人牙周韧带细胞-聚羟基乙酸支架复合体修复牙周组织缺损

BACKGROUND: In recent years, tissue engineering technology as a new model for tissue regeneration has provided new ideas and methods for the repair of periodontal tissue defects. OBJECTIVE: To investigate the effect of human periodontal ligament cells-polyglycolic acid scaffold complex for repair of periodontal tissue defects. METHODS: Passage 4 human periodontal ligament cells at a density of 1.5×109/L were seeded onto the polyglycolic acid scaffold to prepare cell-scaffold complex. Then mongrel dogs were selected to make animal models of periodontal tissue defects and then randomly assigned into experimental group subjected to cell-scaffold complex implantation or control group subjected to direct coronal reset and suture of the gingival flap. Collagen content, new blood capillaries, new cementum, new alveolar bone and new periodontal ligament were detected within 4 weeks after operation; hematoxylin-eosin staining of periodontal tissue defects was done at 8 weeks after operation. RESULTS AND CONCLUSION: In the experimental group, the collagen content, number of newborn capillaries, amount of new cementum, new alveolar bone and new periodontal ligament tissues were significantly higher than those in the control group at postoperative 1, 2, 3, 4 weeks (P < 0.05). At 8 weeks after operation, in the experimental group, there were more vessels arranging on the connective tissue surface of new alveolar bone, the alveolar bone showed a sawtooth-like interlinking with the periodontal tissues in the presence of a thin layer of cementum; in the control group, only new alveolar bone and cementum formed below the incisure. These findings indicate that human periodontal ligament cells-polyglycolic acid scaffold complex can promote periodontal tissue regeneration.      

Testing the utility of rationally engineered recombinant collagen-like proteins for applications in tissue engineering

Collagens are attractive proteins as materials for tissue engineering. Over the last decade, significant progress has been made in developing technologies for large-scale production of native-like human recombinant collagens. Yet, the rational design of customized collagen-like proteins for smart biomaterials to enhance the quality of engineered tissues has not been explored. We mapped the D4 domain of human collagen II as most critical for supporting migration of chondrocytes and used this information to genetically engineer a collagen-like protein consisting of tandem repeats of the D4 domain (mD4 collagen). This novel collagen has been utilized to fabricate a scaffold for support of chondrocytes. We determined superior qualities of cartilaginous constructs created by chondrocytes cultured in scaffolds containing the mD4 collagen in comparison to those formed by chondrocytes cultured in bare scaffolds or those coated with wild-type collagen II. Our results are a first attempt to rationally engineer collagen-like proteins with characteristics tailored for specific needs of cartilage engineering and provide a basis for rational engineering of similar proteins for a variety of biomedical applications.     

骨髓间充质细胞复合胶原-壳聚糖材料联合骨搬移修复胫骨缺损：随机对照实验方案

背景：骨髓间充质干细胞发挥成骨作用需要支架材料的辅助,一方面支架材料不仅可将细胞运载至骨缺损区域,另一方面还可作为新骨生长的框架结构。胶原-壳聚糖复合材料是骨组织工程较为理想的支架材料之一,同时其具有骨诱导性,比常规支架材料更优越的成骨能力。骨搬移技术在临床上在修复长段骨缺损方面已得到广泛应用,但也存在成骨慢、外固定时间长、骨不连等缺憾。如何进一步加快骨形成速度,减少并发症发生,已成当前亟待解决的问题。实验假设：骨髓间充质干细胞复合胶原-壳聚糖支架移植能提高胫骨缺损骨搬移修复效果。 方法/设计：随机对照动物实验。分为体外和体内实验两部分。体外实验中取月龄一两个月的新西兰大白兔股骨骨髓,提取骨髓间充质干细胞,培养至第3代,将细胞悬液滴于胶原-壳聚糖支架材料,构建骨髓间充质干细胞复合胶原-壳聚糖支架。体内实验选用24只三四月龄新西兰大白兔,被随机分配接受如下干预：骨搬移、支架植入、骨搬移联合支架植入。研究的主要观察指标为植入材料与骨缺损界面的生长情况、X射线检测的缺损区骨修复情况、苏木精-伊红染色及扫描电镜观察缺损区成骨情况、免疫组织化学染色检测成骨区Ⅰ型胶原蛋白的表达情况、扫描电子显微镜观察移植材料与宿主骨的界面键合情况、超微结构及新骨的生成。 讨论：实验结果将有助于确定对骨缺损进行骨搬移治疗过程中,应用骨髓间充质干细胞复合胶原-壳聚糖支架移植促进骨缺损再生修复效果的可行性。 实验方案获基金支持情况：获辽宁省科学技术计划项目资助(2012225019)。 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     

