碳纤维-聚乳酸-聚乙二醇复合支架的制备及性能检测

背景：长期实验发现聚乳酸-聚乙二醇支架的力学性能及细胞相容性能较差,因此多数研究向支架中加入其他材料,以提高其生物活性及力学性能。 目的：制备改性碳纤维-聚乳酸-聚乙二醇支架,并检测其性能。 方法：采用溶液潘注/粒子沥滤法制备改性碳纤维-聚乳酸-聚乙二醇复合支架。对比改性碳纤维-聚乳酸-聚乙二醇复合支架与聚乳酸-聚乙二醇支架的超微结构、孔隙率、吸水性、降解率及力学性能。将改性碳纤维-聚乳酸-聚乙二醇复合支架与聚乳酸-聚乙二醇支架分别与SD大鼠成骨细胞共培养,12 h后采用沉淀法检测细胞黏附率;培养1,3,5,7,9 d后,采用 MTT 法检测细胞增殖。 结果与结论：聚乳酸-聚乙二醇支架材料表面孔结构分布均匀,孔径为(404.0±10.5) µm;改性碳纤维-聚乳酸-聚乙二醇支架碳纤维表面见大量纵向沟槽,表面孔结构分布均匀,孔径为(433.0±3.0) µm,两组支架孔径比较差异有显著性意义(P < 0.05)。改性碳纤维-聚乳酸-聚乙二醇支架的孔隙率、吸水性、弹性模量和抗压强度、降解率、细胞黏附率与增殖率均高于聚乳酸-聚乙二醇支架(P < 0.05)。表明改性碳纤维的加入改善了聚乳酸-聚乙二醇复合支架的力学性能及细胞相容性。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     

聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架修复喉软骨缺损

背景：喉软骨缺损传统的修复方法受到供体来源、排斥反应等限制,因而难以推广。 目的：观察聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架修复喉软骨缺损的效果。 方法：将20只Wistar 大鼠随机分为聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架组和聚乳酸-乙醇酸共聚物支架组,建立喉软骨缺损模型后分别采用聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架和聚乳酸-乙醇酸共聚物支架修复。 结果与结论：聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架组大鼠造模后3,5,7 d时喉骨缺损直径显著小于聚乳酸-乙醇酸共聚物支架组;聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架组大鼠喉软骨缺损部位基本修复,表面平整,且与周围其他组织之间没有明显界限;而聚乳酸-乙醇酸共聚物支架组大鼠喉软骨缺损部位存在凹陷,表面粗糙,和周围组织存在明显界限。说明聚乳酸-乙醇酸共聚物/羟基磷灰石复合支架能够促进喉软骨缺损部位修复,修复喉软骨缺损的效果更理想。  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     

不同比例聚乳酸羟基乙酸复合骨支架的低温沉积制造及性能

背景：研究证实,在聚乳酸羟基乙酸中加入磷酸三钙或珍珠粉可以使两者的性能互补,不仅为细胞提供良好的生长环境,而且能使细胞更快、更好地生长。 目的：通过低温层积制造技术制备以聚乳酸羟基乙酸为基体、复合珍珠粉或磷酸三钙的支架材料。 方法：采用低温层积制造技术制备聚乳酸羟基乙酸与珍珠粉或磷酸三钙质量比分别为10∶0、5∶2、7∶3和6∶4的聚乳酸羟基乙酸/珍珠粉或聚乳酸羟基乙酸/磷酸三钙复合支架,检测支架的微观结构、接触角、压缩弹性模量。将生长至基本融合的MC3T3-E1细胞以1×10⁴/cm³的密度接种至纯聚乳酸羟基乙酸无孔支架、纯聚乳酸羟基乙酸有孔支架、5∶2聚乳酸羟基乙酸/珍珠粉和5∶2聚乳酸羟基乙酸/磷酸三钙支架上,接种1,3 h,采用流式细胞仪检测细胞黏附率;接种1,4,7 d,利用Alamar Blue法检测细胞增殖。 结果与结论：纯聚乳酸羟基乙酸支架具有相互交联贯通的微孔结构,微孔大小3-15 μm;5∶2聚乳酸羟基乙酸/珍珠粉或5∶2聚乳酸羟基乙酸/磷酸三钙支架具有较好的连续微孔结构,孔径大小为10-25 μm。随着珍珠粉或磷酸三钙含量的增加,复合支架的亲水性增加。加入珍珠粉或磷酸三钙能够提高复合支架的压缩力学性能,但随着含量增加,支架力学性能呈现先增强后减弱。珍珠粉或磷酸三钙的加入,改善了聚乳酸羟基乙酸的细胞亲和力,改善了支架的生物相容性,其中以5∶2聚乳酸羟基乙酸/珍珠粉复合支架生物相容性最好。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;组织工程全文链接：     

仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原的制备及其细胞相容性

背景：目前骨组织工程常用的支架材料主要有无机材料、有机高分子材料及天然衍生材料等,上述材料各有优缺点,为了充分发挥各类材料的优势,弥补其不足,目前多采用联合材料制备复合支架。 目的：制备新型仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原,并观察其对骨髓间充质干细胞增殖、黏附及分化的影响。 方法：制备壳聚糖/纳米羟基磷灰石/胶原复合支架材料,扫描电镜观察支架材料表面微观形貌;采用真空吸附法将骨形态发生蛋白7多肽与支架材料复合,高效液相色谱仪检测骨形态发生蛋白7多肽在体外的释放规律;将骨髓间充质干细胞接种到复合骨形态发生蛋白7多肽的仿生支架材料上,以未复合多肽的支架材料作为对照,检测支架材料表面细胞增殖、黏附率、生长形态及碱性磷酸酶活性。 结果与结论：壳聚糖/纳米羟基磷灰石/胶原支架材料呈多孔状,孔径10~100 µm;骨形态发生蛋白7多肽可以从支架材料中缓慢释出;在复合多肽的仿生支架材料表面,骨髓间充质干细胞的黏附及向成骨细胞方向分化能力均明显强于对照组(P < 0.05),而增殖能力与对照组差异无显著性意义(P > 0.05)。说明新型仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原是一种理想的骨组织工程支架材料,具有良好的细胞相容性。     

聚乳酸/壳聚糖纳米纤维/纳米羟基磷灰石支架与兔软骨细胞的相容性

背景：传统的支架材料存在疏水性强,材料表面缺乏细胞表面受体特异结合的生物活性分子,材料的酸性降解产物易引发无菌性炎性反应等不足。根据仿生原理及软骨真实结构和构成来选择和制备组织工程软骨支架能够获得理想效果。 目的：制备聚乳酸/壳聚糖纳米纤维/纳米羟基磷灰石支架,评价其与兔膝关节软骨细胞的生物相容性,探讨其应用于关节软骨组织工程的可行性。 方法：采用二次相分离技术制备聚乳酸/壳聚糖纳米纤维/纳米羟基磷灰石复合支架,将第3代新西兰兔软骨细胞接种至复合支架材料上复合培养,倒置相差显微镜下观察细胞生长情况。细胞-支架复合物在24孔板中培养5 d以后,将其植入裸鼠皮下8周。 结果与结论：聚乳酸/壳聚糖纳米纤维/纳米羟基磷灰石支架材料经化学合成后,具有合适的三维多孔结构,孔隙率为90%,孔径300~450 μm;植入裸鼠皮下8周后Ⅱ型胶原免疫组织化学染色和甲苯胺蓝染色显示细胞-支架复合物中的软骨细胞可以像天然软骨一样分泌黏多糖和Ⅱ型胶原。提示生物材料聚乳酸/壳聚糖纳米纤维/纳米羟基磷灰石对于兔软骨细胞有良好的生物相容性,可作为生物组织工程支架。     

