Preparation and in vitro evaluation of silk fibroin microspheres produced by a novel ultra-fine particle processing system

The objective of this study was to prepare silk fibroin SF microspheres containing the enhanced green fluorescent protein (EGFP) by using a novel ultra-fine particle processing system (UPPS) and to evaluate the microspheres as possible carriers for long-term delivery of sensitive biologicals. The drug content, encapsulation efficiency, and in vitro release were evaluated by Microplate Absorbance Reader. The particle size distribution and morphology of the microspheres were analyzed by Malvern Master Sizer 2000 and scanning electron microscopy. The distribution of EGFP and the interactions between SF and EGFP were investigated by Confocal Laser Scanning Microscopy, FTIP, Raman and NMR spectroscopy. The results showed that spherical microspheres with narrow size distribution, glossy and dense surface were successfully manufactured by using UPPS technology and over 95% of EGFP encapsulation efficiency and uniform drug distribution in the microspheres were achieved. Furthermore, a burst free and sustained release of encapsulated EGFP for a period of 50 days in deionized water was obtained. In conclusion, the novel UPPS technology could be used to manufacture SF matrix microspheres as a potential long-term protein delivery system to improve patient compliance and convenience.     

丝蛋白为单分子模板诱导牙体组织样羟基磷灰石体外仿生合成

目的依据生物矿化的有机基质调控理论,实现牙体硬组织样羟基磷灰石的体外仿声合成。方法运用碳乙基二亚胺盐酸盐和N-羟基丁二酰亚胺介导缩合反应将蚕丝蛋白以肽键键合到牙体组织表面,覆盖原来的-NH3位点,以过饱和矿化液作为离子供体实现晶体生长。结果所得晶体呈矮柱状,30~50nm长,垂直于牙体组织表面,相互平行排列。经X射线衍射（XRD）和扫描电镜（SEM）检测证实新生晶体为羟基磷灰石,硬度接近正常牙本质。结论本研究初步实现了牙体组织样羟基磷灰石的体外仿生合成。     

壳聚糖-丝素蛋白-磷酸三钙复合体用于牙周组织工程支架初探

目的构建壳聚糖-丝素蛋白-磷酸三钙多孔复合体,观察其微观结构与体内外降解情况,探讨其作为牙周组织工程软骨支架的可行性。方法采用二次冻干技术制备壳聚糖-丝素蛋白-磷酸三钙复合体,冰冻切片和扫描电镜观察微观形态;将壳聚糖-丝素蛋白-磷酸三钙复合体支架置于人工降解液及植入大鼠背部肌肉,观察体内外降解情况及生物相容性。结果壳聚糖-丝素蛋白-磷酸三钙复合体呈海绵状,孔隙较均匀,孔形态不规则,孔隙之间彼此联通,孔隙率约80%,孔径200μm左右。4周体外降解率60%,在植入早期可见一过性炎性反应,随后逐渐降解,12周时基本降解吸收。结论壳聚糖-丝素蛋白-磷酸三钙多孔复合体具有良好的三维立体结构及可降解性,是一种可行的牙周组织工程支架。     

聚氨酯与丝素粉体共混膜的血液吸附性

背景：为了改善医用聚氨酯的亲水性和血液相容性,利用共混的方法制备聚氨酯/丝素粉体共混膜,但是粉体的加入会显著提高共混膜的吸水性,因此会影响体外血液相容的表征。 目的：观察丝素粉体的加入对聚氨酯/丝素粉体共混膜亲水性和血液吸附性能的影响。 设计、时间及地点：体外对比观察实验,于2008-08/10在武汉科技学院新型纺织材料绿色加工及其功能化教育部重点实验室和医院实验室完成。 材料：蚕丝纤维由浙江桐乡市思源纺织有限公司提供,医用聚氨酯由DOW Chemical 公司提供。 方法：将蚕丝纤维在质量浓度为10 g/L,浴比为1∶20的Na2CO3溶液中煮沸3 h,洗涤晾干后利用自制磨盘磨制成乳白色粉体而得到非水溶性丝素粉体。将丝素粉体加入到聚氨酯溶液中利用液体交换的方法制备了不同丝素粉体含量(0%,10%,30%,50%,70%)的聚氨酯与丝素粉体共混膜。 主要观察指标：扫描电子显微镜观察共混膜表面形貌。计算单位体积共混膜上吸附血液红细胞、白细胞、血红蛋白、血小板的数量。 结果：当丝素粉体含量在50%以下时,丝素粉体被包含在聚氨酯大分子中间。当丝素粉体含量在70%时,丝素粉体均匀分布在共混膜表面。随着丝素粉体含量的增加,共混膜吸附血液各组分数量增加。随着时间的延长,共混膜吸附血液的量增加,直到达到动态平衡。在吸附动态平衡过程中,血小板的吸附量下降,主要归功于丝素粉体对其他细胞吸附能力要强于血小板。 结论：丝素粉体加入可以明显改善材料的亲水性,并且随着丝素粉体含量的增加,共混膜对血液的吸附能力增强。     

