Effect of acellular dermal matrix as a delivery carrier of adipose-derived mesenchymal stem cells on bone regeneration

The purpose of this study is to evaluate the effect of acellular dermal matrix (ADM) as a delivery carrier of adipose-derived mesenchymal stem cells (ASCs) on bone regeneration in athymic murine calvarial bone defect. Paired-critical size defects in nude rat skull were made. The right-side defects received ASCs/ADM or only ADM, whereas the left-side defect was not treated. In 3D images, new bone formation in the ASCs/ADM group was apparent at 4 wk, but in the ADM group at 8 wk. At 4 and 8 wk, bone mineral density and tissue volume in rats that received ASCs/ADM were significantly greater than rats that received ADM and control groups. Histological examination revealed that the defect was repaired by bone in the ASCs/ADM group, whereas only minimal bone island with fibrous connection was observed in the control group. In histomorphometric analysis, the total healing score in the ASCs/ADM group at 4 wk was significantly higher than the ADM and negative control group, whereas the score of 8 wk was similar between the ASCs/ADM and ADM group. ASCs/ADM implants promote new bone formation more rapidly than ADM only or no treatment. ADM seeded with ASCs may be potentially useful as a future biomaterial option in bone implants.     

组织工程骨修复兔桡骨节段性缺损血液流变性及局部血流量的变化

目的 观察组织工程骨修复骨缺损过程中，实验动物血液流变性和骨缺损修复区血流量的变化。方法 选择30只新西兰白兔，制作15mm长的桡骨节段性骨缺损模型，根据植入不同移植材料分为实验组和对照组，实验组于动物左侧桡骨缺损区植入组织工程骨，对照组植入部分脱蛋白骨，观察各组动物术后1h、7h、14d血液流变性和术后14d骨缺损修复区血流量的变化。结果 实验组与对照组比较，血液流变学指标和骨缺损修复区血流量差异显著。组织工程骨修复骨缺损，实验动物全身血液黏度降低，骨缺损修复区局部血流量增加。结论 与单纯材料比较，组织工程骨可促进血液流变学及局部血流量的改善。     

不同来源蚕丝蛋白修复骨软骨组织缺损的效果比较

背景：目前还没有研究比较不同种属来源蚕丝蛋白修复骨软骨的效果。 目的：观察桑蚕和柞蚕来源蚕丝蛋白支架材料修复骨软骨缺损的效果差异。 方法：取新西兰兔20只,制备单侧膝关节骨软骨缺损模型,随机分为5组：其中1组不植入任何材料,作为空白对照;实验1组将3层桑蚕丝蛋白支架粘在一起,充填于缺损处;实验2组将1个包被转化生长因子β3的桑蚕丝蛋白支架与2个包被骨形态发生蛋白2的桑蚕丝蛋白支架粘在一起,充填于缺损处;实验3组将3层柞蚕丝蛋白支架粘在一起,充填于缺损处;实验4组将1个包被转化生长因子β3的柞蚕丝蛋白支架与2个包被骨形态发生蛋白2的柞蚕丝蛋白支架粘在一起,充填于缺损处。术后8周,取关节骨软骨修复区行组织病理学观察,检测Ⅰ型和Ⅱ型胶原蛋白表达。 结果与结论：实验1组胶原蛋白广泛分布于缺损区全层;实验2组胶原纤维在修复区表面呈平行分布,在中间和底部呈垂直顶部的方向分布;实验3组在修复区表面可见胶原;实验4组在支架表面和底部可见软骨样细胞有成团分布。4个实验组修复区Ⅰ型胶原蛋白呈强阳性表达;实验1组、实验2组修复区Ⅱ型胶原蛋白呈微弱表达,实验3组、实验4组修复区Ⅱ型胶原蛋白呈强阳性表达。表明两种蚕丝蛋白均能修复骨软骨缺损,桑蚕丝蛋白倾向于形成骨组织,柞蚕丝蛋白倾向于形成软骨组织。 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      