羟基丁酸-羟基辛酸聚合物/胶原软骨组织工程支架的细胞亲和性

背景：已有很多实验证明,单独高分子材料或生物性材料制备的组织工程支架无法满足组织工程研究。 目的：评价羟基丁酸-羟基辛酸聚合物/胶原组织工程支架的生物学特性及细胞亲和性。 方法：以羟基丁酸-羟基辛酸聚合物作为主体材料,按质量分数复合不同比例(2%,4%,6%,8%,10%)的胶原,采用溶剂浇铸-颗粒沥滤法制备组织工程支架。通过扫描电镜观察材料内部结构及孔径大小,液体位移法测定材料孔隙率。将羟基丁酸-羟基辛酸聚合物/胶原支架、羟基丁酸-羟基辛酸聚合物支架分别与兔软骨细胞复合培养,MTT法测定细胞的生长曲线,扫描电镜观察细胞在材料上的生长黏附情况。 结果与结论：羟基丁酸-羟基辛酸聚合物/胶原复合软骨组织工程支架孔径大小200 μm左右,孔隙率为(85±2)%,细胞亲水性随加入胶原比例的增加而升高。与羟基丁酸-羟基辛酸聚合物支架比较,不同比例的羟基丁酸-羟基辛酸聚合物/胶原支架可明显促进软骨细胞的黏附、增殖。证实羟基丁酸-羟基辛酸聚合物/胶原复合支架具备更好的细胞亲和性。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;组织工程全文链接：     

大鼠成骨细胞与壳聚糖/羟基磷灰石复合支架降解产物的生物相容性

背景：人们对壳聚糖/羟基磷灰石复合多孔生物支架在体内的降解过程并非十分清楚,而且有关其降解产物对成骨细胞的影响研究也较少。 目的：分析大鼠成骨细胞与壳聚糖/羟基磷灰石复合多孔生物支架降解产物的生物相容性。 方法：将培养的第2代大鼠成骨细胞分别在壳聚糖/羟基磷灰石复合支架降解产物浸提液和含体积分数10%胎牛血清的DMEM培养液中培养,培养第2,4,6,8,10天分别对两组细胞做MTT细胞计数,采用联合会推荐法测定细胞碱性磷酸酶活性,采用BCA蛋白定量法测定总蛋白。 结果与结论：在壳聚糖/羟基磷灰石复合多孔生物支架降解产物浸提液中培养的大鼠成骨细胞增殖速度、细胞碱性磷酸酶活性、细胞总蛋白合成及碱性磷酸酶与总蛋白的比值明显高于在体积分数为10%胎牛血清DMEM培养液中培养的细胞(P < 0.05)。表明壳聚糖/羟基磷灰石复合多孔生物支架的降解产物不仅可促进大鼠成骨细胞的黏附、生长和增殖,还可增强其骨化功能,具有较好的生物相容性。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;组织工程全文链接：     

