骨组织工程支架材料的研究进展

骨组织工程的发展,要求充分结合材料工程与生物工程相关知识,对植入材料进行分子及细胞水平的设计.细胞外基质材料(支架材料)的选择与制备是骨组织工程的一项重要而关键的任务.如何找到能促进并指导细胞黏附、增殖的支架材料是目前骨组织工程研究的热点之一.介绍了骨组织工程相关原理,并综述了几种支架材料的发展研究现状.     

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。     

磷酸钙骨水泥/明胶复合组织工程支架材料的制备及其结构与性能

磷酸钙骨水泥组织工程支架材料具有良好的生物相容性和骨传导性,是一种良好的骨组织工程支架材料,但是这种材料存在力学性能差的缺点,限制了它的应用.本文采用生物相容性良好的可降解明胶材料与磷酸钙骨水泥支架进行复合,制备出的明胶/磷酸钙骨水泥复合支架材料,其压缩强度可达3.7MPa,比复合前磷酸钙支架材料的强度提高了37倍,而且材料具有良好的柔韧性,适合用作为非承重部位骨组织缺损修复用组织工程支架材料.     

骨组织工程材料的研究

组织工程支架材料在组织工程中正发挥着越来越重要的作用.组织工程的核心是构建细胞生物支架材料复合体,其中,三维多孔支架材料发挥着重大作用.除了决定新生组织、器官的形状外,最重要的是为细胞提供获取营养、气体交换、废物排除的环境,为细胞增殖繁衍提供空间.因此,支架材料应是高度多孔的,支架的孔隙大小必须控制,并有严格要求.本文主要介绍了骨组织三维多孔材料的研究现状,并对组织工程支架及骨修复过程做了简要的介绍,并对其发展方向作了展望.     

骨组织工程支架材料的研究进展

综述了骨组织工程支架材料在骨缺损治疗的研究现状,并展望了其未来的发展方向。利用各种材料的优势互补性,将两种或两种以上材料通过恰当的方式组合成复合支架材料,其力学性能和降解速率可根据各组分材料的种类、数量及组合方法的变化进行调节,按照要求制备出具有一定机械强度和降解速率的支架材料。并指出骨组织工程复合支架材料将会成为骨缺损修复中一类富有潜力的生物材料。     

纳米磷酸钙骨组织工程支架材料研究进展

随着纳米和生物技术的进步,国内外学者制备了一系列新型的骨组织工程支架材料.为了更好地认识纳米生物材料的优点和指导制备新型的骨组织工程支架材料,综述了近年来纳米磷酸钙相关支架材料研究进展,着重介绍了纳米磷酸钙陶瓷、纳米磷酸钙复合陶瓷以及纳米磷酸钙/聚合物复合材料制备方法、性能和应用,并总结了各类方法的不足之处和将来发展的...     

壳聚糖类复合材料应用于骨修复的研究进展

壳聚糖是天然多糖类高分子化合物甲壳素的脱乙酰产物,具有良好的生物相容性、可降解性和生物活性,可作为骨修复材料,并可应用于骨组织工程材料中的三维生长支架,作为种子细胞或活性生长因子的生物载体材料.综述了壳聚糖类复合材料在骨填充修复材料、骨组织工程和软骨组织工程方面应用的状况及前景.     

溶胶-凝胶生物活性玻璃与胶原复合多孔支架的生物相容性研究

实验前期用冷冻干燥法合成一种溶胶?凝胶生物活性玻璃(BG/COL)与粗胶原纤维复合的组织工程支架. 本实验将支架与鼠骨髓间充质干细胞(rMSCs)共同培养, 评价支架材料的细胞相容性. 并将复合了成骨细胞的支架材料植入裸鼠皮下, 探讨其异位成骨的性能. 研究结果显示rMSCs可以在BG/COL多孔支架材料表面成功粘附、铺展、并向多孔支架内部迁移, 随着培养时间的延长, 双链DNA(ds DNA)数量增多, 细胞增殖情况与对照组差异明显. 将种在复合材料上的骨髓间充质干细胞诱导培养14d后切片染色, 其碱性磷酸酶(ALP)和钙素表达均呈强阳性. 体内植入实验的裸鼠健康状况良好, 伤口完全愈合, 6w后BG/COL周边及内部有骨组织和血管生成. 由此证明, 这种新型的复合多孔支架材料具有良好的生物相容性, 其复合了成骨细胞的组织工程骨具有良好的诱导成骨的性能, 因此这种材料是理想的应用于骨组织修复和再生的组织工程支架材料.     

骨组织工程用无机支架材料的研究现状

无机生物活性材料作为一种重要的骨组织工程用支架材料,具有明显的优势和广阔的应用前景.从组织工程材料发展历程的角度出发,分别介绍了制备支架的不可降解材料、部分可降解材料和完全可降解材料的演变过程,比较了这3种材料在力学性能方面的各自优缺点,并分析了支架材料在生物相容性方面的改善措施,同时着重介绍了国内外无机组织工程材料近期的研究成果.     