复合同种异体成骨细胞的β-磷酸三钙人工骨修复桡骨缺损

背景：作为骨支架材料,β-磷酸三钙具有良好的生物相容性、骨诱导性及生物力学性能。 目的：探讨β-磷酸三钙复合同种异体成骨细胞修复兔桡骨节段性骨缺损的效果。 方法：建立45只兔单侧桡骨骨缺损模型,随机分为3组,实验组缺损区植入复合同种异体成骨细胞的β-磷酸三钙,对照组缺损区植入β-磷酸三钙,空白对照组缺损区不植入任何材料。植入后4,8,16周观察新骨生成情况,通过形态学、X射线等观察指标客观评价各组成骨及骨缺损修复能力。 结果与结论：随着修复时间的延长,实验组骨缺损逐渐修复,至16周时X射线见支架与宿主骨之间的骨痂已完全骨化,骨缺损完全修复;组织学见缺损区皮质骨连续,髓腔再通,并且不同时间点实验组修复效果明显优于对照组与空白对照组(P < 0.01)。表明复合同种异体成骨细胞的β-磷酸三钙人工骨具有良好的成骨能力,有引导组织再生、防止骨不连的作用。     

可注射性纳米羟基磷灰石、壳聚糖复合材料修复骨缺损的实验研究

目的：观察可注射性羟基磷灰石/壳聚糖复合材料对兔桡骨骨缺损修复效果。方法：18只新西兰白兔双侧桡骨中段建立长度为10mm节段性缺损,将可注射性纳米羟基磷灰石/壳聚糖复合材料植入一侧骨缺损作为实验组,另一侧植入单纯羟基磷灰石材料作为对照组,于第4、8、12周末,分别行大体、X线检查、组织学、电镜检测,观察该材料对骨缺损的修复效果。结果：①大体观察、X线检查提示：实验组骨痂生长良好,骨缺损完全修复,对照组骨缺损部分修复,部分骨皮质不连续。②组织形态学: 术后12周,实验组新生骨皮质连接完整,髓腔完全再通;对照组少量新生骨形成,部分纤维组织填充③电镜检查:12周实验组材料基本降解,被新生骨组织替代。结论：可注射性纳米羟基磷灰石/壳聚糖复合材料骨缺损修复能力较单纯羟基磷灰石好,具有确实的骨缺损修复能力。     

纳米羟基磷灰石复合基因转染生长因子修复牙槽骨缺损

背景：研究发现成骨细胞可促进牙槽骨的形成,而血小板衍生生长因子A因子转染成骨细胞对于牙槽骨形成的作用尚不清楚。 目的：将基因转染的血小板衍生生长因子A重组质粒与纳米羟基磷灰石复合移植到骨缺损处,观察其对骨缺损修复的影响。 方法：将24只新西兰大白兔随机分成实验组与对照组,制作双侧下颌下缘10 mm×6 mm×4 mm骨质缺损,实验组植入血小板衍生生长因子A转染成骨细胞与纳米羟基磷灰石的复合材料,对照组单纯植入纳米羟基磷灰石。术后4,8,12周取材行大体标本、锥形束CT、组织学观察及扫描电镜观察。 结果与结论：术后不同时间点,实验组缺损处新骨生成,成骨细胞、骨小梁、骨陷窝及新生血管修复情况,以及材料与牙槽骨连接处的骨结合均明显优于对照组(P < 0.05)。表明血小板衍生生长因子A转染成骨细胞与纳米羟基磷灰石复合生成的新型材料,有较好的生物相容性,可加速骨组织再生,促进骨组织缺损修复。     

Tissue-engineered bone repair of goat-femur defects with osteogenically induced bone marrow stromal cells

