纳米陶瓷人工骨修复骨缺损的实验研究

目的通过动物实验探讨纳米陶瓷人工骨的骨缺损修复作用及相关问题,为其应用于骨缺损的修复提供依据。方法青紫兰兔45只在单侧桡骨制备骨缺损动物模型,随机分成3组(每组15只),然后用纳米陶瓷人工骨材料植入骨缺损处进行修复作为实验组,以植入陶瓷人工骨为对照组,空白组不植入任何材料;术后4、8、12周分别行大体标本观察、组织学、X线检查、扫描电镜(SEM)测试,比较三组间骨缺损区的成骨情况。结果纳米陶瓷人工骨成骨作用明显优于陶瓷人工骨组和空白对照组,差异有显著性意义(P<0．05)。结论纳米陶瓷人工骨具有良好的成骨能力、生物相容性和一定的降解率,是一种替代自体骨修复骨缺损较理想的材料。     

BMP/PCC人工骨修复长骨大段缺损的实验研究

目的 研究理想的、能较快修复大段骨缺损的人工骨材料。方法 将骨形态发生蛋白（BMP）和多孔复合陶瓷（PCC）结合研制成BMP/PCC人工骨，并将BMP/PCC和PCC人工骨进行兔桡骨大段骨缺损修复的对比研究。术后2、4、8和12周时取材，分别作大体、组织形态学、新骨形成定量分析及生物力学测试。结果 BMP/PCC人工骨内新骨形成量明显多于PCC人工骨。术后12周时，BMP/PCC侧植入部位的抗折强度明显高于PCC侧。结论 BMP/PCC人工骨能更快促进长骨大段骨缺损的修复，是一种较理想的人工骨材料。     

可降解复合人工骨修复骨缺损的实验研究

[目的]探讨硫酸钙（CS）／骨基质明胶（BMG）复合人工骨修复节段性骨缺损的能力。[方法]分别制备CS、BMG，按一定比例复合，植入兔尺骨15mm骨缺损，并随机分为3组，CS／BMG组植入复合人工骨、CS组单纯植入硫酸钙、空白对照组缺损区旷置。标本于术后4、8、12周分批取材，经大体观察、影像学、组织学及四环素荧光示踪检测，观察修复骨缺损的效果。[结果]术后切口均一期愈合，植入区周围未见炎性细胞浸润。CS／BMG组植入4周，缺损区两端及中央均可见岛状新骨生长，8周时材料已完全降解，新骨生长活跃，并逐渐由编织骨重塑为板层骨，12周缺损区被新生骨替代，骨结构逐渐成熟，与宿主骨间形成骨性桥接，髓腔再通，完成骨性修复。CS组4周两端也见新骨生长，但较CS／BMG组成骨量少，中央部位新骨出现时间晚。8周时材料完全降解吸收，植入区可见大量骨痂生长，两端出现板层样新骨，12周缺损区得到基本修复，但骨髓腔轮廓不清。空白组术后形成骨不连。[结论]。CS／BMG复合人工骨具有良好的生物相容性和可降解性，能有效地修复兔尺骨骨缺损，是一种较为理想的骨移植替代材料。     

矿化蚕丝基骨材料修复兔桡骨节段性骨缺损

[目的]探讨仿生制备矿化蚕丝基骨材料在修复兔节段性骨缺损中的作用.[方法]骨缺损模型的设计为：在兔双侧桡骨上各做一个大约1.5 cm的骨缺损,在一侧植入矿化蚕丝基骨材料,另一侧作为对照,未植入任何材料.观察时间阶段为术后4、8、12周.[结果]在术后4、8、12周,分别行大体观察、放射线,组织学切片观察骨缺损的愈合情况.术后12周植入矿化蚕丝基骨材料的一侧兔桡骨缺损完全愈合.对照组缺损处未见骨愈合.[结论]矿化蚕丝基骨材料是比较理想的骨缺损的替代材料.     