磷酸钙骨水泥大孔径多孔组织工程支架的制备及其纤维增强

采用粒子溶出造孔法, 用棒状谷氨酸钠晶体作为造孔粒子, 制备磷酸钙骨水泥多孔支架, 研究了造孔粒子含量和多孔支架孔隙率之间的关系, 并加入甲壳素纤维来改善支架材料的力学性能. 结果表明, 支架材料的孔隙率可达(79.8±2.3)%,孔隙直径100～600μm; 复合纤维后支架的强度提高了3～4倍, 断裂应变显著提高, 可作为非承重部位骨缺损修复的骨组织工程支架材料.     

Electrospun multifunctional tissue engineering scaffolds

Tissue engineering holds great promises in providing successful treat- ments of human body tissue loss that current methods are unable to treat or unable to achieve satisfactory clinical outcomes. In scaffold-based tissue engineering, a high- performance scaffold underpins the success of a tissue engineering strategy and a major direction in the field is to create multifunctional tissue engineering scaffolds for enhanced biological performance and for regenerating complex body tissues. Electrospinning can produce nanofibrous scaffolds that are highly desirable for tissue engineering. The enormous interest in electrospinning and electrospun fibrous structures by the science, engineering and medical communities has led to various developments of the electrospinning technology and wide investigations of eiectrospun products in many industries, including biomedical engineering, over the past two decades. It is now possible to create novel, multicomponent tissue engineering scaffolds with multiple functions. This article provides a concise review of recant advances in the R ＆ D of electrospun multifunctional tissue engineering scaffolds. It also presents our philosophy and research in the designing and fabrication of electrospun multicomponent scaffolds with multiple functions.     

Stem cell homing-based tissue engineering using bioactive materials

Tissue engineering focuses on repairing tissue and restoring tissue functions by employing three elements: scaffolds, cells and biochemical signals. In tissue engineering, bioactive material scaffolds have been used to cure tissue and organ defects with stem cell-based therapies being one of the best documented approaches. In the review, different biomaterials which are used in several methods to fabricate tissue engineering scaffolds were explained and show good properties (biocompatibility, biodegradability, and mechanical properties etc.) for cell migration and infiltration. Stem cell homing is a recruitment process for inducing the migration of the systemically transplanted cells, or host cells, to defect sites. The mechanisms and modes of stem cell homing-based tissue engineering can be divided into two types depending on the source of the stem cells: endogenous and exogenous. Exogenous stem cell-based bioactive scaffolds have the challenge of long-term culturing in vitro and for endogenous stem cells the biochemical signal homing recruitment mechanism is not clear yet. Although the stem cell homing-based bioactive scaffolds are attractive candidates for tissue defect therapies, based on in vitro studies and animal tests, there is still a long way before clinical application.     

Chitosan particles agglomerated scaffolds for cartilage and osteochondral tissue engineering approaches with adipose tissue derived stem cells

It is well accepted that natural tissue regeneration is unlikely to occur if the cells are not supplied with an extracellular matrix (ECM) substitute. With this goal, several different methodologies have been used to produce a variety of 3D scaffolds as artificial ECM substitutes suitable for bone and cartilage tissue engineering. Furthermore, osteochondral tissue engineering presents new challenges since the combination of scaffolding and co-culture requirements from both bone and cartilage applications is required in order to achieve a successful osteochondral construct. In this paper, an innovative processing route based on a chitosan particles aggregation methodology for the production of cartilage and osteochondral tissue engineering scaffolds is reported. An extensive characterization is presented including a morphological evaluation using Micro-Computed Tomography (μCT) and 3D virtual models built with an image processing software. Mechanical and water uptake characterizations were also carried out, evidencing the potential of the developed scaffolds for the proposed applications. Cytotoxicity tests show that the developed chitosan particles agglomerated scaffolds do not exert toxic effects on cells. Furthermore, osteochondral bilayered scaffolds could also be developed. Preliminary seeding of mesenchymal stem cells isolated from human adipose tissue was performed aiming at developing solutions for chondrogenic and osteogenic differentiation for osteochondral tissue engineering applications. An erratum to this article is available at .     

In vitro evaluation of electrospun PCL/nanoclay composite scaffold for bone tissue engineering

Polycaprolactone (PCL) is a widely accepted synthetic biodegradable polymer for tissue engineering, however its use in hard tissue engineering is limited because of its inadequate mechanical strength and low bioactivity. In this study, we used halloysite nanoclay (NC) as an inorganic filler material to prepare PCL/NC fibrous scaffolds via electrospinning technique after intercalating NC within PCL by solution intercalation method. The obtained nanofibrous mat was found to be mechanically superior to PCL fibrous scaffolds. These scaffolds allowed greater protein adsorption and enhanced mineralization when incubated in simulated body fluid. Moreover, our results indicated that human mesenchymal stem cells (hMSCs) seeded on these scaffolds were viable and could proliferate faster than in PCL scaffolds as confirmed by fluorescence and scanning electron microscopic observations. Further, osteogenic differentiation of hMSCs on nanoclay embedded scaffolds was demonstrated by an increase in alkaline phosphatase activity when compared to PCL scaffold without nanoclay. All of these results suggest the potential of PCL/NC scaffolds for bone tissue engineering.     

