纳米纤维素蛋白和脱细胞基质修复口腔黏膜

 BACKGROUND: The sensitivity and mucus secretion of the oral mucosa make oral soft tissues difficult to repair, so patients cannot achieve satisfactory outcomes after treatment. Nano-cellulose protein mainly composed of glycine, alanine and serine has good histocompatibility. However, there is a lack of comparative study about the effect of nano-cellulose protein and acellular matrix in oral mucosa repair, and the clinical effects of the two materials are still under discussion.     

丝素胶原蛋白复合支架联合富血小板血浆修复皮肤损伤

背景：胶原与丝素蛋白复合构建的组织工程支架,在皮肤、神经、血管、骨、软骨等组织工程领域应用广泛。富血小板血浆是血液经过2次离心获得的血小板浓缩物,含有多种组织修复需要的生长因子,可促进组织再生与创面愈合。目的：观察丝素胶原蛋白支架复合富血小板血浆在皮肤创面愈合中的作用。方法：分别制备丝素胶原蛋白支架、SD大鼠富血小板血浆。取8周龄SD大鼠48只,每只背部制作2个直径2 cm的全层皮肤缺损创面,分4组处理：空白组缺损处注射生理盐水,单纯支架组缺损处植入丝素胶原蛋白复合支架,富血小板血浆组创缘注射同种异体富血小板血浆,联合组缺损处植入丝素胶原蛋白复合支架+创缘注射同种异体富血小板血浆,每组12只。造模后检测创面愈合率、创面炎症因子水平、创面组织学观察及相关蛋白表达。结果与结论：(1)联合组造模后第7,14天的创面愈合率大于空白组、单纯支架组、富血小板血浆组(P <0.05)。(2)联合组造模后第7,14天的肿瘤坏死因子α、白细胞介素6水平均低于空白组、单纯支架组、富血小板血浆组(P <0.05)。(3)造模后第14天的苏木精-伊红及Masson染色显示,空白组缺损处仅见少量的新...     

多孔丝素蛋白支架修复兔下颌骨临界性骨缺损

背景：丝素蛋白具有良好的生物相容性和可降解性。 目的：观察多孔丝素蛋白支架原位修复兔下颌骨临界性骨缺损效果。 方法：建立兔双侧下颌骨临界性骨缺损模型,随机选取一侧缺损植入多孔丝素蛋白支架作为实验组,另一侧缺损不作处理作为对照组。 结果与结论：①大体标本：术后12周,实验组骨缺损腔表面完全被新生骨覆盖,材料无脱出;对照组骨缺损腔内充满肉芽组织,骨不连。②X射线骨密度测定：术后2,6,12周,两组骨密度均随着时间延长逐渐增高,组内不同时间点间差异有显著性意义(P < 0.05),且同期实验组高于对照组(P < 0.05)。③组织病理切片苏木精-伊红染色：术后12周,实验组岛状新生骨及骨小梁明显增多,而且粗大而致密,材料内部明显疏松,部分区域塌陷;对照组宿主骨边缘可见散在分布的新生骨组织,但并无粗大骨小梁形成。④骨形态发生蛋白2免疫组织化学染色：术后2,6,12周,两组骨形态发生蛋白2阳性细胞数均随着时间延长逐渐增多,组内不同时间点间差异有显著性意义(P < 0.05),且同期实验组多于对照组 (P < 0.05)。表明多孔丝素蛋白支架用于原位组织工程修复骨缺损具有一定可行性。     

丝素蛋白在组织工程细胞支架方面的研究进展

近年来有关丝素蛋白用做细胞培养基质材料的研究表明，丝素蛋白对多数种类细胞的体外培养表现出较高的细胞附着率和增殖率，与胶原相当，可以用作组织工程细胞支架材料，应用到组织工程皮肤、软骨、血管等诸多领域。本文就丝素蛋白用于细胞培养的研究现状及丝素蛋白在组织工程细胞支架方面的应用前景做一综述。     