腺病毒携带骨形态发生蛋白14基因转染脂肪干细胞修复损伤关节软骨

背景：关节软骨损伤后自我修复能力较弱,主要是由于其缺乏滋养血管并且细胞代谢缓慢等组织特性,目前的治疗方法都不能恢复软骨组织的原有功能,近年来软骨组织工程已引起了越来越多的关注。 目的：观察Ⅰ型胶原海绵支架搭载骨形态发生蛋白14基因转染脂肪干细胞修复兔膝关节软骨损伤的效果。 方法：取兔皮下脂肪组织分离培养脂肪干细胞,用腺病毒真核表达载体Ad-CMV-BMP-14-IRES-hrGFP-1转染脂肪干细胞。Ⅰ型胶原海绵支架搭载转染后的脂肪干细胞,待细胞吸附后对兔膝关节全层软骨缺损进行修复。术后12周取手术关节,从大体方面、组织学方面综合评估缺损修复状况。 结果与结论：骨形态发生蛋白14转染后的脂肪干细胞骨形态发生蛋白14和Ⅱ型胶原蛋白表达及Sox-9基因表达明显高于普通脂肪干细胞。术后12周,支架搭载经骨形态发生蛋白14转染的脂肪干细胞组软骨组织修复良好,平整光滑,光洁度、质地及颜色良好,交界区整合良好。支架搭载脂肪干细胞组软骨组织部分修复,有正常软骨光泽,质地与颜色接近正常,修复组织与正常软骨组织界限明显。单纯支架组几乎崩解塌陷,未见透明样软骨结构形成。结果可见腺病毒携带骨形态发生蛋白14基因转染后脂肪干细胞修复软骨缺损的能力有大幅提升。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;组织工程全文链接：     

组织工程支架材料在脊髓损伤修复中的应用

背景：脊髓损伤最初往往会导致细胞和组织的不断丢失,组织工程支架可以模拟细胞外基质的生理状态,从而有利于细胞的黏附、迁移、扩增和分化。 目的：总结近年来组织工程支架材料联合细胞和/或细胞因子修复脊髓损伤的新进展。 方法：应用计算机检索PubMed、Ovid Medline及CBM数据库中2000-10/2010-10 与组织工程支架材料修复脊髓损伤相关的文章。  结果与结论：组织工程材料治疗脊髓损伤需要3 因素：种子细胞、组织工程支架、细胞因子。组织工程支架对于损伤脊髓断端起到桥接作用,而种植于材料的种子细胞和/或细胞因子可以促进神经轴突的生长和迁移。可用于组织工程支架的材料可分为天然材料和人工合成材料,包括胶原、壳聚糖、琼脂糖/藻酸盐、聚乳酸、纤连蛋白、聚羟基乙酸/聚乳酸、聚β羟丁酸等,动物实验已经取得一些成果,显示组织工程支架材料联合细胞移植修复效果更好,但临床上目前尚无开展组织工程支架材料修复脊髓损伤的研究。     

Bone regeneration by using scaffold based on mineralized recombinant collagen

Bone regeneration was achieved in the 15-mm segmental defect model in the radius of rabbit by using the scaffold based on mineralized recombinant collagen for the first time. The recombinant collagen was recombinant human-like type I collagen, which was produced by cloning a partial cDNA that was reversed by mRNA from human collagen alpha1(I) and transferred to E. coli. The scaffold material nano-hydroxyapatite/recombinant human-like collagen/poly(lactic acid) (nHA/RHLC/PLA) was developed by biomimetic synthesis. Thermo gravimetric analysis, X-ray diffraction and scanning electron microscopy were applied to exhibit that the scaffold showed some features of natural bone both in main component and hierarchical microstructure. The percentages of organic phase and inorganic phase of nHA/RHLC were similar to that of natural bone. The three-dimensional porous scaffold materials mimic the microstructure of cancellous bone. In the implantation experiment, the segmental defect was healed 24 weeks after surgery, and the implanted composite was completely substituted by new bone tissue. The results of the implantation experiment were very comparable with that of the scaffold based on mineralized animal-sourced collagen. It is concluded that the scaffold based on mineralized recombinant collagen maintains the advantages of mineralized animal-sourced collagen, while avoids potential virus-dangers. The scaffold is a promising material for bone tissue engineering.     

