人纳米脱钙骨基质复合物的理化性质和安全性

背景：脱钙骨基质和骨形态发生蛋白已被证实具有良好的骨诱导性,但有关纳米脱钙骨基质的研究较少,其理化性质和生物安全性尚不明确。 目的：在前期实验制备人纳米脱钙骨基质的基础上加载重组人骨形态发生蛋白2,分析人纳米脱钙骨基质复合重组人骨形态发生蛋白2的理化性质及生物安全性。 方法：采用改良Urist法制备人脱钙骨基质,并进行纳米化处理,再将骨形态发生蛋白2与其按特定比例混合,冻干塑型行以下实验：①热源实验：将材料浸提液经耳静脉注入兔体内。②毒性实验：将材料浸提液与生理盐水分别经尾静脉注入小白鼠体内。③植入实验：在兔两侧后肢肌肉内分别植入实验材料和β-磷酸三钙。 结果与结论：冻干塑型后,纳米人脱钙骨基质材料表面致密,孔隙直径100-400 μm,孔隙分布欠均匀,孔隙率小于30%,以碳、氧和氮为主要元素组成。人纳米脱钙骨基质复合重组人骨形态发生蛋白2材料无热源效应,注射后未见兔体温有明显波动。急性全身毒性实验结果表明人纳米脱钙骨基质复合重组人骨形态发生蛋白2材料符合国家相关规定,注射后未见小鼠出现明显毒性反应。人纳米脱钙骨基质复合重组人骨形态发生蛋白2材料植入兔体内的炎症反应明显轻于β-磷酸三钙植入后的反应。结果表明人纳米脱钙骨基质复合重组人骨形态发生蛋白2是一种无毒、组织相容性好、生物利用度高、炎症反应轻的纳米同种异体骨移植替代物。     

磁性复合骨水泥的体外细胞毒性

背景：磁性复合骨水泥作为一种新型骨转移治疗材料,不仅能对骨缺损进行修复,还能在交变磁场下升温杀死骨肿瘤。 目的：检测磁性复合骨水泥对小鼠L929成纤维细胞增殖活性的影响及细胞毒性反应。 方法：采用CCK-8法检测含0%(即磷酸钙骨水泥组),10%,20% Fe3O4的磁性磷酸钙骨水泥浸提液及含0%(即聚甲基丙烯酸甲酯骨水泥组),10%,20%Fe3O4的聚甲基丙烯酸甲酯骨水泥浸提液对对数生长期小鼠L929成纤维细胞的毒性作用,每种浸提液又分为50%与100%两个浓度梯度;以正常培养基培养的小鼠L929成纤维细胞作为阴性对照组。 结果与结论：①在100%浓度梯度下：除含20%Fe3O4的磁性聚甲基丙烯酸甲酯骨水泥组细胞数量较少、细胞形态异常外,其余磁性聚甲基丙烯酸甲酯骨水泥组细胞生长状态良好;含10%Fe3O4的磁性磷酸钙骨水泥组培养24 h时表现出轻度细胞毒性,毒性2级;含20%Fe3O4的聚甲基丙烯酸甲酯骨水泥在24-  72 h为表现出轻、中度细胞毒性,毒性为2,3级。各磁性磷酸钙骨水泥组细胞数量及形态正常。②在50%浓度梯度下：各组细胞形态均正常,细胞毒性为0级或1级。表明磁性聚甲基丙烯酸甲酯骨水泥具有轻、中度细胞毒性,磁性磷酸钙骨水泥细胞相容性良好,基本无细胞毒性。     

钛合金表面新型生物玻璃/纳米羟基磷灰石涂层的细胞相容性评价

目的为检验前期制备的新型生物玻璃／纳米羟基磷灰石涂层的细胞相容性。方法在本实验中，采用L929成纤维细胞在涂层浸提液中的培养，检测了涂层的细胞毒性，采用人体骨髓基质干细胞存涂层上的培养，检测了涂层对人体骨髓基质下细胞增殖和代谢的影响。结果低于浓度的涂层浸提液（〈10％）埘L929细胞增殖具有促进作用，而高浓度的涂层浸提液（〉50％）对L929细胞的增殖具有抑制作用，其中100％的涂层浸提液对L929细胞的增殖抑制比例为20.9％，在细胞毒性分级中处于合格范围内。结论在培养早期，人体骨髓基质干细胞在涂层表面的增殖要优于对照组，涂层显示出良好的细胞相容性。由于合格的细胞毒性和良好的细胞相容性，该涂层的钛合金具有作为骨植入物的应用潜力。     

