骨组织工程用三维支架制备的研究现状

骨组织工程支架材料是骨组织工程研究的关键问题之一。国内外骨组织工程多孔支架的制备主要有溶液浇铸/粒子沥滤法、热致相分离/冻干法、发泡法、激光烧结法等多种方法,但所制备的复合材料强度等性能仍不理想。提高机械性能、大孔径高孔隙率和可塑成型性,并使其具备细胞识别信号将是支架材料研究的热点和难点。     

骨组织工程支架材料聚磷酸钙体外降解规律的研究

为了解决骨组织工程中支架材料的降解速度应与细胞的生长速率相匹配，通过对原料煅烧过程的分析，提出了聚合度的计算方法，并制备出不同聚合度的材料。通过对材料烧结温度的试验，制得了不同晶型的聚磷酸钙多孔材料。结果表明，随着聚合度的增加，材料的抗压强度增大，降解速率变小；不同晶型的材料具有不同的降解速率，非晶CPP最快完全降解为17d，α-CPP最慢30d约降解为5％。凭借其独特的无机聚合物结构及降解性能，实现可控速率的降解。     

HAP/CS/KGM复合骨组织工程支架的研究

以氨水作促凝剂,采用溶胶-凝胶和冷冻干燥法制备HAP/CS/KGM复合支架。HAP在CS作用下呈链状均匀分布在KGM基体中,支架具有适宜的孔隙率、孔径分布和机械性能。XRD分析证实低结晶度HAP和CS间发生了一定的键合作用;FT-IR分析证实KGM分子间及KGM和CS分子间也发生了一定的键合。骨髓间充质干细胞(BMSCs)体外培养表明,HAP/CS/KGM支架相容性好,能够引导定向骨形成。HAP/CS/KGM复合支架的组成和结构特征与人体自然骨非常相似,在骨组织工程中具有潜在的应用价值。     

生物玻璃/胶原复合支架的制备及理化性能研究

以冷冻干燥和纳米合成技术制备生物玻璃和胶原复合支架材料,采用扫描电镜观察、红外光谱分析、差示扫描量热分析、热重分析、弯曲强度测试等分析手段,对复合支架的理化性能进行研究。研究结果表明：制备的支架具有多孔结构。在制备过程中,两相间产生了化学键合作用。由此论证了复合支架的孔隙结构可为细胞生长及细胞外基质的产生提供充分的空间。两相间的键合作用对于提高骨支架材料的热稳定性能、力学性能,减弱植入体内后在体液中的膨胀和浸析反应具有至关重要的作用。     

皮肤组织工程支架材料与制备方法的研究进展

皮肤组织工程支架材料在人工皮肤的构建中起着关键作用,为种子细胞提供了黏附、生长、迁移、增殖、分化和代谢的环境,是皮肤组织工程的重要研究内容。对组织工程化皮肤支架近几年的材料、制备方法的进展进行了综述,并分析了皮肤组织工程支架材料的发展趋势。     

仿生自清洁外墙涂料的制备

根据仿生科学原理,制备具有荷叶效应的拒水自洁外墙涂料。考察了改性丙烯酸酯乳液、改性硅灰石和改性微晶蜡乳液对提高涂料接触角和疏水性能所起的重要作用,重点研究了颜基比、填颜比和改性微晶蜡乳液用量对涂膜接触角和吸水率的影响。在优化的涂料总配方设计条件下,制备的成品外墙涂料不仅各项性能指标达到标准要求,而且涂膜与水的接触角高达约140,°吸水率低至0.32%,具有良好的拒水效果。     

潜在的细菌纤维素/明胶支架材料的制备

实验在pH 1.0,温度40℃,避光条件下,通过高碘酸钠对细菌纤维素（BC）进行氧化,制得双醛细菌纤维素（DHBC）。然后在温度50℃,pH 6.0,DHBC与不同用量的明胶溶液进行作用制得双醛细菌纤维素/明胶（DB-G）3种复合材料（DB-G5,DB-G10,DB-G15）。通过FTIR谱图分析,DB-G中的CO的伸缩振动吸收峰（1 740 cm^-1）消失了,相应地在1 600~1 680 cm^-1和1 500~1 550 cm^-1出现了典型的酰胺Ⅰ的v（CO）和酰胺Ⅱ v（N-H）的红外吸收峰,随着明胶比例增加,吸收峰变宽并发生部分紫移。根据模拟体液（SBF）降解测试结果,DHBC及DB-G表现出了良好的可降解性,降解周期为60~90 d。利用比表面积与孔径分布及SEM的测试分析,DB-G5、DB-G10、DB-G15的孔径变化呈现出了不断减小的趋势。通过TG/DTG的热解温度测试结果,与BC相比,DHBC热解温度迅速降低,最大失重温度（T_max）下降80.1℃。然而与明胶发生交联后,热分解稳定性得到明显提高,DB-G的T_max均大于340℃,但DB-G10和DB-G15的T_max却不足2℃。抗张强度测试表现出类似的情形,与DB-G10相比,DB-G15没有随着明胶用量的进一步提高。综合分析认为,m（DHBC）：m（明胶）以1：10最为合适,即DB-G10可作为一种潜在的组织工程支架材料。     

