Fresh bone marrow introduction into porous scaffolds using a simple low‐pressure loading method for effective osteogenesis in a rabbit model

Recent advances in tissue engineering techniques have allowed porous biomaterials to be combined with osteogenic cells for effective bone regeneration. We developed a simple low‐pressure cell‐loading method using only syringes and stopcocks, and examined the effect of this method on osteogenesis when applied to the combination of highly porous β‐tricalcium phosphate (β‐TCP) and fresh autologous bone marrow. Both block and granule β‐TCP scaffolds were used to prepare implants in three different ways: without bone marrow as a control, with bone marrow that was allowed to penetrate spontaneously under atmospheric pressure (AP group), and with bone marrow that was seeded under low pressure (ULP group). These implants were transplanted into rabbit intramuscular sites, and the samples were examined biologically and histologically. The penetration efficiency of the block implants after marrow introduction was significantly higher in the ULP group than in the AP group. In the transplanted block samples, alkaline phosphatase activity was significantly higher in the ULP group at 2 weeks after implantation, and significantly more newly formed bone was observed in the ULP group at both 5 and 10 weeks compared with the AP group. Similar results were observed even in the experiment using β‐TCP granules, which are smaller than the blocks and frequently used clinically. Because of its convenience and safety, this low‐pressure method might be a novel, effective treatment to promote osteogenesis with bone marrow in clinical bone reconstruction surgeries. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1–7, 2009     

Repair of the radial defect of rabbit with polyester/ tricalcium phosphate scaffolds prepared by rapid prototyping technology

Objective： To evaluate the effects of repairing rabbit radial defects with polyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with bovine bone morphogenetic protein （ bBMP）, and find new carriers for growth factors. Methods： Polyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with and without bovine BMP were used to repair the 15 mm radial defect in rabbit. Then the results of radiography, histology, scaffolds degrade rates and bone mineral density （BMD） were appraised to examine the effects at the 12th week. Results ： At the 12th week postoperatively, all defects treated with bBMP were radiographically repaired. No radius implanted polyester/tricalcium phosphate scaffolds without bBMP showed radiographic and histological union. At experimental groups, longitudinal alignment of lamellar structure was observed histologically at the 12th week,indicating that remodeling of regenerated bone was complete in different degree. Of the three experimental groups, the bony regeneration and remodeling of callus in poly lactide-co-glycolide/tricalcium phosphate （PLGA/ TCP） group was the best. The BMD values were beyond 70% of normal value at the 12th week while the PLGA/ TCP scaffolds group was the highest, and no abnormalities were observed in the surrounding soft tissue in all groups. Conclusions - Polyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with bovine BMP can repair a 15 mm radial defect of rabbit. As for the results, the PLGA/TCP scaffold is ideal and better than poly L-lactide-co-D, L-lactide （ PDLLA/TCP ） scaffold, but the ploy L-lactic acid （PLLA/TCP） is not so good for its low degradation rates.     

骨组织工程中促进血管化策略的研究进展

随着骨组织工程的不断发展,各种新型的骨移植材料为骨缺损的治疗提供了新的选择。目前骨组织工程技术面临的主要难点是保证骨移植材料在植入后早期、快速地实现材料内部的血运重建,即血管化问题。血管长入为骨组织的再生和重建提供必要的营养支持,因此血管化一直是骨组织工程领域研究的焦点。然而目前还没有一种促血管化的金标准策略。支架材料、种子细胞和生长因子作为组织工程3个要素仍是目前各种促血管化策略努力的基本方向,其中多种生长因子、多种细胞复合支架材料联合构建组织工程骨等方法取得了良好的血管化效果,是近来研究的热点。     

