异种脱钙骨基质,骨基质胶的制备

为了提高异种骨移植的成骨率，开展异种脱钙骨基质（ｄｅｍｉｎｅｒａｌｉｚｅｄｘｅｎｏｇｅｎｅｉｃｂｏｎｅｍａｔｒｉｘ，ＸＤＢＭ）或者异种骨基质胶（ｄｅｍｉｎｅｒａｌｉｚｅｄｘｅｎｏｇｅｎｅｉｃｂｏｎｅｍａｔｒｉｘｇｅｌａｔｉｎ，ＸＢＭＧ）加释放系统（ｄ...     

天然珊瑚和同种异体脱钙骨基质作为骨组织工程支架的组织相容性研究

目的：评价天然滨珊瑚(NC)和同种异体脱钙骨(DBM)的组织相容性，探讨其作为骨组织工程支架的可行性。方法：将NC和DBM直接植入动物体内，术后1、2、6周取材，通过大体观察和组织学检查观察生物材料在体内组织反应。结果：两种材料均未引起明显的炎症和排斥反应，对实验动物无不良影响。同时发现DBM组诱导出少量骨组织，NC组未见新生骨。结论：NC和DBM具有良好的组织相容性，DBM还具有鲁诱导性，两种材料可能都是比较理想的骨组织工程支架材料。     

脱细胞骨基质复合材料的研究进展

切割伤、坠落伤、火器伤等导致的骨缺损患者不断增加,骨修复成为骨科发展研究中的热点问题之一。脱细胞骨基质(aceller bone matrix, ACBM)是对骨组织进行一系列物理和化学操作降低其免疫原性,保留了天然骨组织基本结构,在修复骨缺损的治疗中表现出良好的骨传导性、生物相容性和机械性能。但ACBM不能促进间充质干细胞(mesenchymal stem cells, MSCs)分化,骨诱导性差,将ACBM与其他类型材料复合,制成具有成骨活性的复合材料,拓展其在骨组织工程中的应用。本文参考国内外文献,将ACBM复合的材料分为有机材料、无机材料、细胞因子组织细胞及多种材料复合四大部分,从临床研究角度分别阐述同ACBM复合形成的新型材料特性、优点、缺点和临床应用价值等,综述了近几年ACBM相关复合支架材料的研究进展。     

脱细胞骨基质材料的特性及生物安全性观察

目的对脱细胞骨基质（aceller bone matrix，ACBM）的特性及生物安全性进行评价，为进一步研究构建组织工程骨提供新型材料。方法以新鲜猪肋骨为原料制备ACBM，对材料行组织学、形态学及超微结构观察；用X线衍射及能量散射方法行成分分析并对其蛋白含量进行测定；以新鲜骨为对照，观察制备方法对ACBM生物力学的影响。按GB／T16886的有关标准制备材料浸提液，对ACBM进行生物安全性评价。结果ACBM呈乳白色，质硬，松质骨部呈蜂窝状。超微结构观察显示骨小梁结构完整，骨陷窝内无细胞及碎片残留，孔隙率、孔径大小符合要求，而且微孔之间相通，X线衍射结果显示主要成分为羟基磷灰石，钙／磷为1．66，接近人骨组织。其压缩强度、压缩极限及扭转力矩等与新鲜骨组织比较差异无统汁学意义，弹性模量显著增加。急性和亚急性毒理试验、热源试验、溶血试验及肌肉埋植实验均符合GB／T16886标准。结论ACBM作为一种新型骨缺损充填物或骨组织工程基质材料，具有良好的生物安全性。     

天然珊瑚和同种异体脱钙骨基质作为骨组织工程支架的细胞相容性研究

目的 :评价天然滨珊瑚 (NC)和同种异体脱钙骨 (DBM)的细胞相容性 ,探讨其作为骨髓基质细胞的支架载体构建骨组织工程的可行性。方法 :应用体外复合骨髓基质细胞培养法 ,通过倒置显微镜和MTT比色法 ,并对测量结果进行统计学分析 ,研究生物材料对骨髓基质细胞的形态、增殖的影响。结果 :两种材料对骨髓基质细胞形态均未见不良影响 ;NC在各培养时间对骨髓细胞增殖没有明显影响 (P >0 .0 5) ,DBM对骨髓细胞增殖均起促进作用 (P <0 .0 1)。结论 :两种材料均具有良好的细胞相容性 ,可以作为骨髓基质细胞的载体和骨组织工程支架     

