纳米羟基磷灰石/聚己内酯复合大鼠骨髓间充质干细胞的生物相容性

背景：纳米羟基磷灰石/聚己内酯是一种具有优良生物相容性和生物活性的典型生物复合材料。 目的：分析纳米羟基磷灰石/聚己内酯电纺薄膜作为组织工程骨支架的可行性。 方法：采用静电纺丝技术制备纳米羟基磷灰石/聚己内酯电纺薄膜,将其与第3代SD大鼠骨髓间充质干细胞复合培养,在地塞米松、β-磷酸甘油钠、维生素C成骨诱导剂诱导下,诱导骨髓间充质干细胞向成骨细胞转化。 结果与结论：纳米羟基磷灰石/聚己内酯支架具有合适的微孔结构,且孔道相互贯通。①倒置显微镜观察：复合培养 7 d后细胞大部分为梭形,细胞开始分裂;14 d后,细胞生长比较旺盛,数量明显增多,细胞分泌基质并黏附于支架上。②扫描电镜观察：复合培养7 d后大量细胞位于支架孔隙内生长,增殖良好,细胞大多呈梭形,双极突起,形态较佳,呈立体状生长,并分泌基质,有纤维连接蛋白生成。表明纳米羟基磷灰石/聚己内酯支架具有良好的生物相容性,是骨组织工程的良好载体。     

纳米羟基磷灰石/壳聚糖/半水硫酸钙为可注射骨组织工程支架材料的可行性

背景：前期实验采用仿生学原理制备了可注射性纳米羟基磷灰石/壳聚糖/半水硫酸钙复合材料,但其与骨髓间充质干细胞的生物相容性还不十分清楚。目的：探讨纳米羟基磷灰石/壳聚糖/半水硫酸钙作为注射型骨组织工程支架材料的可行性。方法：将第3代兔骨髓间充质干细胞与可注射纳米羟基磷灰石/壳聚糖/半水硫酸钙支架复合培养,作为实验组;以单纯接种培养的骨髓间充质干细胞为对照组,倒置显微镜下观察细胞生长情况,MTT法检测细胞增殖,扫描电镜观察细胞在材料表面生长与增殖。将纳米羟基磷灰石/壳聚糖/半水硫酸钙支架埋植在家兔背部肌袋内,埋植后2,4,6,8周进行病理学观察。结果与结论：实验组细胞生长、增殖良好,与对照组无明显差异。支架埋植后2周,材料周围有中等量中性粒细胞、淋巴细胞和巨细胞浸润,可见小血管与纤维母细胞增生,材料已被炎性细胞分割、围绕散碎;埋植后4周,可见少量淋巴细胞、纤维母细胞聚集,炎症反应进一步消退,肌纤维排列、形态正常;埋植后6周,材料周围炎症反应轻微,组织水肿不明显;埋植后8周,炎症反应基本消退,材料基本降解完成,肌纤维形态基本正常。表明纳米羟基磷灰石/壳聚糖/半水硫酸钙复合物具有良好的细胞相容性和生物降解性,可作为注射型支架材料。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：     

豚鼠骨髓间充质干细胞与纳米羟基磷灰石体外构建组织工程人工听骨

背景：人工合成的纳米羟基磷灰石具有良好的生物活性和相容性,植入体内后能在短时间内与体内的软硬组织形成紧密结合,因此成为广泛应用的骨组织工程材料。 目的：观察豚鼠骨髓间充质干细胞与纳米羟基磷灰石复合多孔陶瓷材料体外复合培养的结合程度,并分析其构建组织工程人工听骨的可行性。 方法：采用细胞差速贴壁法分离培养豚鼠骨髓间充质干细胞,使用流式细胞仪检测CD29、CD45、CD44进行间充质干细胞表面标记物鉴定,并检测其骨细胞分化能力。将骨髓间充质干细胞与纳米羟基磷灰石复合多孔陶瓷共培养1,3,5,7,10 d,电镜观察骨髓间充质干细胞与此种支架材料的复合情况。 结果与结论：培养3 d后,可见大量骨髓间充质干细胞贴附在材料表层,并且形态稳定,生长旺盛,增殖力强,具有极佳的延伸性;培养5 d后可见材料表面已全部覆盖骨髓间充质干细胞,细胞结合紧密,细胞表面可见大量分泌颗粒,胞体明显增大,边缘完整,呈纤维样伸长;7 d后细胞逐渐从材料表面脱落,仍附在材料表面的细胞出现“星形”改变,“伪足”增多;10 d后细胞呈片状脱落。说明纳米羟基磷灰石材料保持了它良好的生物相容性,利于细胞黏附、增殖,可结合大量的骨髓间充质干细胞,用于构建组织工程人工听骨。     