丝素蛋白/壳聚糖三维多孔支架的构建及结构表征**

背景：丝素蛋白和壳聚糖均无毒性且具有良好的生物相容性,但是单一成分作为生物支架时都不能满足支架材料的需求。 目的：制备各种不同组分的丝素蛋白及壳聚糖复合支架材料,观察其微观结构及相关性能,筛选出适合成骨细胞生长的理想支架材料。 方法：通过CaCl2∶C2H5OH∶H2O=1∶2∶8(摩尔比)溶解体系溶解、过滤、浓缩提纯,制备出2%的丝素蛋白溶液,壳聚糖溶解于乙酸溶液配制成的3%壳聚糖溶液,将两者以不同的比例相混合,经数次冷冻干燥后,得到成品支架材料。采用电镜观察形貌,计算孔隙率并对支架的结构进行红外、X射线衍射、电子能谱分析观察。 结果与结论：将壳聚糖和丝素蛋白共混后,互为改性,制备出了结构较稳定的支架材料。其中40%丝素蛋白-60%壳聚糖组具有适合成骨细胞生长的较佳孔径,可作为细胞支架的首选配比。 关键词：丝素蛋白;壳聚糖;骨组织工程;支架;生物材料 doi:10.3969/j.issn.1673-8225.2012.12.025     

丝素蛋白材料在组织工程中的新进展

背景：丝素蛋白支架已被建议运用在组织工程骨和软骨重建、肌腱重建、血管重建,神经重建以及膀胱重建等各方面。 目的：总结丝素蛋白作为支架在生物材料和组织工程领域的应用与发展。 方法：由第一作者应用计算机检索PubMed数据库及中国期刊数据库2000年1月至2011年11月有关丝素蛋白支架制备工艺,丝素蛋白支架修饰方法及丝素蛋白在组织工程中的应用等方面的文献。 结果与结论：丝素蛋白具有机械强度高、生物降解性慢、生物相容性良好、制备工艺多样等特点,支持多种细胞黏附、分化和生长,可应用于人工韧带、血管、骨、神经组织等方面。近期以丝素蛋白支架作为载体,通过多种方式添加各种生物制剂,比如各种生长因子和细胞因子,进一步扩大丝素蛋白在组织工程中的应用范围。     

人牙周韧带细胞-聚羟基乙酸支架复合体修复牙周组织缺损

BACKGROUND: In recent years, tissue engineering technology as a new model for tissue regeneration has provided new ideas and methods for the repair of periodontal tissue defects. OBJECTIVE: To investigate the effect of human periodontal ligament cells-polyglycolic acid scaffold complex for repair of periodontal tissue defects. METHODS: Passage 4 human periodontal ligament cells at a density of 1.5×109/L were seeded onto the polyglycolic acid scaffold to prepare cell-scaffold complex. Then mongrel dogs were selected to make animal models of periodontal tissue defects and then randomly assigned into experimental group subjected to cell-scaffold complex implantation or control group subjected to direct coronal reset and suture of the gingival flap. Collagen content, new blood capillaries, new cementum, new alveolar bone and new periodontal ligament were detected within 4 weeks after operation; hematoxylin-eosin staining of periodontal tissue defects was done at 8 weeks after operation. RESULTS AND CONCLUSION: In the experimental group, the collagen content, number of newborn capillaries, amount of new cementum, new alveolar bone and new periodontal ligament tissues were significantly higher than those in the control group at postoperative 1, 2, 3, 4 weeks (P < 0.05). At 8 weeks after operation, in the experimental group, there were more vessels arranging on the connective tissue surface of new alveolar bone, the alveolar bone showed a sawtooth-like interlinking with the periodontal tissues in the presence of a thin layer of cementum; in the control group, only new alveolar bone and cementum formed below the incisure. These findings indicate that human periodontal ligament cells-polyglycolic acid scaffold complex can promote periodontal tissue regeneration.      