天然牡蛎壳纳米体复合型骨材料修复桡骨缺损的研究

目的研究活性牡蛎壳天然纳米体复合型骨材料作为骨缺损修复材料的可行性。方法 a）研制人工骨材料,并用扫描电镜观察其结构。b）把研制的牡蛎壳复合型骨材料、医用硫酸钙骨材料和自体骨植入人工形成的兔桡骨缺损区域内,进行体内生物相容性实验,通过对实验侧和对照侧进行大体标本X线片观察和组织学的检测,观察新骨形成、骨愈合、生物相容性等情况,评价该材料的骨缺损修复能力。结果天然牡蛎壳纳米体复合型骨材料多孔支架的孔径、孔隙率和抗压强度分别为200～400μm、40%～50%、45～49 M Pa。在2、4、8、12周进行组织学检查及X线检查,观察显示骨缺损修复程度,实验组优于医用硫酸钙组,生物力学测试显示术后12周实验组与自体骨比较抗弯曲强度无明显差别。结论天然牡蛎壳纳米体复合型骨材料相对医用硫酸钙有着更好的生物学特性、骨诱导性、成骨能力,并能更持久的提供支架作用修复骨缺损,在骨组织修复材料方面有应用前景。     

脱钙冻干骨修复种植周骨缺损的扫描电镜观察

目的比较脱钙冻干骨(DFDB)、脱钙冻干骨复合人重组骨形成蛋白-2(rhBMP-2)、脱钙冻干骨联合钛膜的骨修复能力。方法 3条犬股骨种植体周形成4 mm×3 mm×3 mm的骨缺损,分别植入上述3种不同材料。术后4、8、12周分期处死动物,取含种植体的骨段进行扫描电镜观察,观察新骨形成情况及其与种植体之间的缝隙。结果 DFDB可单独用于修复种植体周骨缺损,但成骨作用较慢;DFDB+rhBMP-2和DFDB+钛膜能较早诱导新骨形成,加速骨整合过程。结论DFDB是一种较理想的骨修复材料,复合rhBMP-2或与钛膜联用时效果更佳。     

异位成骨材料修复新西兰兔桡骨干骨缺损

目的探索异位成骨材料修复新西兰兔桡骨干骨缺损的可行性。方法13只新西兰白兔(4周龄,体质量1.5 kg)作为实验动物。取新西兰白兔骨髓间充质干细胞进行成骨诱导,2周后予碱性磷酸酶染色确认其成骨活性。取诱导后的间充质干细胞悬液与β-磷酸三钙生物陶瓷共培养,3天后植入4只新西兰白兔股骨骨膜旁。于植入后第8周收取异位成骨材料,行骨组织切片检查。取8只新西兰兔,制作桡骨干骨缺损动物模型,并将其均分为实验组(4只)和对照组(4只),分别植入异位成骨材料和β-磷酸三钙生物陶瓷修复骨缺损,于术后4、8、12周行手术侧X线摄片,术后12周取修复处骨,行组织切片检查。结果异位成骨植入第8周见植入物成骨完整,获取的成骨材料组织切片显示与股骨干骨细胞结构相似。骨缺损修复动物实验术后X线摄片显示,实验组修复效果显著优于对照组;术后12周修复处骨组织切片显示,实验组新生骨与周边骨组织边界消失,融合度好,骨小梁密度高,新生血管较多。结论异位成骨材料可用于兔桡骨干骨缺损修复。     

