短肽RADAl6-1A组装纤维长度与止血关系研究

目的：RADAl6—1为人工设计的含16个氨基酸残基短肽,可自组装形成稳定的长纤维水凝胶,并具有外科止血功能。主要探讨RADAl6—1自组装成长纤维的时间动力学变化特点及其与止血功能之间的关系。,方法：利用化学合成法人工合成RADAl6—1短肽,制备成短肽溶液,并经超声处理通过圆二色谱分析水溶液中短肽分子的结构特征;通过原子力显微镜扫描分析超声处理前后短肽材料的表面特征;利用流变力学分析短肽由单体自组装成长纤维的时间动力学变化特点。建立脊髓损伤出血和肝创伤出血动物模型,研究RADAl6—1自组装成纤维的长度与止血功能的关系。结果：圆二色谱结果表明,超声前后溶液中短肽均为β-折叠特征;原子力显微镜扫描分析发现RADAl6—1可自组装成长度（786．34±96．54）nm的长纤维,且被超声折断的纤维具有自组装成长纤维的能力;流变力学分析结果显示短肽RADAl6—1单体自组装成长纤维的过程与时间呈正相关,动物止血实验结果显示RADAl6—1自组装纤维长度与完全止血所需时间呈负相关。结论：短肽RADAl6—1溶液可迅速原位水凝胶化成长纤维状,并能在外科手术中作为止血剂迅速止血．     

骨组织工程聚左旋乳酸多孔框架快速成形研究

为制备用于骨组织工程的细胞载体框架结构 ,对快速成形技术制备聚左旋乳酸多孔框架结构的若干基础问题进行了研究。提出了聚左旋乳酸快速成形的精密挤出成形工艺 ,研究了此工艺制备多孔框架结构的设备与工艺过程 ,分析了制备的多孔框架结构应用于组织工程人工骨的可行性。制备的多孔框架结构具有合适的分子量、孔隙结构、孔隙率、机械强度和生物降解性能 ,可以用作骨组织工程的组织再生框架结构     

Hippocampal Neuron-Derived Extracellular Matrix Coated Nanofibrous Scaffold for Neural Tissue Engineering

The aim of this study is to prepare poly-L-lactide( PLLA) electrospun nanofibrous scaffolds coated with hippocampal neuron-derived extracellular matrix( N-ECM)and construct a novel neural tissue engineering scaffold.Neonatal rat hippocampal neurons were seeded on PLLA nanofibers,and then decellularized to derive a cell-free extracellular matrix loaded N-ECM/PLLA modified scaffolds. The morphology and ingredients of N-ECM/PLLA were observed by scanning electron microscopy( SEM) and immunofluorescence staining respectively, and the cytocompatibility of the composite scaffolds was characterized by cell count kit-8( CCK-8) assay. The N-ECM was clearly identified loading on scaffolds when being imaged via SEM and immunofluorescence staining results showed that the N-ECM was made up of fibronectin and laminin. Most importantly, compared with tissue culture polystyrene and pure scaffolds, N-ECM/PLLA scaffolds could effectively facilitate the proliferation of rat adrenal neuroma cells( PC12 cells),indicating their better cell compatibilities. Based on the combination of N-ECM and PLLA biomaterials,the present study has fabricated a unique and versatile neural tissue engineering scaffold,offering a new thought for future neural tissue engineering.     

纳米支架在组织工程中的研究进展

纳米纤维支架技术是组织工程中为了支持细胞形成受损组织生物替代物的新兴技术。纳米支架能模拟天然的细胞外基质,作为三维的模板供细胞吸附、增殖以及分化。主要介绍了纳米纤维支架的结构特性、构建技术以及生物学效应。     

Preparation of PLGA-collagen hybrid scaffolds with controlled pore structures for cartilage tissue engineering

Scaffolds used for cartilage tissue engineering should have high mechanical strength and well-controlled pore structure to provide suitable microenvironments for functional tissue regeneration. In this study, hybrid scaffolds which had open and interconnected pore structure and high mechanical property were prepared by hybridization of PLGA mesh and collagen using ice particulates as porogen templates. Embossing ice particulates template was used to form open pore structures on the scaffold surfaces. Free ice particulates were used to generate interconnected bulk pores in the scaffolds. Hybridization with PLGA mesh provided the scaffolds with high mechanical property. Bovine articular chondrocytes were cultured in the hybrid scaffolds. The unique pore structures facilitated the homogeneous distribution of chondrocytes and cartilaginous matrices throughout the scaffolds. Subcutaneous implantation demonstrated cartilage-like tissue regeneration. The hybrid scaffolds should have a high potential for cartilage tissue engineering.     