丝素蛋白/壳聚糖三维支架材料的制备方法

背景：很多研究表明丝素蛋白、壳聚糖为天然高分子材料,无毒无味,有良好的生物特性和理化性质。 目的：探讨符合软骨组织工程支架材料要求的丝素蛋白/壳聚糖三维支架材料制备方法。 方法：将丝素蛋白与壳聚糖按质量比分别为3∶1,1∶1,1∶3,0∶1的比例混合制备丝素蛋白-壳聚糖复合材料,通过孔径大小、孔隙率、吸水膨胀率及热水溶失率的测定,寻找丝素蛋白/壳聚糖最佳混合比例。 结果与结论：丝素蛋白/壳聚糖按质量1∶1的比例混合更符合要求：孔径90~280 μm,平均孔径为151.72 μm;孔隙率为(92.72±4.78)%;吸水膨胀率为(141.10±6.87)%;热水溶失率交联后较交联前降低,交联前后比较差异有显著性意义(P < 0.05)。说明丝素蛋白/壳聚糖按1∶1复合支架材料符合软骨组织工程支架材料理化性质的要求,该材料有望作为软骨组织工程研究较理想的支架材料。     

生物蛋白胶复合骨髓间充质干细胞修复兔多层软组织缺损

背景：符合软组织生理结构的生物蛋白胶适合作为修复软组织缺损的载体材料。 目的：观察生物蛋白胶复合骨髓间充质干细胞修复软组织缺损的可行性。 方法：在新西兰大白兔大腿处造成深达肌肉层,直径大于3 cm的软组织缺损。将24只新西兰大白兔随机分为3组,实验组将同种异体来源的骨髓间充质干细胞复合生物蛋白胶注射到软组织缺损处,对照组将生物蛋白胶注射到软组织缺损处,模型组造模后不注射。 结果与结论：术后14,21 d创面收缩率,实验组>对照组>模型组(P < 0.01);愈合时间,实验组<对照组<模型组(P < 0.01)。结果显示以生物蛋白胶为载体复合骨髓间充质干细胞能快速的修复多层软组织缺损。     

组织工程支架材料修复关节软骨缺损

BACKGROUND: Articular cartilage repair has been a difficulty in the clinical setting, which is mainly treated with autologous or allogeneic osteochondral grafts, and cartilage periosteum or periosteum grafts. However, the limited source, secondary lesion and immunological rejection force some researchers to search for a novel treatment strategy, cartilage tissue engineering, that is of great significance for cartilage regeneration and repair. OBJECTIVE: To investigate the tissue-engineered scaffolds for the repair of articular cartilage defects. METHODS: The first author searched the PubMed and WanFang databases for the articles addressing tissue-engineered cartilage for articular cartilage defects published between 1991 and 2015 using the keywords “articular cartilage defect, scaffold, tissue engineered cartilage” in English and Chinese, respectively. The irrelative and repetitive literatures were excluded. RESULTS AND CONCLUSION: Finally 48 eligible literatures were enrolled based on the inclusion and exclusion criteria. Cartilage tissue engineering possesses the advantages of controllability, little damage to tissue itself, and biological repair of injured cartilage. Tissue-engineered scaffold material is a critical factor in tissue engineering construction; therefore, it should hold biodegradability and histocompatibility. The commonly used scaffold materials include natural macromolecule materials (collagen, silk fibroin and chitosan), and synthetic polymer materials (polylactic acid and tricalcium phosphate). It is necessary to prepare composite scaffolds with high bioactivity integrate advantages of each material. The tissue engineering is bound to be a hotspot in the field of articular cartilage repair.      

丝素蛋白作为组织工程材料应用于角膜的研究进展

背景：丝素蛋白纤维材料具有透明性、结构可塑性、成分单一性、力学强韧性及生物相容性等特点。 目的：综述国内外丝素蛋白应用于角膜组织工程的研究进展。 方法：由第一作者在标题和摘要中以“silk fibroin, corneal, ocular”或“丝素,角膜”为检索词,检索1980至2011年PubMed及1990至2011年CNKI数据库中关于丝素蛋白角膜的文章。 结果与结论：从天然蚕丝中提取的高分子丝素蛋白,因其良好的生物相容性、独特的力学性能、光学透明性及降解速率可控性,既可以单独应用于角膜组织结构的重建,又可与其他组织材料联合应用,成为角膜组织工程学应用的理想材料。现已证明多种角膜细胞可在丝素纤维膜上良好生长,但体外培养的细胞应用于动物模型的相关研究较少;此外丝素蛋白材料植入角膜内对其产生何种影响的研究数据较缺乏,这些均是亟待解决的问题。     