基于丝素蛋白的药物缓释材料

近年来药物缓释材料的研究正成为医药学者研究的焦点, 药物缓释基材的选择对药物缓释控制能力以及生物相容性等有至关重要的作用。丝素蛋白是一种源于蚕丝的天然高分子材料,稳定无毒、廉价易得,具有良好的降解性和生物相容性等特点,是一种优良的载体材料。文章针对丝素蛋白的结构和特点,综述了基于丝素蛋白作为药物缓释基材的国内外最新研究进展。     

蜘蛛和蛛丝在生物医药等领域的开发与应用前景

就国内外对蜘蛛、蛛丝及蚕丝成分的研究与应用现状进行综述,着重阐述了蜘蛛及蛛丝存医疗保健上的应用情况,并从生物医药等角度论述了蜘蛛及蛛丝的开发与应用价值,提出利用基因技术仿蚕丝药品及保健品对开发研究蜘蛛系列药品及保健品具有十分重要的意义。     

百年来出土简帛涉医文献概述

一个世纪以来,在我国陆续出土了成批简牍帛书,其中有数量可观的医学文献,涉及当时医药卫生的各个方面,具有重要的学术价值。故试将涉医简帛文献的出土概况进行概述。     

神经元在丝素蛋白材料上的生长发育

目的研究神经元在丝素蛋白材料上的生长发育,为神经干细胞结合丝素蛋白材料用于临床移植修复神经系统损伤提供实验依据。方法从新生大鼠脑室下区（SVZ）分离细胞,培养在柞蚕、家蚕两种丝素蛋白溶液制成的薄膜材料上,分别选取各时间段的细胞进行β-Ⅲ-tubulin特异性免疫荧光染色,并统计不同时间段神经元在丝素材料上的成活率及复杂度。结果神经元在柞蚕丝素薄膜上的成活率和复杂度明显比家蚕丝素薄膜高,差异均有统计学意义（均P〈0.05）。结论柞蚕、家蚕丝素薄膜支持神经元的生长,具有良好的生物相容性;柞蚕丝素薄膜比家蚕丝素薄膜更适合神经元的生长。     

Clinical effectiveness of a silk fabric in the treatment of atopic dermatitis

BACKGROUND: In children with atopic dermatitis (AD), eczema is easily aggravated by contact with irritant factors (e.g. aggressive detergents, synthetic and woollen clothes, climatic factors). OBJECTIVES: To evaluate the effectiveness of a special silk fabric (MICROAIR DermaSilk) in the treatment of young children affected by AD with acute lesions at the time of examination. METHODS: Forty-six children (mean age 2 years) affected by AD in an acute phase were recruited: 31 received special silk clothes (group A) which they were instructed to wear for a week; the other 15 served as a control group (group B) and wore cotton clothing. Topical moisturizing creams or emulsions were the only topical treatment prescribed in both groups. The overall severity of the disease was evaluated using the SCORAD index. In addition, the local score of an area covered by the silk clothes was compared with the local score of an uncovered area in the same child. All patients were evaluated at baseline and 7 days after the initial examination. RESULTS: At the end of the study a significant decrease in AD severity was observed in the children of group A (mean SCORAD decrease from 43 to 30; P = 0.003). At the same time, the improvement in the mean local score of the covered area (from 32 to 18.6; P = 0.001) was significantly greater than that of the uncovered area (from 31 to 26; P = 0.112). CONCLUSIONS: The use of special silk clothes may be useful in the management of AD in children.     

Electrospun Biomimic Nanofibrous Scaffolds of Silk Fibroin/Hyaluronic Acid for Tissue Engineering

Abstract

This study aimed to fabricate nanofibrous scaffolds which could biomimic the natural extracellular matrix from aqueous solutions of silk fibroin and hyaluronic acid blends (SF/HA) by means of electrospinning. Scanning electronic microscopy results indicated that electrospun SF/HA nanofibers were ribbon-shaped and their average width obviously decreased with the increase of HA content. However, there is no fiber observed when the volume of HA further increased to 50% of overall volume. After being treated with 75% ethanol vapor for 24 h, the fibers still remained their fibrous morphologies and presented good capability of water-resistance. Fourier transform infrared attenuated total reflectance spectroscopy, ¹³C-CP-MAS nuclear magnetic resonance and differential scanning calorimetry results revealed that HA did not induce SF conformation from random coil to β-sheet. SF conformation converted from random coil to β-sheet after being treated with 75% ethanol vapor. Cell viability studies demonstrated that SF/HA nanofibrous scaffolds significantly promoted cell proliferation. Electrospun SF/HA nanofibers may provide an ideal biomimic tissue-engineering scaffold or vehicle for water-soluble drugs.