脂肪基质细胞构建组织工程骨修复下颌骨缺损的实验研究

背景:以往实验认为,只有经过成骨诱导后的脂肪基质细胞才能作为骨组织工程的种子细胞。然而成骨诱导周期过程复杂,延长了细胞体外培养时间和花费。目的:探讨未经过成骨诱导的犬脂肪基质细胞作为种子细胞,利用组织工程技术修复犬下颌骨缺损的可行性。方法:取12个月龄犬背部皮下脂肪,经胶原酶消化法获得单个核细胞,将培养的第3代细胞与双相磷酸钙陶瓷形成支架复合物。在犬下颌骨两侧制备长20mm、高10mm的箱状缺损,拔除缺损区牙齿,分别植入细胞支架复合物和单纯双相磷酸钙陶瓷支架,不进行干预的区域作为空白对照。植入后4周及8周经组织学检测骨缺损修复情况。结果与结论:支架植入后4周,部分支架材料降解,缺损区形成新生骨,双相磷酸钙陶瓷组成骨量明显少于细胞支架复合物组,形成少量新骨及部分新生血管。8周时,两组形成更多的新骨,广泛分布于骨缺损区域,但双相磷酸钙陶瓷组仍明显少于细胞支架复合物组,差异有显著性意义(P<0.01)。提示脂肪基质细胞复合双相磷酸钙陶瓷可在体内成骨,不经过体外成骨诱导的脂肪基质细胞作为种子细胞,利用组织工程技术可修复下颌骨缺损。     

脂肪基质细胞构建组织工程骨修复下颌骨缺损的实验研究

背景：以往实验认为,只有经过成骨诱导后的脂肪基质细胞才能作为骨组织工程的种子细胞。然而成骨诱导周期过程复杂,延长了细胞体外培养时间和花费。目的：探讨未经过成骨诱导的犬脂肪基质细胞作为种子细胞,利用组织工程技术修复犬下颌骨缺损的可行性。方法：取12个月龄犬背部皮下脂肪,经胶原酶消化法获得单个核细胞,将培养的第3代细胞与双相磷酸钙陶瓷形成支架复合物。在犬下颌骨两侧制备长20mm、高10mm的箱状缺损,拔除缺损区牙齿,分别植入细胞支架复合物和单纯双相磷酸钙陶瓷支架,不进行干预的区域作为空白对照。植入后4周及8周经组织学检测骨缺损修复情况。结果与结论：支架植入后4周,部分支架材料降解,缺损区形成新生骨,双相磷酸钙陶瓷组成骨量明显少于细胞支架复合物组,形成少量新骨及部分新生血管。8周时,两组形成更多的新骨,广泛分布于骨缺损区域,但双相磷酸钙陶瓷组仍明显少于细胞支架复合物组,差异有显著性意义（P〈0.01）。提示脂肪基质细胞复合双相磷酸钙陶瓷可在体内成骨,不经过体外成骨诱导的脂肪基质细胞作为种子细胞,利用组织工程技术可修复下颌骨缺损。     

脂肪间充质干细胞复合骨诱导性磷酸钙陶瓷支架的异位成骨☆

背景：生物材料的骨诱导现象已经在多种动物实验中被证实。目的：考察磷酸钙陶瓷自身固有的诱导骨生成能力在其作为骨组织工程支架时的表现。方法：取健康家犬10只,在每只的背部肌肉内分别植入骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物、非骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物、骨诱导性磷酸钙陶瓷及非骨诱导性磷酸钙陶瓷,植入后8,12周,取出植入材料及其周围组织进行Micro-CT检测和组织形态学检测,评价成骨情况。结果与结论：组织学观察结果显示,骨诱导性磷酸钙陶瓷组及骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物组均有有异位骨生成,并且骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物组的成骨量显著大于骨诱导性磷酸钙陶瓷组(P<0.05);其余两组均无异位成骨。Micro-CT检测结果与组织形态学检测结果一致。结果表明骨诱导性磷酸钙陶瓷作为骨组织工程支架材料有明显的成骨优势,而脂肪间充质干细胞作为种子细胞对异位成骨有明显的促进作用。     

