用于组织工程的去细胞化基质材料研究进展

细胞外基质在调节干细胞分化和诱导新的组织器官重建过程中扮演着重要的角色。在体外通过不同去细胞化方法获得不同来源的去细胞化基质材料,并研究它们在组织工程领域的应用,具有重要的理论意义和临床应用价值。总结了不同来源去细胞化基质材料的制备方法,并分析了其在诱导干细胞分化和组织修复过程中的作用,最后探讨了目前去细胞化基质材料存在的问题和面临的挑战。     

组织工程支架材料研究进展

组织工程在组织或器官的修复和再生中发挥着越来越重要的作用。其中支架材料是组织工程的重要组成部分,能够为种子细胞的粘附、生长、增殖和分化等提供临时的机械支撑以及必要的生长环境,因而显得尤为重要。支架材料按照来源可以分为天然材料、人工合成材料和复合材料。从材料学的角度,介绍了骨、神经、牙齿及血管等组织工程领域中常见的支架材料的研究与应用进展,并对支架材料的发展前景进行了展望。     

组织工程支架材料的研究进展

自19世纪以来,移植手术一直致力于修复由于创伤﹑感染﹑肿瘤所造成的大范围组织缺损,以恢复器官功能。自体移植是目前最常采用的疗法,但供体的有限性限制了其应用,而且会给患者带来很大的痛苦。组织工程的目标是通过种子细胞在三维支架材料上的黏附﹑生长进而修复受损的组织。三维支架是种子细胞形成组织之前赖以生存和依附的载体,能够正确引导新组织的生长。因此支架材料的选择就成了关键,本综述主要介绍目前应用于组织工程的生物支架材料的性能要求﹑发展现状以及发展前景。     

组织工程支架材料

对组织工程各个领域应用的支架材料进行了论述,并对组织工程支架材料的最新研究动态进行了研究和预测。     

丝素蛋白水凝胶材料在组织工程中的应用研究进展

组织工程技术是有望从根本上解决组织或器官损伤及实现功能重建的前沿技术,其关键之一是制备具有良好生物相容性和生物降解性的支架材料。水凝胶由于具有众多良好的特性,成为组织工程研究中一种优良的支架材料。丝素蛋白水凝胶由于独特的性质、多样化的成胶方式以及优异的可加工性成为了支架材料研究的热点,备受学者的青睐并涌现出了大量的研究成果。本文在阐明丝素蛋白凝胶原理的基础上,回顾了目前较为成熟的凝胶化方法,随后重点综述了丝素蛋白水凝胶在组织工程中的研究进展,最后进行了总结和展望,以期为相关领域的研究者提供参考和借鉴。     

骨组织工程支架材料研究进展

综述了生物医用材料在组织工程学中的意义,并分析了近20年来此领域的发展概况,重点分析了骨组织工程材料的研究情况,归纳了高聚物骨组织工程材料及其复合材料的的研究进展。     

体内组织工程构建小口径人工血管的研究进展

小口径血管在临床上有很大需求,但小口径血管再狭窄率很高。体内组织工程是改善小口径血管功能、实现血管再生的有效手段。介绍了小口径人工血管的国内外研究发展动态,详述了作者实验室在构建小口径人工血管方面的设计思路和研究所取得的主要进展。研究包括支架材料结构设计与制备技术,支架材料表面功能化修饰,内皮祖细胞捕捉,血管平滑肌再生,抗凝血和促内皮细胞黏附,血管再生微环境的构建等。最后对小口径人工血管研究尚需解决的科学问题和研究方向进行了讨论。     

中枢神经再生材料研究进展

首先介绍了目前中枢神经再生面临的问题和应对策略,然后系统地综述了脑再生和脊髓再生修复材料的发展。研究发现,成人中枢神经系统内存的神经干细胞和具有特定分化方向的前体细胞具有潜在的、巨大的修复功能;生物支架材料与神经干细胞的联合使用能够较好地控制细胞微环境,有望提高细胞移植后的存活状况,促进中枢神经再生。最后,结合现在中枢神经再生的研究热点——神经干细胞,阐述了中枢神经再生材料调控干细胞的研究进展和潜能,为联合应用生物材料与干细胞促进中枢再生提供了参考。     

胶原作为组织工程软骨支架材料的研究

本文报导了用胶原作为软骨组织的载体材料在组织工程化软骨中的研究情况.本研究采用冷冻干燥方法制备出了Ⅰ-型胶原(sigma)、Ⅱ-型胶原(sigma)和混合型胶原(本室提取)的胶原海绵,并将其用作软骨组织工程的载体支架,比较研究了这三种胶原材料支架在软骨组织工程应用中的效果,筛选出了较理想的软骨组织工程载体材料.     

