【作者】 马新兰；

【导师】 黄毅萍；

【作者基本信息】 安徽大学 ， 有机化学， 2010， 硕士

【摘要】 丝素蛋白具有良好的机械性能、环境稳定性和生物相容性。其分子结构中含有大量的活性基团,如-COOH基团,这些活性基团很容易诱导无机矿物碳酸钙和磷酸钙的沉积,对于矿化起着重要的作用。丝蛋白的结构特点为无机物在其表面的矿化提供了基础,它能为无机物提供成核位点、诱导无机离子沉积。因此近年来,丝素蛋白被作为有机模板而广泛的应用于有机/无机复合生物材料的制备。另外,研究发现非胶原类的大分子聚合物也能明显影响无机矿物的成核和生长。本论文利用丝素蛋白以及大分子聚合物结构上的特点,在丝素蛋白分子中引入各种不同的聚合物,目的在于进一步促进无机矿物的矿化沉积。实验中以有机大分子丝素蛋白为主体,与聚合物分子进行共混膜后,制备共混膜,在一定的温度下进行预矿化后置于1.5倍人体仿生液(1.5×SBF)中,钙磷离子在大分子聚合物/丝素蛋白的表面沉积、成核并最终聚集形成羟基磷灰石,论文着重研究不同大分子聚合物/丝素蛋白的配比、不同预矿化温度对丝素蛋白/羟基磷灰石类骨质复合材料沉积量、钙磷比以及形貌的影响。内容一,仿生合成聚丙烯酸/丝素蛋白/羟基磷灰石复合生物材料。将丝素蛋白与聚丙烯酸进行共混,制备不同配比的聚丙烯酸/丝素蛋白共混膜,将共混膜用乙醇改性后,用氯化钙溶液和磷酸氢二钾溶液进行预矿化处理后置于人体仿生液中仿生制备丝素蛋白/羟基磷灰石复合材料。本实验探讨了乙醇的改性处理对复合材料制备的影响。通过FTIR、XRD、SEM、EDX对样品进行表征。结果显示：1,所制备的复合生物材料中,羟基磷灰石晶体的结晶度较低,与天然骨组织中的磷灰石晶体相似；2,乙醇改性处理后的聚丙烯酸/丝素蛋白共混膜更有利于羟基磷灰石在其表面的生长。内容二,仿生合成聚天冬氨酸/丝素蛋白/羟基磷灰石复合生物材料。制备不同配比的聚天冬氨酸/丝素蛋白共混膜,经乙醇改性处理、于不同的温度下预矿化后置于1.5×SBF中得到有机/无机复合材料。本章实验探讨了聚天冬氨酸/丝素蛋白的配比以及预矿化温度对羟基磷灰石的形貌和沉积量的影响。利用FTIR、XRD、SEM、ICP对样品进行表征。结果显示：PASP/SF的配比以及预矿化温度会影响复合材料的形貌以及沉积量。随着共混膜中PASP含量的增加,SF/HA复合材料中磷灰石的含量增加、Ca/P比增大；预矿化温度的提高同样会促使磷灰石含量的增加、Ca/P比的增大。内容三,论文实验的第三部分研究了小分子的氨基酸—天冬氨酸的加入对丝素蛋白/羟基磷灰石复合材料性质的影响。首先,在预矿化液氯化钙中加入不同质量的天冬氨酸,得到不同的预矿化液。然后将乙醇改性处理后的丝素蛋白膜放入此矿化液中进行预矿化处理,后置于1.5×SBF中24h,得到丝素蛋白/羟基磷灰石复合材料。表征结果显示：天冬氨酸的加入量对复合材料的形貌有较明显影响,同时对于钙磷在丝素蛋白膜表面的沉积也有一定的影响。综上所述,本论文主要以丝素蛋白纤维为模板,调控钙磷在其表面的沉积、成核,制备类骨质羟基磷灰石晶体。在丝素蛋白的调控下,磷灰石晶体在其表面沉积,所制备的类骨质复合生物材料与天然骨具有组成和结构上的统一,是一种理想的复合生物材料。更多还原

