静电纺丝SF/PLGA纤维支架用于血管组织工程的研究

将丝素蛋白（SF）和乳酸-羟基乙酸共聚物（PLGA）溶解在六氟异丙醇中配制成溶液,采用静电纺丝技术制备了SF/PLGA纳米纤维支架,使用扫描电子显微镜（SEM）对纤维支架进行表征,研究了聚合物溶液浓度、纺丝电压、接收距离以及体积流率对纳米纤维形态的影响,从而得到纺丝的最适宜工艺参数。考察了纤维支架表面对HUVECs细胞的相容性。结果表明：HUVECs可以在SF/PLGA纤维支架表面很好的黏附和增殖,支架具有良好的细胞相容性,在组织工程领域有良好的应用前景。     

聚乳酸⁃羟基乙酸共聚物涂层对聚乳酸3D打印支架的性能影响

通过熔融沉积（FDM）三维（3D）打印技术制备了61.7 %孔隙率和良好连通性的3D多孔聚乳酸（PLA）支架,使用浸涂法对PLA支架表面涂覆浓度分别为2 %、4 %、6 %、8 %的聚乳酸⁃羟基乙酸共聚物（PLGA）涂层,获得了不同浓度涂层的PLA/PLGA复合支架。通过扫描电子显微镜（SEM）、接触角测量仪、万能试验机和细胞计数试剂盒⁃8方法等测试手段,探究了不同浓度PLGA涂层对PLA支架的断面微观形貌、支架表面亲水性、力学强度以及细胞在支架上增殖活性等性能的影响规律。结果表明,与未经包裹的PLA支架相比,包裹PLGA的PLA支架表面接触角显著减小,PLGA的质量分数为6 %时接触角最小为（64.7±1.1） °;接种后经24 h培养PLA/PLGA支架表面细胞活性较纯PLA支架显著增强。     

壳聚糖支架材料的制备、表面修饰及细胞粘附性能的研究

通过冷冻干燥法进行壳聚糖(Chitosan)多孔支架材料的制备,使用I型明胶对所制得的支架材料进行表面修饰,用于生物医用可降解复合材料的仿生构建.对所制备的支架材料分别进行密度、孔隙率和降解率等物理性质测定,并使用新西兰兔来源的骨髓间充质干细胞(Bone marrow mesenchymal stem cells, BMSCs)检验支架材料的细胞粘附和生物相容性能.以未经表面处理的该种材料作为对照组,对MSCs-Chitosan复合物分别进行扫描电镜和Hoechst染色等,检测MSCs(间充质干细胞)在支架材料表面的生长、粘附和分布形态.结果显示两种壳聚糖浓度制备的多孔支架材料的空隙率分别为(86.85±2.42)%和(71.50±3.29)%,孔径为90~130 μm,MSCs在经明胶表面修饰的材料表面表现出良好的粘附、伸展性能.此外,本研究还对1-乙基-(3-二甲基氨基丙基)碳酰二亚胺(1-ethyl- (3-dimethylanimopropyl) carbodiimide, EDC)交联剂对壳聚糖基支架性能的影响进行了初步研究.研究表明,通过明胶修饰构建的仿生明胶/壳聚糖人工基质材料,具有良好的生物相容性能,作为一种理想的组织工程用支架材料,适于细胞在其上的粘附与增殖.     

基于改性氧化石墨烯/聚苯胺增强水性聚氨酯防腐涂层的制备及性能研究

为提高填料与水性聚氨酯（WPU）之间的相容性和增加防腐性能,利用聚多巴胺（PDA）修饰氧化石墨烯/聚苯胺（FGO/PANI）纳米填料,用于制备水性聚氨酯涂层。采用傅立叶变换红外光谱（FT-IR）、紫外-可见吸收光谱（UV-vis）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征纳米填料结构,并分析了涂层的力学性能和防腐性能。结果表明：填料PDA/FGO/PANI成功合成且PDA被成功包裹在FGO/PANI的表面,PDA的加入可以有效改善纳米填料与水性聚氨酯之间的相容性,从而增强其力学性能和防腐性能,并且PDA的加入不会破坏PANI的防腐机理。     

碳纤维增强PPO/PA6共混物的研究

通过熔融挤出制备聚苯醚接枝马来酸酐（PPO-g-MAH）作为聚苯醚/尼龙6（PPO/PA6）共混物的相容剂,再与苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物（SEBS）、碳纤维（CF）共混制备PPO/PA6/PPO-g-MAH/SEBS/CF复合材料。CF经侧喂料口加入,通过改变螺杆转速来制备不同CF含量的复合材料。通过动态热机械分析（DMA）、毛细管流变和力学性能测试等方法研究了CF含量变化对复合材料热机械性能、流变行为、力学性能等的影响。再与相同条件下制备的玻璃纤维（GF）复合材料进行比较,通过扫描电子显微镜观察（SEM）和力学性能测试,表明CF能够更好的被基体树脂包覆,制得的复合材料性能更优。     