组织工程化骨修复猕猴长段骨缺损的实验研究

目的 探讨用生物衍生骨材料和骨髓基质干细胞(MSCs)复合后构成的组织工程化骨对异体猕猴长段骨缺损的修复作用。方法 于猕猴胫骨结节抽取MSCs并使诱导分化为成骨样细胞，用5-溴脱氧尿嘧啶核苷(BrdU)标记，培养后与人源生物衍生骨材料体外复合构成组织工程化骨，植入15只异体猕猴修复桡骨2．5cm长段骨缺损作为实验组；用单纯生物衍生骨材料修复对侧同样骨缺损作为对照组；另取2只猕猴双侧桡骨同样部位和大小骨缺损旷置作为空白组。术后1、2、3、6和12周时各处死3只动物取材，空白组12周取材，行大体观察、组织学和免疫组织化学检测。结果 实验组和对照组术后1、2和3周移植物周围组织反应较明显，6周后明显减轻，12周时基本消失。实验组标记成骨样细胞于术后6周仍存在，术后12周基本消失；骨缺损部位骨样组织、软骨、编织骨和板层骨出现时间均较对照组早，且骨愈合时间提前3～6周。实验组骨缺损以多点方式直接成骨，对照组则从两端以“爬行替代”方式成骨。空白组术后12周骨缺损均无愈合。结论 生物衍生骨材料和MSCs复合构建的组织工程化骨异体植入修复猕猴长段骨缺损可超越骨段移植的“爬行替代”过程，使骨缺损能较快愈合。生物衍生骨材料和同种异体MSCs复合组织工程化骨可作为构建骨组织工程的一种较好选择方式。     

多孔磷酸钙人工骨与重组人骨形成蛋白2复合修复骨缺损的实验研究

目的研究多孔磷酸钙人工骨（porous calcium phosphate cement，PCPC）与重组人骨形成蛋白2（recombinant human bone morphogenetic protein2，rhBMP-2）复合后体外的缓释作用及其对兔骨缺损的修复作用。方法采用物理吸附法将rhBMP-2（0．4mg）溶液吸附至PCPC中，制备成PCPC／rhBMP-2复合材料。冻干后，扫描电镜观察复合材料内部形态。以包覆壳聚糖的PCPC／rhBMP-2为实验组，单纯PCPC／rhBMP-2为对照组，测试在模拟体液中的rhBMP-2缓释行为。取新西兰大白兔12只，股骨远端制成直径4．2mm，深5．0mm的骨缺损模型。将包覆壳聚糖的PCPC／rhBMP-2复合材料修复骨缺损作为实验组，以植入单纯PCPC作为对照组。术后观察动物一般情况，于4周和8周取材行X线片和组织学观察。结果扫描电镜显示PCPC／rhBMP-2复合材料孔隙中吸附了大量的rhBMP-2。rhBMP-2体外缓释：对照组rhBMP-2于150h基本全部释放；实验组rhBMP-2于350h缓释量约达99％，较对照组慢。动物实验：动物术后切口无感染，于4周行动自如。X线片示术后4周对照组骨缺损区材料清晰，实验组骨缺损区密度大部分接近宿主骨，材料模糊；8周对照组材料边缘较术后4周模糊，实验组骨缺损区密度已基本接近宿主骨。组织学观察，术后4周对照组可见少量成骨细胞和破骨细胞，实验组可见成熟骨组织和骨髓腔，新生骨逐渐取代材料；8周对照组可见大量成骨细胞和破骨细胞，少量新生骨并向材料内长入，实验组可见成熟骨小梁和骨髓组织。结论PCPC是rhBMP-2较理想的载体材料，复合后具有良好的诱导成骨作用，可作为一种新型复合人工骨修复骨缺损，具有良好的临床应用前景。     

细胞复合β-磷酸三钙生物陶瓷修复软骨缺损的实验研究

[目的]通过将骨髓间充质干细胞（MCSc）诱导的具有软骨细胞、成骨细胞表型的细胞接种到三维多孔β-磷酸三钙（β-TCP）生物陶瓷支架材料上，体外构建骨软骨复合体，探讨以β-TCP为载体建造组织工程化软骨修复骨软骨缺损的可行性。[方法]将β-TCP多孔陶瓷加工成圆柱状，并将其作为构建人工软骨的细胞支架。在支架材料上分别接种从犬骨髓干细胞培养成的具有软骨细胞、成骨细胞表型的细胞，将细胞-支架复合体共同培养1周后，移植到犬关节软骨缺损处。植入后12、16周末取材，进行大体观察、组织学及组织化学等观察。[结果]复合体体内移植后，在犬关节软骨缺损处有新生软骨形成，形成的软骨基本保持了支架材料原有形态。[结论]β-TCP多孔陶瓷可作为支架材料，复合细胞后具有修复软骨缺损的作用。     

