骨髓基质干细胞、骨诱导活性材料和两者复合物治疗兔早期股骨头坏死的疗效比较

目的：比较骨髓基质干细胞（BMSC）、骨诱导活性材料（OAM）和两者复合物对早期股骨头坏死（ANFH）修复的疗效。筛选出最佳方案。为临床应用提供依据。方法：28只新西兰大白兔随机分为A、B、C组，A、B组又分左、右侧组，采用液氮冷冻法建立双侧ANFH模型，A、B右侧组植入BMSC＋OAM构建的组织工程复合物，A左侧组植入复合自体BMSC的明胶海绵，B左侧组植入OAM，C组植入空白明胶海绵，术后2、4、6、8周随机取A、B两组各3只动物、C组1只动物，影像学检查后处死，取双侧股骨头标本进行组织学检查。结果：（1）X线显示，自实验第4周后A、B右侧组钻孔缺损区成骨明显优于左侧组及C组，表现为中心密度增高，缺损腔缩小，边缘模糊．6周时出现骨小梁结构，8周时有正常骨小梁结构；左侧组仅表现为随时间的延长，中心密度及边缘密度逐渐增高，形成硬化线，但无骨小梁结构，C组缺损区出现囊性变扩大并有塌陷。（2）组织学显示，A、B右侧组缺损区，2周时有成骨细胞。4周时有骨小梁及类骨质填充，6周时有成熟骨小粱和骨髓组织出现，8周时骨小梁成熟和骨髓组织形成：A、B左侧组在相同的时间内其组织学修复及新骨塑性与改建均不如各自的右侧组。结论：自体BMSC4-OAM构建的组织工程复合物对免早期ANFH修复作用优于单独应用BMSC和OAM，是目前治疗ANFH的最佳治疗方法     

关节镜辅助下髓芯减压植入复合自体骨髓的骨诱导材料联合钛棒支撑治疗Ⅱ期股骨头坏死

目的评估微创经皮关节镜辅助下髓芯减压植入复合自体骨髓的骨诱导材料联合钛棒支撑治疗Ⅱ期股骨头坏死可行性和临床疗效。方法将2003～2007年确诊的股骨头坏死国际骨科循环学会(ARCO)分期Ⅱ期38例46髋,Ⅱa期10髋、Ⅱb期22髋、Ⅱc期14髋;在C型臂透视定位及关节镜辅助下,经皮微创有效准确地进行髓芯减压,对髋关节腔内和股骨头内病变组织清除彻底,改善股骨头内外环境,植入复合自体骨髓的骨诱导材料,并用钛棒支撑股骨头软骨下骨质。术后6、12、24、36个月进行随诊,以Harris髋关节评分、X线片观察病变分期稳定性及临床疗效为评价指标。治疗前后比较采用Student成组设计Dunnett-t检验。结果术后除24个月这个时间段与12个月时相比较,评分指数改善不明显外,术后其余各时间段之间前后比较及与相对应的术前比较,差异均有统计学意义(P<0.05);手术前后X线分期比较,术后16～24个月有4例Ⅱb期进展为Ⅱc期,其中2例以后未恶化,另2例由Ⅱc期进展为Ⅲ期;原始Ⅱc期有2例髋术后24个月病变开始进展,股骨头塌陷,30个月后行全髋关节置换术(THA);术后总改善率为80.43%,Ⅱa期病变治疗改善最好(90%)...     