Fabrication and characterization of electrospun poly-L-lactide/gelatin graded tubular scaffolds: Toward a new design for performance enhancement in vascular tissue engineering

In this study, a new design of graded tubular scaffolds have been developed for the performance enhancement in vascular tissue engineering. The graded poly-L-lactide (PLLA) and gelatin fibrous scaffolds produced by electrospining were then characterized. The morphology, degradability, porosity, pore size and mechanical properties of four tubular scaffolds (graded PLLA/gelatin, layered PLLA/gelatin, PLLA and gelatin scaffolds) have been investigated. The tensile tests demonstrated that the mechanical strength and also the estimated burst pressure of the graded scaffolds were significantly increased in comparison with the layered and gelatin scaffolds. This new design, resulting in an increase in the mechanical properties, suggested the widespread use of these scaffolds in vascular tissue engineering in order to prepare more strengthened vessels.     

聚氨酯改性及复合支架应用于血管组织工程

通过查阅近年来将聚氨酯作为血管组织工程支架材料的相关文献,介绍了聚氯酯改性的常用方法在血管组织工程支架中的应用情况,综述了聚氨酯表面改性支架和复合支架在血管组织工程中的应用.     

新型前交叉韧带支架材料的构建及其生物相容性的实验研究

探讨以聚羟基丁酸己酯/聚左旋乳酸(PHB/PLLA1∶1)胶原杂化支架作为前交叉韧带组织工程载体材料的可行性。制备"三明治"样结构PHB/PLLA共聚物并测量其孔隙率等指标。以I型胶原对制备的PHB/PLLA支架进行杂化,获得PHB/PLLA胶原杂化支架。扫描电镜观察其表面结构。将兔皮肤成纤维细胞(SF)接种于PHB/PLLA胶原杂化支架,共培养5d后,扫描电镜下观察其在材料上生长情况。PHB/PLLA支架杂化后胶原填充于纤维空隙,分布比较均匀。体外培养的皮肤成纤维细胞成功种植在支架材料上,在材料上粘附、生长良好。说明构建的支架材料具有良好的三维构型和生物相容性,有望为前交叉韧带损伤的修复提供了一种新型的支架材料。     

可降解聚醚酯弹性体PTCG的合成及初步生物学评价

用熔融缩聚法合成聚对苯二甲酸丁二醇酯-co-聚对苯二甲酸环己烷二甲醇酯-b-聚乙二醇(PTCG)聚醚酯弹性体.按照ISO 10993标准,采用L929小鼠成纤细胞对其进行体外细胞毒性测试;以狗的血管平滑肌细胞 (SMCs)为模板细胞,测试细胞在材料表面的贴附性能.采用旋转成型/粒子洗出法制备三维血管支架,接种SMCs后在生物反应器上进行动态培养,探索PTCG作为组织工程血管支架材料的可行性.结果表明,合成的PTCG聚醚酯弹性体无细胞毒性;SMCs在PTCG薄膜表面贴附生长良好;所制备支架的孔径、孔隙率和力学性能等满足组织工程血管支架的要求;体外培养3 d后,大量SMCs长入血管支架并开始分化.     

Electrospun Nanofibers of Hydroxyapatite/Collagen/Chitosan Promote Osteogenic Differentiation of BMSCs

Bone tissue engineering, aiming at developing bone substitutes for repair and regeneration of bone defects instead of using autologous bone grafts, has attracted wide attention in the field of tissue engineering and regenerative medicine. Developing biomimetic biomaterial scaffolds able to regulate osteogenic differentiation of stem cells could be a promising strategy to improve the therapeutic efficacy. In this study, clectrospun composite nanofibers of hydroxyapatite/collagen/chitosan （ HAp/Col/CTS ） resembling the fibrous nanostructure and constituents of the hierarchically organized natural bone, were prepared to investigate their capacity for promoting bone mesenchymal stem cells （BMSCs） to differentiate into the osteogenic lineage in the absence and presence of the osteogenlc supplementation, respectively. Call morphology, proliferation and quantified specific osteogenic protein expression on the electrospun HAp/Coi/CTS scaffolds were evaluated in comparison with different controls including dectrospun nanofibrous CTS, HAp/CTS and tissue culture plate. Our remits showed that the nanofibrous HAp/Col/CTS scaffolds supported better spreading and proliferation of the BMSCs than other substrates （ P 〈 0.01 ）. Expressions of osteogenesis protein markers, alkaline phosphatase （ALP） and Col, were significantly upregulated on the HAp/Col/CTS than those on the CTS （P 〈0.01） and HAp/ CTS （P 〈 0. 05 ） scaffolds in the absence of the osteogeulc supplementation. Moreover, presence of osteogeulc supplementation also proved to enhance osteogeule differentiation of BMSCs on HAp/ Col/CTS scaffolds, indicative of a synergistic effect. This study highlights the potential of BMSCs/HAp/Col/CTS cell-scaffold system for functional bone repair and regeneration applications.     