磷酸钙材料在骨软骨缺损修复支架中的应用

背景：磷酸钙材料与天然骨矿物质相似,具有良好的生物活性、骨传导性和可降解性,在金属植入物涂层及骨缺损修复材料中已有大量研究与应用。 目的：综述不同物相磷酸钙材料的特点及在骨软骨支架中的应用。 方法：应用计算机检索PubMed数据库、中国学术期刊网络出版总库、维普数据库2000年1月至2015年2月的有关文章,中文检索词为“骨软骨,磷酸钙(包括羟基磷灰石、磷酸三钙、聚磷酸钙等),组织工程”,英文检索词为“osteochondral;calcium phosphate;tissue engineering”。 结果与结论：由于磷酸钙具有多种物相和晶型,通过不同工艺方法调控磷酸钙的结构尺寸可以得到丰富的材料体系,如羟基磷灰石、磷酸三钙、聚磷酸钙、无定形磷酸钙等,其生物学性能和力学性能均有所差异,其中以羟基磷灰石的应用最为广泛。将磷酸钙与其他材料复合制备多层的复合支架是骨软骨组织工程研究的一个趋势。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

可控释淫羊藿苷的羟基磷灰石/壳聚糖缓释支架修复骨缺损*

 背景：如何将中药有效活性化合物通过生物支架材料的缓释作用更好的应用于骨科临床尚需大量的研究。目的：通过文献检索和综合分析,客观评估中药活性成分复合淫羊藿苷的缓释支架在骨修复领域应用的可行性。方法：分别用英文检索词“bone defect,icariin,release bracket,chitosan,hydroxyapatite”;中文检索词“骨缺损,淫羊藿苷,壳聚糖,羟基磷灰石,缓释支架”检索CNKI及PubMed数据库1995-01/2010-12相关文章,纳入和研究目的相关的文章进行分析综述。结果与结论：共纳入相关文献24篇,已有研究表明中药淫羊藿苷可促进成骨细胞的生成,抑制骨吸收。而纳米羟基磷灰石-壳聚糖复合支架具有良好的理化性质和细胞相容性,可以应用于组织工程骨的构建。因此在进一步完善纳米级晶体合成工艺的基础上,对淫羊藿苷的释放速度和释放模式加以控制,达到持续、稳定的药物缓释是可行的。     

Silk fibroin electrogelation mechanisms

A silk fibroin gel system (e-gel), formed with weak electric fields, has potential utility in medical materials and devices. The mechanism of silk e-gel formation was studied to gain additional insight into the process and control of the material properties. Silk fibroin nanoparticles with sizes of tens of nanometers, composed of metastable conformations, were involved in e-gel formation. Under electric fields the nanoparticles rapidly assembled into larger nano- or microspheres with size range from tens of nanometers to several microns. Repulsive forces from the negative surface charge of the acidic groups on the protein were screened by the local decrease in solution pH in the vicinity of the positive electrode. By controlling the formation and content of silk fibroin nanoparticles e-gels could be formed even from low concentration silk fibroin solutions (1%). When e-gel formation was reversed to the solution state the aggregated nano- and microspheres dispersed into solution, a significant observation related to future applications for this process, such as drug delivery.     

不同来源蚕丝蛋白修复骨软骨组织缺损的效果比较

背景：目前还没有研究比较不同种属来源蚕丝蛋白修复骨软骨的效果。 目的：观察桑蚕和柞蚕来源蚕丝蛋白支架材料修复骨软骨缺损的效果差异。 方法：取新西兰兔20只,制备单侧膝关节骨软骨缺损模型,随机分为5组：其中1组不植入任何材料,作为空白对照;实验1组将3层桑蚕丝蛋白支架粘在一起,充填于缺损处;实验2组将1个包被转化生长因子β3的桑蚕丝蛋白支架与2个包被骨形态发生蛋白2的桑蚕丝蛋白支架粘在一起,充填于缺损处;实验3组将3层柞蚕丝蛋白支架粘在一起,充填于缺损处;实验4组将1个包被转化生长因子β3的柞蚕丝蛋白支架与2个包被骨形态发生蛋白2的柞蚕丝蛋白支架粘在一起,充填于缺损处。术后8周,取关节骨软骨修复区行组织病理学观察,检测Ⅰ型和Ⅱ型胶原蛋白表达。 结果与结论：实验1组胶原蛋白广泛分布于缺损区全层;实验2组胶原纤维在修复区表面呈平行分布,在中间和底部呈垂直顶部的方向分布;实验3组在修复区表面可见胶原;实验4组在支架表面和底部可见软骨样细胞有成团分布。4个实验组修复区Ⅰ型胶原蛋白呈强阳性表达;实验1组、实验2组修复区Ⅱ型胶原蛋白呈微弱表达,实验3组、实验4组修复区Ⅱ型胶原蛋白呈强阳性表达。表明两种蚕丝蛋白均能修复骨软骨缺损,桑蚕丝蛋白倾向于形成骨组织,柞蚕丝蛋白倾向于形成软骨组织。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程      