梯度掺锶羟基磷灰石骨水泥的体外细胞生物学性能

背景：锶掺入羟基磷灰石骨水泥后可以改善材料的结晶性和相容性,但产生的细胞毒性以及对细胞表面黏附、增殖和表达的影响还需要深入研究。 目的：观察梯度掺锶羟基磷灰石骨水泥的体外细胞生物学性能。 方法：制备4组羟基磷灰石骨水泥试样,分别编为0%,1%,5%和10%掺锶羟基磷灰石骨水泥,每组取6个平行试样紫外线照射灭菌3 h备用。浸提递质为含体积分数10%胎牛血清的DMEM培养液。按照掺锶羟基磷灰石骨水泥粉末质量∶浸提液=1 g∶10 mL比例配制。选用L-929成纤维细胞和幼兔成骨细胞,对成骨细胞进行鉴定。扫描电镜观察幼兔成骨细胞在梯度掺锶羟基磷灰石骨水泥表面的黏附和增殖情况,细胞的表达情况采用碱性磷酸酶活性检测法检测。 结果与结论：①不同掺锶量羟基磷灰石骨水泥的细胞毒性评级均为0或1级,各试样的细胞毒性与其掺锶量、作用时间、浸提液浓度有一定关联性。②适量锶元素的加入可以促进成骨细胞的黏附、增殖及表达,改善材料的溶解动力学,提高其生物降解性,更加符合临床要求。但目前尚缺乏有关的远期实验结果。     

骨基质载体材料的生物学特点及其临床应用

背景：骨组织工程支架材料中的骨基质载体材料为骨缺损修复治疗提供了更为有效的方法。 目的：重点介绍天然衍生骨载体材料-冻干脱钙骨基质、脱蛋白骨基质、脱细胞骨基质在骨组织工程中的应用。 方法：以“骨组织工程、冻干脱钙骨基质、脱蛋白骨基质、脱细胞骨基质、骨缺损;bone tissue engineering,scaffold materials,demineralized bone matrix, deprotein bone matrix,acellular bone matrix,bone defect”为检索词,由第一作者检索1994/2010 PubMed、CNKI及万方数据库等与骨组织工程领域有关的权威性文献。 结果与结论：冻干脱钙骨基质、脱蛋白骨基质及脱细胞骨基质均具有良好的生物相容性、极低的抗原性、无细胞毒性,作为骨组织工程载体材料,保留了骨的天然属性,具有多孔隙结构,可降解性及良好骨传导作用,为骨缺损的治疗开辟了一条新途径。     

贻贝粘蛋白创面修复敷料体外细胞毒性的检测方法

背景：在贻贝粘蛋白创面修复敷料的体外细胞毒性检测中,由于蛋白分子表面带正电荷,1∶9的浸提比会使细胞聚团而导致测定产生误差,影响测定结果。 目的：在已有标准的基础上,根据贻贝粘蛋白特殊的性质及使用状态,改进贻贝粘蛋白创面修复敷料的浸提比例或前处理方法。 方法：①浸提液法：将贻贝粘蛋白创面修复敷料与细胞培养液分别以1∶9、1∶131浸提比例制备浸提液,分别以贻贝粘蛋白创面修复敷料浸提液、天然乳胶浸提液、高密度聚乙烯浸提液及细胞培养液培养L929小鼠成纤维细胞。②直接接触法：分别以蒸馏水、贻贝粘蛋白创面修复敷料溶液、二甲基亚砜及细胞培养液培养L929小鼠成纤维细胞。 结果与结论：采用浸提比1∶9测定样品体外细胞毒性时,细胞产生聚团作用,不适用于样品毒性的检测;调整浸提比为1∶131后,絮凝作用和细胞聚团现象明显降低,提高了检测结果的可信度,显示样品无细胞毒性。直接接触法显示样品无细胞毒性。采用经调整过的浸提液法或直接接触法均可适用于贻贝粘蛋白创面修复敷料体外细胞毒性的检测。     

