自体骨软骨移植与含富集骨髓干细胞松质骨移植修复兔关节软骨缺损

目的:评价自体骨软骨移植与含富集骨髓干细胞松质骨镶嵌移植两种方法修复全层关节软骨缺损的生物学特征和效果。方法:采用新西兰大白兔制作左右后肢全层软骨缺损模型,分别进行自体骨软骨镶嵌移植、含富集骨髓干细胞松质骨镶嵌移植修复,对照组不作任何修复,每组12只。术后第4、8、12周处死动物取材,分别进行膝关节活动度测定、大体观察、光镜观察与电镜观察。结果:移植实验组在第12周时均能以类透明软骨组织修复缺损,对照组为纤维肉芽组织。形态学检查表明,两种方法均能以类透明软骨组织覆盖缺损,骨软骨移植组无明显免疫排斥现象,随着时间延长,修复高度逐渐增加。骨软骨移植组同含富集骨髓干细胞松质骨镶嵌移植组效果无显著差别。结论:骨软骨移植、含富集骨髓干细胞松质骨镶嵌移植两种方法均能以类透明软骨组织修复全层关节软骨缺损,含富集骨髓干细胞松质骨镶嵌移植更适用于较大面积软骨缺损的修复。     

自体软骨细胞团块植入修复兔陈旧性关节软骨缺损的实验研究

目的 观察自体软骨细胞团块植入对兔关节软骨缺损的修复作用. 方法 24只成年新西兰大白兔48侧膝关节,随机分为三组(n=16)并制备双膝关节股骨滑车软骨缺损模型.空白对照组无特殊处理,骨膜移植组将骨膜覆盖缺损并缝合于缺损两侧的股骨髁上,实验组将自体软骨细胞团块植入缺损中.术后3、6个月分别取材(n=8),进行大体和组织学观察,修复组织行Wakitani评分并进行比较. 结果实验组共成功取材11个缺损关节,9个为透明软骨修复,2个因植入细胞生长状态差未修复;骨膜移植组修复组织为纤维软骨或纤维组织,修复组织薄,基质异染弱;空白对照组仅有少量纤维组织填充缺损底部.修复组织Wakitani评分:实验组3.82分,骨膜移植组6.71分,空白对照组9.23分,差异有统计学意义(F=5.96,P=0.00). 结论自体软骨细胞团块植入能较好修复关节软骨缺损,修复的质量与植入细胞的质量有关.     

自体软骨细胞移植修复猪膝关节软骨缺损的实验研究

目的评价传统和复层高密度培养（复层培养）的自体软骨细胞移植修复关节软骨缺损的效果。方法在8头猪16膝髌切迹上下共建立32个全层软骨缺损，右膝为空白和自体骨膜移植对照组，左膝为传统的自体骨膜覆盖下细胞注射移植组和自体骨膜覆盖下复层培养细胞移植组（上下缺损随机进入各对照和实验组）。术后5-6个月对缺损部位行大体、组织学、免疫组织化学检查。采用O’Driscoll软骨组织形态学评分评价软骨缺损的修复质量。结果四组的O’Driscoll软骨组织形态学评分分别为（3．14±1．95）分、（10．57±3．60）分、（16．29±2．63）分、（20．43±1．81）分，各组之间差异均有统计学意义（P〈0．01）。空白对照组缺损被少量的纤维组织覆盖；骨膜移植组被纤维组织和少量的纤维软骨修复，且与周围组织整合差。自体软骨细胞移植（注射组和复层培养组）缺损被塑形良好的修复组织覆盖，组织学、基质特殊染色示修复组织为纤维软骨和透明软骨，与周边软骨和软骨下骨整合良好。复层培养组修复组织的细胞形态、基质染色比注射细胞组更接近正常软骨。结论自体软骨细胞移植可成功修复全层关节软骨缺损。扩增后的软骨细胞经短期复层培养更有利于软骨缺损的修复。     