脱钙骨支架与诱导培养的脂肪基质细胞复合修复免胫骨缺损

背景:脂肪基质细胞经诱导后具备成骨活性已被实验证实,因此,脂肪基质细胞修复骨缺损的研究已成为目前的热点,但脂肪基质细胞修复负重骨缺损修复的相关实验报道较少.目的:通过兔脂肪基质细胞诱导培养为成骨细胞,并与牛脱钙骨复合培养,对兔胫骨骨缺损修复情况的观察,探讨脂肪基质细胞修复骨缺损的可行性.设计、时间及地点:随机对照动物实验,于2008-01/09在天津市第三中心医院动物实验室完成.材料:取新生小牛四肢长骨干干骺端的松质骨置于脱钙液中脱钙、脱脂、去细胞、去抗原和去蛋白等程序处理制备成脱钙骨支架.方法:选取健康成年新西兰大白兔12只,随机选取1只提取腹腔内脂肪组织15 mL,体外分离培养脂肪摹质细胞并行诱导培养证实为成骨细胞后,以1×109L-1浓度种植于脱钙骨支架上,继续培养1周,制成组织工程骨.将12只新西兰大白兔手术制成双侧胫骨骨缺损模型,左下肢植入单纯脱钙骨作为对照组,右下肢植入组织工程骨作为实验组.主要观察指标:X射线、CT检查观察骨缺损处骨痂形成情况,取材后行大体、组织学观察骨缺损处修复情况.结果:大体观察及X射线显示实验组术后12周骨缺损区缺损消失,已骨性愈合,对照组术后12周骨缺损区缺损仍存在,未见完全愈合.组织学观察显示实验组术后12周可见新生骨小梁形成,对照组术后12周未见新生骨小粱形成.测量CT值行配对t检验显示实验组明显优于对照组(P<0.05).结论:脂肪基质细胞经诱导培养具备成骨活性,与细胞支架复合具备修复骨缺损的能力.     

骨诱导性磷酸钙陶瓷为支架的组织工程骨修复狗下颌骨箱状缺损

背景:应用不外加生长因子或细胞而具有骨诱导性的生物材料,在非骨部位构建骨移植物,即体内组织工程骨,其在修复箱状及节段性骨缺损方面,具有更可行的前景.目的:采用骨诱导性钙磷陶瓷材料构建体内组织工程化类骨移植物,探索其应用于修复实验动物下颌骨箱状骨缺损的可行性.方法:以骨诱导性磷酸钙陶瓷材料为支架植入狗肌肉内构建体内组织工程骨,同期在狗自体下颌骨左右两侧各拔除牙弓中段牙2颗,形成约20 mm无牙区.8周后在无牙区形成箱状缺损,同期取出支架即刻移植入一侧自体下颌骨缺损区,对侧骨缺损区直接移植入未经体内构建的磷酸钙陶瓷作为对照.结果与结论:经肌肉内构建的体内组织工程骨移植物的力学性能较单纯磷酸钙陶瓷有明显提高.颌骨缺损区的核吸收强度明显强于对照区,其移植物内长入的骨组织较多,两者的成骨面积差异有非常显著性意义(P < 0.01).说明在修复颌骨大范围缺损中,体内组织工程骨移植物较单纯骨磷酸钙陶瓷替代材料表现出明显的力学和生物学优势,修复效果显著,有良好的应用前景.     

骨髓基质干细胞复合煅烧骨的皮下成骨

背景：研究证明骨髓基质干细胞与煅烧骨支架材料结合后可形成组织工程化骨,但在动物体内的生物相容性及皮下诱导成骨的能力国内报道较少. 目的：观察骨髓基质细胞复合异种煅烧骨植入BALB/c裸鼠背部皮下的成骨性能及煅烧骨材料作为组织工程骨支架材料的可行性. 方法：选用经脱脂及脱蛋白处理后高温煅烧形成的骨支架材料与梯度密度离心法分离培养至第3代的羊骨髓基质干细胞构建细胞-煅烧骨复合物植入 BALB/c 裸鼠背部皮下,选同期对侧背部皮下植入单纯煅烧骨为对照组. 结果与结论：煅烧后的松质骨块为白垩色,表面呈蜂窝状多孔结构,保留了天然松质骨的多孔状空间结构.骨小梁结构完整,孔隙相互连通.骨髓基质干细胞接种到煅烧骨后24 h可见大量细胞黏附于支架上,7 d后细胞分泌大量细胞外基质,细胞与基质分界不清,细胞能在材料上良好地黏附、增殖与生长,细胞活性未受到支架材料的影响.植入4周后,两组均可见煅烧骨边缘出现少量残片,细胞-煅烧骨复合物组煅烧骨孔隙周边可发现骨细胞,对照组煅烧骨表面可见纤维结缔组织包绕.植入后8周,两组均可见到煅烧骨部分降解为片状类骨质,周围有成纤维细胞包绕,排列紧密,形态多样,细胞-煅烧骨复合物组煅烧骨孔隙内可见煅烧骨表面有排列成行的成骨细胞,孔隙间有散在淋巴细胞浸润.对照组标本可见孔隙内有大量结缔组织长入,未见明显成骨迹象.结果说明,经高温煅烧后的松质骨材料,具有良好的生物相容性和生物安全性,可作为骨髓基质干细胞的良好载体,复合后植入体内能够诱导新生骨组织形成,可作为骨缺损组织工程修复的支架材料.     