Tissue engineering can generate bone tissue and has been shown to provide a better means of repairing weight-bearing bone defect. Previous studies, however, have heretofore been limited to the use of nonosteogenically induced bone marrow stromal cells (BMSCs) or the application of slow-degradation scaffolds. In this study, weight-bearing bone was engineered using osteogenically induced BMSCs. In addition, coral was used as a scaffold material, due to its proper degradation rate for the engineering and repair of a goat femur defect. A 25 mm long defect was created at the middle of the right femur in each of 10 goats. The rates of defect repair were compared in an experimental group of ten goats receiving implants containing osteogenically induced BMSCs and in the control group of goats (n = 10) receiving just coral cylinders. In the experimental group, bony union was observed by radiographic and gross view at 4 months, and engineered bone was further remodeled into newly formed cortexed bone at 8 months. There was increased gray density of radiographic rays in the repaired area, which was significantly different (p < 0.05) from that of the control group. H&E staining demonstrated that trabecular bone was formed at 4 months. Moreover, irregular osteon was observed at 8 months. Most importantly, the tissue-engineered bone segment revealed a similarity to the left-side normal femur in terms of bend load strength and bend rigidity, showing no significant difference (p > 0.05). In contrast, the coral cylinders of the control group showed no bone formation. Furthermore, almost complete resorption of the carrier had occurred, being evident at 2 months in the control group. H&E staining demonstrated that a small amount of residual coral particle was surrounded by fibrous tissue at 4 months whereas the residues disappeared at 8 months. Based on these results, we conclude that engineered bone from osteogenically induced BMSCs and coral can ideally heal critical-sized segmental bone defects in the weight-bearing area of goats.     

Ectopic and in situ bone formation of adipose tissue-derived stromal cells in biphasic calcium phosphate nanocomposite

Adipose-derived stromal cells (ASCs) have the potential to differentiate into a variety of cell lineages both in vitro and in vivo. A novel biodegradable biphasic calcium phosphate nanocomposite (NanoBCP) comprising beta-tricalcium phosphate matrix and hydroxyl apatite nanofibers is favorable for bone tissue engineering. In this study, ASCs were harvested from Sprague-Dawley (SD) rats and induced to osteogenesis before seeded into porous NanoBCP scaffold. To determine ectopic in vivo osteogenic differentiation, these constructs were implanted in nude mice subcutaneously. Meanwhile, the ability of engineered constructs to stimulate in situ bone repair was assessed in rat critical-size cranial defects. The defects were filled with NanoBCP containing osteogenic ASCs in experimental group; with cell-free NanoBCP in negative controls; and with nothing in blank controls. The retrieved specimens were analyzed with morphological, histological, and molecular methods. Histological analysis of the retrieved specimens from nude mice in experimental group showed obvious ectopic bone formation. There were positive expression of osteopontin (OPN) and osteocalcin (OCN) at RNA and protein level. As for the cranial defects, there was complete repair in experimental group, but only partial repair in negative controls. The radiographs, H&E staining, and Masson's trichrome method showed better bone regeneration at experimental sites. Combining osteogenic ASCs with NanoBCP can lead to formation of ectopic new bone. Furthermore, the approach can also stimulate bone regeneration and repair for the large size bone defects.     

应用羟基磷灰石生物陶瓷及口腔膜引导骨再生修复牙周骨缺损

背景：羟基磷灰石生物陶瓷以天然优质海洋珊瑚为原料,在珊瑚骨架上形成羟基磷灰石薄层,保留珊瑚天然孔孔相同的支架结构,为组织生长提供了良好空间。 目的：观察羟基磷灰石生物陶瓷膜引导骨再生修复牙周骨缺损的临床效果。 方法：将42例下颌第一磨牙牙周病致骨缺损患者随机分组：实验组采用羟基磷灰石生物陶瓷结合口腔修复膜充填修复骨缺损,对照组采用单独羟基磷灰石生物陶瓷充填修复。 结果与结论：临床随访观察12个月,两组牙周组织附着丧失、牙周探诊深度较治疗前明显改善(P < 0.05),且实验组牙周组织附着丧失、牙周探诊深度改善优于对照组(P < 0.05);实验组骨缺损区新骨形成密度和骨量均优于对照组(P < 0.05)。表明采用羟基磷灰石生物陶瓷充填骨缺损区同时覆盖生物膜的引导骨再生技术可获得良好的骨引导再生效果,修复骨缺损。     