海藻酸钠/壳聚糖复合凝胶的制备与细胞毒性评价

背景：海藻酸钠和壳聚糖分别是聚阳离子和聚阴离子的天然高分子材料,二者可以互为交联剂形成复合凝胶,避免使用普通交联剂产生的细胞毒性。 目的：制备海藻酸钠壳聚糖复合凝胶并评价其体外细胞毒性。 方法：以0.25 mol/L乙酸溶解壳聚糖,制成质量浓度30 g/L溶液,再以0.1 mol/L的NaOH中和酸性得到壳聚糖絮状沉淀,将壳聚糖絮状沉淀与质量浓度3%海藻酸钠等比例混合,高频振动混匀,使二者形成复合凝胶。使用傅里叶变换红外光谱、扫描电镜分析观察凝胶成分和交联纤维网络结构。分别以海藻酸钠壳聚糖复合凝胶24,72 h浸提液、聚乙烯24,72 h浸提液及苯酚溶液培养L-929细胞,体外检测其细胞毒性。 结果与结论：傅里叶变换红外光谱检测到海藻酸钠壳聚糖复合凝胶特征性峰值改变,扫描电镜显示其内部形成丰富间隙的空间网络结构。浸提液法检测海藻酸钠壳聚糖复合凝胶的细胞毒性为合格,表明海藻酸钠/壳聚糖复合凝胶具有成为组织工程支架材料的良好条件。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

海藻酸钙止血敷料与临床常用3种止血敷料体外细胞毒性的比较

背景：止血敷料是作用于创伤表面与人体组织直接接触,其生物相容性是评价敷料优劣的重要指标之一,以海藻酸钙为原料的制备的止血敷料有着廉价、相容性好等优点已成为研究的热点。目的：观察海藻酸钙止血敷料的细胞毒性,并与明胶止血海绵、纳吸棉、普通纱布等材料作对比。方法：①浸提液法：以DMEM高糖培养液作为浸提介质,分别制备海藻酸钙止血敷料、明胶止血海绵、纳吸棉、普通纱布浸提液,并设置100%,75%,50%,25%,10% 5个浓度梯度;采用上述材料浸提液培养L-929小鼠成纤维细胞24 h,以含体积分数10%DMEM高糖培养液为空白对照,以含5%二甲基亚砜DMEM高糖培养液为阳性对照组,观察细胞增殖及形态变化。②直接接触法：将L-929小鼠成纤维细胞分别接种于海藻酸钙止血敷料、明胶止血海绵、纳吸棉、普通纱布上培养24 h,观察细胞形态变化。结果与结论：①浸提液法：不同浓度梯度海藻纤维止血敷料、纱布、纳吸棉浸提液的细胞毒性均为1级,符合GB/T16886/ISO10993 医疗器械生物学评价标准;100%,75%明胶止血海绵浸提液的细胞毒性为3级,严重抑制细胞增殖。②直接接触法：纱布与海藻纤维止血敷料的细胞毒性1级,纳吸棉为2级,明胶止血海绵的细胞毒性为3级。表明海藻酸钙止血敷料无细胞毒性。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

松质骨基质材料应用于牙周组织工程的可行性*☆

背景：松质骨基质材料具有骨诱导性和骨传导性双重特性,已被成功应用于骨再生及骨组织工程研究。 目的：分析松质骨基质材料的细胞相容性与毒性,探讨其应用于牙周组织工程的可行性。 方法：采用改良组织块法体外培养人牙周膜细胞,将其接种于松质骨基质三维支架上复合培养,采用细胞计数方法和扫描电镜观察人牙周膜细胞在松质骨基质支架上的附着、生长情况,并通过MTT测试法和碱性磷酸酶活性检测法观察松质骨基质浸提液对人牙周膜细胞增殖及功能表达的影响。 结果与结论：扫描电镜可见松质骨基质具有良好的多孔网状结构,人牙周膜细胞在松质骨基质上贴附紧密,生长旺盛,伸展充分,而人牙周膜细胞在不同浓度材料浸提液中的生长、增殖及碱性磷酸酶活性与阴性对照组相比差异无显著性意义。表明松质骨基质具有良好的三维空间结构和细胞相容性,且无细胞毒性,有望应用于牙周组织再生及牙周组织工程研究。     