脂肪干细胞与小肠黏膜下层构建仿生骨膜的体内成骨

背景:脂肪干细胞与小肠黏膜下层两者具有良好的组织相容性,但将二者复合构建仿生骨膜修复骨缺损的效果如何尚需进一步验证.目的:探讨以小肠黏膜下层为支架材料复合成骨诱导的脂肪干细胞构建仿生骨膜,体内成骨的可行性.方法:取兔腹股沟区的脂肪分离培养脂肪干细胞经成骨诱导后,与猪小肠黏膜下层复合体外培养3 周,构建仿生骨膜.将仿生骨膜埋置于裸鼠皮下,并以小肠黏膜下层复合未成骨诱导的脂肪干细胞的复合材料置于裸鼠皮下做对照.结果与结论:兔脂肪干细胞经成骨诱导后与小肠黏膜下层体外复合培养,见两者黏附良好,细胞分泌大量的细胞外基质.植入4,8,12 周组织学和透射电镜观察见有大量骨组织形成,未成骨诱导材料复合物组内无成骨细胞.仿生骨膜植入体内8 周免疫组织化学测试骨钙蛋白、骨桥蛋白呈阳性反应.提示仿生骨膜植入裸鼠体内后可形成具有良好血运的新生骨组织.     

脂肪干细胞与小肠黏膜下层构建仿生骨膜的体内成骨

背景：脂肪干细胞与小肠黏膜下层两者具有良好的组织相容性,但将二者复合构建仿生骨膜修复骨缺损的效果如何尚需进一步验证。目的：探讨以小肠黏膜下层为支架材料复合成骨诱导的脂肪干细胞构建仿生骨膜,体内成骨的可行性。方法：取兔腹股沟区的脂肪分离培养脂肪干细胞经成骨诱导后,与猪小肠黏膜下层复合体外培养3周,构建仿生骨膜。将仿生骨膜埋置于裸鼠皮下,并以小肠黏膜下层复合未成骨诱导的脂肪干细胞的复合材料置于裸鼠皮下做对照。结果与结论：兔脂肪干细胞经成骨诱导后与小肠黏膜下层体外复合培养,见两者黏附良好,细胞分泌大量的细胞外基质。植入4,8,12周组织学和透射电镜观察见有大量骨组织形成,未成骨诱导材料复合物组内无成骨细胞。仿生骨膜植入体内8周免疫组织化学测试骨钙蛋白、骨桥蛋白呈阳性反应。提示仿生骨膜植入裸鼠体内后可形成具有良好血运的新生骨组织。     

羟基磷灰/磷酸三钙双相生物陶瓷诱导成骨的成骨方式探讨

目的 探讨羟基磷灰／磷酸三钙（HA/TCP）双相生物陶瓷诱导成骨的成骨方式。方法 将HA/TCP材料制成柱状，采用肌内植入法植入版纳小耳猪腰背部肌肉，术后l、2、3月取材，进行组织学、酶组织化学以及偏振光显微镜观察。结果 术后1月和2月材料内未观察到新骨的形成，在3月材料内有明显的骨组织出现，在新骨边缘有线状排列的成骨细胞，其碱性磷酸酶染色阳性，新生骨组织基质主要为Ⅰ型胶原。结论 HA/TCP具有骨诱导性，新生骨组织与正常骨组织有着一致的胶原成分，其成骨方式为膜内成骨。     