骨髓基质干细胞联合血管束植入构筑血管化组织工程骨修复兔大段骨缺损

目的 研究兔骨髓基质干细胞(BMSCs)联合动静脉血管束植入异种脱蛋白松质骨(XDCB)构筑血管化组织工程骨修复兔桡骨中远段完全骨膜骨缺损的能力. 方法 从兔髂嵴捕骨髓培养制备兔BMSCs,将第5代BMSCs种植于多孔XDCB,并进行成骨诱导2周制备组织工程骨,手术中分离兔桡动、静脉血管束.动物模型为制备24只兔舣侧桡骨中远段完全骨膜骨缺损1.5 cm共48侧,分4组修复(n=12),A组为空白未治疗组,B组为单纯材料+血管束植入组(XDCB+VB),C组为组织工程骨组(XDCB+BMSCs),D组为组织工程骨+血管束植入组(XDCB+BMSCs+VB),符组交叉配对.分别于术后4、8、12周行X线片、大体解剖、组织切片、生物力学等检查,观察各组骨缺损修复效能及移植物血管化情况.结果 D组骨缺损修复效能(术后12周新骨面积比2.02%±0.16%)及血管化情况(术后12周血管面积比6.89%±0.32%)优于C组(1.50%±0.28%和3.17%±0.19%),而C组又优于B组(1.59%±0.19%和6.52%±0.23%),A组骨缺损未修复,各组结果差异有统计学意义(P<0.05).结论 BMSCs联合动静脉血管束植入构筑的血管化组织工程骨能促进成骨过程和新生骨的血管化,显著提高组织工程骨修复大段骨缺损的能力.     

Evaluation of bovine-derived bone protein with a natural coral carrier as a bone-graft substitute in a canine segmental defect model

The efficacy of a bone-graft substitute (bovine-derived bone protein in a carrier of natural coral) in the healing of a segmental defect of a weight-bearing long bone was evaluated. Twenty dogs, divided into two groups, underwent bilateral radial osteotomies with creation of a 2.5 cm defect. On one side of each dog, the defect was filled with autogenous cancellous bone graft. Contralateral defects received, in a blinded randomized fashion, cylindrical implants consisting of natural coral (calcium carbonate) or calcium carbonate enhanced with a standard dose of bovine-derived bone protein (3.0 mg/implant; 0.68 mg bone protein/cm³). The limbs were stabilized with external fixators, and all animals underwent monthly radiographs. They were killed at 12 (group 1) or 24 (group 2) weeks, and regenerated bone was Studied by biomechanical testing and histology. Radiographic union developed in all 20 radii with autogenous cancellous bone grafts and in all 10 of the radii with the composite implants. None of the radii with implants of calcium carbonate alone showed radiographic evidence of union. This represented a statistically significant difference between implant types. In addition, calcium carbonate implants both with and without bone protein demonstrated radiographic evidence of near total resorption of the radiodense carrier by 12 weeks. This resorption facilitated radiographic evaluation of healing. Mean values for. biomechanical parameters of radii with the composite implants exceeded those for the contralateral controls at 12 and 24 weeks; the difference was statistically significant at 12 weeks. Histology revealed scant residual calcium carbonate carrier at either time in the defects with calcium carbonate implants; however, a moderate amount was present in defects with the composite implants. In these specimens, the residual carrier was completely surrounded by newly formed bone that may have insulated the calcium carbonate from further degradation. The present study used a carrier of granular calcium carbonate reconstituted with bovine type-I collagen to deliver an osteoinductive protein to the defect site. This carrier is of nonhuman origin (eliminating the risk of disease transmission or antigenicity) and resorbs rapidly. In this model, bovine-derived bone protein in a natural coral carrier performed consistently better than the gold standard autogenous cancellous bone graft in terms of the amount of bone formation and strength of the healed defect. This may have implications for removal of hardware or resumption of weight-bearing in certain clinical situations. These data also indicate that coralline calcium carbonate alone. represents a poor option as a bone-graft substitute in this critical-sized segmental defect model.     