Fetal tissue engineering: chest wall reconstruction

Background/Purpose: This study was aimed at applying fetal tissue engineering to chest wall reconstruction.Methods: Fetal lambs underwent harvest of elastic and hyaline cartilage specimens. Once expanded in vitro, fetal chondrocytes were seeded onto synthetic scaffolds, which then were placed in a bioreactor. After birth, fetal cartilage constructs (n = 10) were implanted in autologous fashion into the ribs of all lambs (n = 6) along with identical, but acellular scaffolds, as controls (n = 6). Engineered and acellular specimens were harvested for analysis at 4 to 12 weeks postimplantation. Standard histology and matrix-specific staining were performed both before implantation and after harvest on all constructs.Results: Regardless of the source of chondrocytes, all fetal constructs resembled hyaline cartilage, both grossly and histologically, in vitro. In vivo, engineered implants retained hyaline characteristics for up to 10 weeks after implantation but remodeled into fibrocartilage by 12 weeks postoperatively. Mononuclear inflammatory infiltrates surrounding residual PGA/PLLA polymer fibers were noted in all specimens but most prominently in the acellular controls.Conclusions: Engineered fetal cartilage can provide structural replacement for at least up to 10 weeks after autologous, postnatal implantation in the chest wall. Fetal tissue engineering may prove useful for the treatment of severe congenital chest wall defects at birth.     

胶原/羟基磷灰石支架负载软骨细胞修复兔膝关节骨软骨缺损

目的 探讨胶原复合梯度羟基磷灰石(Col/HA)双相支架负载软骨细胞修复兔膝关节骨软骨缺损的可行性及疗效.方法 构建Col/HA双相支架,将软骨细胞种植于支架培养1周,再将软骨细胞-支架复合体移植修复兔膝关节股骨髁的骨软骨缺损,并对骨软骨缺损的修复进行检测.结果 光镜及扫描电镜观察显示软骨细胞在Col/HA支架中贴附良好,表型维持稳定,分泌胞外基质.大体观察和组织学检测显示,植入体内16周后实验组软骨层呈透明软骨样修复,软骨下骨缺损有新骨构建;对照组骨软骨缺损修复不良,组织学检测以纤维性组织或纤维软骨组织形成.Wakitani评分显示实验组修复组织优于对照组,差异有统计学意义(P＜0.05).结论 双相Col/HA复合支架可作为骨软骨组织工程支架,负载软骨细胞可修复兔膝关节骨软骨缺损,重建关节软骨的结构和功能.     

同种异体脂肪干细胞复合脱钙骨修复大鼠尺骨缺损

目的探讨同种异体脂肪干细胞修复管状骨缺损的可行性。方法获取SD大鼠的腹股沟处脂肪,分离培养脂肪干细胞（Adipose-Derived Stem Cells,ADSCs）;鼠第3代ADSCs与脱钙骨复合,24 h后进行成骨诱导培养。检测细胞在材料表面的生长及成骨分化能力。建立鼠两侧尺骨缺损模型,分别植入鼠ADSCs-脱钙骨复合物（实验侧）和单纯脱钙骨材料（对照侧）;8周、24周后取样,行DR和组织学检测,观察成骨情况。结果 ADSCs能在脱钙骨上很好地黏附和生长,并维持成骨分化能力。细胞-材料复合物植入24周后,DR显示实验侧有新生骨基质长成,对照侧未见骨组织生成。组织学检测显示,实验侧缺损区被典型的骨组织取代,可见新生骨小梁附着于脱钙骨表面;对照侧只有少量的骨组织和纤维组织充填。结论 ADSCs-脱钙骨材料复合物植入,能成功修复临界大小的管状骨缺损。     

转染Ang-1间充质干细胞加强兔骨缺损修复的实验研究

目的 研究转染血管生成素-l(angiopoiten—1．Ang—1)基因的骨髓间充质干细胞(bone-mesenchvmal stem cells，BMSCs)对免骨缺损的修复作用。方法以脂质体介导pCDNA3．Ang—1质粒转染体外分离培养的兔BMSCs，与TCP陶瓷复合，修复兔桡骨15mm长节段性骨缺损?以未转染细胞作对照，进行电镜、组织学及核素扫描等方法检测骨修复情况。结果细胞与TCP材料复合后生长良好。组织学检查见转染细胞组毛细血管生长及新骨形成活跃，核素扫描见实验组局部血供丰富、代谢旺盛。结论Ang—l转染细胞组血供增加和骨修复加速，与细胞因子局部定向释放，加强血管形成及骨代谢有关。Ang—1修饰的BMSCs预构人工骨有助于加速骨缺损的修复?     