带血管骨膜和同种脱钙骨基质联合移植与自体骨移植修复骨缺损 …

目的 了解带血管骨膜（ＶＰ）和同种脱钙骨基质（ＤＢＭ）联合移植替代自体骨移植修复大段骨缺损的可能性。方法 以兔桡骨中央２５ｍｍ的大段骨缺损为模型，通过Ｘ线观察、Ｘ线平片骨缺损修复Ｌａｎｅ评分、组织学观察、骨组织形态计量分析和生物力学测试，比较术后４，８，１６周时ＶＰ＋ＤＢＭ联合移植与自体骨移植修复骨缺损的效果。结果 术后４周ＶＰ＋ＤＢＭ联合移植及自体骨移植均已较好地完成了缺损的修复，而前者的Ｌａｎ     

脱钙骨基质与左旋聚乳酸/聚磷酸钙纤维对骨髓间充质干细胞黏附作用的比较

目的探讨左旋聚乳酸／聚磷酸钙纤维（PLLA／CPPf）与同种异体的脱钙骨基质（DBM）对BMSCs黏附作用的差异，为构建组织工程骨提供理想的支架材料。方法用扫描电镜观察两种支架材料的孔径；通过测吸水率比较其亲水性。将普通培养瓶培养的第3代BMSCs分别成骨诱导培养1周后，在体外分别与PLLA／CPPf和同种异体的DBM复合构建组织工程骨，于构建后10h计算细胞黏附率，并用扫描电镜观察比较两种支架材料对BMSCs黏附作用的差异。构建后每天在相差显微镜下观察BMSCs在两种支架材料上的生长情况，构建后第10天再行扫描电镜观察BMSCs在两种支架材料上的生长情况。结果DBM的孔径明显较PLLA／CPPf的大，孔隙率高，体外构建后10hDBM组的细胞黏附率为（91．3±8．2）％，PLLA/CPPf组为（82．2±7．7）％，两者之间差异具有统计学意义（P〈0．05）。DBM组于术后第3天网孔间出现细胞外基质，且随着时间的推移，基质变得稠密，而PLLA／CPPf的细胞外基质鲜见；第10天的扫描电镜也证实DBM组的细胞在支架材料上数量多，且细胞外的基质分泌较多。结论DBM较PLLA／CPPf更适于BMSCs的黏附生长，是理想的组织工程支架材料。     

以脱细胞犬动脉为基质的血管支架体外再细胞化

目的 对已成功制备的以脱细胞犬动脉为基质的血管支架进行体外再细胞化研究.方法 多聚环氧化合物家族的乙二醇缩水甘油醚(ethylene glycol diglycidyl ether,EX-810)、去离子水和超声共同作用于犬主动脉,制备血管支架,并在体外对其进行有效的再细胞化,包括人脐动脉平滑肌细胞(smooth muscle cell,SMC)的种植,人脐静脉内皮细胞(endothelial cell,EC)的种植,以及两种细胞的复合种植.结果 本文提出的制备血管支架适合SMC和EC的生长,以合适的接种密度进行再细胞化即可获得致密的细胞层;提高细胞的种植密度可以加速支架的再细胞化进程.SMC和EC复合种植模型中,高密度接种的EC能够在不同密度的SMC上生长,形成较为致密的EC单层;但共培养的EC的形态和覆盖率受SMC接种密度的影响.结论 在脱细胞犬动脉上成功实现EC和SMC的单独种植和联合种植.     

组织工程脱细胞角膜基质联合干细胞诱导分化制备异体角膜移植材料研究

目的研究脱细胞角膜基质联合干细胞制备异体角膜移植材料的安全性和有效性。方法应用酶-深低温法对猪角膜基质进行处理,制备猪脱细胞角膜基质。采用微注射法注入骨髓间充质干细胞进行共培养,制备异体角膜移植材料,并将其植于角膜病变的新西兰大白兔,评价术后组织工程角膜的系统性功能。结果脱细胞角膜基质的显微结构显示板层结构完整,未见细胞残留。共培养后光镜观察角膜基质细胞可于脱细胞角膜基质内生长,细胞形态具有纤维细胞特征,但分布不够均匀。移植术后,组织工程角膜愈合良好,未见明显的炎症及排斥反应。结论脱细胞角膜基质联合干细胞诱导分化制备异体角膜移植材料具有免疫排斥率低,组织相容性佳的特性。     