骨组织工程多孔支架材料性质及制备技术

多孔性生物可降解支架的选择和制备是组织工程技术成功运用的关键。从骨架的材料要求、常用的骨架材料、骨架的制备技术等几个方面对组织工程和生物降解支架的研究进行了综述 ,并对该研究的前景进行了展望     

不同类型多孔结构生物材料支架制备及其性能优化

多孔支架是组织工程应用中的关键环节,类似细胞外基质的作用,支撑细胞的粘附和随后细胞向组织的衍化。虽然目前已采用多种制备技术研发出大量的多孔支架,但是多孔生物材料支架的制备和性能优化,仍然是组织工程支架领域的研究热点。结合实验室工作,综述了多种制备不同类型多孔结构生物材料支架的制备技术,主要包括颗粒和纤维堆积型支架、泡沫浸渍法支架和颗粒制孔支架等的制备技术,并阐述了这些制备技术对多孔结构支架的孔结构、贯通性和力学性能的改善效果。其目的旨在提供满足组织工程需求的多孔生物材料支架。     

Polymer-bioceramic composites for tissue engineering scaffolds

Designing tissue engineering scaffolds with the required mechanical properties and favourable microstructure to promote cell attachment, growth and new tissue formation is one of the key challenges facing the tissue engineering field. An important class of scaffolds for bone tissue engineering is based on bioceramics and bioactive glasses, including: hydroxyapatite, bioactive glass (e.g. Bioglass^®), alumina, TiO₂ and calcium phosphates. The primary disadvantage of these materials is their low resistance to fracture under loads and their high brittleness. These drawbacks are exacerbated by the fact that optimal scaffolds must be highly porous (>90% porosity). Several approaches are being explored to enhance the structural integrity, fracture strength and toughness of bioceramic scaffolds. This paper reviews recent proposed approaches based on developing bioactive composites by introducing polymer coatings or by forming interpenetrating polymer-bioceramic microstructures which mimic the composite structure of bone. Several systems are analysed and scaffold fabrication processes, microstructure development and mechanical properties are discussed. The analysis of the literature suggests that the scaffolds reviewed here might represent the optimal solution and be the scaffolds of choice for bone regeneration strategies.     

Nanofibrous scaffold engineering using electrospinning

Scaffold plays a critical role in tissue engineering where it provides necessary structural support for the cells to accommodate and to guide their growth in the three dimensional space into a specific tissue. Therefore, engineering scaffolds favorable for cell/tissue growth is of great importance and a pre-requisite for scaffold-based tissue engineering. Electrospinning is a versatile method that has been recently adapted in engineering nano-fibrous scaffolds that mimic the structural features of biological extracellular matrix (ECM). It offers many advantages over conventional scaffold methodologies, for example, capable of producing ultra-fine fibers with high porosity, high spatial orientation, high aspect ratio, and high surface area, which are highly required for the initial cell attachment, tissue formation, and continued function. Considering these astonishing merits, this article emphasis on nano-fibrous scaffold engineering by electrospinning.     

A comparative study of the chondrogenic potential between synthetic and natural scaffolds in an in vivo bioreactor

Abstract

The clinical demand for cartilage tissue engineering is potentially large for reconstruction defects resulting from congenital deformities or degenerative disease due to limited donor sites for autologous tissue and donor site morbidities. Cartilage tissue engineering has been successfully applied to the medical field: a scaffold pre-cultured with chondrocytes was used prior to implantation in an animal model. We have developed a surgical approach in which tissues are engineered by implantation with a vascular pedicle as an in vivo bioreactor in bone and adipose tissue engineering. Collagen type II, chitosan, poly(lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) were four commonly applied scaffolds in cartilage tissue engineering. To expand the application of the same animal model in cartilage tissue engineering, these four scaffolds were selected and compared for their ability to generate cartilage with chondrocytes in the same model with an in vivo bioreactor. Gene expression and immunohistochemistry staining methods were used to evaluate the chondrogenesis and osteogenesis of specimens. The result showed that the PLGA and PCL scaffolds exhibited better chondrogenesis than chitosan and type II collagen in the in vivo bioreactor. Among these four scaffolds, the PCL scaffold presented the most significant result of chondrogenesis embedded around the vascular pedicle in the long-term culture incubation phase.     

Tissue Mimicry in Morphology and Composition Promotes Hierarchical Matrix Remodeling of Invading Stem Cells in Osteochondral and Meniscus Scaffolds

An integral approach toward in situ tissue engineering through scaffolds that mimic tissue with regard to both tissue architecture and biochemical composition is presented. Monolithic osteochondral and meniscus scaffolds are prepared with tissue analog layered biochemical composition and perpendicularly oriented continuous micropores by a newly developed cryostructuring technology. These scaffolds enable rapid cell ingrowth and induce zonal‐specific matrix synthesis of human multipotent mesenchymal stromal cells solely through their design without the need for supplementation of soluble factors such as growth factors.