组织工程支架材料研究进展及发展趋势

对生物支架材料的基本要求、分类、研究现状及前沿动态作了较全面系统的概述,对组织工程支架材料目前存的问题、研究的重点和热点做了归纳分析,并对其发展趋势进行了展望,预测组织工程支架材料将向分子设计、仿生设计、纳米化、应用基因技术及细胞分化技术等方向发展.     

骨组织工程用支架材料研究进展

骨组织工程用支架材料是骨组织工程研究的主要内容之一 ,按来源可将支架分为天然支架材料和合成支架材料 ,本文综述了骨组织工程用支架材料的研究和应用。     

骨软骨组织工程仿生梯度支架研究进展

骨软骨缺损是导致关节发病和残疾的重要原因,骨软骨组织工程是修复骨软骨缺损的方法之一。骨软骨组织工程方法涉及仿生梯度支架的制造,该支架需模仿天然骨软骨组织的生理特性（例如从软骨表面到软骨下骨之间的梯度过渡）。在许多研究中骨软骨仿生梯度支架表现为离散梯度或连续梯度,用于模仿骨软骨组织的特性,例如生物化学组成、结构和力学性能。连续型骨软骨梯度支架的优点是其每层之间没有明显的界面,因此更相似地模拟天然骨软骨组织。到目前为止,骨软骨仿生梯度支架在骨软骨缺损修复研究中已经取得了良好的实验结果,但是骨软骨仿生梯度支架与天然骨软骨组织之间仍然存在差异,其临床应用还需要进一步研究。本文首先从骨软骨缺损的背景、微尺度结构与力学性能、骨软骨仿生梯度支架制造相关的材料与方法等方面概述了离散和连续梯度支架的研究进展。其次,由于3D打印骨软骨仿生梯度支架的方法能够精确控制支架孔的几何形状和力学性能,因此进一步介绍了计算仿真模型在骨软骨组织工程中的应用,例如采用仿真模型优化支架结构和力学性能以预测组织再生。最后,提出了骨软骨缺损修复相关的挑战以及骨软骨组织再生未来研究的展望。例如,连续型骨软骨仿生梯度支架需要更相似地模拟天然骨软骨组织单元的结构,即力学性能和生化性能的过渡更加自然地平滑。同时,虽然大多数骨软骨仿生梯度支架在体内外实验中均取得了良好的效果,但临床研究和应用仍然需要进行进一步深入研究。     

Development of cryogenic prototyping for tissue engineering

A major challenge in tissue engineering has been the creation of scaffolds with controlled complex geometries. Rapid prototyping (RP) has the ability to produce complex three-dimensional structures with precise control of pore size, geometry and connectivity. In this paper, a novel technique utilising RP technology for the fabrication of tissue engineering scaffolds is presented. The main advantage of this cryogenic prototyping (CP) technique is the low operating temperatures which will allow the processing of temperature sensitive and bioactive components. Microstructure of CP Chitosan scaffolds fabricated can be controlled by processing parameters, such as the processing temperature. The macrostructure of the scaffolds is controlled by 3D computer aided design (CAD). In addition, in vitro studies with Chitosan CP scaffolds have shown that the scaffold designs are useful in promoting cell infiltration and alignment. Preliminary in vivo studies show encouraging results of cellular infiltration as well as vascularisation.     

Development of cryogenic prototyping for tissue engineering

A major challenge in tissue engineering has been the creation of scaffolds with controlled complex geometries. Rapid prototyping (RP) has the ability to produce complex three-dimensional structures with precise control of pore size, geometry and connectivity. In this paper, a novel technique utilising RP technology for the fabrication of tissue engineering scaffolds is presented. The main advantage of this cryogenic prototyping (CP) technique is the low operating temperatures which will allow the processing of temperature sensitive and bioactive components. Microstructure of CP Chitosan scaffolds fabricated can be controlled by processing parameters, such as the processing temperature. The macrostructure of the scaffolds is controlled by 3D computer aided design (CAD). In addition, in vitro studies with Chitosan CP scaffolds have shown that the scaffold designs are useful in promoting cell infiltration and alignment. Preliminary in vivo studies show encouraging results of cellular infiltration as well as vascularisation.     

Silk fibroin-based scaffolds for tissue engineering

Silk fibroin (SF) from the Bombyx mori silkworm exhibits attractive potential applications as biomechanical materials, due to its unique mechanical and biological properties. This review outlines the structure and properties of SF, including of its biocompatibility and biodegradability. It highlights recent researches on the fabrication of various SF-based composites scaffolds that are promising for tissue engineering applications, and discusses synthetic methods of various SF-based composites scaffolds and valuable approaches for controlling cell behaviors to promote the tissue repair. The function of extracellular matrices and their interaction with cells are also reviewed here.     