利福平硫酸钙植入剂修复动物骨缺损的体内实验研究

目的探讨利福平硫酸钙植入剂（RCPPs）在体内的生物相容性、降解情况及成骨特点。方法将利福平硫酸钙植入剂（RCPPs）随机植入成年新西兰白兔1．5cm的桡骨缺损内．并设立不植入任何材料的空白对照。观察利福平硫酸钙植入剂（RCPPs）植入后动物的局部反应；于术后6、12周取材．作X线、大体标本及组织形态学观察，分析不同时期组织反应、骨缺损修复及材料降解情况。结果利福平硫酸钙植入剂（RCPPs）植入后无明显的局部不良反应。X线检查、大体标本及组织形态学观察显示利福平硫酸钙植入剂（RCPPs）的成骨方式主要是骨传导成骨，至术后12周时骨缺损基本修复，RCPPs与宿主骨结合紧密。而空白对照骨缺损断端仅有少量骨修复，形成骨不连。利福平硫酸钙植入剂（RCPPs）植入后即开始其降解过程，12周以后材料周围出现较多吞噬有材料颗粒的巨噬细胞和多核口细胞，仍有部分材料未降解吸收。结论利福平硫酸钙植入剂（RCPPs）具有持续的成骨能力、良好的生物相容性。     

Efficacy of autograft and freeze-dried allograft to enhance fixation of porous coated implants in the presence of interface gaps.

Autogenous cancellous bone and freeze-dried allogeneic cancellous bone were tested in a total of 41 adult male mongrel dogs. In each humerus, an implant with a commercially pure titanium fiber metal porous coating was placed in an overreamed cavity so that a uniform 3-mm gap was present between the implant and host cancellous bone. Graft material was placed in the gap of one humerus while the gap of the other humerus was left empty and served as a paired negative control. Histologically, both autograft and allograft appeared to aid repair of the defect, but quantitatively only autograft enhanced new bone formation within the defect. Treatment with autograft significantly increased the amount of bone ingrowth within the implants by nearly three-fold at 4 weeks and eight-fold at 8 weeks. The enhancing effect was recognizable as early as 2 weeks. The strength of fixation was increased by nearly seven-fold at 4 weeks and two-fold at 8 weeks in the autograft group, but this was only statistically significant at 4 weeks. Treatment with allograft did not enhance bone ingrowth at any time period, but had a small positive effect on strength of fixation at 4 weeks.     

Ivan Petrovich Pavlov

Twelve African green monkeys were implanted with recombinant human osteogenic protein-1 (rhOP-1) placed on a bovine bone-derived Type I collagen carrier to characterize healing in an ulna segmental bone defect model at 1, 3, 12, and 20 weeks postoperative. Defect healing was evaluated by plain film radiography, computed tomography (CT), magnetic resonance imaging (MRI), bone mineral density (BMD), and histologic analysis. Radiographically, new bone formation was observed as early as 3 weeks postoperative. By 6 weeks, new bone was visible in five of six defects. Increased quantity and mineralization of the new bone were apparent by 12 weeks. Reformation of the medullary cavity with appearance of marrow elements was demonstrated by CT and MRI at 20 weeks. BMD studies revealed a significant increase in the presence of bone with time. Histology at 1 week demonstrated that the implant material was well contained in the defect, and a proliferation of cells occurred at the defect borders. At 3 weeks cell proliferation continued and cell phenotype differentiation was recognized. By 12 weeks substantially less residual carrier was found in the defects, and calcifying tissues with plump chondrocytes, osteoblasts, and immature woven bone were observed. Areas of lamellar and woven bone were identified at 12 weeks, with advanced remodeling and revascularization observed at 20 weeks. The use of osteoinductive implants may provide an alternative to autologous and allogeneic bone tissue in the therapeutic approach to bone defects and promotion of fusion by eliminating the donor site morbidity associated with autogenous bone and the decreased efficacy and potential for disease transmission associated with allogeneic bone.     

Bone tissue engineering in a critical size defect compared to ectopic implantations in the goat.