Optimization of bone tissue engineering in goats: a peroperative seeding method using cryopreserved cells and localized bone formation in calcium phosphate scaffolds

BACKGROUND: Bone tissue engineering by combining cultured bone marrow stromal cells with a porous scaffold is a promising alternative for the autologous bone graft. Drawbacks of the technique include the delay necessary for cell culture and the complicated logistics. We investigated methods to bypass these drawbacks. Furthermore, we investigated the localization of bone formation inside the scaffold. METHODS: Bone marrow stromal cells from seven goats were culture expanded and cryopreserved. One week before surgery, some of the cells were thawed, cultured, and seeded on porous calcium phosphate scaffolds. The constructs were cultured for another week until implantation. The remaining cryopreserved cells were thawed just before implantation and peroperatively resuspended in plasma before combining with the scaffold. Scaffolds impregnated with fresh bone marrow, devitalized cultured constructs, and empty scaffolds served as controls. All samples were implanted in the back muscles of the goats for 9 weeks. RESULTS: Histologic examination showed minimal (<1%) bone in the empty and devitalized scaffolds, 4.2 +/- 5.1 bone area percent in the bone marrow samples, and significantly more bone in both the cultured and peroperatively seeded constructs (11.7 +/- 2.5 and 14.0 +/- 2.0%). The peripheral 350 microm of the implants contained significantly less bone. CONCLUSION: Peroperative preparation of osteogenic constructs with cryopreserved cells is feasible. These constructs yield substantially more bone than the scaffolds alone or scaffolds impregnated with fresh bone marrow. Bone deposition is much less on the scaffold periphery.     

Apatite-coated silk fibroin scaffolds to healing mandibular border defects in canines

Tissue engineering has become a new approach for repairing bony defects. Highly porous osteoconductive scaffolds perform the important role for the success of bone regeneration. By biomimetic strategy, apatite-coated porous biomaterial based on silk fibroin scaffolds (SS) might provide an enhanced osteogenic environment for bone-related outcomes. To assess the effects of apatite-coated silk fibroin (mSS) biomaterials for bone healing as a tissue engineered bony scaffold, we explored a tissue engineered bony graft using mSS seeded with osteogenically induced autologous bone marrow stromal cells (bMSCs) to repair inferior mandibular border defects in a canine model. The results were compared with those treated with bMSCs/SS constructs, mSS alone, SS alone, autologous mandibular grafts and untreated blank defects. According to radiographic and histological examination, new bone formation was observed from 4 weeks post-operation, and the defect site was completely repaired after 12 months for the bMSCs/mSS group. In the bMSCs/SS group, new bone formation was observed with more residual silk scaffold remaining at the center of the defect compared with the bMSCs/mSS group. The engineered bone with bMSCs/mSS achieved satisfactory bone mineral densities (BMD) at 12 months post-operation close to those of normal mandible (p > 0.05). The quantities of newly formed bone area for the bMSCs/mSS group was higher than the bMSCs/SS group (p < 0.01), but no significant differences were found when compared with the autograft group (p > 0.05). In contrast, bony defects remained in the center with undegraded silk fibroin scaffold and fibrous connective tissue, and new bone only formed at the periphery in the groups treated with mSS or SS alone. The results suggested that apatite-coated silk fibroin scaffolds combined with bMSCs could be successfully used to repair mandibular critical size border defects and the premineralization of these porous silk fibroin protein scaffolds provided an increased osteoconductive environment for bMSCs to regenerate sufficient new bone tissue.     