自体骨髓间充质干细胞和软骨细胞共培养复合同种异体完全脱蛋白骨修复关节软骨全层缺损的研究

[目的]探讨自体骨髓间充质干细胞(bone m arrow-derived m esenchym al stem cells,BMSCs)与软骨细胞共培养复合同种异体完全脱蛋白骨(fu lly deprote in ized bone,FDB)修复关节软骨缺损的可行性,评价修复效果,为优化种子细胞源提供依据。[方法]取浓度为3×106/m l的第二代BMSCs和软骨细胞,按2:1比例混匀共培养作为种子细胞。FDB与共培养细胞复合接种植入修复缺损为实验A组、单纯FDB为对照B组和不处理为空白对照C组,移植8、16周后经人体观察、组织学评分和免疫组化染色评价缺损的修复。[结果]共培养的软骨细胞基质合成丰富,细胞增殖快。A组缺损修复组织呈软骨样,表面光滑平坦,与周围软骨整合的软骨细胞更为成熟。B组和C组的修复组织呈纤维组织和无修复。组织学评分表明A组优于B、C 2对照组,差异具有统计学意义(P<0.01),B组与C组差异无统计学意义(P>0.05)。免疫组化染色显示A组修复组织的细胞为透明软骨样细胞,柱状排列,Ⅱ型胶原染色阳性,与周围软骨及软骨下骨整合良好。[结论]自体BMSCs与软骨细胞共培养作为种子细胞,BMSCs能增强软骨细胞的增殖,促进软骨细胞基质合成,缩短软骨细胞培养时间和减少传代次数,节省大量的软骨细胞,与FDB复合后能有效修复关节软骨缺损。     

培养软骨移植修复关节软骨缺损的实验研究

目的：为探讨一种新的关节软骨缺损修复方法。方法：将体外培养２周形成软骨样组织,移植修复兔关节软骨全层缺损。于移植术后２、４、８周分别行功能评价、大体形态及组织学检查。结果：全部实验兔于术后２周内恢复正常活动。２周时移植修复组织由非成熟透明软骨组成。４周时部分移植组出现成熟透明软骨。８周时移植组关节软骨缺损全部由成熟透明软骨充填修复,修复组织与邻近关节软骨融合。培养软骨移植修复关节软骨全层缺损明显优于自身修复（Ｐ＜００１）。结论：本实验提示使用具有高有丝分裂率的软骨细胞,经离心管培养形成骺软骨样组织,植入关节软骨全层缺损后,软骨细胞生长良好,逐渐成熟和转化,能发挥良好的修复作用。     

hIGF-I基因增强Mosaicplasty技术重建膝负重区大面积骨软骨复合缺损实验研究

目的研究hIGF-I基因增强组织工程提高Mosaicplasty修复大面积骨软骨缺损的修复质量，改善骨软骨的整合。 方法制造山羊膝关节股骨髁大面积骨软骨缺损模型，使用自制Mosaicplasty器械，植入2 mm直径骨软骨柱镶嵌充填缺损，以hIGF-I基因转染的骨髓基质干细胞复合可注射藻酸钙凝胶填充残余缺损。同时设立未转染hIGF-I基因的骨髓基质干细胞组、Mosaicplasty组和对照组。术后4 w、8 w、16 w处死动物，行大体观察、光镜、电镜观察，磁共振检查比较修复效果。 结果骨软骨缺损在16 w时IGF-I基因增强Mosaicplasty组移植物固定牢固，关节面平滑，移植物间界限消失，新生软骨组织类似于正常软骨，4~16 w修复效果逐渐改善，优于其他各组。光镜观察见移植的骨软骨生长良好，与新生软骨组织紧密相连，新生的软骨细胞排列规整，细胞外基质分布均一。对照组无明显修复。MRI观察类似大体观察结果。 结论使用转染hIGF-I基因的骨髓基质干细胞复合可注射藻酸钙凝胶可促进Mosaicplasty后骨软骨的整合，改善其修复效果。     