仿生超疏水表面的制备技术及其进展

仿生超疏水表面具有防水、自清洁等优良特性.自然界中存在许多无污染、自清洁的动植物表面,如超疏水的荷叶表面、超疏水各向异性的水稻叶表面、超疏水的暗翼表面等.影响材料表面润湿性的主要因素育材料表面能、表面粗糙度和表面微一纳结构.超疏水表面的自清洁功能源自于表面形貌与低表面能物质的共同作用,可以通过两类技术路线来制备超疏水表面:控制材料表面能和修饰微细结构表面.     

壳聚糖基骨组织工程支架材料的研究进展

壳聚糖是甲壳素脱乙酰基的产物,是第二大天然高分子,由于其良好的生物相容性、生物可降解性和成型性,作为骨组织工程支架材料越来越受到重视.对壳聚糖为主的复合骨组织工程支架的相关研究进行综述,可以掌握其在不同的材料体系中的功能作用,并可预见壳聚糖基生物材料在骨组织工程中的发展潜力.     

动物运动仿生的反思与出路

提出了一种结构简单的不对称转动机构一半转机构。空中、水里、陆上运动的动物具有不同的运动方式,因此半转机构也必须用不同的方式去实现它们的运动效果。用半转机构实现飞行仿生的可能性可以借助Weis—Fogh机构的原理得到确认。用半转机构实现水中与陆地上的动物运动效果仿生也是可能的。     

Microstructure and mechanical properties of calcium phosphate cement/gelatine composite scaffold with oriented pore structure for bone tissue engineering

The macroporous calcium phosphate(CPC) cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede’s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this work might be a potential scaffold for bone tissue engineering.     

组织工程用多孔支架制备工艺进展

组织工程用多孔支架不仅要有普通生物材料具有的性能，而且对其孔径、孔隙率、比表面积等物理性能也有一定的要求，而这些物理性能与多孔支架的制备工艺密切相关．现主要对组织工程多孔支架常用的制备方法进行了回顾，并从成形工艺特点、支架的孔隙特征等方面对各种制备方法进行了比较，最后讨论了多孔支架的发展趋势．     

组织工程用多孔支架技术的开发现状

针对人体生物工程技术的发展，综述了组织工程用多孔支架制备技术的发展现状：其传统技术涉厦非织造成型技术、三维编织技术、相分离／乳化法、溶液浇铸／粒子溶出法、熔融成型法、气体发泡法等．新型快速成型技术包括立体光刻法、选择性激光烧结、熔融沉积成型、分层实体制造、三维立体喷涂等．研究认为，传统技术的组合优化和新兴的快速成型技术是当前技术的发展方向。     

Preparation of new tissue engineering bone-CPC/PLGA composite and its application in animal bone defects

To investigate the feasibility of implanting the biocomposite of calcium phosphate cement (CPC)/polylactic acid-polyglycolic acid (PLGA) into animals for bone defects repairing, the biocomposite of CPC/PLGA was prepared and its setting time, compressive strength, elastic modulus, pH values, phase composition of the samples, degradability and biocompatibility in vitro were tested. The above-mentioned composite implanted with bone marrow stromal cells was used to repair defects of the radius in rabbits. Osteogenesis was histomorphologically observed by using an electron-microscope. The results show that compared with the CPC, the physical and chemical properties of CPC/PLGA composite have some differences in which CPC/PLGA composite has better biological properties. The CPC/PLGA composite combined with seed cells is superior to the control in terms of the amount of new bones formed after CPC/PLGA composite is implanted into the rabbits, as well as the speed of repairing bone defects. The results suggest that the constructed CPC/PLGA composite basically meets the requirements of tissue engineering scaffold materials and that the CPC/PLGA composite implanted with bone marrow stromal cells may be a new artificial bone material for repairing bone defects because it can promote the growth of bone tissues.     