猪来源关节软骨脱细胞支架的生物安全性研究

目的评价猪来源关节软骨脱细胞支架的生物安全性。方法取猪四肢关节软骨,分别制备脱细胞和未脱细胞软骨支架。在人软骨细胞中分别加入浓度为100%、50%、25%的脱细胞软骨支架浸提液[无血清DMEM培养液与支架表面积按1ml:(3～6)cm2比例混合,37℃静置72h],计算相对增殖率,判定其体外细胞毒性。0.9%NaCl与支架表面积按1ml:(3～6)cm2比例混合,37℃静置72h制备脱细胞软骨支架浸提液,分别用于全身急性毒性实验(小白鼠)、溶血实验、热原检测实验、皮内刺激实验(大白兔),分别观察其体内毒性、溶血程度、热原和刺激情况。在大白兔体内分别埋植脱细胞软骨支架与未脱细胞软骨支架,观察炎症反应和细胞免疫情况。结果猪脱细胞软骨支架浸提液对细胞生长无抑制作用,无细胞毒性。注射支架浸提液后小白鼠一般情况良好,无全身急性毒性反应。支架浸提液溶血程度为1.3%,无溶血作用。支架浸提液无热原存在且原发刺激指数为0分,皮内刺激实验阴性。脱细胞软骨支架与未脱细胞软骨支架相比免疫原性小,无炎症反应和淋巴细胞浸润。结论猪来源关节软骨脱细胞支架具有良好的生物相容性,将有可能成为理想的天然生物材料,具有良好的应用前景。     

Combined effects of phosphatidylcholine and demineralized bone matrix on bone induction

The osteoinductivity of demineralized bone matrix (DBM) becomes significantly reduced if the specimens are further delipidated with chloroform-methanol. The addition of phosphatidylcholine (PC), a major constituent of the lipid fraction present in the calcification front during normal bone formation, can restore the biological activity. Active endochondral bone formation is observed in the DBM/PC implants placed in the anterior abdominal wall musculature or subcutaneously for 28 days. When PC is added to generate a putty containing 60% PC and 40% DBM, biochemical parameters associated with osteoinductivity are significantly enhanced. Biological responses evaluated histologically and by determination of alkaline phosphatase activity are in very good agreement. The DBM/PC putty has good handling properties, can be molded into different shapes, and does not wash away from the application site. An advantage of adding PC is that it not only enhances the handling properties, but also boosts the osteoinductivity of the preparation.     

Combined Effects of Phosphatidylcholine and Demineralized Bone Matrix on Bone Induction

The osteoinductivity of demineralized bone matrix (DBM) becomes significantly reduced if the specimens are further delipidated with chloroform-methanol. The addition of phosphatidylcholine (PC), a major constituent of the lipid fraction present in the calcification front during normal bone formation, can restore the biological activity. Active endochondral bone formation is observed in the DBM/PC implants placed in the anterior abdominal wall musculature or subcutaneously for 28 days. When PC is added to generate a putty containing 60% PC and 40% DBM, biochemical parameters associated with osteoinductivity are significantly enhanced. Biological responses evaluated histologically and by determination of alkaline phosphatase activity are in very good agreement. The DBM/PC putty has good handling properties, can be molded into different shapes, and does not wash away from the application site. An advantage of adding PC is that it not only enhances the handling properties, but also boosts the osteoinductivity of the preparation.     