静电纺丝聚乳酸复合物纳米纤维材料与小鼠神经干细胞的生物相容性

背景:聚乳酸聚乙醇酸支架材料广泛应用于组织工程学领域,但其细胞黏附性较差、缺乏活性功能基团以及疏水性较强等缺点限制了其进一步的发展和应用。目的:观察小鼠神经干细胞与静电纺丝聚乳酸聚乙醇酸/聚乙二醇共聚物纳米纤维支架材料的体外相容性。方法:自孕15 d CD-1小鼠胚胎大脑皮质分离培养小鼠神经干细胞。静电纺丝法制备聚乳酸聚乙醇酸和聚乳酸聚乙醇酸/聚乙二醇纳米纤维支架材料,扫描电镜观察材料结构;取第5代神经干细胞分别接种于聚乳酸聚乙醇酸和静电纺丝聚乳酸聚乙醇酸/聚乙二醇纳米纤维支架材料上,进行体外培养。结果与结论:扫描电镜检测显示,两种支架材料呈现相互交联的多孔网状结构。聚乳酸聚乙醇酸组和静电纺丝聚乳酸聚乙醇酸/聚乙二醇组纤维直径和孔隙率差异无显著性意义(P0.05)。CCK-8检测显示,两种材料无明显细胞毒性。神经干细胞在支架材料中生长良好,两组吸光度值均随培养时间延长而增大,两组在培养1,3,5,7,9,11 d吸光度值差异均有显著性意义(P0.05)。两组材料培养3,6,9 h,静电纺丝聚乳酸聚乙醇酸/聚乙二醇组的细胞黏附率明显高于聚乳酸聚乙醇酸组(P0.05)。Hoechst染色显示两组细胞核质均染,形态正常,静电纺丝聚乳酸聚乙醇酸/聚乙二醇组细胞数量明显多于聚乳酸聚乙醇酸组(P0.05)。扫描电镜观察显示,与聚乳酸聚乙醇酸组相比,静电纺丝聚乳酸聚乙醇酸/聚乙二醇组神经干细胞在支架上的生长情况和基质分泌更好。结果说明,静电纺丝法制备的静电纺丝聚乳酸聚乙醇酸/聚乙二醇纳米纤维支架细胞生物相容性良好,安全无毒,具备合适的孔径和孔隙率,适宜神经干细胞生长,是一种适用于组织工程优质的支架载体。     

改性纳米羟基磷灰石/聚乳酸-聚羟乙酸复合骨髓基质干细胞修复兔桡骨缺损*

背景：前期试验证实骨髓基质干细胞能够在改性纳米羟基磷灰石/聚乳酸-聚羟乙酸材料表面黏附、增殖,该材料具有良好的生物安全性。 目的：观察骨髓基质干细胞与改性纳米羟基磷灰石/聚乳酸-聚羟乙酸材料复合修复兔桡骨缺损的效果。 方法：建立兔15 mm桡骨缺损模型,随机分为3组：空白对照组不进行任何处理,实验组植入改性纳米羟基磷灰石/聚乳酸-聚羟乙酸+骨髓基质干细胞组织工程化骨,对照组植入单纯改性纳米羟基磷灰石/聚乳酸-聚羟乙酸支架材料。 结果与结论：①X射线评价：术后1~12周,实验组骨缺损修复程度及速度明显优于空白对照组与对照组(P < 0.05)。②组织学检测：实验组术后4周即可观察到新生骨和纤维组织长入材料空隙,局部形成陷窝结构;8周时新生骨组织增多,部分可观察到成熟的骨小梁结构;12周时可见大量成熟骨细胞,骨小梁排列紧密,移植材料逐步被新生骨取代,与正常骨组织形态基本一致,且骨小梁出现时间早于空白对照组与对照组。说明骨髓基质干细胞复合改性纳米羟基磷灰石/聚乳酸-聚羟乙酸构建的组织工程化骨能够促进骨缺损处新骨的生成,较单纯支架材料具有明显优势。     

电纺丝技术制备生物活性复合纤维支架及其体外降解性

背景：聚乳酸/羟基磷灰石类复合材料支架常用的制备方法主要有冷压法、粒子沥滤法、热致相分离法等,但是在增强材料界面的结合、调节材料的降解速率、改善材料的强度等方面仍不能满足要求。 目的：制备左旋聚乳酸/羟基磷灰石复合纳米纤维支架。 方法：采用静电纺丝法制备聚乳酸/羟基磷灰石复合纳米纤维支架。以扫面电镜对纤维的结构形态进行分析,并观察其在PBS中浸泡不同时间的体外降解过程。 结果与结论：羟基磷灰石纳米粒子与聚乳酸/基体间存在化学键合,纳米粒子使纤维直径增大且表面粗糙程度增加,这种结构将有利于细胞在纤维膜上的伸展和和繁殖。羟基磷灰石的引入,抑制了聚乳酸降解过程中的自催化作用,减缓了聚乳酸的降解速度。说明电纺丝技术制备的聚乳酸/羟基磷灰石复合支架在组织工程支架材料方面具有潜在的应用前景。     