自体软骨细胞修复关节软骨缺损的机制探讨

目的:观察团块样自体软骨细胞植入关节软骨缺损后的病理变化,探讨自体软骨细胞移植修复关节软骨缺损的病理生理机制。方法:24只3.0kg以上4～6月龄新西兰大白兔,雌雄不限,随机分为两组:实验组和对照组。实验组12只,20%的速眠新(1mg/kg)肌肉注射麻醉后取肩关节软骨组织,0.2%Ⅱ型胶原酶消化分离软骨细胞,体外单层培养,细胞长成肉眼可见的膜状后收集固体的组织样细胞团,动物再次麻醉制造双膝股骨滑车4.0mm×6.0mm方形缺损,植入细胞团块,骨膜覆盖,缝合骨膜于双股骨髁上。对照组12只,同实验组手术方法进行缺损单纯骨膜移植。1、3、12、24周两组各3只动物空气栓塞处死取材,观察细胞团块变化和缺损修复情况。结果:1周时软骨细胞朝向关节面部分细胞变大变圆,产生大量基质;3周时此种变化更加明显,但骨膜与细胞团块已然不能分开;12周时缺损为类透明软骨组织修复;24周时修复组织为透明软骨样组织,对照组为纤维软骨组织修复。结论:关节软骨细胞体外聚集培养形成的细胞团块内的细胞有迁移生长能力;细胞团块移植方法植入的细胞数量大,表型好,细胞在缺损内不会流失;关节软骨缺损修复是由植入的细胞团块生长分化而来;自体关节软骨细胞团块植入关节缺损内后,在关节应力的影响下,先从朝向关节面的一侧逐渐发生细胞成熟分化和软骨基质产生,逐渐完成缺损的修复。     

关节软骨源性多孔支架复合自体软骨细胞修复兔关节软骨缺损的长期疗效观察

[目的]对关节软骨源性多孔支架复合自体软骨细胞复合体修复兔膝关节软骨缺损的长期效果进行观察和评价。[方法]实验动物新西兰大白兔共10只,分两组:(1)关节软骨源性支架对照组:缺损内置入关节软骨源性支架;(2)关节软骨源性支架复合细胞组:缺损内置入关节软骨源性支架-自体软骨细胞复合体。手术后15个月取材做大体摄像,甲醛固定、10%EDTA脱钙,石蜡切片,采用四种组织化学染色法(HE、奥新兰(AB)、甲苯胺兰(TO)、藩红花"O"染色)和Ⅱ型胶原免疫组化染色,观察修复后的兔关节软骨组织细胞形态特征。[结果]关节软骨源性支架对照组,大体观察关节表面有凹陷。石蜡切片HE染色见未修复缺损处为梭形细胞,纤维软骨,缺损处AB、甲苯胺兰、藩红花"O"染色为阴性,Ⅱ型胶原染色为阳性;关节软骨源性支架复合细胞组,大体见关节软骨表面修复平整、光滑。常规HE染色镜下见软骨全层修复良好,为透明软骨细胞,可见软骨陷窝潮线排列结构。细胞外基质特染:AB、甲苯胺兰、藩红花"O",Ⅱ型胶原特种染色均为阳性。[结论]组织学观察结果发现,关节软骨源性支架组为纤维软骨组织结构,未能完全修复膝关节软骨缺损;而关节软骨源性支架复合细胞组关节软骨缺损修复良好,未见退变,具有软骨组织的特征。     

软骨移植与软骨下骨钻孔修复全层关节软骨缺损的比较实验研究

目的 :评价软骨移植、软骨下骨钻孔修复关节软骨缺损的生物特性和效果差异。方法 :采用重复拉丁方设计 ,将 36只雄性新西兰大白兔按三个因素三个水平进行随机区组 ,对左右后肢按设计好的创面大小制造全层软骨缺损。软骨移植组将不同家兔关节软骨交换嵌入移植。钻孔组依创面大小制造孔直径、间距、深度相同的骨孔 ,深达松质骨。对照组缺损不作任何修复。术后 4、8、1 2周处死取材 ,分别进行大体观察、光镜观察、电镜观察 ,对观察指标进行量化统计学分析。结果 :(1 )两实验组在第 1 2周时均能以类透明软骨组织修复缺损 ,而对照组为纤维肉芽组织 ,统计学分析表明各组间有显著性差异 (P <0 .0 1 )。 (2 )光镜观察表明两种手术方法均能以软骨的方式修复缺损 ,软骨移植组无明显免疫排斥迹象 ,软骨细胞有活性 ,各组间有显著性差异 (P <0 .0 1 )。 (3)形态学分析表明 ,随时间延长 ,光密度与修复高度渐增 ,其中软骨移植组优于其他各组 (P <0 .0 1 )。 (4)随时间延长修复效果逐渐改善。小创面修复效果与中等创面间无明显差异。 (5)电镜观察表明 ,两种手术方法均有软骨细胞生成 ,细胞器发达。对照组符合纤维肉芽组织特征。结论 :(1 )软骨移植、钻孔均能以类透明软骨的结局修复关节软骨缺损 ,软骨细胞生物学特性类似     