骨修复用纳米羟基磷灰石/聚酰胺66的体内外生物相容性(英文)

背景:采用基于纳米羟基磷灰石溶胶新方法制备纳米羟基磷灰石/聚酰胺66复合材料,该材料提高了纳米羟基磷灰石在聚酰胺66基体中的均匀分布和二者的有效键合,进而有利于改善材料的生物性能,有望成为新型骨修复材料。目的:评价纳米羟基磷灰石/聚酰胺66复合材料体内外生物相容性。方法:①将原代培养的成骨细胞与纳米羟基磷灰石/聚酰胺66及聚酰胺66材料复合培养,使用倒置相差显微镜和场发射扫描电子显微镜观察材料周围及表面的细胞形态。②将纳米羟基磷灰石/聚酰胺66复合材料植入兔右侧胫骨,将聚酰胺66作为对照组材料植入兔左侧胫骨。在术后2,8周,取材料周围骨组织进行病理组织切片观察。结果与结论:①纳米羟基磷灰石/聚酰胺66和聚酰胺66未表现出明显的细胞毒性,纳米羟基磷灰石/聚酰胺66材料周围细胞形态好于聚酰胺66,且纳米羟基磷灰石/聚酰胺66表面细胞数量多于聚酰胺66,在复合培养的第3天差异尤其显著(P0.01)。②在植入早期,与纳米羟基磷灰石/聚酰胺66相接的骨组织成骨细胞活跃且该组材料周围的骨形成过程较对照组更快。结果说明纳米羟基磷灰石/聚酰胺66复合材料较聚酰胺66有更好的生物相容性。     

纳米羟基磷灰石聚酰胺复合材料在人工肱骨头柄界面的结合能力

背景：纳米羟基磷灰石/聚酰胺66是一种新型的纳米仿生复合材料,具有良好的组织相容性以及骨传导性,但其植入体内后和骨界面的接合生长如何、临床应用是否安全等尚需要进一步研究。目的：观察纳米羟基磷灰石/聚酰胺复合材料在人工肱骨头柄界面的结合能力。方法：将兔随机分为2组,均进行肩关节肱骨头转换,复合材料组植入纳米羟基磷灰石/聚酰胺人工肱骨头;对照组植入自体髂骨。置换后对兔进行骨髓间充质干细胞原代培养,再将骨髓间充质干细胞与纳米羟基磷灰石/聚酰胺复合材料共培养进行观察。结果与结论：细胞培养24 h后,骨髓间充质干细胞在复合材料局部生长情况较好。复合材料组培养1,4 h的细胞黏附率显著高于对照组(P < 0.05)。复合材料组共培养4.5,5.5,6.5 h细胞吸光度值百分率值显著高于对照组(P < 0.05);置换24周后复合材料组表面骨组织、纤维层的比例变化幅度及覆盖率最高(P < 0.05)。结果证实,纳米羟基磷灰石/聚酰胺复合材料植入体柄具有一定的界面骨结合能力,可使界面骨整合良好。     

纳米羟基磷灰石/聚酰胺材料的体内成骨能力

背景：作为骨修复重建材料,纳米羟基磷灰石具有良好生物相容性及骨传导性,但临床上中单一使用纳米羟基磷灰石尚存在许多不足。目的：观察纳米羟基磷灰石/聚酰胺材料的体内成骨能力。方法：取24只新西兰大白兔,进行纳米羟基磷灰石/聚酰胺人工肱骨头置换,分别于置换后3,6,12,24周,进行X射线观察、组织学观察。结果与结论：①X射线观察：不同时间点材料上端皮质均未出现骨皮质变薄、异位骨化等发生,纳米羟基磷灰石/聚酰胺材料无碎裂迹象,材料四周皮质均可见模糊界面,密度随着时间的增加而增加。②组织学观察：置换后3周,可见大量细胞,包括间充质细胞、单核巨噬细胞等;置换后6周,仍可见界膜内的大量纤维组织、成纤维细胞、单核巨噬细胞,而软骨细胞和成骨细胞分布较少;置换后12周,大范围原始骨小梁开始形成且多呈扁平状,排列整齐有序;置换后24周,组织界膜被骨细胞充斥,骨小梁表面的细胞较规则,骨组织原始细胞开始转变为板层状骨。说明纳米羟基磷灰石/聚酰胺材料具有良好的成骨能力。 ;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     