重组人骨形成蛋白2诱导的骨膜细胞构建组织工程骨的实验研究

目的通过组织工程技术方法，研究细胞-材料复合体体内骨再生的能力。方法采用材料学自组装技术的原理．以Ⅰ型胶原蛋白为分子模板．引导钙磷盐在液相中的矿化，制备具有天然骨基质层状结构的羟基磷灰石／胶原复合材料，并以热致分相法制备羟基磷灰石／胶原-聚乳酸[hydroxyapatite／collagen—poly-(L—lactic acid)，HAC—PLA]复合三维多孔框架，与重组人骨形成蛋白2(recombinant human bone morphogenetic protein2，rhBMP-2)诱导分化后的兔骨膜细胞构建组织工程骨，进行体外电镜及组织学观察。将3月龄裸鼠18只，分为3组，每组6只。A组皮下注射经rhBMP-2处理后的骨膜细胞悬液，B组植入未复合细胞的HAC—PLA，C组植入rhBMP-2处理后的细胞-材料复合体。术后8周取材行组织学观察，C组与B组及A组进行比较。结果三维多孔HAC—PLA框架材料孔隙率大于90％，孔径为50～300μm。骨膜细胞经500ng／ml的rhBMP-2处理后，与改善亲水性后的HAC—PLA三维多孔框架复合，构建组织工程骨。电镜显示接种的细胞能在此组织工程骨内部生长增殖，术后8周C组有新骨形成，A组注射部位表面平整，无新生物，B组为纤维组织，无骨及软骨形成。结论所构建的组织工程骨有望成为骨创伤修复治疗一种新的技术。     

自体骨髓间充质干细胞复合壳聚糖/羟基磷灰石支架修复兔膝骨软骨缺损

目的 探讨骨髓间充质干细胞(bone mesenehymal stem cells,BMSCs)复合壳聚糖(chitosan,CS)/羟基磷灰石(hydmxyapatite,HA)支架修复兔膝关节局部骨软骨缺损.方法 选健康日本大耳白兔36只,2～3月龄,体重1.7～2.0 kg,每只抽取自体骨髓4～6ml,体外分离培养BMSCs后以2×107/ml密度植于CS/HA支架上体外培养10 h,制成BMSCs-CS/HA支架复合物.将36只实验动物手术制成右膝股骨外侧髁负重区骨缺损模型后,随机分成A、B、C 3组,每组12只.A组植入BMSCs-CS/HA复合物,B组植入单纯CS/HA支架;C组不作任何植入,为空白对照组.分别于术后6周、12周各处死6只动物,取材后进行大体、组织学观察6根据改良Wakitani评分标准进行评分,评估软骨组织的修复情况,并行成组设计方差分析.结果 A组术后6周即可重建关节软骨缺损;修复软骨在观察期内逐渐变厚,软骨下骨有少量骨修复;术后12周透明软骨样修复,表面光整,与周围软骨色泽相近,软骨下骨有部分修复.而B组和C组12周时缺损区仍为纤维软骨样纤维组织修复,色泽浅黄.术后6、12周各组组织学半定量评分显示:股骨髁负重区修复A组评分明显优于B、C组(F=27.26,P＜0.05).结论 自体BMSCs复合CS/HA支架在体内环境下可形成透明软骨修复兔膝关节负重区骨软骨缺损.     