【Abstract】 Silk fibers from Bombyx mori fibroin have been used as biomedical material for a long time, because of their outstanding mechanical properties, environmental stability and biocompatibility. SF plays an important role for the mineralization, its molecular structure contains a large number of active groups, such as-COOH group, which is easy to induce inorganic mineral phase deposited, such as calcium carbonate and calcium phosphate deposition. Silk fibroin provides a lot of nucleation sites for inorganic mineral deposited. In recent years, silk fibroin was widely used as organic template for the preparation of organic/inorganic composites. Meanwhile, many studies have shown that non-collagen macromolecular polymers can significantly affect the nucleation and growth of inorganic mineral phase.In the study, in order to enhance the deposition of inorganic mineral, blend membranes consist of silk fibroin (SF) and different polymers were prepared. Silk fibroin was mixed with polymers to prepared different blend ratio membranes. After ethanol treatment and premineralization process, the films were immersed into a simulated body fluid with the ion concentration 1.5 times higher than that of the standard one. This process was to induce nucleation and growth of calcium and phosphorus ions on the membrane surface, and after 24h the hydroxyapatite-deposited SF films were got. We have investigated the influence of the blend ratio of polymers/SF and pre-mineralization temperature on the content of the precipitation, calcium/phosphorus ratio and morphology.For the first content of the thesis, the polyacrylic acid/silk fibroin/hyaroxyapatite (PAA/SF/HA) composite materials were synthesized. PAA/SF blend membranes were prepared by mixing SF and PAA together. Two different methods were used for the films treatment. The first one, the films were treated with 60%(v/v) ethanol, through a treatment with the use of Ca(OH)2 and K2HPO4 solution, the films were then immersed into SBF to induce apatite deposition. As contract, another film was untreated with ethanol, then dealed with the same method in the next process. This study investigated effect of ethanol treatment on the composite material. The results from the tests of SEM, XRD, EDX and FTIR showed that the hydroxyapatite crystals in the composite had low crystallinity, which was close to that in the natural bone. Furthermore, ethanol treatment significantly enhanced the HA deposition on the blend films.The second part, polyaspartic acid/silk fibroin/hyaroxyapatite (PASP/SF/HA) composite materials were synthesized. PASP/SF blend membranes were prepared by mixing different content SF and PASP together. These films were treated with 60% (v/v) ethanol, through a treatment with the use of Ca(OH)2 and K2HPO4 solution, the films were then immersed into SBF to induce apatite deposition. This study investigated the effect of the PASP/SF blend ratio and temperature of premineralization on the amount of HA deposition and its morphology. The results from the tests of SEM, XRD, ICP and FTIR showed that the amount of crystals increased with the PASP/SF ratio increasing. Meanwhile, a gradual increase of Ca/P ratio was also appeared through PASP/SF enhanced. Furthermore, the amount of apatite deposition and its Ca/P ratio were increased as the temperature of precalcification increased. A change of morphology was found as the PASP/SF blend ratio and precalcification temperature changed.At the third part of this thesis, the effect of aspartic acid on the SF/HA deposition was also studied. We prepared four kinds of precalcification solution by adding different volume of ASP into SF solution. After treated with 60%(v/v) ethanol solution, SF films were pretreated with the four kinds precalcification solution. The pretreatment films were then then immersed into SBF 24h to induce apatite deposition. The SEM, XRD, ICP and FTIR results showed that the amount of ASP in the precalcification can significantly influence the morphology of composite. The amount of deposition and its Ca/P ratio were also influenced by the ASP content.In summary, silk fibroin was used as organic template to control the nucleation and growth of calcium and phosphorous on its surface. On the regulation of silk fibroin, the apatite crystals can successfully deposited on SF surface. The composition and structure of SF/HA composite were similar to the natural bone.更多还原