3D打印制备HA/PCL复合材料组织工程支架的研究

应用熔融沉积成型技术（FDM）制备羟基磷灰石（HA）/聚己内酯（PCL）组织工程支架,探讨其内部结构和力学性能。以羟基磷灰石和聚己内酯为原料,采用熔融共混技术分别制备HA质量分数为20%的nano-HA/PCL和micro-HA/PCL复合材料,使用自主研发的熔体微分FDM 3D打印机制备HA/PCL复合材料组织工程支架。通过显微镜观察发现,所制备的nano-HA/PCL和micro-HA/PCL组织工程支架具有均匀分布且相互连通的近似矩形的孔隙。nano-HA/PCL和micro-HA/PCL组织工程支架的断面图分析结果表明,nano-HA/PCL组织工程支架中HA粒子分布均匀,而micro-HA/PCL组织工程支架中HA粒子发生了团聚,导致nano-HA/PCL组织工程支架的拉伸强度和弯曲强度均高于micro-HA/PCL组织工程支架。因此,利用熔体微分FDM 3D打印机打印生物活性nano-HA/PCL复合材料组织工程支架在骨组织工程中具有潜在的应用前景。     

软骨组织工程新进展

软骨组织工程技术为治疗骨、软骨疾病提供了一种新的方法，其主要技术路线是，通过种子细胞和生物活性支架的体外共培养实现软骨组织的再生，并最终完成组织的修复与重建。种子细胞的选择、支架的构建，培养条件的优化对软骨再生有重要作用，从而成为目前软骨工程领域的研究重点。     

Green Electrospun Silk Fibroin/Galactose Chitosan Composite Nanofibrous Scaffolds for Hepatic Tissue Engineering

The electrospun nanofibrous scaffolds made of proteins and polysaccharides were thought to be able to simulate the structure of natural extracellular matrix well.Silk fibroin(SF)and chitosan(CS)are probably the most widely used natural materials in biomedical fields including liver tissue engineering for their good properties and wide variety of sources.The asialoglycoprotein receptors of hepatocyte were reported to specifically recognize and interact with galactose.In this work,a green electrospun SF/galactosylated chitosan(GC)composite nanofibrous scaffold was fabricated and characterized.The data indicated that the addition of GC greatly influenced the spinning effect of SF aqueous solution,and the average diameter of the composite nanofibers was about 520nm.Moreover,the green electrospun SF/GC nanofibrous scaffolds were demonstrated significantly enhancing the adhesion and proliferation of hepatocyte(RH35)according to our data.The present study did a useful exploration on constructing scaffolds for liver regeneration by green electrospinning,and also laid a good foundation for the further applicative research of this green electrospun scaffolds in liver tissue engineering.     

几种骨组织工程复合支架材料在模拟生理溶液中的生物矿化性能比较

采用生物活性玻璃(BG)、磷酸三钙(TCP)、羟基磷灰石(HA)等生物活性陶瓷与3-羟基丁酸酯-3-羟基戊酸酯的共聚物(PHBV)复合,制备了性能良好的骨组织工程支架材料,分析了PHBV/BG,PHBV/TCP,PHBV/HA三种复合多孔支架在模拟生理溶液中的一系列化学反应,以及多孔材料在模拟生理溶液中浸泡后的成分、结构和微观形貌的变化.研究结果表明,三种复合支架材料在模拟生理溶液中发生了降解反应而失重;PHBV/BG和PHBV/TCP在模拟生理溶液中还发生了生物矿化反应,在表面形成矿化沉积层,为具有骨生物活性的结晶态类骨碳酸羟基磷灰石;而PHBV/HA在模拟生理溶液中没有明显的生物活性反应.     