黄芪多糖/壳聚糖/聚乳酸为支架的组织工程骨修复牙周组织缺损的实验研究

目的 探讨以黄芪多糖／壳聚糖／聚乳酸（astragalus polysaccharides／chitosan／polylacticacid，AP／C／PLA）为支架的组织工程技术修复水平型牙周组织缺损的可行性。方法成年健康雄性杂种犬10只，体重13±2kg，以犬骨髓基质细胞（marrow stromalcells，MSCs）为种子细胞，分别与AP／C／PLA及C／PLA支架构建组织工程复合物。10只实验犬于双侧下颌第3、4前磨牙颊侧制备水平型牙周缺损模型。将牙周缺损模型随机分为4组（n=10）：A组，缺损直接龈瓣冠向复位缝合，作为空白对照；B组，缺损处植人AP／C／PLA和条件培养基，龈瓣冠向复位缝合，作为培养基对照；C组，缺损处复合植入C／PLA和MSCs，龈瓣冠向复位缝合，作为材料对照；D组，缺损处复合植入AP／C／PLA和Mscs，龈瓣冠向复位缝合，作为实验组。术后8周，分别收集牙周标本行大体观察、X线片及组织学观测。结果 体外诱导培养的MSCs表达1型胶原及碱性磷酸酶，具有成骨细胞活性。各组动物对手术耐受性好，术后观察期内未见支架材料暴露，伤口愈合良好。X线片检查可见，A组牙槽骨密度及高度无明显增加；B组骨密度有一定程度增加，根分叉处增高的牙槽骨量少，邻间牙槽骨无明显增加；C组骨密度增加，根分又处牙槽骨基本恢复原有高度，邻间牙槽骨增加不明显；D组骨密度明显增加，根分叉处和邻间牙槽骨基本恢复原有高度。组织学观察显示，与A组相比，D组形成更多的新生牙槽骨、牙周膜和牙骨质，且新生牙槽骨矿化程度高，骨板排列趋向规则，出现整齐同心圆状的哈佛系统，基本具备骨组织的正常结构；牙槽骨与牙周膜的连接面呈锯齿状，沿根面还可见薄层的牙骨质沉积；新生牙周膜纤维呈束状，排列较密集且呈方向性，类似Sharpey’s纤维。A、B、C、D组新生牙槽骨高度分别为0．83±0．30、1．46±0．55、2．67±0．26及2．90±0.41mm；新生牙骨质高度分别为0．78±0．45、1．30±0．60、2．29±0．18及2．57±0．22mm；新生结缔组织附着高度分别为0．80±0．22、1．33±0．34、2．23±0．42及2．64±0．27mm；各指标D组与A、B、C组比较，差异均有统计学意义（P〈0．05）。结论 以AP／C／PLA为支架材料构建的组织工程骨修复水平型牙周骨缺损可以获得部分牙周组织再生。     

新型神经支架材料的构建及其与骨髓基质干细胞复合的实验研究

[目的]研制出一种可用于修复周围神经缺损的组织工程支架材料,并观察体外培养的骨髓基质干细胞在支架材料中的生长情况。[方法]以I型胶原蛋白和明胶通过冷冻干燥技术制备胶原蛋白支架材料。扫描电镜观察内部结构的排列规律及走行,测量其孔径大小、孔隙率等指标。将骨髓基质干细胞复合到胶原蛋白支架材料中共培养5 d后,扫描电镜下观察其在材料内部的生长情况。[结果]构建的材料均为圆柱状,内部为孔径均匀且平行排列的微管结构,体外培养的骨髓基质干细胞成功种植在支架材料上,在材料内部生长良好。[结论]构建的支架材料具有良好的三维空间构形和生物相容性,为神经损伤的修复提供了一种新型的支架材料。     

转染BMP-2基因的兔BMSCs种植PLA/PCL支架体外构建组织工程骨

目的:用腺病毒载体将人骨形态发生蛋白-2(BMP-2)基因导入兔骨髓基质干细胞(BMSCs),种植PLA/PCL(聚乳酸/聚己内酯)支架体外构建组织工程骨.方法:蛋白印迹法检测转染后细胞BMP-2的表达,流式细胞仪和ALP活性检测分析基因转染对细胞增殖分化的影响.然后将转染后细胞接种到PLA/PCL支架上,扫描电镜观察细胞贴附、生长状况.结果:转染后,BMSCs表达BMP-2,S期细胞比例和ALP活性明显增高.扫描电镜见转染细胞分布均匀,伸展良好.结论:BMP-2基因转染BMSCs,可促进细胞增殖分化.转染后细胞在PLA/PCL支架上生长良好,BMP-2基因治疗的组织工程骨构建成功.     