丝素蛋白/羟基磷灰石支架对成骨诱导脂肪干细胞活性及成骨性能的影响

背景：成骨诱导后的脂肪干细胞与可降解丝素蛋白/羟基磷灰石支架复合,可望研制出一种具有良好生物相容性及成骨性能的新型骨融合材料。 目的：探讨丝素蛋白/羟基磷灰石支架对成骨诱导脂肪干细胞增殖活性及成骨性能的影响。 方法：获取大鼠脂肪干细胞后体外贴壁培养、扩增,将第3代细胞用条件培养液进行成骨方向的定向诱导培养、扩增,然后接种到预湿的丝素蛋白/羟基磷灰石材料上作为实验组,以相同条件下置入盖玻片和脂肪干细胞培养作为对照组。倒置相差显微镜观察细胞在材料中的生长情况,MTT法检测材料对细胞增殖活性的影响,碱性磷酸酶活性测定评价其成骨能力。 结果与结论：成骨诱导后的脂肪干细胞在丝素蛋白/羟基磷灰石材料上能够良好地黏附和增殖。实验组和对照组细胞增殖活性及碱性磷酸酶活性比较,差异无显著性意义(P > 0.05),证实脂肪干细胞活性及成骨性能不受材料影响,说明丝素蛋白/羟基磷灰石复合材料具有良好的细胞相容性。 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     

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。     

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     

聚左旋乳酸多孔支架材料复合人脐带间充质干细胞的异位成骨

背景：聚左旋乳酸材料有良好的支撑作用,具有三维模板作用,为细胞黏附、增殖和分化提供场所。 目的：以人脐带间充质干细胞作为种子细胞、多孔聚左旋乳酸作为支架材料构建组织工程化骨异位成骨的可行性及效果。 方法：制备聚左旋乳酸多孔支架材料。用酶消化法分离培养人脐带间充质干细胞,传代培养、鉴定及诱导成骨,ALP染色检测骨向分化。将人脐带间充质干细胞与聚左旋乳酸材料复合培养,MTT及扫描电镜检测细胞增殖和细胞材料复合情况,应用矿化诱导7 d的细胞材料复合物植入兔大腿肌袋模型观察组织工程骨的异位成骨能力。4周后应用组织学观察新骨的形成情况。 结果与结论：与聚左旋乳酸多孔支架材料复合的人脐带间充质干细胞生长良好,细胞增殖未受影响,扫描电镜示细胞在支架材料上吸附、生长良好。体外对人脐带间充质干细胞骨向诱导后ALP染色阳性。矿化诱导的人脐带间充质干细胞复合聚左旋乳酸材料植入动物4周时,形成明显的块状组织,质地坚硬。组织学检查见新形成的组织有成骨细胞及其周围有血管长入。提示聚左旋乳酸多孔材料对种子细胞人脐带间充质干细胞的增殖无影响;人脐带间充质干细胞细胞与聚左旋乳酸多孔材料复合体可在异位形成骨组织。     

In Vitro and In Vivo Evaluation of a nHA/PA66 Composite Membrane for Guided Bone Regeneration

A nano-hydroxyapatite/polyamide 66 (nHA/PA66) composite with good bioactivity and osteoconductivity is employed to develop a novel porous membrane with an asymmetric structure. In order to investigate the biocompatibility and the effect on guided bone regeneration (GBR) of nHA/PA66 porous membrane, the proliferation, viability, morphology and alkaline phosphatase activity (ALP) of the osteoblast-like cell line (MG63) cultured on the membrane were studied in vitro. In vivo biocompatibility and osteogenesis of the fabricated membrane were assessed by comparing guiding rats calvarial bone defects regeneration with "gold standard" GBR material, expanded polytetrafluoroethylene (e-PTFE) membrane. In vitro experiments showed that the nHA/PA66 composite membrane had good cell affinity and cytocompatibility, in favor of cell proliferation. The in vivo study showed that the nHA/PA66 asymmetric porous membrane had a good GBR effect. All the results indicate that the asymmetric porous nHA/PA66 composite GBR membrane with good biocompatibility, high bioactivity and osteoconductivity exhibits good GBR effect and has a potential to be applied in GBR fields, especially in dental tissue regeneration.     