聚乳酸-羟基乙酸共聚物/硅酸钙三维多孔骨组织工程支架的构建与性能

BACKGROUND: Some disadvantages exsist in commonly used poly(lactic-co-glycolic acid) (PLGA) scaffolds, including acidic degradation products, suboptimal mechanical properties, low pore size, poor porosity and pore connectivity rate and uncontrollable shape. OBJECTIVE: To construct a scaffold with three-dimensional (3D) pores by adding calcium silicate to improve the properties of PLGA, and then detect its degradability, mechanical properties and biocompatibility. METHODS: PLGA/calcium silicate porous composite microspheres were prepared by the emulsion-solvent evaporation method, and PLGA 3D porous scaffold was established by 3D-Bioplotter, and then PLGA/calcium silicate composite porous scaffolds were constructed by combining the microspheres with the scaffold using low temperature fusion technology. The compositions, morphology and degradability of the PLGA/calcium silicate porous composite microspheres and PLGA microspheres, as well as the morphology, pore properties and compression strength of the PLGA 3D scaffolds and PLGA/calcium silicate composite porous scaffolds were measured, respectively. Mouse bone marrow mesenchymal stem cells were respectively cultivated in the extracts of PLGA/calcium silicate porous composite microspheres and PLGA microspheres, and then were respectively seeded onto the PLGA 3D scaffolds and PLGA/calcium silicate composite porous scaffolds. Thereafter, the cell proliferation activity was detected at 1, 3 and 5 days. RESULTS AND CONCLUSION: Regular pores on the PLGA microspheres and internal cavities were formed, and the PH values of the degradation products were improved after adding calcium silicate. The fiber diameter, pore, porosity and average pore size of the composite porous scaffolds were all smaller than those of the PLGA scaffolds. The compression strength and elasticity modulus of the composite porous scaffolds were both higher than those of the PLGA scaffolds (P < 0.05). Bone marrow mesenchymal stem cells grew well in above microsphere extracts and scaffolds. These results indicate that PLGA/calcium silicate composite porous scaffolds exhibit good degradability in vitro, mechanical properties and biocompatibility.     

快速成型方法制备组织工程支架的研究与应用

背景：快速成型是基于材料堆积法,结合计算机、数控、激光和材料技术于一体的高新制造技术。 目的：综述快速成型技术在组织工程支架制备中的应用。 方法：由第一作者检索万方数据库、中国知网数据库和Elsevier Science Direct Online有关支架材料的生物力学性能、支架材料发展前景及快速成型技术在支架材料制备领域中应用研究等方面的文献。 结果与结论：快速成型技术应用于组织工程支架的制备已经越来越成熟,快速成型技术不但克服了传统制造方法中存在的支架复杂外形制造困难和内部微结构无法控制的缺陷,而且还可以通过有限元分析预先对支架的结构进行优化,以实现改善支架机械强度等某些特殊的要求。但是,由于组织器官的特殊性和排外性及细胞的黏附条件,不但要从结构上改善支架,而且需要快速成型技术与具有组织相容性及可降解的材料相结合,使支架植入生物体后,细胞能更好地增殖和分化,促进组织再生,修复缺损组织。     

Reinforced nanohydroxyapatite/polyamide66 scaffolds by chitosan coating for bone tissue engineering