磷酸钙骨水泥／骨形态蛋白人工骨复合骨髓基质细胞构建组织工程骨

背景:体外实验证明磷酸钙骨水泥/骨形态蛋白人工骨具有较强的骨诱导作用,但足磷酸钙骨水泥/骨形态蛋白人工骨能否作为骨髓基质细胞的生长支架报道较少.目的:验证磷酸钙骨水泥/骨形态蛋白人工骨做为骨组织工程支架材料的可行性.设计、时间及地点:观察实验,于2008 03/2009-03在上海市第九人民医院口腔组织工程实验室完成.材料:磷酸钙骨水泥/骨形态蛋白人工骨产品由瑞邦公司提供,大孔径200～500μm,小孔径1～5μ m,孔隙率为70%.两岁的健康毕格犬1只.方法:抽取成年毕格犬的骨髓,贴壁法获得骨髓基质细胞,经成骨诱导培养液体外培养、扩增、诱导后观察细胞增殖情况.将培养的第2代细胞接种于多孔型活性磷酸钙骨水泥,进行超微结构观察,并将多孔型活性磷酸钙骨水泥/骨髓基质细胞复合物植入毕格犬背部皮下,2,4周后进行组织学检测.主要观察指标:倒置相差纤维镜下观察细胞的生长、增殖情况;碱性磷酸酶染色、Von Kossa染色、骨钙素免疫细胞化学染色鉴定骨细胞的形成标志:扫描电镜观察细胞材料复合情况;苏木精-伊红染色观察体内异位成骨情况.结果:碱性磷酸酶染色呈阳性;Von Kossa染色可见钙结节形成;骨钙素免疫细胞化学染色呈阳性;超微结构观察可见细胞生长附着于材料网孔内表面;组织学检测提示4周时复合物内有新骨形成.结论:多孔型活性磷酸钙骨水泥/骨髓基质细胞复合物显示良好的成骨活性,磷酸钙骨水泥/骨形态蛋白人工骨可以用于骨组织工程支架材料.     

骨诱导性磷酸钙陶瓷支架在脂肪组织中构建体内组织工程骨

背景：作为体内组织工程骨的构建场所,非骨组织的选择至关重要。早期研究大多选用肌肉作为异位骨移植物的构建区域,但其位置较深,可利用面积小、手术操作复杂,不利于临床推广。目的：采用体内骨组织工程的方法,探索骨诱导性磷酸钙陶瓷支架在不同非骨组织中构建骨移植物的可行性。方法：选取家犬的背部肌肉组织和脂肪组织为构建区,分别植入骨诱导性磷酸钙陶瓷支架以构建体内组织工程骨移植物。于移植后4,8,12,16周取样进行单光子计算机断层扫描及组织学检测,观察其构建过程,比较各个观测时间内,不同构建区的骨移植物中新骨组织的形成情况,评价不同非骨构建区域对体内骨组织骨移植物形成的影响。结果与结论：骨诱导性磷酸钙陶瓷支架在肌肉组织和脂肪两处非骨组织中均可形成体内组织工程骨移植物,在构建初期,肌肉组中新骨形成的时间比脂肪组早,骨量也较多,但随着构建时间的延长,两组的新生骨量差异逐渐减小。提示,应用体内骨组织工程的方法在肌肉和脂肪组织均可构建出具有生命活性的自体骨移植物。与肌肉组织比较,脂肪组织面积宽广,位置浅表,因此在脂肪组织中构建体内组织工程骨移植物更有临床应用前景。     

In vitro and in vivo assessment of nanostructured porous biphasic calcium phosphate ceramics for promoting osteogenesis in an osteoporotic environment

Treatment of bone defects in osteoporotic patients with bone substitutes is difficult, due to insufficient osseointegration. The development of appropriate biomaterials to solve the problem requires the assessment of the material performance in an osteoporotic environment, which is rarely investigated. Herein, nanostructured biphasic calcium phosphate (nBCP) ceramics were prepared via the incorporation of hydroxyapatite nanoparticles (HANPs) into porous biphasic CaP (BCP) substrates, leading to an increase of over 500% in the specific surface area. Primary osteoblasts harvested from osteoporotic rats were cultured on the nBCP ceramics, and it was found that the osteoblast functions, including proliferation, alkaline phosphatase activity, osteocalcin secretion and expression of osteogenic genes, were significantly enhanced compared with osteoblasts grown on non-nanostructured BCP ceramics. To further assess the osteoinduction ability, the ceramics were implanted in the femur of osteoporotic rats. Compared to the rats implanted with non-nanostructured BCP ceramics, a higher amount of mechanically matured bone was newly formed in the rats with nBCP ceramics after 6 weeks of implantation. Such enhanced osteoinduction ability of the nBCP ceramics may be due to the incorporated HANPs, as well as the nanostructured topography induced by the HANPs. These results indicate good in vitro and in vivo osteoinductivity of the nBCP ceramics in an osteoporotic environment and offer potential benefits for treating bone defects in osteoporotic patients.