Preparation and characterization of nano-hydroxyapatite/silk fibroin porous scaffolds

Novel tissue engineering scaffold materials of nano-hydroxyapatite (nHA)/silk fibroin (SF) biocomposite were prepared by freeze-drying. The needle-like nHA crystals of about 10 nm in diameter by 50-80 nm in length, which were uniformly distributed in the porous nHA/SF scaffolds, were prepared by a co-precipitation method with a size. The as-prepared nHA/SF scaffolds showed good homogeneity, interconnected pores and high porosity. XRD and FT-IR analysis suggested that the silk fibroin was in beta-sheet structure, which usually provides outstanding mechanical properties for silk materials. In this work, composite scaffolds containing as high as 70% (w/w) nHA were prepared, which had excellent compressive modulus and strength, higher than the scaffolds at low nHA content level and other porous biodegradable polymeric scaffolds often considered in bone-related tissue engineering reported previously. The cell compatibility of composite scaffolds was evaluated through cell viability by MTT assay. All these results indicated that these nHA/SF scaffold materials may be a promising biomaterial for bone tissue engineering.     

Biocompatibility and osteogenesis of biomimetic nano-hydroxyapatite/polyamide composite scaffolds for bone tissue engineering

In this study, we prepared nano-hydroxyapatite/polyamide (n-HA/PA) composite scaffolds utilizing thermally induced phase inversion processing technique. The macrostructure and morphology as well as mechanical strength of the scaffolds were characterized. Mesenchymal stem cells (MSCs) derived from bone marrow of neonatal rabbits were cultured, expanded and seeded on n-HA/PA scaffolds. The MSC/scaffold constructs were cultured for up to 7 days and the adhesion, proliferation and differentiation of MSCs into osteoblastic phenotype were determined using MTT assay, alkaline phosphatase (ALP) activity and collagen type I (COL I) immunohistochemical staining and scanning electronic microscopy (SEM). The results confirm that n-HA/PA scaffolds are biocompatible and have no negative effects on the MSCs in vitro. To investigate the in vivo biocompatibility and osteogenesis of the composite scaffolds, both pure n-HA/PA scaffolds and MSC/scaffold constructs were implanted in rabbit mandibles and studied histologically and microradiographically. The results show that n-HA/PA composite scaffolds exhibit good biocompatibility and extensive osteoconductivity with host bone. Moreover, the introduction of MSCs to the scaffolds dramatically enhanced the efficiency of new bone formation, especially at the initial stage after implantation. In long term (more than 12 weeks implantation), however, the pure scaffolds show as good biocompatibility and osteogenesis as the hybrid ones. All these results indicate that the scaffolds fulfill the basic requirements of bone tissue engineering scaffold, and have the potential to be applied in orthopedic, reconstructive and maxillofacial surgery.     

Preparation and characterization of nano-hydroxyapatite/silk fibroin porous scaffolds

Novel tissue engineering scaffold materials of nano-hydroxyapatite (nHA)/silk fibroin (SF) biocomposite were prepared by freeze-drying. The needle-like nHA crystals of about 10 nm in diameter by 50–80 nm in length, which were uniformly distributed in the porous nHA/SF scaffolds, were prepared by a co-precipitation method with a size. The as-prepared nHA/SF scaffolds showed good homogeneity, interconnected pores and high porosity. XRD and FT-IR analysis suggested that the silk fibroin was in β-sheet structure, which usually provides outstanding mechanical properties for silk materials. In this work, composite scaffolds containing as high as 70% (w/w) nHA were prepared, which had excellent compressive modulus and strength, higher than the scaffolds at low nHA content level and other porous biodegradable polymeric scaffolds often considered in bone-related tissue engineering reported previously. The cell compatibility of composite scaffolds was evaluated through cell viability by MTT assay. All these results indicated that these nHA/SF scaffold materials may be a promising biomaterial for bone tissue engineering.     