High porosity of scaffold is always accompanied by poor mechanical property; the aim of this study was to enhance the strength and modulus of the highly porous scaffold of nanohydroxyapatite/polyamide66 (n-HA/PA66) by coating chitosan (CS) and to investigate the effect of CS content on the scaffold physical properties and cytological properties. The results show that CS coating can reinforce the scaffold effectively. The compress modulus and strength of the CS coated n-HA/PA66 scaffolds are improved to 32.71 and 2.38 MPa, respectively, being about six times and five times of those of the uncoated scaffolds. Meanwhile, the scaffolds still exhibit a highly interconnected porous structure and the porosity is approximate about 78%, slightly lower than the value (84%) of uncoated scaffold. The cytological properties of scaffolds were also studied in vitro by cocultured with osteoblast-like MG63 cells. The cytological experiments demonstrate that the reinforced scaffolds display favorable cytocompatibility and have no significant difference with the uncoated n-HA/PA66 scaffolds. The CS reinforced n-HA/PA66 scaffolds can meet the basic mechanical requirement of bone tissue engineering scaffold, presenting a potential for biomedical application in bone reconstruction and repair.     

Preparation and properties of poly(lactide-co-glycolide) (PLGA)/ nano-hydroxyapatite (NHA) scaffolds by thermally induced phase separation and rabbit MSCs culture on scaffolds

Biodegradable polymer/bioceramic composites scaffold can overcome the limitation of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. To better mimic the mineral component and the microstructure of natural bone, novel nano-hydroxyapatite (NHA)/polymer composite scaffolds with high porosity and well-controlled pore architectures as well as high exposure of the bioactive ceramics to the scaffold surface is developed for efficient bone tissue engineering. In this article, regular and highly interconnected porous poly(lactide-co-glycolide) (PLGA)/NHA scaffolds are fabricated by thermally induced phase separation technique. The effects of solvent composition, polymer concentration, coarsening temperature, and coarsening time as well as NHA content on the micro-morphology, mechanical properties of the PLGA/NHA scaffolds are investigated. The results show that pore size of the PLGA/NHA scaffolds decrease with the increase of PLGA concentration and NHA content. The introduction of NHA greatly increase the mechanical properties and water absorption ability which greatly increase with the increase of NHA content. Mesenchymal stem cells are seeded and cultured in three-dimensional (3D) PLGA/NHA scaffolds to fabricate in vitro tissue engineering bone, which is investigated by adhesion rate, cell morphology, cell numbers, and alkaline phosphatase assay. The results display that the PLGA/NHA scaffolds exhibit significantly higher cell growth, alkaline phosphatase activity than PLGA scaffolds, especially the PLGA/NHA scaffolds with 10 wt.% NHA. The results suggest that the newly developed PLGA/NHA composite scaffolds may serve as an excellent 3D substrate for cell attachment and migration in bone tissue engineering.     

新鲜骨髓吸出物直接种植于支架构建组织工程韧带

背景：有关于应用新鲜骨髓吸出物直接局部注射修复韧带部分损伤的报道,少有提及应用新鲜骨髓吸出物直接种植于支架构建组织工程韧带的研究报道。 目的：评价将新鲜骨髓吸出物直接种植于支架构建组织工程韧带的可行性。 方法：构建丝素纤维/小肠黏膜下层复合支架后,骨髓种植组将骨髓吸出物直接种植于复合支架上;细胞种植组将骨髓间充质干细胞种植于复合支架上;以未接种任何物质的复合支架作为空白对照,检测各组细胞黏附密度、细胞增殖活性及细胞外基质分泌情况。将骨髓种植组复合物植入兔前交叉韧带横断处,12周后取材评价骨髓种植组材料体内生物相容性。 结果与结论：骨髓种植组孵育4 h后的细胞黏附密度、不同时间点细胞增殖率显著高于细胞种植组(P < 0.05)。骨髓种植组及细胞种植组Ⅰ型、Ⅲ型胶原分泌量均显著高于空白对照组(P < 0.05),但骨髓种植组及细胞种植组两组间Ⅰ型、Ⅲ型胶原分泌量差异无显著性意义。骨髓种植组材料植入兔体内未引起致死性免疫排斥反应及严重炎症反应,未见明显韧带再生及血管化。说明新鲜骨髓吸出物直接种植于支架可构建组织工程韧带,并且体内短期生物相容性良好。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;组织工程全文链接：     