Quantification of various growth factors in different demineralized bone matrix preparations

Besides autografts, allografts, and synthetic materials, demineralized bone matrix (DBM) is used for bone defect filling and treatment of non-unions. Different DBM formulations are introduced in clinic since years. However, little is known about the presents and quantities of growth factors in DBM. Aim of the present study was the quantification of eight growth factors important for bone healing in three different "off the shelf" DBM formulations, which are already in human use: DBX putty, Grafton DBM putty, and AlloMatrix putty. All three DBM formulations are produced from human donor tissue but they differ in the substitutes added. From each of the three products 10 different lots were analyzed. Protein was extracted from the samples with Guanidine HCL/EDTA method and human ELISA kits were used for growth factor quantification. Differences between the three different products were seen in total protein contend and the absolute growth factor values but also a large variability between the different lots was found. The order of the growth factors, however, is almost comparable between the materials. In the three investigated materials FGF basic and BMP-4 were not detectable in any analyzed sample. BMP-2 revealed the highest concentration extractable from the samples with approximately 3.6 microg/g tissue without a significant difference between the three DBM formulations. In DBX putty significantly more TGF-beta1 and FGFa were measurable compared to the two other DBMs. IGF-I revealed the significantly highest value in the AlloMatrix and PDGF in Grafton. No differences were accessed for VEGF. Due to the differences in the growth factor concentration between the individual samples, independently from the product formulation, further analyzes are required to optimize the clinical outcome of the used demineralized bone matrix.     

Calcium sulfate-carboxymethylcellulose bone graft binder: Histologic and morphometric evaluation in a critical size defect

Calcium sulfate (CS) is widely used as a bone graft binder and expander. Recent reports indicate that carboxymethylcellulose (CMC) can improve the clinical properties of CS when used as binder for particulate bone grafts; however, limited information is available on the effects of CMC on bone regeneration. The purpose of this study was to evaluate the histologic and morphometric characteristics of bone formation in calvarial defects grafted with a CS-based putty containing 10% CMC in combination with allogeneic demineralized bone matrix (DBM). Bone formation and graft/binder resorption were compared with a surgical grade CS and DBM in paired critical-sized calvarial defects in 25 Wistar rats (350-450 g). Six animals each provided paired defects at 7, 14, 21, and 28 days postsurgery for nondecalcified processing and microscopic analysis. Defects grafted with CS or CS-CMC putty as the DBM binder exhibited similar patterns and proportions of bone formation, fibrous tissue/marrow, and residual DBM particles. Comparable mean +/- SD proportions of new bone formation (31.7 +/- 9.5 and 33.7 +/- 12.9), fibrous tissue/marrow (54.2 +/- 8.3 and 53.0 +/- 10.8), residual DBM particles (8.3 +/- 6.8 and 10.1 +/- 6.3), and residual binder material (5.5 +/- 4.6 and 3.7 +/- 3.5) were found at 28 days for defects grafted with CS and CS-CMC putty, respectively. Thus, CMC was found to improve the handling characteristics of CS and, when used in conjunction with DBM, supported comparable levels bone formation and patterns of binder/scaffold resorption as CS and DBM in a calvarial defect model.     

异种脱钙骨基质联合骨髓间充质干细胞植入豚鼠鼓泡腔增强成骨作用*

背景：目前在矫形外科和颅面重建中已有脱钙骨基质和骨髓间充质干细胞的相关应用,但用于乳突腔填塞尚缺乏研究。 目的：探寻异种脱钙骨基质和骨髓间充质干细胞联合植入乳突腔的成骨效能。 方法：全骨髓贴壁培养法分离近交系雌性豚鼠骨髓间充质干细胞,牛股骨头松质骨制备牛髂骨脱钙骨基质。20只豚鼠随机数字表法分为脱钙骨基质与骨髓间充质干细胞联合植入鼓泡腔的实验组和取自体髂骨植入鼓泡腔的对照组。 结果与结论：植入1个月后两组的成骨量差异无显著性意义;植入后2个月实验组成骨量多于对照组,差异有显著性意义    (P < 0.05)。说明异种脱钙骨基质与骨髓间充质干细胞联合植入乳突腔能有效促进乳突填塞后骨的形成。     

Biocompatibility and effect on osteogenesis of poly(ortho ester) compared to poly(DL-lactic acid)