浓缩红骨髓/富血小板纤维蛋白复合载自体骨膜碎片修复下颌骨缺损

背景：富血小板纤维蛋白支架结构有利于红骨髓中间充质干细胞及各种生长因子的生长,促进最终成骨。 目的：探讨浓缩红骨髓/富血小板纤维蛋白复合载自体骨膜碎片支架材料修复兔下颌骨缺损的可行性。 方法：制备新西兰大白兔双侧下颌骨人工制备骨缺损模型,采用自身对照方法,左侧为实验侧,植入自体浓缩红骨髓/富血小板纤维蛋白复合载自体骨膜碎片与纳米羟基磷灰石支架材料;右侧为对照侧,植入自体骨膜碎片复合纳米羟基磷灰石支架材料。术后2,4,8,12周制备组织标本,行大体观察、影像学分析、苏木精-伊红染色、扫描电镜检测。 结果与结论：影像学检查及组织学染色显示,实验侧骨缺损处愈合程度、成骨速度及质量明显优于对照侧;扫描电镜显示实验侧复合材料与组织相容性好,无炎症刺激反应;牙CT分析数据及新骨形成情况分别证明实验侧骨密度CT值显著高于对照侧(P < 0.05),实验侧新生骨面积显著高于对照侧(P < 0.05)。表明浓缩红骨髓/富血小板纤维蛋白复合载自体骨膜碎片支架材料具有明显骨诱导作用,可望成为临床应用中修复颌骨缺损的新型材料。     

Effect of nano-structured bioceramic surface on osteogenic differentiation of adipose derived stem cells

Tissue engineering strategies to construct vascularized bone grafts potentially revolutionize the treatment of massive bone loss. The surface topography of the grafts plays critical roles on bone regeneration, while adipose derived stem cells (ASCs) are known for their capability to promote osteogenesis and angiogenesis when applied to bone defects. In the present study, the effects of hydroxyapatite (HAp) bioceramic scaffolds with nanosheet, nanorod, and micro-nano-hybrid (the hybrid of nanorod and microrod) surface topographies on attachment, proliferation and osteogenic differentiation, as well as the expression of angiogenic factors of rat ASCs were systematically investigated. The results showed that the HAp bioceramic scaffolds with the micro-/nano-topography surfaces significantly enhanced cell attachment and viability, alkaline phosphatase (ALP) activity, and mRNA expression levels of osteogenic markers and angiogenic factors of ASCs. More importantly, the biomimetic feature of the hierarchical micro-nano-hybrid surface topography showed the highest stimulatory effect. The activation in Akt signaling pathway was observed in ASCs cultured on HAp bioceramics with nanorod, and micro-nano-hybrid surface topographies. Moreover, these induction effects could be repressed by Akt signaling pathway inhibitor LY294002. Finally, the in vivo bone regeneration results of rat critical-sized calvarial defect models confirmed that the combination of the micro-nano-hybrid surface and ASCs could significantly enhance both osteogenesis and angiogenesis as compared with the control HAp bioceramic scaffold with traditional smooth surface. Our results suggest that HAp bioceramic scaffolds with micro-nano-hybrid surface can act as cell carrier for ASCs, and consequently combine with ASCs to construct vascularized tissue-engineered bone.     

聚碳酸亚丙酯/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞修复兔骨缺损

背景：骨组织工程细胞移植技术是近年来的研究热点,支架材料是其重要组成部分,同时也是三大要素中最有望取得突破性进展的环节,随着组织工程材料工艺的革新,有望为更好地修复骨缺损带来新的希望。 目的：评价聚碳酸亚丙酯/壳聚糖纳米纤维(propylene carbonate/chitosan nanofibers,PPC/CSNF)三维多孔支架复合骨髓间充质干细胞(bone marrow mesenchymal stem cell,BMSCs)修复兔股骨髁部骨缺损的能力。 方法：二次相分离法制作PPC/CSNF复合三维多孔支架,将第3代的BMSCs 种植到复合材料上。36只新西兰大白兔右侧股骨髁制作直径6 mm深10 mm骨缺损,于缺损处实验组植入复合BMSCs的PPC/CSNF多孔支架,对照组植入单纯PPC/CSNF多孔支架,标准组于兔髂后上棘取自体松质骨移植于缺损部位,空白组不做处理。术后第4,8,12周取材,通过大体观察、放射学检查和组织学检查等方法评价其修复缺损情况。 结果与结论：实验组放射学评价与标准组无显著差异,两组结果均优于对照组(P< 0.05);实验组大体标本与标准组基本一致;实验组组织学检查新骨生成速度、生成量优于对照组(P < 0.05);空白组不能自行修复骨缺损,最后缺损由纤维组织充填。结果显示PPC/CSNF多孔支架具有较好的细胞和组织相容性,复合兔BMSCs能加速新骨形成,可用于修复兔股骨髁部骨缺损。     