Nanostructured porous biphasic calcium phosphate ceramics are able to significantly promote bone defect healing in an osteoporotic environment.     

Unique and reliable rat model for the assessment of cell therapy: bone union in the rat mandibular symphysis using bone marrow stromal cells

Many kinds of bone graft materials have been developed and reported to repair various bone defects. The defects are usually created by surgical resection of pre‐existing bone tissue. However, spontaneous healing of bone defects without implantation of materials could be seen, because bone tissue possesses inherent repairing property. The central portion of the lower jaw bone in many animals consists of fibrous tissue and is called the mandibular symphysis. It persists even in old animals and thus can be interpreted as a physiological bone gap or a non‐healing bone defect. We implanted calcium phosphate porous ceramics alone or composites of the ceramics and bone marrow stromal cells (BMSCs) into the bone defect (mandibular symphysis) to examine whether it could be filled with new bone tissue, resulting in bone union. Eight weeks after implantation, micro‐computed tomography (micro‐CT) and histological and biomechanical analyses demonstrated that bone union of the mandibles occurred in all rats with composites but in none of those with ceramics alone. These results showed that the rat mandibular symphysis is a unique bone defect site for the evaluation of bone graft materials. These analyses demonstrated that ceramics alone could not contribute to bone healing in the defect; however, supplementation with BMSCs drastically changed the properties of the ceramics (turning them into osteogenic ceramics), which completely healed the defect. As BMSCs can be culture‐expanded using small amounts of bone marrow, the use of the composites might have clinical significance for the reconstruction of various bone tissues, including facial bone. Copyright © 2012 John Wiley & Sons, Ltd.     

Phosphoserine‐modified calcium phosphate cements: bioresorption and substitution

This work reports the effects of phosphoserine addition on the biodegradability of calcium phosphate cements. The characteristics of a phosphoserine‐modified calcium phosphate cement without collagen in a large animal model are presented here for the first time. Critical size bone defects in the proximal tibia of 10 sheep were filled with the bone cement, and five sheep with empty defects were included as controls. The sheep were sacrificed after either 10 days or 12 weeks, and bones were processed for histological, histomorphometric and enzyme histochemical analyses as well as transmission electron microscopic examination. After 12 weeks, there was no significant reduction in either the implant or the bone defect cross‐sectional area. Different amounts of fibrous tissue were observed around the implant and in the bone defect after 12 weeks. The direct bone–implant contact decreased after 12 weeks (p = 0.034). Although the implanted material properly filled the defect and promoted an initial activation of macrophages and osteoblasts, the resorption and simultaneous substitution did not reach expected levels during the experimental time course. Although other studies have shown that the addition of phosphoserine to calcium phosphate cements that have already been modified with collagen I resulted in an acceleration of cement resorption and bone regeneration, this study demonstrates that phosphoserine‐modified calcium phosphate cements without collagen perform poorly in the treatment of bone defects. Efforts to use phosphoserine in the development of new composites should take into consideration the need to improve osteoconduction simultaneously via other means. Copyright © 2010 John Wiley & Sons, Ltd.     

复合同种异体成骨细胞的β-磷酸三钙人工骨修复桡骨缺损

背景：作为骨支架材料,β-磷酸三钙具有良好的生物相容性、骨诱导性及生物力学性能。目的：探讨β-磷酸三钙复合同种异体成骨细胞修复兔桡骨节段性骨缺损的效果。方法：建立45只兔单侧桡骨骨缺损模型,随机分为3组,实验组缺损区植入复合同种异体成骨细胞的β-磷酸三钙,对照组缺损区植入β-磷酸三钙,空白对照组缺损区不植入任何材料。植入后4,8,16周观察新骨生成情况,通过形态学、X射线等观察指标客观评价各组成骨及骨缺损修复能力。结果与结论：随着修复时间的延长,实验组骨缺损逐渐修复,至16周时X射线见支架与宿主骨之间的骨痂已完全骨化,骨缺损完全修复;组织学见缺损区皮质骨连续,髓腔再通,并且不同时间点实验组修复效果明显优于对照组与空白对照组（P〈0.01）。表明复合同种异体成骨细胞的β-磷酸三钙人工骨具有良好的成骨能力,有引导组织再生、防止骨不连的作用。     