静电纺PLGA管状支架的构建及其生物力学性能

以具有良好生物相容性、生物可降解性的聚丙交乙交酯(PLGA)为原料,以高速旋转的滚轴为收集装置,通过静电纺丝法,制备PLGA管状支架(d=6mm)。研究不同工艺及乙醇处理对PLGA管状支架形貌结构、微细结构和生物力学性能的影响。结果表明:当纺丝液质量分数为7%,滚轴转速为1500r/min时,可制得纤维形貌规整、分布均匀,直径为(1660±218)nm,孔隙率为80.6%的PLGA管状支架;经乙醇处理后,其孔隙率减小,玻璃化温度和热分解温度提高,热稳定性增强;断裂强度、爆破强度及缝合强力均显著提高。     

聚乙烯醇/牛I型胶原支架材料的制备及评价

研究了一种聚乙烯醇(PVA)和胶原(COL)复合支架材料的制备方法。采用氨基硅烷对PVA海绵表面进行了氨基化修饰后，通过戊二醛溶液交联牛Ⅰ型胶原(COL)，最后通过赖氨酸溶液封闭，获得一种PVA/COL复合支架材料。采用扫描电镜(SEM)、X光电子能谱仪(XPS)、傅里叶红外光谱(FT-IR)等手段对支架材料的理化性能进行表征，并通过细胞实验对支架材料的生物学性能进行评价。结果表明，经过COL修饰的PVA孔隙率为21.33%，平均孔径为168.68 ?m且均匀分布，支架材料接触角为20.03°。对支架材料的生物学评价结果表明C3A细胞在复合材料上黏附良好，优于PVA组；CCK-8增殖检测结果表明细胞在复合材料上呈增殖生长趋势，与对照组PVA相比差异显著(P?0.01)。将PVA和COL复合制备得到的支架材料具有良好的理化及生物学特性，具有广阔的应用前景。     

用硅烷偶联剂处理生物玻璃表面及其复合支架的制备

为了改善溶胶-凝胶生物活性玻璃与高分子材料的相容性,用硅烷偶联剂氨丙基三乙氧基硅烷对生物活性玻璃进行表面处理,并用X射线光电子能谱对处理后的生物活性玻璃的表面进行元素分析.结果表明:偶联剂通过Si-O-Si键被引入到生物活性玻璃表面.用处理后的生物活性玻璃与壳聚糖-明胶复合制备了多孔支架.扫描电子显微镜观察发现:复合多孔支架的两相相容性好,界面结合紧密;支架的孔隙连通、排列规则.力学测试表明:改性后的溶胶-凝胶生物活性玻璃与壳聚糖-明胶制备的复合支架力学性能得到明显改善.     

可注射nHA/PU复合多孔骨修复支架制备及表征

兼具良好孔隙率和原位任意塑形固化的可注射复合多孔骨修复材料在临床不规则骨缺损的治疗方面显示出巨大的优势。本研究通过优化双组分设计,以水为发泡剂制备可注射纳米羟基磷灰石/聚氨酯（nHA/PU）复合多孔支架。利用扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、力学测试及Gillmore针测试等手段对制备的支架进行结构形貌、化学组成、力学性能和固化时间表征。结果表明,本研究制备的可注射nHA/PU复合多孔支架孔隙率高、孔隙贯通性好,孔径分布在100~700μm,适宜细胞和组织向孔内生长;添加20% nHA显著提高了PU支架的力学强度,但降低了支架的孔隙率;可注射支架在8h固化,适宜临床操作。本研究制备的可注射nHA/PU复合多孔支架在不规则骨缺损修复领域具有较大的应用潜力。     

碳纳米管/碳纤维混杂多尺度增强体研究现状

碳纳米管(CNTs)优异的力学性能使其成为复合材料的理想增强材料,将CNTs引入到碳纤维(CF)表面制备CNTs/CF纳、微米复合增强体,可同时改善复合材料的界面剪切强度和冲击强度,从而获得具有优异综合性能的复合材料。本文综述了CNTs/CF混杂多尺度增强体的制备方法及其复合材料的性能。     

3D Composite scaffolds using strontium containing bioactive glasses

In this study, it was aimed to fabricate and characterize three-dimensional composite scaffolds derived from Sr-doped bioactive glass for bone tissue engineering applications. The scaffolds were fabricated by using polymer foam replication technique and coated with gelatin to be able to improve the properties of them. The porous scaffolds were successfully synthesized using optimized process parameters. Both coated and uncoated scaffolds favored precipitation of calcium phosphate layer when they were soaked in simulated body fluid (SBF). Gelatin coating improved the mechanical properties of the scaffold and also it did not change the bioactive behavior of the scaffold. It was observed that there was a good pore interconnectivity maintained in the scaffold microstructure. Results indicated that scaffolds can deliver controlled doses of strontium toward the SBF medium. That is the determinant for bone tissue regeneration, as far as strontium is known to positively act on bone remodeling.     