聚左旋乳酸/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞修复兔骨缺损**△

背景：骨髓间充质干细胞具有向多种间质细胞谱系分化的能力,且支架材料的性能对骨缺损的修复有重要影响。 目的：观察聚左旋乳酸/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞治疗骨缺损。 方法：对骨缺损模型兔分别采用空白植入、髂后上棘自体松质骨移植、聚左旋乳酸/壳聚糖纳米纤维多孔支架移植和复合了骨髓间充质干细胞的聚左旋乳酸/壳聚糖纳米纤维多孔支架移植修复缺损部位。 结果与结论：至移植12周,移植复合了骨髓间充质干细胞的聚左旋乳酸/壳聚糖纳米纤维多孔支架的实验兔的缺损处有骨组织生成,支架材料降解,已完成缺损修复,其修复情况接近松质骨组;髂后上棘自体松质骨移植的实验兔的缺损修复完好,新形成的骨组织较规则;只植入聚左旋乳酸/壳聚糖纳米纤维多孔支架的实验兔有少量骨组织形成,材料部分降解;空白植入的实验兔缺损处无新生骨组织生成,主要由纤维结缔组织填充。说明新型的生物支架材料聚左旋乳酸/壳聚糖纳米纤维三维多孔支架与来源于新西兰大白兔的骨髓间充质干细胞复合培养后,植入同种异体兔股骨髁缺损处,使骨缺损的修复速度加快,表现为较好的体内诱导成骨的作用。     

Repair of articular cartilage defect in non-weight bearing areas using adipose derived stem cells loaded polyglycolic acid mesh

The current study was designed to observe chondrogenic differentiation of adipose derived stem cells (ASCs) on fibrous polyglycolic acid (PGA) scaffold stabilized with polylactic acid (PLA), and to further explore the feasibility of using the resulting cell/scaffold constructs to repair full thickness articular cartilage defects in non-weight bearing area in porcine model within a follow-up of 6 months. Autologous ASCs isolated from subcutaneous fat were expanded and seeded on the scaffold to fabricate ASCs/PGA constructs. Chondrogenic differentiation of ASCs in the constructs under chondrogenic induction was monitored with time by measuring the expression of collagen type II (COL II) and glycosaminoglycan (GAG). The constructs after being in vitro induced for 2 weeks were implanted to repair full thickness articular cartilage defects (8 mm in diameter, deep to subchondral bone) in femur trochlea (the experimental group), while scaffold alone was implanted to serve as the control. Histologically, the generated neo-cartilage integrated well with its surrounding normal cartilage and subchondral bone in the defects of experimental group at 3 months post-implantation, whereas only fibrous tissue was filled in the defects of control group. Immunohistochemical and toluidine blue staining confirmed the similar distribution of COL II and GAG in the regenerated cartilage as the normal one. A vivid remolding process with post-operation time was also witnessed in the neo-cartilage as its compressive moduli increased significantly from 50.55% of the normal cartilage at 3 months to 88.05% at 6 months. The successful repair thus substantiates the potentiality of using chondrogenic induced ASCs and PGA/PLA scaffold for cartilage regeneration.     