复合壳聚糖纳米微球聚乳酸-羟基乙酸/纳米羟基磷灰石缓释载体系统对蛋白的缓释作用

背景：聚乳酸-羟基乙酸支架材料具有良好的生物相容性、无毒、可以良好的塑性,并具有一定的强度和韧性。但其降解产物为酸性,会影响局部pH值变化,不利组织生长。 目的：制备能够良好缓释蛋白类药物的复合支架。 方法：以牛血清蛋白为模型药物,以离子凝胶法制备壳聚糖微球。将微球与纳米羟基磷灰石和聚乳酸-羟基乙酸按一定比例混合,以冰粒子为致孔剂,采用粒子沥虑-冷冻干燥复合工艺制备CMs/nHA/PLGA复合缓释支架。利用扫描电镜、透射电镜、压泵仪和力学性能测试仪检测复合支架的形态和性能,并考察其在体外对蛋白类药物释放的规律。 结果与结论：制备的壳聚糖纳米微球形态良好,呈规则球形或类球形,粒径分布在220~770 nm,以380~650 nm为多。微球对药物的载药量为39.2%,包封率为68.3%,两者均与牛血清蛋白的初始量相关,载药量随牛血清蛋白初始量的增加而增加,包封率则反之。复合支架呈白色多孔状,孔径为125~355 mm,孔与孔之间联通良好,孔隙率达83.4%,压缩强度为1.4~ 2.1 MPa,10周降解率为28.6%。PLGA/nHA支架对牛血清蛋白的2 d累积释放量为85%,而壳聚糖和CMs/nHA/PLGA复合支架对牛血清蛋白的9 d累积释放量分别是为48.9%和35.7%。提示制作的壳聚糖纳米微球和CMs/nHA/PLGA支架材料对牛血清蛋白有良好的缓释作用,复合支架材料形态好,强度和降解速率合适。     

Collagen-calcium phosphate cement scaffolds seeded with umbilical cord stem cells for bone tissue engineering

Human umbilical cord mesenchymal stem cells (hUCMSCs) avoid the invasive procedure required to harvest bone marrow MSCs. The addition of collagen fibers into self-setting calcium phosphate cement (CPC) may increase the scaffold strength, and enhance cell attachment and differentiation. The objectives of this study were to develop a novel class of collagen-CPC composite scaffolds, and to investigate hUCMSC attachment, proliferation, and osteogenic differentiation on collagen-CPC scaffolds for the first time. Collagen fibers in CPC improved the load-bearing capability. Flow cytometry showed that the hUCMSCs expressed cell surface markers characteristic of MSCs, and were negative for hematopoietic and endothelial cell markers. hUCMSCs proliferated rapidly in all CPC composite scaffolds, with cell number increasing by sevenfold in 8 days. Cellular function was enhanced with collagen fibers in CPC scaffolds. Cell density increased from (645±60) cells/mm(2) on CPC with 0% collagen, to (1056±65) cells/mm(2) on CPC with 8% collagen (p<0.05). The actin stress fibers inside the hUCMSCs were stained, and the fluorescence intensity was doubled when the collagen in CPC was increased by 0% to 8%. RT-PCR showed that hUCMSCs on CPC with collagen had higher osteogenic expression than those on CPC without collagen. Alizarin Red S staining revealed a great increase in mineralization by hUCMSCs on CPC with collagen than that without collagen. In conclusion, hUCMSCs showed excellent proliferation, differentiation, and synthesis of bone minerals in collagen-CPC composite scaffolds for the first time. The novel hUCMSC-seeded collagen-CPC construct with superior cell function and load-bearing capability is promising to enhance bone regeneration in a wide range of orthopedic and craniofacial applications.     