藻酸钙复合自体软骨细胞修复羊膝关节负重区软骨缺损的实验研究

[目的]以中国山羊为动物模型,观察藻酸钙复合自体软骨细胞修复膝关节负重区软骨缺损的可行性。[方法]取羊肩关节软骨,分离、培养软骨细胞,蕃红"O"、 Giemsa及Ⅱ型胶原免疫组织化学染色对其进行鉴定。将自体软骨细胞与藻酸钙凝胶复合,修复山羊股骨髁负重区全层软骨缺损(直径6 mm),实验分为四组:(1)缺损旷置组:缺损内未植入任何组织;(2)骨膜覆盖组:自体骨膜覆盖缺损区;(3)藻酸钙+骨膜组:凝胶植入软骨缺损区,并用自体骨膜覆盖;(4)藻酸钙+细胞+骨膜组:藻酸钙复合自体软骨细胞植入软骨缺损区,自体骨膜覆盖;分别于手术后3、6个月取材,通过大体观察及组织学评分检测修复效果。[结果]软骨细胞复合物蕃红"O"、 Giemsa染色及Ⅱ型胶原免疫组化染色结果均为阳性,将藻酸钙凝胶-软骨细胞复合物用于羊负重区关节面软骨缺损修复,从大体观察和组织学评分进行比较,发现各组均有不同程度的组织修复,藻酸钙+细胞+骨膜组效果最好,与其他组差异有统计学意义(P<0.05)。[结论]藻酸钙凝胶-软骨细胞复合物结合自体骨膜覆盖,可较好修复山羊膝关节负重区软骨缺损。     

"双相"组织工程软骨修复兔关节骨软骨缺损

目的探讨“双相”异体骨基质明胶（bonematrixgelatin,BMG）作为组织工程软骨载体,与同体骨髓间充质干细胞（marrowmesenchymalstemcells,MSCs）结合,构建组织工程软骨修复兔关节骨软骨缺损的效果。方法4月龄新西兰兔32只,雌雄不限,体重2～3kg。①体外实验：取5只新西兰兔,处死后取髂骨和四肢骨,制备一侧松质骨,一侧皮质骨的“双相”异体BMG载体,扫描电镜观察。另取新西兰兔18只,抽取骨髓,分离MSCs并诱导成软骨分化;将诱导而来的软骨前体细胞与“双相”BMG载体复合构建组织工程软骨,分别于1、3和5周取材行Masson、PAS染色和扫描电镜观察。②体内实验：将抽取骨髓的18只及余下的9只新西兰兔制成双侧股骨内髁骨软骨缺损模型,将前期制备的组织工程软骨同体植入18只兔的右股骨内髁骨软骨缺损（A组）,左侧缺损移植异体BMG（B组）,其余9只双侧软骨缺损未予处理作为空白对照（C组）,分别于术后1、3和6个月取材,行大体、组织学和Ⅱ型胶原mRNA原位杂交观察,改良Wakitani法评分,比较各组修复效果差异。结果①体外实验：“双相”BMG松质骨面孔隙大小100-800μm,细胞于其中增生,形成富含细胞的软骨层;皮质骨面孔隙大小10～40pm,细胞层状覆盖于其表面,可作为起支撑作用的软骨下骨。②体内实验：A组术后1个月即可重建关节骨软骨缺损;修复软骨在观察期内逐渐变薄,但在6个月内始终保持关节面及软骨下骨结构完整。B、C组未能修复缺损,缺损周边软骨磨损加剧。改良Wakitani评分显示A组在3个时间点的各项评分结果,除6个月软骨厚度外,其它指标均优于B、C组,且差异有统计学意义（P〈0．01）。Ⅱ型胶原mRNA原位杂交显示,A组缺损区修复组织中细胞阳性染色率明显高于B、C组,且差异有统计学意义（P〈0．01）。结论“双相”异体BMG可作为组织工程软骨载体材料,其结合自体MSCs诱导的软骨前体细胞制备的组织工程软骨,可修复兔关节软骨和软骨下骨。     