以珊瑚转化羟基磷灰石为支架材料构建组织工程骨的实验研究

目的 探讨以珊瑚转化羟基磷灰石（CHA）作为骨组织工程支架材料的可行性。寻找最佳支架材料,为组织工程研究开辟新的途径。方法 取4周龄兔骨髓,分离骨髓基质细胞,体外培养,诱导分化为成骨细胞,胰酶消化后离心收集细胞,接种至高温灭菌的CHA材料,无菌条件下植入8只裸鼠皮下组织中,对照组为同体单纯植入CHA,分别于6、8周取材,行大体观察、X线摄征及组织学染色,观察新骨形成情况。结果 实验组6周时大体标本浅红色,X线片有较高密度阻射影像,组织学检查可见有新骨形成,8周时大体标本呈红色,质硬,X线阻射影像密度更高,镜下可见大量新骨形成并相互连接成骨小梁样结构。骨细胞位于陷窝中,对照组8周大体标本均为白色,周围软组织包裹,X线片仅见CHA阻射影。组织学检查无新骨形成,为大量纤维组织长入CHA孔洞内。结论 CHA可作为骨组织工程的支架材料,具有广阔的应用前景。     

双相磷酸钙组织工程骨块重建股骨头内骨缺损的实验研究

目的 观察在体外构建的具有仿生结构的双相磷酸钙（biphasic calcium phosphate，BCP）组织工程骨块植入犬股骨头缺损内的骨再生情况及预防股骨头塌陷的效果。方法 以犬股骨头的松质骨样本Micro—CT（micro—computed tomography）图像为基础，提取其中的图像信息，利用三维凝胶叠层成形法制备出具有仿骨小梁结构的陶瓷支架。在体外利用诱导分化的自体骨髓间充质细胞与仿生BCP支架复合，构建组织工程骨块，将其植入10只犬的股骨头负重区骨缺损内；另取10只火作为对照组，在股骨头骨缺损区内打球植入自体松质骨粒，对比观察仿生BCP骨块的植入效果。结果 制备出的股骨头仿生BCP支架具有良好的三维空间结构，支架小梁具有一定的方向性，呈板状模型；细胞在支架表面大量生长。植入动物体内30周后，实验组火股骨头外形基本完整，新生骨质包绕支架小梁并沿支架表面生长，而对照组犬股坩头均出现不同程度的塌陷。结论 仿生BCP组织工程骨块具有良好的生物相容性，植入犬股骨头负曩区骨缺损后，能在一定程度上防止股骨头塌陷。     

自体脂肪干细胞复合珊瑚修复犬颅骨标准缺损的初步研究

目的 应用自体脂肪干细胞(adipose-derived stem cells,ADSCs)复合珊瑚构建组织工程化骨,修复犬颅骨标准缺损.方法 体外扩增培养、成骨诱导Beagle犬ADSCs,将第2代细胞接种在珊瑚支架上共同培养.制造实验犬双侧颅骨全层标准缺损(20 mm×20 mm),一侧以细胞材料复合物修复作为实验组(n=7),另一侧以单纯珊瑚材料修复作为对照组(n=7).术后24周分别通过影像学、大体形态观察、生物力学检测、组织学方法检测颅骨缺损的修复效果.结果 成骨诱导的犬ADSCs体外呈现成骨特性,在珊瑚支架上生长良好.3D-CT重建显示术后12周实验组有新生骨痂形成,对照组材料大部分降解;24周时实验组为骨性愈合,对照组为骨不连.24周时实验组缺损修复百分比为(84.19±6.45)%,显著高于对照组的(25.04 ±18.82)%(P<0.01).大体观察见实验组由新生骨痂修复缺损,对照组缺损边缘可见少量骨痂形成,主要为软组织充填;24周生物力学检测修复组织能耐受的最大压力载荷,实验组为(73.45±17.26)N,为犬顶骨最大压力负荷(104.27±22.71)N的70%,两者比较差异有统计学意义(P<0.01),对照组为软组织无法完成上述检测.HE染色见实验组有较多成熟骨呈骨性愈合,对照组为纤维性愈合.结论 自体成骨诱导的ADSCs复合珊瑚形成的组织工程化骨可修复犬颅骨标准缺损.     