快速成型聚乳酸-聚羟乙酸/磷酸三钙支架修复兔桡骨缺损

背景：理想的骨修复材料除必须具有生物相容性、可吸收性、利于血管化及迅速被新生组织替代的孔隙率,还需要有与骨组织相似三维结构。 目的：检验快速成型工艺制作的聚乳酸-聚羟乙酸/磷酸三钙支架复合骨形态发生蛋白修复兔桡骨缺损的效果。 方法：将乳酸乙醇酸共聚物溶于1,4-二氧六环中并混合粉末状磷酸三钙制备成液态的浆料,放入生物材料快速成形机TissFormTM制备出直径5 mm,长15 mm的圆柱形人工骨载体材料。按每个材料15 mg的标准,采用预湿、负压复合骨形态发生蛋白、冻干3步处理,制备出活性人工骨材料。健康新西兰大白兔20只,制备右前肢桡骨中上段15 mm骨缺损模型,实验组和对照组分别植入复合骨形态发生蛋白的活性人工骨和未复合骨形态发生蛋白的单纯支架。通过影像学、组织学、材料降解及骨密度评价修复兔桡骨缺损的效果。 结果与结论：12周时实验组骨缺损愈合,新生骨痂连接缺损断端并塑形,支架材料近于完全降解,各检测指标与对照组比较差异均有显著性意义,对照组骨缺损内未见新骨形成。结果表明复合骨形态发生蛋白的聚乳酸-聚羟乙酸/磷酸三钙支架可以很好的修复兔15 mm骨缺损,且降解速度与成骨速度匹配良好。     

骨髓间充质干细胞复合异体骨修复松质骨缺损

背景：有研究表明骨髓间充质干细胞及异体骨可促进骨缺损的修复,但骨髓间充质干细胞复合异体骨对于松质骨缺损的修复效果至今少有报道。 目的：观察骨髓间充质干细胞复合异体骨修复兔松质骨缺损效果。 方法：在新西兰大白兔双侧股骨外侧髁造成0.6 cm×1.2 cm 的松质骨缺损,一侧设为模型组,骨缺损处植入复合骨髓间充质干细胞的异体骨,另一侧设为对照组,单纯植入异体骨。 结果与结论：植入后4,8,12周,大体观察、X射线检查和苏木精-伊红染色观察结果显示,模型组在新骨成长方面,缺损区修复方面均优于对照组。植入后12周,模型组骨缺损区可见大量骨小梁形成及成熟的板层骨组织,骨缺损基本修复。对照组骨缺损区仅可见大量编织骨形成,骨缺损尚未得到有效修复。模型组Lane-Sandhu法X射线结合组织学观察评分高于对照组(P < 0.05)。生物力学检测结果显示,植入后12周,模型组股骨髁最大压力载荷、载荷/应变比值均高于对照组(P < 0.05),最大应变位移较对照组低(P < 0.05)。结果证实,骨髓间充质干细胞复合异体骨可有效修复兔股骨髁松质骨缺损,且修复效果明显优于单纯异体骨移植。     

注射型可吸收聚氨基酸/硫酸钙复合材料动物体内降解吸收及促成骨作用*

背景：注射型人工骨可经皮穿刺注射植入体内,对机体创伤较小,同时该型材料可以任意塑形,能较好地充填骨缺损,但目前临床上尚无在体内能完全降解吸收且具有较好促成骨作用的注射型人工骨产品。 目的：评估注射型可吸收聚氨基酸/硫酸钙复合材料(硫酸钙含量70%)动物体内的降解吸收及促成骨作用,观察其修复骨缺损的能力。 方法：取48只新西兰大白兔,在股骨外髁处制备直径为5 mm、深10 mm的骨缺损模型,以随机数字表法分为实验组和对照组,实验组将注射型可吸收聚氨基酸/硫酸钙复合材料植入骨缺损处,对照组未予干预。 结果与结论：X射线平片示：实验组骨缺损逐渐被骨痂填充,术后16周,骨缺损处恢复正常松质骨密度,塑形完成;对照组骨缺损处修复不明显。组织学检查(苏木精-伊红、MASSON染色)示：术后4周,材料开始降解,新生原始骨小梁长入材料内;术后12周,编织骨开始转化为板层骨;术后16周,材料完全被降解吸收,新生骨组织完全修复骨缺损。结果显示注射型聚氨基酸/硫酸钙复合材料在动物内能够完全降解、吸收,具备一定的成骨活性,可望用作骨修复材料。     

Comparative study between coral-mesenchymal stem cells-rhBMP-2 composite and auto-bone-graft in rabbit critical-sized cranial defect model