脱细胞软骨支架材料修复兔关节软骨缺损

目的 观察异种异体脱细胞软骨支架材料(ACM)复合同种异体兔骨髓间充质干细胞(rBMSCs)修复兔股骨内髁关节软骨缺损的效果.方法 (1)密度梯度离心和差速贴壁法获得原代兔BMSCs,选择第3代BMSCs作为种子细胞;(2)利用冷冻干燥、胰酶消化和化学去垢剂等方法制备脱细胞软骨支架材料;(3)3个月龄新西兰兔股骨内髁制备直径4 mm,深3 mm砌关节软骨缺损模型,24只新西兰兔以2个时间段随机分为3组,Ⅰ ACM-BMSCs组:第3代BMSCs 1×106个/ml与ACM于37℃5%CO2饱和湿度复合48 h;Ⅱ ACM组;Ⅲ空白对照组.(4)移植6、12周后大体及组织学观察,免疫组织化学染色观察修复组织Ⅱ型胶原,Wakitani评分评估修复效果.结果 (1)大体观察及组织学观察:6和12周Ⅰ组再生组织与正常关节软骨面平齐,修复部位表面较平整,界限模糊,接近正常软骨.Ⅱ组修复组织表面不平整并有明显下陷,修复组织全层可见成纤维样细胞,深层可见极少数透明软骨样细胞.Ⅲ组未见明显修复,肉芽组织形成伴成纤维样细胞增生;(2)Wakitani组织学评分可见在不同的时间段I组和Ⅱ组均低于Ⅲ组,差异有统计学意义(P<0.05),Ⅰ组和Ⅱ组间组织学评分差异无统计学意义(P>0.05).(3)免疫组织化学:ACM-BMSCs组修复组织的细胞为软骨样细胞,可见柱状排列,周围软骨基质Ⅱ型胶原染色阳性.结论 以ACM为支架材料,同种异体BMSCs为种子细胞制备的组织工程化软骨对兔股骨内髁关节软骨缺损有修复作用,形成的新生软骨为透明软骨样组织.     

兔自体松质骨颗粒修复关节软骨损伤

目的研究兔自体松质骨颗粒在膝关节软骨损伤处移植后能够诱导软骨组织生成、促进关节软骨损伤修复的现象。方法 12只新西兰大白兔麻醉后在兔的右侧膝关节股骨远端内、外侧髁负重区用电钻分别造成直径、深度均为3 mm的骨软骨缺损创面,取同侧髂骨松质骨,制成直径约为1 mm松质骨颗粒植入股骨内侧髁软骨缺损处,作为实验组,外侧髁软骨缺损不做处理作为对照组。术后12周进行膝关节大体观察、病理切片染色,评估关节软骨损伤的修复情况。结果兔膝关节实验组软骨缺损处被新生软骨填充,软骨面光滑,组织切片染色显示有关节软骨形成。对照组缺损创面仍然凹陷,仅在缺损边缘有少量软骨生长。结论兔自体松质骨颗粒在膝关节软骨损伤处能够诱导软骨生成,促进关节软骨的修复,是一种良好的关节软骨损伤修复方法。     

同种异体间充质干细胞复合纤维蛋白修复骨缺损

[目的]探讨骨髓间充质干细胞(m esenchym al stem cells,MSCs)的体外培养,以及同种异体MSCs复合纤维蛋白修复兔股骨髁松质骨缺损的效果。[方法]在日本大耳兔双侧股骨髁制作0.6 cm×1.0 cm松质骨缺损,左侧植入同种异体MSCs纤维蛋白复合物,右侧单纯植入纤维蛋白。分别于术后2、5、8周行放射学、组织学检查,以了解骨缺损修复情况。[结果]单纯植入纤维蛋白的一侧不能自行愈合。植入复合物的一侧术后2周可见少量骨组织生成,5周可见大量模糊骨痂,术后8周骨缺损基本愈合。除少量炎性细胞浸润外,各期均未见明显免疫排斥反应。[结论]同种异体MSCs复合纤维蛋白可有效修复兔股骨髁松质骨缺损,8周内机体的免疫排斥反应较弱。     

