内衬上皮的管状组织工程软骨构建的实验研究

目的研究以聚丙交酯-乙交酯共聚物[poly（DL-lactide-co-glycolide）,PLGA]包埋甲壳胺无纺布为细胞支架,在有免疫力的动物体内构建内衬上皮的管状组织工程软骨的可行性,为喉、气管缺损的修复探索新方法。方法取1月龄兔耳廓软骨,收集体外培养第3～4代的软骨细胞,接种于经多聚赖氨酸处理的以PLGA包埋甲壳胺无纺布的片状细胞支架材料上,体外培养7～10d后包裹于兔腹部缝制的皮管上并深埋于体内,分别于6、12、18周取材行大体和组织学观察以及HE染色、甲苯胺蓝染色和Masson＇s三色染色。结果同种异体软骨细胞/PLGA包埋甲壳胺无纺布的细胞支架复合物体外培养1周时有基质产生;植入体内6周后,复合物中有基质分泌,软骨细胞不成熟;12周时,软骨细胞接近成熟并形成凹陷,内衬上皮的管状组织工程软骨形成;18周时,新生软骨基本接近正常软骨。结论以PLGA包埋甲壳胺无纺布为细胞支架,同种异体软骨细胞与细胞支架所形成的复合物在有免疫力的动物体内可构建出内衬上皮的管状组织工程软骨。     

组织工程人角膜基质体外重建的研究进展

从种子细胞和载体支架两个方面的最新研究成果,对组织工程人角膜基质的体外重建及其研究中存在的问题与解决途径进行综述。     

纳米纤维支架在骨组织工程中的应用

纳米纤维支架是具有纳米级别的天然骨分级结构和多孔结构,近年来在骨组织工程中得到广泛应用。骨组织工程由种子细胞、支架和生长因子3个部分组成,其中寻找能够促进细胞长入和引导新骨生长的三维组织工程支架是骨组织工程研究的重点。纳米纤维支架与天然骨细胞外基质形态结构相似,能够促进细胞附着和干细胞分化,所以成为目前促进骨组织再生的理想支架。本文综述了纳米纤维支架制备技术的最新研究进展。     

交联透明质酸植入角膜超声生物显微镜观察

目的探讨交联透明质酸材料对兔角膜组织的生物学反应影响,评价其作为角膜组织工程支架材料的可行性。方法将交联透明质酸材料植入兔角膜基质层间内3个月,超声生物显微镜观察该材料在角膜内生物学反应。结果观察期内交联透明质酸材料与兔角膜基质愈合良好,超声生物显微镜检测到兔眼角膜中间有一高回声条带,随着观察时间延长,角膜中央高回声条带有减弱。结论交联透明质酸材料植入兔角膜后无排异等反应发生,材料逐渐降解吸收,其生物相容性良好,是一种理想的角膜组织工程支架材料。     

Intra-myocardial growth hormone administration ameliorates arrhythmogenesis during ischemia–reperfusion in rats

Growth hormone, currently under evaluation for the prevention of left ventricular remodeling post-myocardial infarction, displays antiarrhythmic properties in the acute setting. However, it is uncertain whether these actions are retained after ischemia/reperfusion. Using implanted telemetry transmitters, we examined the effects of prolonged, intra-myocardial growth hormone administration in conscious rats. During a 24-h observation period, ventricular tachyarrhythmias and sympathetic activation were attenuated in treated rats, whereas infarct-size was unchanged. These findings call for further study on the antiarrhythmic effects of growth hormone and on the underlying mechanisms.     