Enhanced bone tissue regeneration by antibacterial and osteoinductive silica-HACC-zein composite scaffolds loaded with rhBMP-2

Next-generation orthopedic implants with both osteoinductivity and antibacterial ability are greatly needed. In the present study, biodegradable rhBMP-2 loaded zein-based scaffolds with a macroporous structure were synthesized, and SBA-15 nanoparticles and hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were incorporated into the scaffolds to produce an anti-infective composite scaffold for delivery of osteogenic factors that facilitate the functional repair of bone defects. The silica/HACC/zein scaffolds developed here showed bioactivity, biocompatibility, and effective antibacterial activity. Confocal laser scanning microscopy (CLSM) was used to quantitatively measure the bactericidal efficacy with respect to bacterial adhesion. Results showed that the sample zein-HACC-S20 exhibited long-lasting antibacterial activity against Escherichia coli and Staphylococcus aureus up to 5 d. At a low dosage of rhBMP-2 (ca. 80 μg), the scaffolds released rhBMP-2 protein efficiently at a relatively slow rate, even after 27 d. An ALP activity and ECM mineralization assay showed that the zein-HACC-S20 scaffolds exhibited significant early osteogenic differentiation by generating enhanced ALP product on day 14 and ECM mineralization on day 21. In a mouse model of thigh muscle pouches, zein-S20 and zein-HACC-S20 groups resulted in obvious bone formation and gave more extensive mineralization to the implants than silica free groups, indicating effective bone induction in vivo. In a rabbit model of critical-sized radius bone defects (20 mm in length and 5 mm in diameter), the bone defects were almost fully repaired and bone marrow cavity recanalization was detectable by 3D micro-CT technique and histological analysis after 12 weeks. In this way, the zein-HACC-S20 scaffolds were proven to significantly promote the bone repair. They also demonstrated considerable promise for tissue engineering. Silica/HACC/zein scaffolds with both antibacterial activity and the ability to induce osteogenesis have immense potential in orthopedics and other biomedical applications.     

Biotechnology, material sciences and bone repair

Summary It is very likely that the need for bone substitutes will increase in the next decade. The present substitutes are generally bioactive and osteoconductive. Glassy or ceramic materials have been used up to now to act as a guide for bone healing tissue and were shown to admit bone apposition at their surface, probably due to the epitaxial growth of carbonated apatite crystals on it. Different forms of bone substitutes have been developed which do not show exactly the same properties. The reaction of bone tissue against bioactive material debris shows major differences from that of polymers or metals.In vitro models were developed to study the interface between bone cells and extracellular matrix, and the surface of bioactive material. Biotechnology makes available some morphogenetic proteins or growth factors in large quantities for combination with osteoconductive material which then can become osteoinductive. Bioartificial bone tissue constituted by a primary osteogenic cell line immobilised at the surface of osteoconductive materials made it possible to obtain osteogenic materials. The ideal bone biomaterial is still to be engineered. The combination of material sciences and molecular biology will help to optimise the next generation of material surfaces.     

聚乳酸-骨基质明胶多孔复合材料制备及骨诱导活性研究

目的采用CO2超临界法制备一种新型的具有生物活性的聚乳酸（poly lactic acid，PLA）-骨基质明胶（bone matrix gelatin，BMG）多孔复合型骨支架材料，并检测骨诱导活性。方法选取健康成人供体皮质骨进行脱脂、脱钙和脱蛋白处理制备BMG，将按体积比3：1混合的BMG—PLA及纯PLA，分别置入超临界CO2反应装置中，同时加入粒径为100～200,am的NaCl颗粒作为制孔剂，反应制备多孔PLA—BMG和PLA复合材料。在含10％胎牛血清的DMEM高糖培养基中培养MC3T3-E1成骨前体细胞，按20μl／孔2×10^4／ml浓度的细胞悬液加入含不同材料的24孔培养板内共培养2周，其中PLA—BMG组：每孔含100μg粉碎的PLA—BMG复合材料；PLA组：每孔含100μg粉碎的PLA材料；DMEM高糖培养基组作为对照组；每组设6个复孔。通过茜素红S染色法染色钙化结节，定量分析钙化面积；收集共培养细胞并在1m10．2％的Nonidet P-40溶液中超声裂解，检测细胞内钙含量和ALP活性。结果超临界CO2法所制备PLA—BMG多孔复合材料中BMG与PLA混合均匀，孔隙大小为50～150μm，孔径联通性好；PLA—BMG组ALP活性、钙含量及钙化面积均值分别为325．59±70．40U／gprot、3．51±1．64mmol／gprot和42．98％±4．44％，均高于PLA组63．62±30．01U／gprot、1．04±0．21mmol／gprot和9．55％±1．94％，及对照组2．40±1．47U／gprot、0．70±0．24mmol／gprot和0．86％±0．41％，比较差异均有统计学意义（P〈0．05），且PLA组的ALP活性及钙化结节面积与对照组也有统计学意义（P〈0．05）。结论采用CO2超临界法制备的PLA—BMG多孔复合支架材料具有良好的骨诱导活性，有可能作为一种有前景的骨植入材料及骨组织工程支架材料。     