CS/PVA凝胶负载Ad-hTGF-β1转染的BMSCs移植修复兔关节软骨缺损

目的 探讨温敏型CS/PVA凝胶负载Ad-hTGF-β1转染的骨髓间充质干细胞(BMSCs)移植修复兔关节软骨缺损的实验效果.方法 体外分离培养兔BMSCs,在Ad-hTGF-β1转染1周后,用细胞免疫化学方法检测hTGF-β1在细胞内的表达.用24只成年新西兰大白兔制造关节软骨缺损模型,双侧后肢均用于实验,动物模型随机分为4组,各组动物6只.A组:凝胶复合转染BMSCs修复组;B组:凝胶复合未转染BMSCs修复组;C组:凝胶修复组;D组:空白对照组.在术后16周时处死动物取材,通过大体标本和组织学染色观察评价各组修复效果,按照改良Pinoda法评分,对各组修复效果进行统计学分析.结果 免疫组化证实体外培养的BMSCs在Ad-hTGF-β1转染后表达hTGF-β1蛋白,阳性率为85.4%.术后16周取材见凝胶复合转染细胞组关节软骨缺损部位为软骨样组织填充,组织学观察见再生的软骨组织细胞排列及细胞密度与正常软骨相似,Ⅱ型胶原免疫组化阳性,Pineda评分同其它各组相比差异有统计学意义(P＜0.05).结论 CS/PVA凝胶作为一种温敏型可注射支架材料,其负载hTGF-β1转染的BMSCs移植可用于兔关节软骨缺损修复.

Abstract：

Objective To investigate the experiment effects of rabbit joint articular cartilage defects repaired by thermosensitive CS/PVA composite hydrogel engineered hTGF-β1 transfected bone marrow mesenchymal stem cells. Methods Bone marrow mesenchymal stem cells were isolated and cultured in vitro. The positive rate of transfection was defected by cell immunohistochemistry methods after Ad-hTGF-β1 transfected for 1 week. Twenty-four adult New Zealand white rabbits with full articular cartilage defects were randomly divided into 4 groups, each group had 6 animals, both hind limbs were used in the experiment. Group A: hydrogel combined with transfected cells; Group B: hydrogel combined with untransfected cells; Group C: hydrogel group; Group D: blank control group. Specimens and histological observation were used to evaluate the repair effect after 16 weeks according to Pineda's score. Results The positive rate of hTGF-β1 expression in BMSCs was about 85.4% after transfection. After 16 weeks the defects of group A were repaired by cartilage-like tissue, the cell arrangement and densities of regenerated cartilage were similar to normal cartilage, type Ⅱ collagen immunohistochemistry were positive. There was a significant difference in Pineda's score compaired with other groups (P ＜ 0.05). Conclusion Rabbit articiular cartilage defects could be repaired by CS/PVA hydrogel engineered hTGF-β1-transfected bone marrow mesenchymal stem cells.     

兔骨髓间充质干细胞修复膝关节软骨缺损的实验研究

目的研究由同种异体兔骨髓间充质干细胞(MSCs)诱导分化的软骨细胞和聚乳酸-聚乙醇酸共聚物(PLGA)双层支架构建复合体对兔软骨缺损的修复作用。方法用密度梯度离心法和贴壁培养法获得5月龄兔骨髓来源间充质干细胞,在体外培养并进行分化诱导后作为种子细胞复合双层PLGA构建成复合体。36只兔在股骨髁间制造骨软骨缺损模型,分成三组,A组植入复合体,B组植入单纯双层PLGA支架,C组植入自体骨软骨。第24周取材进行大体观察、组织学检查和Wakitani评分。结果 A组及C组植入物愈合良好,组织学检查见Ⅰ、Ⅱ型胶原纤维形成。A组可见透明软骨修复。Wakitani评分A组2.75,B组7.00,C组1.98,A、C组与B组间统计学分析单项指标得分差异有统计学意义(P0.05),A组与C组间差异无统计学意义(P0.05)。结论诱导兔MSCs+PLGA双层支架能较好地修复兔膝关节骨软骨损伤。     

Repairing articular cartilage defects with tissueengineering cartilage in rabbits