Tissue engineered bone has become a bone substitute for the treatment of bone defects in animal research. This study investigated the osteogenesis capacity of coral-MSCs-rhBMP-2 composite with the auto-bone-graft as control. Coral-MSCs-rhBMP-2 composite were fabricated by coral (as main scaffold), rhBMP-2 (as growth factor), and MSCs (cultured from iliac marrow as seed cells). Critical-sized defects (d = 15 mm) were made on forty rabbits crania and treated by different composite scaffolds: iliac autograft (n = 8), coral (n = 8), rhBMP-2/coral (n = 8), and MSCs/rhBMP-2/coral (n = 8). The defects were evaluated by gross observation, radiographic examination, histological examination, and histological fluorescence examinations after 8 and 16 weeks. The results showed that repair of bone defect was the least in coral group, and significant ingrowth of new bone formation and incorporation could be seen with 77.45% +/- 0.52% in radiopacity in MSCs/rhBMP-2/coral group, which was similar to that in iliac autograft group (84.61% +/- 0.56% in radiopacity). New bone formation in MSCs/rhBMP-2/coral group was more than that in rhBMP-2/coral group. And osteogenesis rate in MSCs/rhBMP-2/coral group (10.23 +/- 1.45 microm) was much faster than that in rhBMP-2/coral group (5.85 +/- 2.19 microm) according to histological fluorescence examination. Newly formed bone partly came from induced MSCs in composite scaffold according to bromodeoxyuridine immunohistochemical examination. These data implicated that MSCs could produce synergic effect with coral-rhBMP-2, and the tissue engineered bone of coral-MSCs-rhBMP-2 is comparable to auto-bone-graft for the repair of critical-sized bone defect.     

RGD多肽表面修饰对羟基磷灰石修复骨缺损微循环的影响

目的了解精氨酸-甘氨酸-天冬氨酸(Arg-Gly-Asp,RGD)多肽表面修饰的羟基磷灰石(hydroxyapatite,HA)修复骨缺损过程中,实验动物血液流变学和骨缺损修复区血流量的变化.方法选择20只新西兰白兔,制作15mm长的桡骨节段性骨缺损模型,根据植入不同移植材料分为实验组和对照组,实验组于动物左侧桡骨缺损区植入MSC复合RGD多肽表面修饰的HA培养制备的组织工程骨,对照组植入MSC复合HA培养制备的组织工程骨,观察各组动物术后7d、14d血液流变学和术后14d骨缺损修复区血流量的变化.结果实验组与对照组比较,血液流变学指标和骨缺损修复区血流最差异显著,实验动物全身血液黏度和红细胞聚集指数降低,骨缺损修复区的局部血流量增加.结论 RGD多肽表面修饰对以HA为支架材料组织工程骨的修复有明显优化作用.     

同种异体软骨细胞-聚羟基乙酸支架复合物修复甲状软骨缺损

BACKGROUND: Tissue-engineered bone can be obtained by the combination of chondrocytes and polyglycolic acid scaffold. OBJECTIVE: To investigate the effect of allogeneic chondrocytes/polyglycolic acid scaffold compound in the repair of thyroid cartilage defects in rabbits. METHODS: Twenty New Zealand adult rabbits were randomly divided into experimental group with implantation of allogeneic chondrocytes/polyglycolic acid scaffold compound and control group with implantation of polyglycolic acid scaffold. Gross and histological observations were done at 4 and 8 weeks after implantation.   RESULTS AND CONCLUSION: (1) Gross observation results: 4 weeks after surgery, cartilage defects in the experimental group were repaired certainly, and no necrosis appeared in the repair area; in the control group, the defects were filled with muscle and connective tissues. At 8 weeks after implantation, cartilage defects in the experimental group were further repaired, with unclear repair boundaries, and in the control group, cartilage defects were no repaired and showed a notable boundary with the surrounding normal cartilage tissues. (2) Immunohistochemical staining results: the expression of type II collagen in the experimental group was higher than that in the control group (P < 0.05) at 4 and 8 weeks after implantation. These findings indicate that the allogeneic chondrocytes/polyglycolic acid scaffold compound can promote the repair of thyroid cartilage defects in rabbits.