矿化胶原基材料与BMP－2复合用于兔腰椎横突间融合

目的 用兔的脊柱后路横突间融合模型来评价一种新型的仿生矿化胶原基质：nHAC／PLA复合或不复合生长因子rhBMP-2的骨形成能力。方法64只兔子分为4组：自体髂骨,nHAC／PLA,自体骨 nHAC／PLA,nHAC／PLA BMP-2。术后6周和10周观察。结果自体骨 nHAC／PLA和nHAC／PLA BMP-2与自体骨移植的效果相当。结论nHAC／PLA BMP-2可代替自体骨移植用于骨科手术中。     

磷酸钙活性人工骨与自体骨颗粒环抱式植骨治疗四肢骨不连

目的探讨固化型磷酸钙活性人工骨(CPC/rhBMP-2)与自体骨颗粒环抱式植骨治疗四肢非感染性萎缩型骨不连的临床疗效。方法对2013年9月至2017年9月年间治疗的16例四肢非感染性萎缩型骨不连患者进行回顾性分析,其中男12例,女4例;年龄(37.06±16.31)岁(16～67岁)。骨不连部位:下肢11例(胫骨6例、股骨3例、跟骨1例、腓骨1例),上肢5例(桡骨3例、锁骨1例、手舟骨1例),所有患者均行断端新鲜化,骨缺损中央植入自体骨颗粒,外周植入CPC/rhBMP-2形成环抱式植骨。术后复查X线片观察骨折愈合情况,记录并发症发生情况,随访患者直到骨折愈合。采用上肢功能障碍评定量表(DASH)、下肢功能量表(LEFS)和SF-12生活质量量表对治疗前、后进行疗效评定。结果本组16例均获随访,随访时间(16.93±4.06)月(12～26月)。X片显示全部病例均获得骨性愈合,愈合时间(5.43±2.25)月(3～10月);术后DASH、LEFS和SF-12评分与术前比较均有统计学差异(P<0.05)。结论固化型磷酸钙活性人工骨(CPC/rhBMP-2)和自体骨颗粒环抱式植骨治疗四肢萎缩型骨不连的愈合率及安全性高,疗效可靠。     

骨泥的制备及其诱导成骨实验研究

目的研制一种可随意塑型、填充不规则骨缺损的骨植入材料并观察其成骨效果。方法以羧甲基纤维素钠(CMCNa)为粘合剂复合脱矿骨粉制备骨泥,并将骨泥植入大鼠股肌袋内,通过大体观察,X线片,碱性磷酸酶(ALP)测定,组织学观察及成骨面积测定,研究该植入物在肌袋内的成骨效果。结果CMCNa植入体内4周完全被降解吸收,无毒性反应。与骨粉粘合性好,可随意塑型,对骨缺损填充完全。动物实验大体观察,伤口无红肿及脓性渗出,愈合良好,无死亡。X线片显示骨泥不离散。全脱矿骨泥植入体内后2周,ALP均值高于表面脱矿骨泥组。表明全脱矿骨泥植入后可形成软骨和骨组织,成骨良好。结论CMCNa复合全脱矿骨粉制备的骨泥具有诱导成骨活性,可随意塑型,使用方便,可为临床提供一种填充不规则骨缺损的骨植入材料。