自体脂肪间充质干细胞复合人脐带Wharton胶支架修复兔膝关节软骨缺损****◇

背景：脐带Wharton胶富含透明质酸,糖胺多糖及胶原等,成分与天然软骨细胞外基质类似,因此由人脐带提取的Wharton胶很可能是一种较为理想的软骨组织工程支架材料。 目的：评价自体脂肪间充质干细胞复合人脐带Wharton胶支架修复兔膝关节软骨缺损的效果。 方法：将终浓度为1010 L -1、成软骨方向诱导后的兔自体脂肪间充质干细胞与人脐带Wharton胶支架复合,继续培养1周构建组织工程软骨,对兔膝关节全层软骨缺损进行修复(实验组),并与单纯支架修复的对照组及空白组进行比较。术后3个月对修复组织行大体观察、组织学检测、糖胺多糖、总胶原定量检测及生物力学测定。 结果与结论：实验组的缺损多为透明软骨修复,对照组以纤维组织修复为主,空白组无明显组织修复。提示脂肪间充质干细胞作为软骨组织工程种子细胞具有可行性;实验构建的组织工程软骨能有效的修复关节软骨缺损,人脐带Wharton胶可作为软骨组织工程良好的支架材料。     

Engineering Structurally Organized Cartilage and Bone Tissues

The field of tissue engineering promises to deliver biological substitutes to repair or replace tissues in the body that have been injured or diseased. The clinical demand for musculoskeletal tissues is particularly high, especially for cartilage and bone defects. Although they are generally considered biologically simple structures, musculoskeletal tissues consist of highly organized three-dimensional networks of cells and matrix, giving rise to tissue structures with remarkable mechanical properties. Although the field of cartilage and bone tissue engineering has progressed significantly in recent years, the development of structurally ordered tissues has not been accomplished. More strategies are needed to ensure that the appropriate cell and matrix organization is being achieved in the engineered tissues. This review emphasizes how different cell types and scaffold designs can be used to modulate tissue properties and engineer more complex tissue structures, with emphasis on cartilage and bone tissues.     

Generation of bioactive nano-composite scaffold of nanobioglass/silk fibroin/carboxymethyl cellulose for bone tissue engineering

Abstract

The development of bone tissue construct through tissue engineering approach offers a great promise in meeting the increasing demand for repair and regeneration of damaged and/or diseased bone tissue. For the generation of bone tissue engineered construct, polymer-ceramic composite matrices with nanostructure architecture and mesenchymal stem cells (hMSCs) of human origin are of prime requirement. Keeping these in view, in the present work a novel electrospun nanofibrous silk fibroin (SF)/carboxymethyl cellulose (CMC)/nano-bioglass (nBG) composite scaffold that mimics native bone extracellular matrix with appropriate composition was designed and fabricated by free liquid surface electrospinning technique. The scaffold possesses desired morphological, structural, biodegradability, bioactivity, surface roughness and mechanical properties thereby exhibited an excellent platform to support the growth of cells. The in-vitro culture of hMSCs over the developed scaffold has shown adhesion, proliferation and viability of cells, thus facilitated cell-scaffold construct generation and further extracellular bone matrix formation through osteogenic differentiation as evident from alkaline phosphatase activity, biomineralization, immunostaining and Runx2/osteocalcin expression assessment. Thus, the developed hMSCs seeded scaffold construct might be suitable for bone tissue engineering applications.     

纳米级多孔负载人骨形成蛋白2基因修饰支架对前成骨细胞株分化的影响

BACKGROUND: Bone tissue transplantation or osteogenic material filling is after used for bone defect repair. To remove autologous bone tissues can lead to additional damage and secondary deformity, therefore, it is extremely urgent to search for a new osteogenic material. OBJECTIVE: To construct the porous β-tricalcium phosphate (β-TCP)/collagen scaffold modified with human bone morphogenetic protein 2 (hBMP2) gene, and to observe its effects on differentiation of MC3T3-E1 cell lines. METHODS: The porous β-TCP/collagen scaffold modified with hBMP2 gene was prepared. Then in vitro culture system of MC3T3-E1 cell lines with composite scaffold was established. There were scaffold and plate groups, and each group was divided into two subgroups according to the different concentrations of plasmid. Samples were collected and observed morphologically by scanning electron microscope and light microscope after complex culture. After 1, 3, 7 and 14 days of induction, calcium nodules were observed through alizarin red staining, the cell cycle was detected by real-time PCR, and expressions of α I-chain collagen type I gene, Osterix and bone sialoprotein were observed. RESULTS AND CONCLUSION: The number of cells adhered, differentated and distributed on the composite scaffold was significantly higher than that of the single scaffold (P < 0.05). Alizarin red staining and real-time PCR detection showed that the osteogenesis ability of MC3T3-E1 cell lines in the scaffold group was stronger than that in the plate group. To conclude, the porous β-TCP/collagen scaffold modified with hBMP2 gene is an appropriate candidate for bone defect repair.     