术中富集骨髓细胞构建组织工程骨成骨能力的研究

目的 观察术中富集骨髓干细胞构建的组织工程骨在山羊脊柱横突间融合的成骨效果,为组织工程骨探索一种新型的构建方法.方法 将多聚左旋赖氨酸(poly-L-lysine,PLL)修饰于山羊脱钙骨基质(demineralized bone matrix,DBM)制备成基质材料(PLL-DBM);以山羊横突间隙为植骨模型,观察PIL-DBM富集骨髓细胞构建的组织工程骨(Ⅰ A组)的成骨能力;对照组为自体髂骨组(Ⅰ B组)、DBM富集骨髓组(Ⅱ C组)、空白DBM组(Ⅱ D组).于术后第16周取融合段标本行X线片、三维CT及CT值检测和生物力学检测,对比分析、评价其成骨能力.结果 X线表现:ⅠA组、Ⅰ B组融合范围基本相同,明显较ⅡC组宽,Ⅱ D组基本无融合.三维CT:Ⅰ A组的CT值为(696.76±102.75)HU,ⅠB组的CT值为(766.03±69.24)HU,二者差异无统计学意义(P>0.05),均明显较ⅡC组高(P<0.05),Ⅱ C组CT值较ⅡD组高(P<0.01).生物力学性能:Ⅱ A、Ⅰ B两组最大载荷、抗弯强度比较差异均无统计学意义(P>0.05),ⅠA组较Ⅱ C组高(P<0.01,0.05),Ⅰ B组较ⅡC组高(P<0.01),ⅡC组较ⅡD组高(P<0.01). 结论 PLL-DBM术中富集骨髓干细胞快速构建的组织工程骨是一种理想的组织工程骨,其成骨能力与自体髂骨相当.     

载桂皮醛同轴静电纺丝纳米纤维膜的构建及性能评价

目的 用同轴静电纺丝技术构建桂皮醛纳米纤维膜并评价其药物缓释功能.方法 用N,N-二甲基甲酰胺和二氯甲烷混合溶剂溶解聚己内酯和致孔剂聚乙二醇4000为壳层纺丝液,用无水乙醇溶解聚乙烯吡咯烷酮-K90和桂皮醛为芯层纺丝液;在电压为15 kV、接收距离为14cm、芯层纺丝液流速为0.1 mm/min、不同壳层纺丝液流速(0...     

异种无细胞真皮基质与薄自体皮复合移植后细胞外基质的变化

目的观察异种无细胞真皮基质与薄自体皮复合移植后细胞外基质的动态变化。方法以SD大鼠为动物模型,在其背部造成4 cm×5 cm的全层皮肤缺损。大鼠分为薄自体皮移植组和猪无细胞真皮基质+薄自体皮移植组,分别于移植后1,2,3,4,8,12,16周取标本,检测羟脯氨酸含量、Ⅰ/Ⅲ型前胶原mRNA的表达、透明质酸含量及纤维连接蛋白的变化。结果猪无细胞真皮基质与薄自体皮复合移植后,各时相点羟脯氨酸含量、Ⅰ型前胶原mRNA的表达均低于薄自体皮移植组(P<0.05);Ⅲ型前胶原mRNA的表达与薄自体皮移植组差异无统计学意义(P>0.05);透明质酸含量高于薄自体皮移植组(P<0.05);而纤维连接蛋白的表达在早期高于薄自体皮移植组,后期则低于薄自体皮移植组(P<0.05)。结论猪无细胞真皮基质与薄自体皮复合移植后能够减少胶原合成和Ⅰ型前胶原mRNA的表达,增加皮肤中透明质酸含量,从而减轻瘢痕增生。纤维连接蛋白早期表达增高有利于创面愈合及基底膜的重塑,而后期表达降低有助于减轻瘢痕增生。     

异种无细胞真皮组织相容性及血管化实验研究

目的：研究异种无细胞真皮的组织相容性及血管化速度,并将结果与异体无细胞真皮的相关结果进行比较分析。方法：制备巴马香猪无细胞真皮和大鼠无细胞真皮,将二者同时皮下埋植于同一大鼠受体,1、4、8、12w后取材,组织学切片观察其组织相容性;将二者分别进行单纯无细胞真皮移植,1、2、3、4w后分别取材,组织学切片观察其血管化速度。结果：异种无细胞真皮与异体无细胞真皮皮下埋植后各时间点组织学反应相似,未引起受体免疫排斥反应,胶原结构未降解;单纯无细胞真皮移植后,异种无细胞真皮与异体无细胞真皮均能在2w内完成血管化进程,且二者之间同一时间点新生血管数量无显著差异。结论：异种无细胞真皮与异体无细胞真皮同样具有组织相容性好、血管化速度快等生物学特性,理论上可替代异体无细胞真皮应用于临床。     

Enhancement of bone formation with a synthetic matrix containing bone morphogenetic protein-2 by the addition of calcium citrate

Purpose

The aim of the study was to test whether calcium citrate combined with rhBMP-2 was able to enhance bone regeneration compared with a matrix containing only rhBMP-2.

Methods

In each of experimental mice, one cylinder of calcium citrate–rhBMP-2 or rhBMP-2 alone was implanted into the thigh muscle pouches of the mouse. The following two treatment modalities were randomly allocated: (1) empty control with rhBMP-2 alone in a gelatin matrix and (2) a gelatin matrix including both calcium citrate and BMP-2. After several weeks, bone granules were obtained by histological analysis.