组织工程用多孔支架制备工艺进展

组织工程用多孔支架不仅要有普通生物材料具有的性能,而且对其孔径、孔隙率、比表面积等物理性能也有一定的要求,而这些物理性能与多孔支架的制备工艺密切相关.现主要对组织工程多孔支架常用的制备方法进行了回顾,并从成形工艺特点、支架的孔隙特征等方面对各种制备方法进行了比较,最后讨论了多孔支架的发展趋势.     

In vitro and in vivo characterization of homogeneous chitosan-based composite scaffolds

With a homogeneous distribution of hydroxyapatite (HAP) crystals in polymer matrix, composite scaffolds chitosan/ HAP and chitosan/collagen/HAP were fabricated in the study. XRD, SEM and EDX were used to characterize their components and structure, in vitro cell culture and in vivo animal tests were used to evaluate their biocompatibility. HAP crystals with rod-like shape embeded in chitosan scaffold, while HAP fine-granules bond with collagen/chitosan scaffold compactly. A homogenous distribution of Ca and P elements both in chitosan/HAP scaffold and chitosan/collagen/HAP scaffold was defined by EDX pattern. The presence of collagen brought a more homogenous distribution of HAP due to its higher ability to induce HAP precipitation. The results of in vitro cell culture showed that the composite’s biocompatibility was enhanced by the homogenous distribution of HAP. In vivo animal studies showed that the in vivo biodegradation was effectively improved by the addition of HAP and collagen, and was less influenced by the homogeneous distribution of HAP when compared with a concentrated distribution one. The composite scaffolds with a homogeneous HAP distribution would be excellent alternative scaffolds for bone tissue engineering.     

In Vitro Biomineralization of Glutaraldehyde Crosslinked Chitosan Films

The biomimetic approach was applied to study the in vitro biomineralization of series of the chitosan films crosslinked ty glutaraldehyde. The deposited calcium phosphate comings were studied using scanning electron microscopy and energy dispersive X-ray analysis. Initially, the treatment in simulated body fluid (SBF) results in the formation of single layer of calcium phosphate particles over the film surface. As immersion time in SBF increases, further nucleation and growth produce a simulated calcium phosphate coating. The Ca/P molar ratio of the calcium phosphate increases with the immersion time, showing a rapid formation of calcium-deficient phosphate material from the phase of octac 1 alcium phosphate. The different glutaraldehyde crosslinking degree influeaces the morphology and magnitude of the calcium phosphate coatings on the surface of the chitosan films.     

Design and preparation of bone tissue engineering scaffolds with porous controllable structure

A novel method of designing and preparing bone tissue engineering scaffolds with controllable porous structure of both macro channels and micro pores was proposed. The CAD software UG NX3.0 was used to design the macro channels’ shape, size and distribution. By integrating rapid prototyping and traditional porogen technique, the macro channels and micro pores were formed respectively. The size, shape and quantity of micro pores were controlled by porogen particulates. The sintered β-TCP porous scaffolds possessed connective macro channels of approximately 500 μm and micro pores of 200–400 μm. The porosity and connectivity of micro pores became higher with the increase of porogen ratio, while the mechanical properties weakened. The average porosity and compressive strength of β-TCP scaffolds prepared with porogen ratio of 60wt% were 78.12% and 0.2983 MPa, respectively. The cells’ adhesion ratio of scaffolds was 67.43%. The ALP activity, OCN content and cells micro morphology indicated that cells grew and proliferated well on the scaffolds. Funded by the Postdoctor Science Fund of China (No. 20070410715) and Shanghai Excellent Youth Special Fund (No. 17014)     

水凝胶在组织工程中的应用进展

介绍水凝胶的形成及其作为支架和免疫隔膜材料在组织工程中的研究进展，根据水凝胶支架材料的用途，将其分类为填充缺损物支架、生物活性分子控制释放载体、组织／细胞转载系统等3个方面进行阐述。     

生物活性聚合物及其复合材料在骨组织工程中的应用进展

骨是世界上第二大需要移植的组织,每年至少有400万次手术使用骨移植物和骨代替材料.传统的治疗方法的局限性影响了当前的治疗选择,并且由于创伤、癌症、感染和关节炎引起的骨缺损现象不断增加,在临床治疗中对骨移植物的需求也持续上升.自体移植物和异体移植物是临床治疗骨缺损的常用方法,而慢性炎症、疾病传播和免疫排斥反应的发生阻碍了...