Fabrication and characterization of hydrophilic poly(lactic-co-glycolic acid)/poly(vinyl alcohol) blend cell scaffolds by melt-molding particulate-leaching method

Porous PLGA/PVA scaffolds were fabricated by blending poly(lactic-co-glycolic acid) (PLGA) with polyvinyl alcohol (PVA) to improve the hydrophilicity and cell compatibility of the scaffolds for tissue engineering applications. PLGA/PVA blend scaffolds with different PVA compositions up to 20wt% were fabricated by a melt-molding particulate-leaching method (non-solvent method). The prepared scaffolds were investigated by scanning electron microscopy (SEM), mercury intrusion porosimetry, the measurements of water contact angles and bi-axial tensile strengths, etc. for their surface and bulk characterizations. The scaffolds exhibited highly porous and open-cellular pore structures with almost same surface and interior porosities (pore size, 200-300 microm; porosity, about 90%). The PLGA/PVA blend scaffolds with PVA compositions more than 5% were easily wetted in cell culture medium without any prewetting treatments, which is highly desirable for tissue engineering applications. In vitro cell compatibility of the control hydrophobic PLGA and hydrophilized PLGA/PVA (5wt%) blend scaffolds was compared by the culture of human chondrocytes in the scaffolds and the following analyses by MTT assay and SEM observation. It was observed that the PLGA/PVA blend scaffold had better cell adhesion and growth than the control PLGA scaffold. For in vivo evaluation of tissue compatibility, the scaffolds were implanted into the skull defects of rabbits. The results were evaluated by histology examinations. The PLGA/PVA (5wt%) blend scaffold showed better bone ingrowth into the scaffold and new bone formation inside the scaffold than the PLGA scaffold. It seems that 5% addition of PVA to PLGA to fabricate PLGA/PVA blend scaffolds is enough for improving the hydrophilicity and cell compatibility of the scaffolds.     

骨髓间充质干细胞在淫羊藿苷/羟基磷灰石/聚乳酸-羟基乙酸共聚物支架上的成骨

文题释义：纳米结构：是尺寸介于分子和微米尺度间的物体结构。当纳米羟基磷灰石与高分子材料物理混合后,羟基磷灰石会发生自聚,从而在材料表面产生纳米结构。这种纳米结构有利于细胞(如骨髓充间质干细胞)的黏附,是骨修复材料表面细胞增殖和后期成骨分化的基础。成骨分化：当干细胞接受诱导时可以向成骨细胞转变。淫羊藿苷高分子复合支架与间充质干细胞共培养一段时间后,其骨分化标志物碱性磷酸酶和骨钙素的活性增高,同时成骨相关基因和蛋白(Runx-2、COLⅠ)表达水平上升,即细胞在淫羊藿苷诱导下发生了成骨分化。  摘要背景：近年来,骨组织工程技术为临床治疗骨缺损提供了全新的思路和模式。该研究首次将传统中药与组织工程支架的纳米结构结合,以期探索并构建一种可用于骨缺损治疗的新型骨组织替代材料。目的：研究淫羊藿苷(icariin,ICA)/羟基磷灰石(hydroxyapatite,HA)/聚乳酸-羟基乙酸共聚物(poly(lactic-co-glycolic acid),PLGA)复合支架的成骨活性。方法：将HA与PLGA通过物理共混的方式制成HA/PLGA复合支架,然后将其浸泡于不同浓度的ICA溶液中,从而得到ICA/HA/PLGA支架。利用兔骨髓间充质干细胞分别对复合支架的细胞黏附、增殖、成骨作用和细胞毒性进行评价。细胞黏附、细胞增殖和细胞毒性采用MTT法进行检测,碱性磷酸酶活性和骨钙素活性采用ELISA法进行检测,成骨相关基因和蛋白表达水平分别用荧光定量PCR和Western blot法进行检测。结果与结论：①PLGA中加入适量HA可以提高支架的力学强度,且在HA含量为10%时效果最佳,拉伸强度为(1.67±0.37) MPa;压缩模量为(4.17±1.62) MPa,且会在支架表面形成纳米结构;该微结构可以促进骨髓间充质干细胞在支架表面的黏附;②ICA不会影响骨髓间充质干细胞在复合支架上的增殖,且1.00 µmol/L ICA水溶液浸泡后的ICA/HA/PLGA复合支架具有最优的成骨分化功能,其碱性磷酸酶活性、骨钙素活性、成骨相关基因和蛋白(Runx-2和COLⅠ)的表达水平均最高;③ICA/HA/PLGA复合支架无细胞毒性;④结果表明,HA(10%)/ICA(1.00 µmol/L)/PLGA支架具有良好的机械性能、成骨作用和生物相容性,是一种具有良好应用潜力的骨组织工程支架。ORCID: 0000-0002-9770-9109(王德欣) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Preparation,characterization and in vitro analysis of novel structured nanofibrous scaffolds for bone tissue engineering