富血小板血浆促进脂肪间充质干细胞的体内外成骨

背景：添加富血小板血浆可促进细胞体外成骨表型的快速转化,从而有效成骨.目的：观察富血小板血浆对脂肪间充质干细胞体内和体外成骨能力的影响.方法：第3代兔脂肪间充质干细胞进行成骨诱导培养,分为对照组和富血小板血浆组.细胞接种到钙磷陶瓷支架上后,体内外观察细胞/载体复合物的成骨情况.结果与结论：两组细胞随着诱导时间的延长碱性磷酸酶活性增高,达到高峰值后随后逐渐下降,诱导后14 d时,富血小板血浆组即达到高峰值,对照组18 d达到高峰值.细胞/载体复合体切片Von Kossa染色显示两组载体的孔隙内衬面呈多层黑染状,有大量钙盐沉积.甲苯胺蓝染色显示载体的孔隙中可见成熟的骨质存在,周边区域较中心多.体外钙盐沉积对照组多,体内成骨面积富血小板血浆组多（P 〈 0.05）.说明,富血小板血浆可有效诱导脂肪间充质干细胞体内和体外成骨.     

Cells responding to surface structure of calcium phosphate ceramics for bone regeneration

Surface structure largely affects the inductive bone‐forming potential of calcium phosphate (CaP) ceramics in ectopic sites and bone regeneration in critical‐sized bone defects. Surface‐dependent osteogenic differentiation of bone marrow stromal cells (BMSCs) partially explained the improved bone‐forming ability of submicron surface structured CaP ceramics. In this study, we investigated the possible influence of surface structure on different bone‐related cells, which may potentially participate in the process of improved bone formation in CaP ceramics. Besides BMSCs, the response of human brain vascular pericytes (HBVP), C2C12 (osteogenic inducible cells), MC3T3‐E1 (osteogenic precursors), SV‐HFO (pre‐osteoblasts), MG63 (osteoblasts) and SAOS‐2 (mature osteoblasts) to the surface structure was evaluated in terms of cell proliferation, osteogenic differentiation and gene expression. The cells were cultured on tricalcium phosphate (TCP) ceramics with either micron‐scaled surface structure (TCP‐B) or submicron‐scaled surface structure (TCP‐S) for up to 14 days, followed by DNA, alkaline phosphatase (ALP) and quantitative polymerase chain reaction gene assays. HBVP were not sensitive to surface structure with respect to cell proliferation and osteogenic differentiation, but had downregulated angiogenesis‐related gene expression (i.e. vascular endothelial growth factor) on TCP‐S. Without additional osteogenic inducing factors, submicron‐scaled surface structure enhanced ALP activity and osteocalcin gene expression of human (h)BMSCs and C2C12 cells, favoured the proliferation of MC3T3‐E1, MG63 and SAOS‐2, and increased ALP activity of MC3T3‐E1 and SV‐HFO. The results herein indicate that cells with osteogenic potency (either osteogenic inducible cells or osteogenic cells) could be sensitive to surface structure and responded to osteoinductive submicron‐structured CaP ceramics in cell proliferation, ALP production or osteogenic gene expression, which favour bone regeneration. Copyright © 2017 John Wiley & Sons, Ltd.     

Basic fibroblast growth factor enhances osteogenic and chondrogenic differentiation of human bone marrow mesenchymal stem cells in coral scaffold constructs

Temporomandibular joint (TMJ) disorders are commonly occurring degenerative joint diseases that require surgical replacement of the mandibular condyle in severe cases. Transplantation of tissue-engineered mandibular condyle constructs may solve some of the current surgical limitations to TMJ repair. We evaluated the feasibility of mandibular condyle constructs engineered from human bone marrow-derived mesenchymal cells (BMSCs). Specifically, human BMSCs were transfected with basic FGF (bFGF) gene-encoding plasmids and induced to differentiate into osteoblasts and chondroblasts. The cells were seeded onto mandibular condyle-shaped porous coral scaffolds and evaluated for osteogenic/chondrogenic differentiation, cell proliferation, collagen deposition and tissue vascularization. Transfected human BMSCs expressed bFGF and were highly proliferative. Osteogenesis was irregular, showing neovascularization around new bone tissue. There was no evidence of bilayered osteochondral tissue present in normal articulating surfaces. Collagen deposition, characteristic of bone and cartilage, was observed. Subcutaneous transplantation of seeded coral/hydrogel hyaluran constructs into nude mice resulted in bone formation and collagen type I and type II deposition. Neovascularization was observed around newly formed bone tissue; bFGF expression was detected in implanted constructs seeded with bFGF expressing hBMSCs. This report demonstrates that engineered porous coral constructs using bFGF gene-transfected human BMSCs may be a feasible option for surgical transplantation in TMJ repair.