用于软骨下骨修复的镁基支架

骨关节炎（osteoarthritis,OA）作为一种可以导致残疾的退行性疾病,常累及软骨下骨。受损的关节软骨和软骨下骨很难自愈,用于功能修复的组织工程支架是一种有前途的治疗方法。近年来,镁合金因其良好的机械和生物学性能被视为可降解多孔支架有希望的候选者。然而,目前对于适用于软骨下骨缺损修复的镁基支架的结构设计和优化方案还没有定论。归纳了镁合金用于骨软骨支架的研究进展,包括多孔支架的制造方法;添加合金元素和表面改性的优化策略;参数化与非参数化的结构设计;镁基支架的机械、降解和生物学性能及其影响因素。讨论了未来研究的潜在方向。旨在为多孔镁基支架的开发和临床应用提供参考。     

高链玉米淀粉对聚己内酯组织工程支架材料结构与性质的影响

采用高链玉米淀粉改性聚己内酯（PCL）,通过溶剂浇铸/粒子沥滤法制备聚己内酯/淀粉（SPCL）组织工程支架;考察了改性后支架材料的化学结构、结晶性、亲水性和细胞相容性.结果表明,适量淀粉的引入能够降低支架材料的结晶性、改善材料的亲水性和细胞相容性,70％PCL/30％淀粉支架材料的细胞粘附率、增殖率和细胞活性为最佳,有望应用在骨组织工程中.     

细菌纤维素组织工程支架的仿生矿化研究

骨骼创伤已经成为当今影响人类健康的一大病症。因此,骨修复材料就成为研究的一大热点。骨组织工程支架作为重要的骨修复材料,可以诱导成骨细胞生长并为新骨生长提供条件。传统的骨组织工程支架包括合成高分子(如聚乳酸、聚乙醇酸等)和天然高分子(如胶原、壳聚糖等)。与传统支架材料相比,细菌纤维素(BC)具有良好的生物相容性、精细的纳米空间三维网络结构,有作为组织工程支架的潜能。通过仿生矿化处理,BC纳米纤维表面可以生长出羟基磷灰石(HA)的晶体颗粒,且HA颗粒均匀覆盖在纳米纤维表面。通过热分析得出,仿生矿化处理会使BC的热稳定性得到一定的提升。     

海藻酸盐复合凝胶在骨组织工程中的研究进展

骨组织工程支架是以修复缺损的骨并恢复其功能为目的而开发出的人工支架。海藻酸盐是世界上含量最丰富的海洋生物高分子聚合物,其在骨组织工程材料中的应用已被大量研究报道。虽然海藻酸盐作为骨组织支架材料具有优异的生物相容性、良好的生物可降解性和无免疫原性等优点,但是仍存在机械强度较弱、缺乏细胞特异性结合位点、支架结构在生理环境中易被破坏等缺点,严重限制其在骨组织工程中的应用。目前,研究者已经研究出几大类海藻酸盐复合支架材料,这些材料均表现出优异的力学性能和生化性能,因此,海藻酸盐复合支架材料可能在骨组织修复和再生方面具有较高的应用价值。本文主要针对海藻酸盐复合支架材料在骨组织工程中的应用作简要概述。     

静电纺丝在组织工程支架材料制备中的应用

综述了静电纺丝的基本原理和过程参数,重点描述了静电纺丝及同轴共纺技术在组织工程支架材料领域的应用,最后对电纺技术在组织工程支架材料领域应用中存在的问题和面临的挑战进行了讨论.     

VE TPGS-Loaded Silk Fibroin/Hydroxybutyl Chitosan Nanofibrous Scaffolds for Skin Care Application

Vitamin E（ VE） is an ideal antioxidant and a stabilizing agent in biological membranes. In this study,silk fibroin（ SF） /hydroxybutyl chitosan（ HBC） nanofibrous scaffolds are loaded with VE tocopherol polyethylene glycol 1000 succinate（ VE TPGS） via electrospinning. SEM images show that the average nanofibrous diameter has no significant difference when the content of VE TPGS increases to 4. 0%（ SF / HBC）. However,the average nanofibrous diameter decreases largely to 200 nm when the VE TPGS content reaches 6. 0%. Furthermore,VE TPGS presents a sustained release behavior from the nanofibrous scaffolds. Cell viability studies of mouse skin fibroblasts（ L929） demonstrate that VE TPGS loaded SF / HBC nanofibrous scaffolds present good cellular compatibility.Moreover,the incorporation of VE TPGS could strengthen the ability of SF / HBC nanofibrous scaffolds on protecting the cells against oxidation stress using the Tertbutyl hydroperoxide（ t-BHP）-induced oxidative injury model. Therefore,VE TPGS-loaded SF /HBC nanofibrous scaffolds might be potential candidates for personal skin care,wound dressing and skin tissue engineering scaffolds.