Multifunctional nanofibrous scaffold for tissue engineering

In tissue engineering, scaffolds with multiscale functionality, especially with the ability to release locally multiple or specific bioactive molecules to targeted cell types, are highly desired in regulating appropriate cell phenotypes. In this study, poly (epsilon-caprolactone) (PCL) solutions (8% w/v) containing different amounts of bovine serum albumin (BSA) with or without collagen were electrospun into nanofibres. As verified by protein release assay and fluorescent labelling, BSA and collagen were successfully incorporated into electrospun nanofibres. The biological activity of functionalised fibres was proven in the cell culture experiments using human dermal fibroblasts. By controlling the sequential deposition and fibre alignment, 3D scaffolds with spatial distribution of collagen or BSA were assembled using fluorescently labelled nanofibres. Human dermal fibroblasts showed preferential adhesion to PCL nanofibres containing collagen than PCL alone. Taken together, multiscale scaffolds with diverse functionality and tunable distribution of biomolecules across the nanofibrous scaffold can be fabricated using electrospun nanofibres.     

Scaffolds for central nervous system tissue engineering

Traumatic injuries to the brain and spinal cord of the central nervous system (CNS) lead to severe and permanent neurological deficits and to date there is no universally accepted treatment. Owing to the profound impact, extensive studies have been carried out aiming at reducing inflammatory responses and overcoming the inhibitory environment in the CNS after injury so as to enhance regeneration. Artificial scaffolds may provide a suitable environment for axonal regeneration and functional recovery, and are of particular importance in cases in which the injury has resulted in a cavitary defect. In this review we discuss development of scaffolds for CNS tissue engineering, focusing on mechanism of CNS injuries, various biomaterials that have been used in studies, and current strategies for designing and fabricating scaffolds.     

聚苯胺基导电可降解聚合物在组织工程中的研究进展

聚苯胺在电刺激下可调节细胞活性,促进细胞的黏附、生长和分化而备受关注。聚苯胺基导电可降解聚合物支架具有良好的电活性、生物相容性和可降解性,满足实际使用要求。研究支架降解速率与新组织形成之间的拟合是组织工程面临的挑战,对促进组织生长和愈合有着深远的意义。介绍了聚苯胺基导电可降解聚合物研究现状和发展方向,展望了导电可降解高聚合物在组织工程领域中的发展前景。     

Morphology-controllable modeling approach for a porous scaffold structure in tissue engineering

Heterogeneous structures represent an important new frontier for twenty-first-century engineering. In this paper, based on the shape function in the finite element method, a morphology-controllable modelling approach for constructing tissue engineering (TE) bone scaffold with various irregular pores is presented. The modelling approach consists of both irregular element modelling and the whole bone scaffold modelling. Accepting the elements’ information after all-hex mesh generation as inputs, the basic pore-making element can be mapped into various irregular elements based on the shape function. In the bone scaffold modelling, the Boolean difference between the contour model of the solid entity and the pore model which can be constructed by the Boolean operation union would generate a porous bone scaffold model. Compared to the stochastic geometry method and the discrete element packing method, the bone scaffold model obtained in this paper has a continuous, smooth contour and various irregular pores. Moreover, a decrease in computational complexity is achieved in this paper.     

The role of the surface on microglia function: implications for central nervous system tissue engineering

In tissue engineering, it is well accepted that a scaffold surface has a decisive impact on cell behaviour. Here we focused on microglia—the resident immune cells of the central nervous system (CNS)—and on their response to poly(trimethylene carbonate-co-ε-caprolactone) (P(TMC-CL)) fibrous and flat surfaces obtained by electrospinning and solvent cast, respectively. This study aims to provide cues for the design of instructive surfaces that can contribute to the challenging process of CNS regeneration. Cell morphology was evidently affected by the substrate, mirroring the surface main features. Cells cultured on flat substrates presented a round shape, while cells with elongated processes were observed on the electrospun fibres. A higher concentration of the pro-inflammatory cytokine tumour necrosis factor-α was detected in culture media from microglia on fibres. Still, astrogliosis is not exacerbated when astrocytes are cultured in the presence of microglia-conditioned media obtained from cultures in contact with either substrate. Furthermore, a significant percentage of microglia was found to participate in the process of myelin phagocytosis, with the formation of multinucleated giant cells being observed only on films. Altogether, the results presented suggest that microglia in contact with the tested substrates may contribute to the regeneration process, putting forward P(TMC-CL) substrates as supporting matrices for nerve regeneration.