Objective: To investigate the effect of cancellous bone matrix gelatin ( BMG ) engineered with allogeneic chondrocytes in repairing articular cartilage defects in rabbits. Methods: Chondrocytes were seeded onto three-dimensional cancellous BMG and cultured in vitro for 12 days to prepare BMG-chondrocyte complexes. Under anesthesia with 2.5% pentobarbital sodium (1ml/kg body weight), articular cartilage defects were made on the right knee joints of 38 healthy New Zealand white rabbits (regardless of sex, aged 4-5 months and weighing 2. 5-3 kg) and the defects were then treated with 2. 5% trypsin. Then BMG-chondrocyte complex ( Group A, n = 18 ), BMG (Group B, n = 10), and nothing (Group C, n = 10) were implanted into the cartilage defects, respectively. The repairing effects were assessed by macroscopic, histologic, transmission electron microscopic ( TEM ) observation, immunohistochemical examination and in situ hybridization detection, respectively, at 2, 4, 8, 12 and 24 weeks after operation. Results: Cancellous BMG was degraded within 8 weeks after operation. In Group A, lymphocyte infiltration was observed around the graft. At 24 weeks after operation, the cartilage defects were repaired by cartilage tissues and the articular cartilage and subchondral bone were soundly healed. Proteoglycan and type II collagen were detected in the matrix of the repaired tissues by Safranin-O staining and immunohistochemical staining, respectively. In situ hybridization proved gene expression of type II collagen in the cytoplasm of chondrocytes in the repaired tissues. TEM observation showed that chondrocytes and cartilage matrix in repaired tissues were almost same as those in the normal articular cartilage. In Group B, the defects were repaired by cartilage-fibrous tissues. In Group C, the defects were repaired only by fibrous tissues. Conclusions: Cancellous BMG can be regarded as the natural cell scaffolds for cartilage tissue engineering. Articular cartilage defects can be repaired by cancellous BMG engineered with allogeneic chondrocytes. The nature of repaired tissues is closest to the normal cartilage. Local administration of trypsin can promote the adherence of repaired tissues to host tissues. Transplantation of allogeneic chondrocytes has immunogenicity, but the immune reaction is weak.     

Bone matrix and marrow versus cancellous bone in rabbit radial defects

Summary Implants of demineralized bone matrix induce new bone formation. In order to estimate the possible clinical usefulness of this phenomenon, autologous cancellous bone grafts were compared with composite grafts of bone matrix and marrow. Cancellous bone from the tuber ischii of the rabbit was transplanted to a preformed radial defect in the same animal. On the opposite side, a similar defect was filled with a mixture of either allogenous or autogenous bone-matrix particles and autogenous bone marrow. After 25 days, calcium 45 was injected intravenously. Three days later the animals were killed. Standardized segments of the rabbit's forearms, containing the middle of the defect, were cut out, ashed, and analyzed for ⁴⁵Ca activity. No side difference in ⁴⁵Ca deposition was found. The callus ash weight of the allogenous matrix-transplanted side was approximately 60% of that of the cancellous bone side. This side difference of ash weights corresponds to the estimated initial mineral content of the cancellous graft. Nontransplanted defects had very low ash weight and ⁴⁵Ca activity. Thus, in the rabbit, composite grafts of bone matrix and marrow produce a bone yield comparable to that of cancellous bone.     

Implantation of bone marrow-derived buffy coat can supplement bone marrow stimulation for articular cartilage repair

Objective

Bone marrow stimulation (BMS) has been regarded as a first line procedure for repair of articular cartilage. However, repaired cartilage from BMS is known to be unlike that of hyaline cartilage and its inner endurance is not guaranteed. The reason presumably came from a shortage of cartilage-forming cells in blood clots derived by BMS. In order to increase repairable cellularity, the feasibility of autologous bone marrow-derived buffy coat transplantation in repair of large full-thickness cartilage defects was investigated in this study.

Methods

Rabbits were divided into four groups: the defect remained untreated as a negative control; performance of BMS only (BMS group); BMS followed by supplementation of autologous bone marrow buffy coat (Buffy coat group); transplantation of autologous osteochondral transplantation (AOTS) as a positive control.

Results

Repair of cartilage defects in the Buffy coat group in a rabbit model was more effective than BMS alone and similar to AOTS. Gross findings, histological analysis, histological scoring, immunohistochemistry, and chemical assay demonstrated that supplementation of autologous bone marrow buffy coat after BMS arthroplasty effectively repaired cartilage defects in a rabbit model, and was more effective than BMS arthroplasty alone.

Conclusion

Supplementation of autologous bone marrow-derived buffy coat in cases of BMS could be a useful clinical protocol for cartilage repair.