In vitro ossification and remodeling of mineralized collagen I scaffolds

A promising strategy of bone tissue engineering is to repair bone defects by implanting biodegradable scaffolds that can undergo remodeling and be replaced completely by autologous bone tissue. For this purpose, it is necessary to create scaffolds that can be degraded by osteoclasts and enable osteoblasts to build new mineralized bone matrix. In order to achieve this goal a new porous material has been developed using biomimetically mineralized collagen I. These scaffolds were co-cultured with osteoclast-like cells and osteoblasts in order to characterize the capacity of these cells to remodel the material in vitro. It was possible to show the development of biologically active osteoclast- like cells that were able to invade and degrade the scaffold. They degraded the scaffold by internalizing it as intracellular vesicles, thereby making room for osteoblasts to invade and build new bone matrix. In addition, it could be shown that osteoblasts proliferated, differentiated, and produced new mineralized extracellular matrix. Hence, it could be shown that co-culture of osteoclastlike cells and osteoblasts on biomimetically mineralized collagen I is a promising approach for bone tissue engineering. In addition, it can be applied to study the process of bone remodeling in vitro.     

Hierarchically biomimetic bone scaffold materials: nano-HA/collagen/PLA composite

A bone scaffold material (nano-HA/ collagen/PLA composite) was developed by biomimetic synthesis. It shows some features of natural bone both in main composition and hierarchical microstructure. Nano-hydroxyapatite and collagen assembled into mineralized fibril. The three-dimensional porous scaffold materials mimic the microstructure of cancellous bone. Cell culture and animal model tests showed that the composite material is bioactive. The osteoblasts were separated from the neonatal rat calvaria. Osteoblasts adhered, spread, and proliferated throughout the pores of the scaffold material within a week. A 15-mm segmental defect model in the radius of the rabbit was used to evaluate the bone-remodeling ability of the composite. Combined with 0.5 mg rhBMP-2, the material block was implanted into the defect. The segmental defect was integrated 12 weeks after surgery, and the implanted composite was partially substituted by new bone tissue. This scaffold composite has promise for the clinical repair of large bony defects according to the principles of bone tissue engineering.     

Collagen I gel promotes homogenous osteogenic differentiation of adipose tissue-derived mesenchymal stem cells in serum-derived albumin scaffold

Repair of bone defects is a difficult clinical problem for reconstructive surgeons. Bone tissue engineering using an appropriate scaffold with cells is a new therapy for the repair of bone defects. The aim of this study was to evaluate the in vitro osteogenesis of canine adipose tissue-derived mesenchymal stem cells (Ad-MSCs) cultured in a combination of collagen I gel and a porous serum-derived albumin scaffold. A serum-derived albumin scaffold was prepared with canine serum by cross-linking and freeze-drying procedures. Ad-MSCs were seeded into serum-derived albumin scaffolds with or without collagen I gel, and were exposed to osteogenic differentiation conditions in vitro. After 28?days of in vitro culture, the distribution and osteogenic differentiation of Ad-MSCs cultured in the scaffold were evaluated by scanning electron microscopy, histology, immunohistochemistry, alkaline phosphatase (ALP) activity assay, and calcium colorimetric assay. Ad-MSCs showed more homogeneous distribution and osteogenic differentiation in the scaffold with collagen I gel than without collagen I gel. ALP activity and extracellular matrix mineralization in the construct with type I collagen were significantly higher than in the construct without type I collagen (p?<?0.05). In conclusion, the combination of collagen I gel and the serum-derived albumin scaffold enhanced osteogenic differentiation and homogenous distribution of Ad-MSCs.     

