质对蚕丝的形态结构、力学性质、在体内的降解性质及生物相容性的影响均有差异,都加快了蚕丝在体内的降解速率,并且维持了蚕丝的纤维状形态和一定的力学性能。效果由优至劣的顺序为:氢氧化钠、盐酸、碳酸氢钠、饱和石灰水、醋酸、氯化钙、磷酸。
[Abstract]:Silk is a natural silk fiber produced by silkworm (commonly known as silkworm) or tussah larvae. It is called mulberry silk and tussah silk. The silk in this article refers to the silk. In the formation of silk, the silk gland of the silkworm larvae is secreted to produce silk fibroin (silk fibroin), and sericin (sericin) and silk fibroin is produced in the middle silk gland. Silk is mixed with sericin when it is mixed with Sericin to form cocoon silk in vitro. Silk without sericin treated silk is called raw silk, and silk treated by degel is called cooked silk. Silk is a natural material with good biocompatibility. It has been widely used in research and practice in the field of biological medicine. The surgical suture line (silk thread) is silkworm silk. A typical example of application in the field of bio medicine. According to the different degradation properties, biotissue engineering materials can be divided into two types, one is the material that requires no degradation in the animal body, such as artificial blood vessels made of polytetrafluoroethylene, metal materials for Department of orthopedics fixed use and some materials for dental use. In the process of using this kind of material, people hope that with the regeneration of this kind of material, it is hoped that these materials will be degraded gradually and eventually completely metabolized with the regeneration of the tissue. This requires that the degradation rate of this kind of material match the rate of tissue regeneration. This restricts the application of silk in tissue engineering. To this end, this study attempts to explore whether the chemical treatment of silk in vitro can promote its degradation in the body. Tissue engineering materials require certain mechanical properties, different uses, and different requirements for mechanical properties. Artificial blood vessels need better toughness and elasticity, and department of orthopedics fixed materials need to be used. For better hardness, the mechanical properties of the artificial nerve are lower and the nerve graft operation can be tolerated. This study hopes to maintain the fiber status and certain mechanical properties while the silk part is degraded during the process of chemical treatment in vitro. The number of silk fibers will decrease, but there is no significant change in the shape and diameter of some silk fibers. We suspect that this is due to the inflammatory reaction mediated cell phagocytosis, while the phagocytosis of the cells is usually accompanied by tissue fibrosis. Therefore, this study is to investigate the silk in rat skin. The expression of inflammatory factors and collagen during the process of implantation. In this paper, the silk was used as the main material, and cooked by boiling 30 min sericin in 1% sodium carbonate solution, and then using 0.05 moL/L, 0.1 moL/L, 0.5 moL/L NaOH, NaHCO3, HCl, H3PO4, CH3COOH, CaCl2 solution and saturated lime water treatment, respectively, at the 1,2,3 and 4 weeks, respectively. Material, testing the mechanical properties, weighing the weight loss rate, detecting the content of crude protein and pH in the above solution; scanning electron microscope to observe its surface morphology; subcutaneous implantation in rats, paraffin section, H.E staining observation, frozen section immunofluorescence staining, and RT-PCR detection of the expression of inflammation and collagen related genes in.7 chemical substances The degradation of silk in vitro shows the concentration effect. The degradation of silk in vitro by chemical substances from strong to weak is in order of sodium hydroxide saturated lime water hydrochloric acid sodium bicarbonate phosphate solution in order of calcium chloride. The results of scanning electron microscope show that the diameter of monofilament in each experiment group decreases compared with the direct diameter of the monofilament before treatment. But the degree of reduction is different, the degree of shrinkage of fiber diameter from large to small is saturated lime water sodium hydroxide acetate sodium bicarbonate and calcium chloride in turn. The mechanical test results show that with the increase of chemical treatment concentration, the time prolongs, the mechanical strength of silk fiber will decrease significantly. The reduction degree from large to small is the vinegar. Sodium bicarbonate sodium hydroxide hydrochloric acid saturated lime water. With the prolongation of the chemical treatment time, the hardness of silk fiber increases, from large to small, the order of sodium bicarbonate hydrochloric acid phosphate saturated lime water sodium hydroxide in the order of large to small. The change of silk elasticity with the treatment time is little, the order of silk elasticity from large to small is the order of Sodium bicarbonate calcium chloride hydrochloric acid saturated lime water sodium hydroxide. The silkworm silk treated by subcutaneously implanted chemical treated silkworm was stained with H.E. The results showed that the silkworm silk in each group had different degrees of degradation. According to the number of silkworm residues in the unit area, the phagocytosis of the silkworm silk was determined from weak to strong order. For the control group, the phosphoric acid treatment group, the hydrochloric acid treatment group, the acetic acid treatment group, the lime water treatment group, the sodium hydroxide treatment group, the calcium chloride treatment group and the sodium bicarbonate treatment group. According to the average cross-sectional area of the silkworm silk, we can see that the degradation degree of the silkworm silk is from strong to weak to the hydrochloric acid treatment group, the phosphoric acid treatment group, the acetic acid treatment group and the hydrogen carbonate. Sodium chloride treatment group, calcium chloride treatment group, sodium hydroxide treatment group, lime water treatment group and control group.RT-PCR test showed that different chemical treatments had different effects on the biocompatibility of silk material. The biocompatibility of silkworm silk was in turn from strong to weak, phosphoric acid treatment group, hydrochloric acid treatment group, acetic acid treatment group, lime water treatment group, sodium hydroxide. Treatment group, calcium chloride treatment group, sodium bicarbonate treatment group. Therefore, the 7 chemical substances have different effects on the morphological structure, mechanical properties, degradation properties and biocompatibility of silk, which have accelerated the degradation rate of silk in the body, and maintain the fibrous form and certain mechanical properties of silkworm silk. The order of deterioration is sodium hydroxide, hydrochloric acid, sodium bicarbonate, saturated lime water, acetic acid, calcium chloride, and phosphoric acid.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

【参考文献】