Silk fibroin microtubes for blood vessel engineering

Currently available synthetic grafts demonstrate moderate success at the macrovascular level, but fail at the microvascular scale (<6mm inner diameter). We report on the development of silk fibroin microtubes for blood vessel repair with several advantages over existing scaffold materials/designs. These microtubes were prepared by dipping straight lengths of stainless steel wire into aqueous silk fibroin, where the addition of poly(ethylene oxide) (PEO) enabled control of microtube porosity. The microtube properties were characterized in terms of pore size, burst strength, protein permeability, enzymatic degradation, and cell migration. Low porosity microtubes demonstrated superior mechanical properties in terms of higher burst pressures, but displayed poor protein permeability; whereas higher porosity tubes had lower burst strengths but increased permeability and enhanced protein transport. The microtubes also exhibited cellular barrier functions as low porosity tubes prevented outward migration of GFP-transduced HUVECs, while the high porosity microtubes allowed a few cells per tube to migrate outward during perfusion. When combined with the biocompatible and suturability features of silk fibroin, these results suggest that silk microtubes, either implanted directly or preseeded with cells, are an attractive biomaterial for microvascular grafts.     

Silk fibroin layer-by-layer microcapsules for localized gene delivery

Herein, we describe the delivery of plasmid DNA (pDNA) using silk fibroin (SF) layer-by-layer assembled microcapsules. Deposition of fluorescently labeled SF onto polystyrene (PS) template particles resulted in increasing fluorescence intensity and decreasing surface charge in correlation to SF layer number. After removal of the PS core, hollow, monodisperse, and structurally stable SF microcapsules of variable size and shell thickness were obtained. Plasmid DNA encoding for enhanced green fluorescent protein (eGFP) was loaded onto 1 or 4 μm capsules, either by incorporation of pDNA within the innermost layer of the shell or by adsorption to the microcapsules surface, and in vitro pDNA release, cytotoxicty and eGFP expression were studied. Sustained pDNA release over 3 days was observed using both loading techniques, being accelerated in the presence of protease. DNA loaded SF microcapsules resulted in efficient cell transfection along with low cytotoxicity after 3 days incubation compared to treatment with pDNA/branched polyethylenimine complexes. Among the tested conditions highest transfection efficiencies were achieved using 1 μm capsules where pDNA was adsorbed to the capsule surface. Our results suggest that SF microcapsules are suitable for the localized delivery of pDNA, combining low cytotoxicity and high transfection efficiency.     

Silk fibroin in ocular tissue reconstruction

The silk structural protein fibroin displays potential for use in tissue engineering. We present here our opinion of its value as a biomaterial for reconstructing tissues of clinical significance within the human eye. We review the strengths and weaknesses of using fibroin in those parts of the eye that we believe are most amenable to cellular reconstruction, namely the corneoscleral limbus, corneal stroma, corneal endothelium and outer blood-retinal barrier (Ruysch's complex). In these areas we find that by employing the range of manufacturing products afforded by fibroin, relevant structural assemblies can be made for cells expanded ex vivo. Significant questions now need to be answered concerning the effect of this biomaterial on the phenotype of key cell types and the biocompatibility of fibroin within the eye. We conclude that fibroin's strength, structural versatility and potential for modification, combined with the relative simplicity of associated manufacturing processes, make fibroin a worthy candidate for further exploration.