Results

Histomorphometric analysis showed the greatest amount of newly formed bone was observed in the group that contained 10.0 mg calcium citrate with 2.0 mg rhBMP-2 (p < 0.05). Quantitative histomorphometry revealed in the calcium citrate–rhBMP-2 group an obvious increase in the fractional area and the average new bone mineral density of newly formed bone at 2, 4 and 6 weeks than in the rhBMP-2 group (p < 0.05). At 2 weeks time-point, the mature cancellous bone had formed in the calcium citrate–rhBMP-2 group.

Conclusions

From this study, it can be concluded that calcium citrate combined with rhBMP-2 significantly enhances bone regeneration in muscle. This synthetic gelatin matrix containing calcium citrate/gelatin granules fulfils a number of criteria required for an ideal carrier system for rhBMP-2. The calcium ions that calcium citrate releases into the surrounding environment can activate bone formation when used as part of a combination of calcium citrate and BMP-2.     

无细胞毒性猪去细胞真皮基质制备及转归研究

DM植入SD大鼠皮下后未引发免疫排斥.术后3周,PADM与创面黏附牢固,不易从创面揭离;术后24周仍然可见其结构;早期PADM被大量炎性细胞浸润,随时间延长成纤维细胞逐渐增多,并出现新生的毛细血管,胶原纤维逐渐排列规则、致密.结论 高渗盐水/氢氧化钠方法 制备PADM过程简单,所得真皮基质无细胞毒性,生物安全性高,在体内可作为真皮支架长期存在.     

Preparation and biological evaluation of 153Sm-DOTMP as a potential agent for bone pain palliation

BACKGROUND: Designing ideal radiopharmaceuticals for use as bone pain palliative agents requires the use of a moderate energy beta emitter as the radionuclide and a polyaminophosphonic acid as the carrier molecule. Cyclic polyaminophosphonic acid ligands are known for endowing higher thermodynamic stability and kinetic inertness of the radiolabelled agent when complexed with radiolanthanides. AIM: To use Sm (T1/2=46.27 h, Ebeta,max=0.81 MeV, Egamma=103 keV) as the radioisotope, obtainable at an adequate specific activity and high radionuclidic purity by irradiation of a natural Sm2O3 target, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene phosphonic acid (DOTMP) as the carrier ligand. RESULTS: The radiolabelling yields under optimized conditions were near quantitative with the additional merit of using a relatively low ligand:metal ratio of 2:1 unlike the 250-fold excess of ligands used in the case of the established agent, Sm-EDTMP. Radiochemical purity was retained with insignificant dissociation on storage up to 10 d at room temperature. Biodistribution studies in Wistar rats demonstrated selective skeletal uptake (4.52%+/-0.49% of injected activity per gram in tibia at 30 min post-injection) with rapid blood clearance and minimal uptake in any of the major organs. No leaching of skeletal activity was observed up to 48 h post-injection. Scintigraphic studies carried out in rabbits also showed significant skeletal accumulation and almost no retention of activity in other vital organs/tissues.     

Iron, zinc and magnesium nutrition and athletic performance

During the last decade there has been considerable interest in the idea that dietary trace elements supplementation can result in an improvement in athletic performance. The current paper discusses this idea as it relates to 3 elements: iron, zinc and magnesium. Emphasis has been placed on examining the implicit assumptions underlying the idea that mineral supplements help the athlete. These assumptions include the beliefs that the athlete has a higher than normal requirement for minerals; that the athlete consumes a diet inadequate in these minerals; and that a marginal deficiency of these elements has a direct effect on athletic performance. Evidence is presented that both iron deficiency and magnesium deficiency can result in a significant reduction in exercise performance; however, the biochemical lesions underlying the reductions in exercise performance have not been identified. There is evidence that dietary magnesium intake may be suboptimal in some individuals, thus dietary supplementation of this element may be useful in some population groups. Excessive magnesium supplementation is not thought to be a serious health problem. Similar to magnesium dietary iron supplements can improve athletic performance in individuals severely deficient in this element. However, few studies have documented a need for iron supplements in healthy athletes. If iron supplements are used, it is important that the level of supplementation is not excessive, as excess iron in the diet can result in an induced zinc deficiency. In marked contrast to iron and magnesium, there is little evidence for the idea that zinc deficiency influences exercise performance in humans. Despite this fact, zinc supplements have been widely advocated for the athlete, as it is known that intense exercise can result in changes in zinc metabolism. If zinc supplements are used, it is important that they are not excessive, as excess zinc in the diet can result in a secondary copper deficiency.