In a previous study, a three-dimensional nanofibrous spiral scaffold for bone tissue engineering was developed, which showed enhanced human osteoblast cell attachment, proliferation and differentiation compared with traditional cylinder scaffolds, owing to the incorporation of spiral structures and nanofiber. However, the application of these scaffolds to bone tissue engineering was limited by their weak mechanical strength. This limitation triggered the design for novel structured scaffolds with reinforced physical characteristics. In this study, spiral polycaprolactone (PCL) nanofibrous scaffolds were inserted into poly(lactide-co-glycolide) (PLGA) microsphere sintered tubular scaffolds to form integrated scaffolds to provide mechanical properties and bioactivity appropriate for bone tissue engineering. Four experiment groups were designed: PLGA cylinder scaffold; PLGA tubular scaffold; PLGA tubular scaffold with PCL spiral structured inner core; PLGA tubular scaffold with PCL nanofiber containing spiral structured inner core. The morphology, porosity and mechanical properties of the scaffolds were characterized. Furthermore, human osteoblastic cells were seeded on these scaffolds, and the cell attachment, proliferation, differentiation and mineralized matrix deposition on the scaffolds were evaluated. The integrated scaffolds had Young’s modulus 250–300 MPa, and compressive strength 8–11 MPa under uniaxial compression. With the addition of an inner highly porous insert to the tubular shell, human osteoblast cells seeded on the integrated scaffolds showed slightly higher cell proliferation, 20–25% more alkaline phosphatase expression and twofold higher calcium deposition than those on the cylinder and tubular scaffolds. Furthermore, compared with sintered PLGA cylinder scaffolds, the integrated scaffolds allowed better cellular infiltration Therefore, this design demonstrates great potential for integrated scaffolds in bone tissue engineering applications.     

Repair of mandibular defects using MSCs-seeded biodegradable polyester porous scaffolds

PLLA, PLA-PEG and PLGA porous scaffolds with pore size ranging from 100 to 250 microm and porosity over 85% were fabricated by a solution-casting/salt-leaching method. The porous structure and porosity of the scaffold were mainly dependent on volume fraction and size of the porogens of NaCl particles. The effects of the polymeric materials on the cell culture behavior and bone formation in vitro in their scaffolds were studied. In vitro cell culture in the scaffolds of the three polymers demonstrated that mesenchymal stem cells (MSCs) had a good adhesion and spread. The composite matrixes cultured for several days possessed preliminary functions of tissue-engineering bone, with signs of the calcium knur formation and the expression of osteocalcin and collagen I in mRNA, especially that of PLA-PEG and PLGA. These cell-loaded porous scaffolds showed effective repair of mandibular defect of rabbits in vivo. Contrastive experiments demonstrated that the MSCs/PLGA scaffold owned better ability facilitating for the MSCs proliferation, differentiation and defect repair. These composite scaffolds can be a potential effective tool for treating mandibular and other bone defects.