Implantation of demineralized bone induces new bone formation by the action of contained growth factors, of which bone morphogenetic proteins are of prime importance. A biodegradable polymer may be used as a carrier for demineralized bone particles or recombinant bone growth factors to prevent displacement of the implant, preserve its volume and shape, and assure sustained release of the incorporated active components. A polymer for this use should be biocompatible and completely absorbed without interfering with the osteogenesis. We investigated the host-tissue response and effect on demineralized bone-induced bone formation by two biodegradable polymers, a poly(ortho ester) and an amorphous low-molecular poly(DL-lactic acid). Both polymers had a plastic consistency, could easily be molded, and adhered well to the demineralized bone particles. Demineralized bone particles were implanted alone and in combination with each of the polymers in the abdominal muscles of 45 male Wistar rats. Four weeks after the operation the implants were recovered and subjected to (85)Sr uptake analysis to quantify bone formation and histologic examination. The poly(ortho ester) provoked little inflammation; it was largely absorbed by 4 weeks, and no qualitative or quantitative effect on bone formation was found. The poly(DL-lactic acid) provoked a chronic inflammation with multinuclear giant cells, macrophages with engulfed material, and proliferating fibroblasts; part of the material was still present, and the bone formation was inhibited.     

Histological evaluation of an impacted bone graft substitute composed of a combination of mineralized and demineralized allograft in a sheep vertebral bone defect

Demineralized bone matrix (DBMs) preparations are a potential alternative or supplement to autogenous bone graft, but many DBMs have not been adequately tested in clinically relevant animal models. The aim of current study was to compare the efficacy of a new bone graft substitute composed of a combination of mineralized and demineralized allograft, along with hyaluronic acid (AFT Bone Void Filler) with several other bone graft materials in a sheep vertebral bone void model. A drilled defect in the sheep vertebral body was filled with either the new DBM preparation, calcium sulfate (OsteoSet), autologous bone graft, or left empty. The sheep were euthanized after 6 or 12 weeks, and the defects were examined by histology and quantitative histomorphometry. The morphometry data were analyzed by one-way analysis of variance with the post hoc Tukey-Kramer test or the Student's t-test. All of the bone defects in the AFT DBM preparation group showed good new bone formation with variable amounts of residual DBM and mineralized bone graft. The DBM preparation group at 12 weeks contained significantly more new bone than the defects treated with calcium sulfate or left empty (respectively, p < 0.05, p < 0.01). There was no significant difference between the DBM and autograft groups. No adverse inflammatory reactions were associated with any of the three graft materials. The AFT preparation of a mixture of mineralized and demineralized allograft appears to be an effective autograft substitute as tested in this sheep vertebral bone void model.     

Hyaluronidase-bound membrane as a biomaterial for implantable fuel cells.

A new biomaterial containing covalently bound hyaluronidase was prepared. An application of this enzyme membrane is to improve the performance of an implantable fuel cell. Hyaluronic acid is a contributor to the viscosity of tissue fluids but can be a potential fuel source because of its sugar content. The incorporation of immobilized hyaluronidase would not only contribute to a more available fuel supply by splitting hyaluronic acid but, perhaps more importantly, enhance the rate of mass transport of fuel, O2, and reaction products by reducing the viscosity near the electrode membranes. Hyaluronidase was bound to Sepharose gel and its thermoplastic membrane after activation by cyanogen bromide. Fourteen and 22% of the activities were recovered from the gel and membrane, respectively. The activity of the bound enzyme was stable for six months at 0 degrees C. The addition of hyaluronic acid, 1 mg/ml, to a typical implantable type bioautofuel cell in vitro increased external solution viscosity from 1.1 to 2.5-2.8 cP and reduced voltage output under 10 komega by 60% in 3 hr. When the hyaluronidase bound membrane was placed at the anode, viscosity of the glucose-hyaluronic acid solution was lowered to 1.8 cP and the cell output increased to the original level of a glucose-fueled cell in 3 hr. Glucosamine-equivalent released from hyaluronic acid at the electrode was 3.1 mg after 22.5 hr. This represents 90% of the theoretical consumption. Restoration of the cell output was probably a combination of the enhanced transport of fuel, O2 and products, and/or appearance of a new fuel, glucosamine-equivalent.