重组人骨形态发生蛋白2诱导骨修复的应用及前景

背景：重组人骨形态发生蛋白2具备诱导成骨时间更早、成骨量较天然骨形态发生蛋白2多、生物学活性好、生物相容性好、成本低等特点,已成为近年来临床骨科创伤疾病防治研究的热点。 目的：总结重组人骨形态发生蛋白2在骨组织工程及骨修复领域应用中的优势、不足及目前国内外的研究进展。 方法：经第一作者检索CNKI数据库及SPRINGERLINK数据库2005至2011年与重组人骨形态发生蛋白2在诱导骨再生、骨组织修复有关研究进展方面的文献,英文检索词为“rhBMP-2,bone tissue engineering,bone repair materials”,中文检索词为“重组人骨形态发生蛋白2,骨组织工程,骨修复”。共检索出98篇,最终保留30篇进行归纳总结。 结果与结论：骨骼内天然骨形态发生蛋白2含量稀少、提取成本高昂,临床应用严重受限。重组人骨形态发生蛋白2有显著的成骨诱导能力,在骨组织工程及骨修复领域展现了巨大的潜在应用价值。体外试验无细胞毒性具有良好的生物相容性可供临床应用,其中重组人骨形态发生蛋白2和重组人骨形态发生蛋白7现已被应用于外科整形手术诱导骨再生,但由于重组人骨形态发生蛋白2是外源性细胞生长因子,临床应用多为超生理剂量,故潜在有软组织水肿,皮肤红疹、局部炎症反应、异位骨化和免疫反应等不良后果的危险,所以重组人骨形态发生蛋白2用于人体后的安全性研究还须长期密切关注。找到理想的载体,有效控制其在体内缓释是重组人骨形态发生蛋白2应用研究的关键问题。     

股骨头坏死的组织工程修复

背景：随着组织工程学技术的发展,改变了治疗骨缺损的传统治疗模式。由于骨组织是可再生组织,医学研究者们越来越重视组织工程在股骨头坏死治疗中的应用。 目的：总结股骨头坏死的组织工程修复手段,探索再生医学在骨组织工程领域的医用前景。 方法：从组织工程医学关注的几个前沿领域,包括 “干细胞、组织构建与生物力学、骨科生物材料、人工假体置换、植骨移植”等出发,检索与这些组织工程技术手段修复股骨头坏死相关研究的文献,时间限定为2000-01/2011-12,排除重复研究和Meta分析类文章,对30篇具有代表性的文献进行综合分析。 结果与结论：随着再生医学的进步,组织工程技术已经广泛应用于股骨头坏死的修复,包括：不同来源干细胞移植治疗股骨头坏死、炎症因子与股骨头坏死分析、股骨头坏死有限元模型的构建及生物力学分析、各种高分子生物骨支架材料修复股骨头坏死、人工骨植入及人工髋关节置换等。但目前组织工程在股骨头坏死治疗过程中仍处在动物实验和经验性治疗水平。                                                                         关键词：股骨头坏死;干细胞;生物材料;髋关节置换;植骨;生物力学 doi:10.3969/j.issn.1673-8225.2012.13.034     

功能型骨组织工程支架修复结核性骨缺损

BACKGROUND: Repairing tuberculosis bone defect has become a research focus with the development of anti-tuberculosis functional bone tissue engineering scaffold. OBJECTIVE: To evaluate the preparation, drug release performance and osteogenic properties of the anti-tuberculosis functional bone tissue engineering scaffold. METHODS: PubMed, Chinese Journal Full-text Database, Wanfang databases were searched by computer for articles addressing functional bone tissue engineering scaffold for repair of tuberculosis bone defect. The keywords were “bone tissue engineering scaffold; tuberculosis; bone defect” in English and Chinese. RESULTS AND CONCLUSION: The anti-tuberculosis functional bone tissue engineering scaffold has good drug delivery, biocompatibility, osteogenic properties and anti-tuberculosis properties. As a good choice to avert bone defect relapse, the scaffold enables a long and stable drug release into bone defects to enhance the therapeutic efficacy of anti-tuberculosis drugs topically. Given the technical deficiencies, we can only combine two drugs with the anti-tuberculosis bone tissue engineering scaffold, although the combined use of three or four anti-tuberculosis drugs is preferred. Additionally, a complete course of anti-tuberculosis treatment often lasts for 6-12 months, which cannot be achieved by the existing anti-tuberculosis bone tissue engineering scaffold. Up to now, the effect of this scaffold has not yet been confirmed in animal models, although how to prepare this scaffold has been reported.     