Fabrication and Characterization of Multicomponent Polysaccharide/Nanohydroxyapatite Composite Scaffolds

Carrageenan–hyaluronic acid/nanohydroxyapatite/microcrystalline cellulose composite scaffolds with various amounts of microcrystalline cellulose content (from 0 to 60?wt%) were prepared using freeze-drying method. The results showed highly porous (from 94.0?±?1.09 to 85.0?±?1.05%) composite scaffolds with high water-uptake capacity, average pore size ranging 200–650?µm, and improved mechanical properties (in dry and wet states). Additionally, cytocompatibility of composite scaffolds was evaluated by in vitro culture of osteoblast (MC3T3-E1) cells for 1 and 3 days of incubation and demonstrated good cell adhesion, infiltration, and proliferation. Thus, as-obtained composite scaffolds may have promising application in low-loading bone tissue engineering applications.     

Mechanical strength and biocompatibility of bredigite (Ca7MgSi4O16) tissue-engineering scaffolds modified by aliphatic polyester coatings

Bredigite (Ca₇MgSi₄O₁₆) is a bioceramic with excellent bioactivity and bioresorbability; nonetheless, its inadequate mechanical strength and biocompatibility limit its tissue-engineering application. In this research, interconnected porous bredigite scaffolds were fabricated by sol-gel, sacrificial sponge replica and sintering processes for bone tissue engineering. In order to improve their strength and cytocompatibility, the scaffolds were coated with poly(lactic-co-glycolic acid) (PLGA) via immersion in acetone-based solutions containing different concentrations (5, 10 and 15% w/v) of the polymer. Based on the results, the PLGA coatings to 10% do not suppress the porosity characteristics of the scaffolds appropriate for tissue engineering. It was also found that the polymeric coatings significantly enhance the compressive strength of the ceramic scaffolds, where this alteration is improved by increasing the PLGA concentration of the coating solution. In addition, the viability of stem cells on the bredigite scaffolds are improved by using the PLGA coatings, with the optimal concentration of 10% PLGA according to MTT and cell attachment studies.     

Preparation and characterization of Chitosan and PLGA‐based scaffolds for tissue engineering applications

Three dimensional (3D) biodegradable porous scaffolds play a crucial role in bone tissue repair. In this study, four types of 3D polymer/hydroxyapatite (HAp) composite scaffolds were prepared by freeze drying technique in order to mimic the organic/inorganic nature of the bone. Chitosan (CH) and poly(lactic acid‐co‐glycolic acid) (PLGA) were used as the polymeric part and HAp as the inorganic component. Properties of the resultant scaffolds, such as morphology, porosity, degradation, water uptake, mechanical and thermal stabilities were examined. 3D scaffolds having interconnected macroporous structure and 77–89% porosity were produced. The pore diameters were in the range of 6 and 200 µm. PLGA and HAp containing scaffolds had the highest compressive modulus. PLGA maintained the strength by decreasing water uptake but increased the degradation rate. Scaffolds seeded with SaOs‐2 osteoblast cells showed that all scaffolds were capable of encouraging cell adhesion and proliferation. The presence of HAp particles caused an increase in cell number on CH‐HAp scaffolds compared to CH scaffolds, while cell number decreased when PLGA was incorporated in the structure. CH‐PLGA scaffolds showed highest cell number on days 7 and 14 compared to others. Based on the properties such as interconnected porosity, high mechanical strength, and in vitro cell proliferation, blend scaffolds have the potential to be applied in hard tissue treatments. POLYM. COMPOS., 36:1917–1930, 2015. © 2014 Society of Plastics Engineers     

Evaluation of mechanical behavior,bioactivity, and cytotoxicity of chitosan/akermanite-TiO2 3D-printed scaffolds for bone tissue applications