多孔β-磷酸三钙/胶原支架与犬牙周膜细胞三维复合体的构建

目的:探索用多孔β-磷酸三钙/胶原(β-TCP/col)支架与犬牙周膜细胞(PDLCs)在体外构建三维复合体.方法:分离培养犬PDLCs,并对其来源进行鉴定;利用甲基噻唑基四唑法检测β-TCP/col浸提液对PDLCs增殖的影响;并将第3代PDLCs以2×10⁵/mL的浓度接种于β-TCP/col支架上进行三维复合体的体外构建,用扫描电镜观察.结果:β-TCP/col浸提液对犬PDLCs增殖无不良影响;PDLCs可在材料的三维结构上贴附生长,细胞充分伸展,且表面可见明显分泌物. 结论:多孔β-磷酸三钙/胶原支架与犬牙周膜细胞具有良好的生物相容性,二者可在体外构建成三维复合体,提示该材料具有成为牙周组织工程理想支架材料的潜力.     

成骨诱导自体脂肪源性干细胞用于修复兔颅骨缺损

目的探讨脂肪源性干细胞作为骨组织工程的种子细胞在修复骨缺损中的应用前景。方法提取兔脂肪源性干细胞,成骨诱导,将成骨诱导前后的脂肪源性干细胞种植到自制松质骨支架上,将细胞-支架复合物和单纯支架材料,分别移植至兔颅骨缺损部位。术后14周,处死取材,Micro-CT扫描。结果与未诱导的脂肪源性干细胞复合支架、单纯支架以及空白处理对比,成骨诱导后的脂肪源性干细胞复合支架成骨量显著增高,差异具有统计学意义。结论脂肪源性千细胞可作为骨组织工程的种子细胞,其成骨诱导后与自制松质骨复合植入体内,能显著促进骨缺损的修复。     

Deubiquitination complex platform: A plausible mechanism for regulating the substrate specificity of deubiquitinating enzymes

Deubiquitinating enzymes (DUBs) or deubiquitinases facilitate the escape of multiple proteins from ubiquitin‒proteasome degradation and are critical for regulating protein expression levels in vivo. Therefore, dissecting the underlying mechanism of DUB recognition is needed to advance the development of drugs related to DUB signaling pathways. To data, extensive studies on the ubiquitin chain specificity of DUBs have been reported, but substrate protein recognition is still not clearly understood. As a breakthrough, the scaffolding role may be significant to substrate protein selectivity. From this perspective, we systematically characterized the scaffolding proteins and complexes contributing to DUB substrate selectivity. Furthermore, we proposed a deubiquitination complex platform (DCP) as a potentially generic mechanism for DUB substrate recognition based on known examples, which might fill the gaps in the understanding of DUB substrate specificity.     

Multilayered biomimetic scaffolds for cartilage repair of the talus. A systematic review of the literature

ObjectiveThe aim of the present review was to analyze the available evidence in the literature on the clinical and radiological outcomes of multilayered biomimetic scaffolds in the treatment of osteochondral lesions of the talus (OLTs).DesignA systematic search was performed in three databases to identify clinical trials, where the multilayered biomimetic scaffolds were used for the treatment of OLTs. The PRISMA guidelines were followed. Qualitative analysis of the relevant data of the included studies was executed. The methodological quality of the analyzed studies was assessed with a modified Coleman Methodology Score (CMS).ResultsA total of 10 studies with 87 patients were included in the analysis. Only three multilayered biomimetic scaffolds have been investigated in clinical trials for the treatment of OLTs. The worst clinical and radiological outcomes, as well as safety profile were observed for the TruFit scaffold (Smith & Nephew, Andover, MA, USA), which had already been withdrawn from the market. The other two scaffolds (MaioRegen, Finceramica, Italy; Agili-C, Cartiheal, Israel) performed significantly better in the majority of the reviewed studies, especially in the clinical aspect. The radiological findings, the improvements of MOCART scores, the completeness of lesions’ fill, and the structure of regenerated tissue were much more inconsistent.ConclusionsTwo of the multilayered biomimetic scaffolds demonstrated an adequate potential in the treatment of complex OLTs. However, limited studies availability and their low level of medical evidence request further high-level investigations before the clinical decision making for such scaffolds in the treatment of OLTs can be defined.