智能水凝胶在骨类硬组织再生和修复中的应用

BACKGROUND: Intelligent hydrogel as a new material is widely used in biological medicine, tissue engineering, memory element switch, biological enzyme immobilization and other related fields, and exhibits good biological characteristics. Intelligent hydrogels provide a new approach for regeneration and repair of bone and other hard tissues.  OBJECTIVE: To summarize the latest developments of intelligent hydrogel in the biological medicine and tissue engineering in order to find out new methods for regeneration and repair of bone and other hard tissues. METHODS: A computer-based research of CNKI, PubMed and EBSCO-MEDLINE databases was performed to retrieve relevant literatures about the application of intelligent hydrogel in regeneration and repair of bone and other hard tissues published from 2000 to 2015. The keywords were “hydrogel, bone tissue engineering, bone defect, regeneration, repair” in Chinese and English, respectively. RESULTS AND CONCLUSION: Intelligent hydrogels are classified into pH-sensitive, temperature-sensitive, light-sensitive, multiple-sensitive and other sensitive hydrogels. In order to improve the mineralization ability of the hydrogel and construct the three-dimensional polymer scaffold of hydrogel, the main structure of the hydrogel materials can be mixed with various signal factors, thus achieving the multi-utility and multi-function of the material system, which will become the development trend of tissue engineering construction.      

组织工程骨材料在运动性骨缺损修复中的评价

目的：评价组织工程化人工骨材料的性能和应用,寻找合理的骨缺损修复材料。 方法：以“组织工程,骨缺损,人工骨,纳米材料” 为中文关键词;以“tissue engineering, bone defect, artificial bone, biological degradation”为英文关键词,采用计算机检索1993-01/2009-10相关文章。纳入与有关组织工程相关的文章;排除重复研究或Meta分析类文章。以30篇文献为主,重点进行了讨论组织工程纳米级人工骨材料的种类及其性能。 结果：可生物降解并具有生物活性的组织工程人工骨材料可作为一种较理想的支架材料应用于骨缺损修复组织工程。修复效果相当或接近自体骨,来源充足,既无免疫排斥反应,又避免取自体骨给患者带来的痛苦和并发症,不影响运动员重返赛场,运动员患者乐于接受。复合材料人工骨在解除运动员患者的后顾之忧的同时,也带来巨大的社会效益。基于纳米羟基磷灰石复合重组人骨形态发生蛋白2制成的支架,不但具有理想的生物相容性、生物降解性和较高的亲和性,而且能提高了骨诱导活性,能够促进新骨的形成。可生物降解并具有生物活性的组织工程人工骨材料在临床使用的初步情况表明,与人体生物相容性良好,无免疫排斥反应,愈合情况良好。 结论：骨缺损是常见的运动损伤,一直为运动损伤研究热点。组织工程化骨缺损修复的研究近年来发展迅速,为运动损伤骨缺损修复带来了契机。组织工程复合材料可以发挥不同材料的优势,弥补单一材料的不足,是一种比较理想的支架材料。     

Bone Tissue Engineering Using Human Mesenchymal Stem Cells: Effects of Scaffold Material and Medium Flow

We report studies of bone tissue engineering using human mesenchymal stem cells (MSCs), a protein substrate (film or scaffold; fast degrading unmodified collagen, or slowly degrading cross-linked collagen and silk), and a bioreactor (static culture, spinner flask, or perfused cartridge). MSCs were isolated from human bone marrow, characterized for the expression of cell surface markers and the ability to undergo chondrogenesis and osteogenesis in vitro, and cultured for 5 weeks. MSCs were positive for CD105/endoglin, and had a potential for chondrogenic and osteogenic differentiation. In static culture, calcium deposition was similar for MSC grown on collagen scaffolds and films. Under medium flow, MSC on collagen scaffolds deposited more calcium and had a higher alcaline phosphatase (AP) activity than MSC on collagen films. The amounts of DNA were markedly higher in constructs based on slowly degrading (modified collagen and silk) scaffolds than on fast degrading (unmodified collagen) scaffolds. In spinner flasks, medium flow around constructs resulted in the formation of bone rods within the peripheral region, that were interconnected and perpendicular to the construct surface, whereas in perfused constructs, individual bone rods oriented in the direction of fluid flow formed throughout the construct volume. These results suggest that osteogenesis in cultured MSC can be modulated by scaffold properties and flow environment.