Fabrication and biocompatibility of an antimicrobial composite membrane with an asymmetric porous structure

A composite slurry from silver ion-substituted nano-hydroxyapatite, titania nano-particles and polyamide 66 (Ag-nHA/TiO(2)/PA66) was prepared and used to fabricate a novel antimicrobial membrane with a gradient porous structure for guided bone regeneration (GBR). Subsequently, assays were performed to determine the cytocompatibility, as well as the bone biocompatibility of the prepared membranes. To investigate the cytocompatibility of the Ag-nHA/TiO(2)/PA66 membrane, in vitro studies were done with osteoblast-like cells (MG63) and the viability, alkaline phosphatase activity (ALP) and morphology of cells cultured on the membrane were determined. The bone biocompatibility of the membranes was finally assessed in animal experiments, in which nano-hydroxyapatite/polyamide 66 (nHA/PA66) and pure polyamide 66 (PA66) membranes were compared. The in vitro cell-culture experiments showed that Ag-nHA/TiO(2)/PA66 antimicrobial membrane evoked good cell affinity and cytocompatibility. The in vivo study showed that Ag-nHA/TiO(2)/PA66 asymmetric porous barrier membrane resulted in complete closure of 5-mm bone defects as created in the skull of rats after 8 weeks of implantation. In conclusion, the Ag-nHA/TiO(2)/PA66 membrane has the potential to be applied in GBR, especially in infected tissue or areas with high bacteria concentration.     

Biocompatibility and osteogenesis of biomimetic Bioglass-Collagen-Phosphatidylserine composite scaffolds for bone tissue engineering

A novel biomimetic composite scaffold Bioglass-Collagen-Phosphatidylserine (BG-COL-PS) was fabricated with a freeze-drying technique. The macrostructure and morphology as well as mechanical strength of the scaffolds were characterized. Scanning electronic microscopy (SEM) showed that the BG-COL-PS scaffolds exhibited interconnected porous structures with pore sizes of several microns up to about 300 μm. The scaffolds have a porosity of 75.40% and the corresponding compressive strength of 1.5469 Mpa. Rat mesenchymal stem cells (rMSCs) were seeded on BG-COL-PS or BG-COL scaffolds and cultured for 21 days in vitro. Based on the results of SEM, dsDNA content, alkaline phosphatase (ALP) activity, osteogenic gene expression analysis and alizarin red staining, the responses of MSCs to the scaffold exhibited a higher degree of attachment, growth as well as osteogenic differentiation than those on BG-COL scaffolds in vitro. To investigate the in vivo biocompatibility and osteogenesis of the composite scaffolds, both pure BG-COL-PS scaffolds and MSC/scaffold constructs were implanted in rat femurs defects for 6 weeks and studied histologically and radiographically. The in vivo results showed that BG-COL-PS composite scaffolds exhibited good biocompatibility and extensive osteoconductivity with host bone. Moreover, the BG-COL-PS/MSC constructs dramatically enhanced the efficiency of new bone formation than pure BG-COL-PS scaffolds or BG-COL/MSC constructs. All these results demonstrate the usefulness of PS composited BG-COL-PS scaffolds for inducing enhanced bone formation. The BG-COL-PS scaffolds fulfill the basic requirements of bone tissue engineering scaffold and have the potential to be applied in orthopedic and reconstructive surgery.     

Fabrication and Biocompatibility of an Antimicrobial Composite Membrane with an Asymmetric Porous Structure

A composite slurry from silver ion-substituted nano-hydroxyapatite, titania nano-particles and polyamide 66 (Ag-nHA/TiO₂/PA66) was prepared and used to fabricate a novel antimicrobial membrane with a gradient porous structure for guided bone regeneration (GBR). Subsequently, assays were performed to determine the cytocompatibility, as well as the bone biocompatibility of the prepared membranes. To investigate the cytocompatibility of the Ag-nHA/TiO₂/PA66 membrane, in vitro studies were done with osteoblast-like cells (MG63) and the viability, alkaline phosphatase activity (ALP) and morphology of cells cultured on the membrane were determined. The bone biocompatibility of the membranes was finally assessed in animal experiments, in which nano-hydroxyapatite/polyamide 66 (nHA/PA66) and pure polyamide 66 (PA66) membranes were compared. The in vitro cell-culture experiments showed that Ag-nHA/TiO₂/PA66 antimicrobial membrane evoked good cell affinity and cytocompatibility. The in vivo study showed that Ag-nHA/TiO₂/PA66 asymmetric porous barrier membrane resulted in complete closure of 5-mm bone defects as created in the skull of rats after 8 weeks of implantation. In conclusion, the Ag-nHA/TiO₂/PA66 membrane has the potential to be applied in GBR, especially in infected tissue or areas with high bacteria concentration.