This report aimed to evaluate the mechanical behavior, bioactivity, and cytotoxicity of novel chitosan/akermanite-TiO₂ (CS/AK/Ti) composite scaffolds fabricated using the 3D-printing method. The morphological and structural properties of these scaffolds were characterized by Fourier transform spectroscopy (FTIR) and scanning electron microscopy (SEM). The mechanical behavior was examined by measuring the compressive strength, while the bioactivity was estimated in the simulated body fluid (SBF), and also the cytotoxicity of the scaffolds was assessed by conducting cell culturing experiments in vitro. It was found that the mechanical properties were considerably affected by the amount of TiO_2. The scaffolds had the possessed bone-like apatite forming ability, which indicated high bioactivity. Furthermore, L929 cells spread well on the surface, proliferated, and had good viability regarding the cell behaviors. The outcomes confirmed that the morphological, biological, and mechanical properties of developed 3D-composite scaffolds nearly mimicked the features of natural bone tissue. In summary, these findings showed that the 3D-printed scaffolds with an interconnected pore structure and improved mechanical properties were a potential candidate for bone tissue applications.     

PLGA/nHA hybrid nanofiber scaffold as a nanocargo carrier of insulin for accelerating bone tissue regeneration

The development of tissue engineering in the field of orthopedic surgery is booming. Two fields of research in particular have emerged: approaches for tailoring the surface properties of implantable materials with osteoinductive factors as well as evaluation of the response of osteogenic cells to these fabricated implanted materials (hybrid material). In the present study, we chemically grafted insulin onto the surface of hydroxyapatite nanorods (nHA). The insulin-grafted nHAs (nHA-I) were dispersed into poly(lactide-co-glycolide) (PLGA) polymer solution, which was electrospun to prepare PLGA/nHA-I composite nanofiber scaffolds. The morphology of the electrospun nanofiber scaffolds was assessed by field emission scanning electron microscopy (FESEM). After extensive characterization of the PLGA/nHA-I and PLGA/nHA composite nanofiber scaffolds by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM), the PLGA/nHA-I and PLGA/nHA (used as control) composite nanofiber scaffolds were subjected to cell studies. The results obtained from cell adhesion, alizarin red staining, and Von Kossa assay suggested that the PLGA/nHA-I composite nanofiber scaffold has enhanced osteoblastic cell growth, as more cells were proliferated and differentiated. The fact that insulin enhanced osteoblastic cell proliferation will open new possibilities for the development of artificial scaffolds for bone tissue regeneration.     

Synthesis,characterization and in-vitro behavior of natural chitosan-hydroxyapatite-diopside nanocomposite scaffold for bone tissue engineering

Composite materials based on a combination of biodegradable polymers and bioactive ceramics, including chitosan and hydroxyapatite are discussed as suitable materials for scaffold fabrication. Diopside is a member of bioactive silicates; it is a good choice for hard tissue engineering because of its biocompatibility with host tissue and high mechanical strength. Chitosan and hydroxyapatite were extracted from shrimp shell and bovine bone, respectively and diopside nanoparticles were prepared by the sol-gel method. The present study reports on a chitosan composite which was reinforced by hydroxyapatite and diopside; the scaffolds were fabricated by the freeze-drying method. The so-produced chitosan-hydroxyapatite-diopside (CS-HA-DP) scaffolds were further cross-linked using tripolyphosphate (TPP) to achieve enhanced mechanical strength. The ratios of the ceramic components in composites were 5-58-37, 10-55-35, and 15-52-33 (diopside-hydroxyapatite-chitosan, w/w %). The physicochemical properties of scaffolds were investigated using Fourier-transform infrared spectrometry (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) techniques. The effect of scaffolds composition on bioactivity and biodegradability were studied well. To investigate mechanical properties of samples, compression test was done. Results showed that the composite scaffold with 5% DP has the highest mechanical strength. The porosity of composites dropped from 92% to 76% by increasing the amount of DP. Cytocompatibility of the scaffolds was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, alkaline phosphatase (ALP) activity, and cell attachment studies using human osteoblast cells. Results demonstrated no sign of toxicity and cells were found to be attached to the pore walls within the scaffolds; moreover, results illustrated that the developed composite scaffolds could be a potential candidate for tissue engineering.     

骨组织工程中的碳纤维材料

归纳了聚合物支架材料在提高其力学性能方面的一些研究工作,并综述了碳纤维材料在骨组织工程上应用的进展.分析表明,骨组织工程是修复骨缺损的有效方法之一,而碳纤维材料的结构性能优势使其成为提高组织工程支架性能的首选材料之一.在提高聚合物支架力学性能的同时,进一步提高材料的生物活性和促进骨的修复是目前研究的重点和难点.指出可通过对碳纤维材料的改性、有序排列等手段来进一步提高碳纤维材料的作用.