Since the application of the autologous bone graft, the need for an alternative has been recognized. Tissue engineering (TE) of bone by combining bone marrow stromal cells (BMSCs) with a porous scaffold, is considered a promising technique. In this study we investigated the potential of tissue engineered bone to heal a critical sized defect in the goat. Orthotopic bone formation was compared to ectopic bone formation in comparable constructs. TE constructs were prepared from goat BMSCs and porous biphasic calcium phosphate ceramic scaffolds. These constructs and scaffolds without cells were implanted paired in critical sized iliac wing defects. Comparable samples were implanted intramuscularly. After 9 (n=7) and 12 (n=8) weeks implantation, the samples were analyzed histomorphometrically. After 9-weeks implantation in the iliac wing defect, significantly more bone apposition was found in the TE condition. After 12 weeks, the defects were almost completely filled with bone, but no significant advantage of TE was determined anymore. This contrasted with the intramuscular samples where TE implants showed significantly more bone at both time points. In conclusion, bone TE is feasible in critical sized defects. However, when appropriate osteoconductive/inductive materials are applied the effect of cell seeding may be temporary.     

涂层双相陶瓷复合BMSC修复骨缺损的实验观察

目的比较双相陶瓷（Biphasie calcium phosphate，BCP）经低结晶羟基磷灰石（Low crystalline hydroxyapatite，LcHA）涂覆改性后构建的组织工程化骨（LcBCP）与单纯BCP复合骨髓基质干细胞（Bone marrow stromal cells，BMSCs）修复兔桡骨节段性缺损的成骨差异。方法BMSCs复合LcBCP（实验组）修复12只兔左侧桡骨15mm缺损；BMSCs复合BCP（对照组）植入右侧桡骨同样大小缺损，植入后第4、8和12周取材，通过大体形态、组织学、影像学和生物力学检测骨缺损修复效果。结果BMSCs—LcBCP复合物在体内骨缺损处生长良好。X线检测显示实验组连接处骨痂形成，对照组连接处在各个时间点愈合稍差。12周时，实验组骨修复良好，髓腔再通，组织学显示板层骨形成，连接处骨性愈合；对照组连接处尚有较多编织骨形成。实验组和对照组生物力学检测有统计学差异。结论BMSCs—LcBCP复合物可修复兔桡骨节段性缺损，低品态羟基磷灰石涂层有助于增强双相陶瓷的成骨能力。     

Bone ingrowth into weight-bearing porous fiber titanium implants. Mechanical and biochemical correlations

Bone ingrowth into weight-bearing porous fiber Ti-6Al-4V implants in rat tibias was assessed for the amount, composition, and mineralization rate 3, 12, and 26 weeks after implantation. The data were compared with the ipsi- and contralateral metaphyseal controls and related to the ultimate bending stresses of the distal bone/implant interfaces. From the 3rd to the 12th week there was rapid bone ingrowth and also marked decline in mineralization rate of the ingrowing bone. After 12 weeks the implants were macroscopically pervaded by bone. The ultimate bending stresses increased from the 3rd to the 12th week and reached 45% of that of controls after 26 weeks. There was a linear proportionality between the amount of bone ingrowth and interfacial strength but a curvilinear relationship between bone maturity in terms of calcium/hydroxyproline and calcium/phosphorous ratios and interfacial strength. Stepwise multiple regression analysis showed that the interfacial strength depends on the amount and the maturity of the ingrown bone. Compared with the calcium/hydroxyproline ratio, the calcium/phosphorous ratio was an unreliable predictor of interfacial strength.     

多孔金属钽假体在骨缺损修复中的应用

目的对多孔金属钽假体治疗骨缺损的研究现状作一综述。方法广泛查阅多孔金属钽假体特性及其治疗各种骨缺损的相关文献,并进行综述。结果多孔金属钽假体凭其特性,在某些类型的骨缺损治疗中效果显著。结论多孔金属钽假体存在着自身优缺点,在符合其适应证的前提下使用可取得较好近期疗效,为临床骨缺损修复提供了种新参考,但远期疗效需进一步观察。