组织工程骨-软骨复合体修复犬股骨头负重区大面积骨软骨缺损的实验研究

目的 探讨采用犬股骨头负重区骨和天然软骨制备的骨-软骨双层支架复合成软骨诱导的骨髓间质干细胞(bone marrow mesenchymal stem cells,BMSCs)修复犬股骨头负重区大面积骨软骨缺损的疗效.方法 利用软骨细胞外基质作为软骨支架部分,犬股骨头负重区骨柱经脱细胞处理后作为骨支架部分,采用相分离技术制备骨-软骨双层支架.将成软骨诱导的BMSCs种植到双层支架上体外构建组织工程骨-软骨复合体,并以此修复犬股骨头负重区大面积骨软骨缺损(直径11 mm,高10 mm),第3、6个月时分别取材,行大体、X线片、组织学、Micro-CT和生物力学等检测.结果 X线片及大体观察:3个月时可见股骨头负重区出现轻度塌陷;6个月时出现严重塌陷,呈重度骨关节炎改变.组织学观察:第3、6个月时软骨缺损部分均以纤维组织或纤维软骨充填,周围软骨退变,骨缺损部分不同程度塌陷,与宿主骨质结合紧密.第3、6个月时骨软骨缺损的骨体积分数均低于正常股骨头,差异有统计学意义.6个月时重建软骨下骨的刚度明显低于正常股骨头,差异有统计学意义.结论 结构性骨-软骨双层支架复合成软骨诱导的BMSCs修复犬股骨头负重区骨软骨缺损效果不佳,易导致股骨头塌陷.

Abstract：

Objective To investigate the effects of the novel scaffold on repairing large,high-loadbearing osteochondral defects of femoral head in a canine model.Methods The biphasic scaffolds were fabricated using cartilage extracellular matrix (ECM)-derived scaffold (cartilage layer) and acellular bone matrix (bone layer) by phase separation technique.Articular high-load-bearing osteochondral defects with a diameter of 11-mm and the depth of 10-mm were created in femoral heads.The defects were treated with constructs of a biphasic scaffold seeded with chondrogenically induced bone marrow-derived mesenehymal stem cells (BMSCs).The outcomes were evaluated for gross morphology,histological,biomechanical and micro-CT analysis at the third and sixth month after implantation.Results The gross and X-ray results showed femoral head slightly collapsed at the third month and severely collapse at the sixth month.Histological analysis showed cartilage defects were repaired with fibrous tissue or fibrocartilage with severe osteoarthritis and the varied degrees of the collapse of femoral heads were presented.Micro-CT showed that the values of bone volume fraction in defect area were always lower than those of the normal area in the femoral heads.Biomechanical analysis showed rigidity of the subchondral bone in defect area was significantly lower than that in normal area in the femoral heads at the sixth month.Conclusion The ECM-derived,integrated biphasic scaffold seeded with chondrogenically induced BMSCs could not successfully repair the large high-load-bearing osteochondral defects of the femoral head.     

新型双相陶瓷材料复合成骨细胞构建人工骨及其体内成骨的观察

目的 观察骨髓来源的成骨细胞与新型双相陶瓷材料复合培养后细胞生长状况及其体内异位成骨能力。方法 将来源于兔骨髓的成骨细胞与新法制备的HA/TCP共培养2周,通过相差显微镜、扫描电镜观察体外细胞生长情况;然后将复合物自体异位植入体内,6周后观察体内成骨情况。结果 扫描电镜显示材料表面和孔隙内均有成骨细胞生长,有良好增殖活动性和稳定细胞表型,材料中心区未见细胞生长;植入体内6周后取材见内植物有新骨形成、多位于内植物表面,可见成骨细胞、骨细胞、髓腔样结构、板层样骨基质等正常骨组织结构。结论 新型双相陶瓷支架可用作组织工程骨的细胞外基质材料,骨髓来源的成骨细胞可用作骨组织工程的种子细胞。     

Clinical relevance of scaffolds for cartilage engineering

The repair of articular cartilage defects in patients' knees presents a particular challenge to the orthopedic surgeon because cartilage lacks the ability to repair or regenerate itself. Various cartilage repair techniques have not produced a superior or uniform outcome, which has led to a new generation of cartilage repair based on tissue-engineering strategies and the use of biological scaffolds. Clinical advances have been made regarding the regeneration of articular cartilage, and continue to be made toward the achievement of a suitable treatment method for resurfacing osteochondral defects, through cartilage tissue engineering and the use of pluripotent cells seeded on bio-scaffolds.