聚乙醇酸负载软骨细胞构建气管软骨环的研究

目的应用组织工程原理,研究软骨细胞接种于聚乙醇酸支架中进行气管软骨环的构建的可行性.方法按气管软骨环的形状制备模具,将聚乙醇酸无纺网置于模具中,用聚乳酸塑形;用Ⅱ型胶原酶消化法收集兔软骨细胞,将浓度的5×107/ml接种于聚乙醇酸支架中,体外继续培养1周后,植入裸鼠背部皮下组织中,2个月后取材,通过大体标本观察、组织学检查观察气管软骨环的构建情况.结果植入后2个月,在裸鼠背部隐约可见形成的环状结构,质地较坚韧;取材后见形成的组织与气管软骨环基本一致,具有良好的弹性和支撑能力;组织学检查见新形成的组织由软骨构成.结论聚乙醇酸负载软骨细胞,可以有效进行气管软骨环的构建.     

Marginal soft tissue recessions with and without attached gingiva

Changes in the position of the labial/buccal soft tissue margin of gingival recessions were investigated. In twenty-five subjects, fifty-two teeth without attached gingiva and fifty-four teeth with attached gingiva were selected. On the average, changes were minimal over the five year period in both groups. Statistically significant loss of attachment was found in the group of teeth with attached gingiva. The validity of the assumption, that the presence of attached gingiva reduces the risk of further loss of attachment, appears to be questionable.     

组织工程方法构建复合培养细胞的引导组织再生膜

目的：探讨可吸收引导组织再生胶原膜（BME10－X）的生物相容性，构建引导组织再生膜。方法：用组织工程方法将人牙周膜成纤维细胞与BME10－X复合培养，培养第7、14d进行组织学及扫描电镜、透射电镜观察。结果：人牙周膜成纤维细胞可在BME10－X上贴附、增殖，分泌大量的细胞外基质，复层生长形成纤维组织结构，基本形成具有活性细胞及其基质的膜样组织，BME10－X在培养一周即出现可见的吸收。结论：BME10－X具有良好的生物相容性，可作为牙周膜细胞的载体应用于牙周组织工程研究。     

Tools for tissue engineering of mineralized oral structures

This paper presents a short review of three groups of tools which can be or are used for the tissue engineering of mineralized oral structures: growth factor delivery systems (GFDS) and surface bioactivation with covalent bound peptides or with nanomechanically linked proteins. According to the reported personal experience of the authors, GFDS have to face the following challenging issue before being used routinely in dentistry, e.g., as a tool for reparative dentinogenesis or bone healing: adaptation of the GFDS design to the tissue where it will be implanted in order to deliver the right dose of growth factor (GF) at the right time. The bioactivation of surfaces, for example of dental implants, with covalent bound peptides or nanomechanically linked proteins represents a second innovative way to improve dental health in the future. Here we report on the experimental use of cyclic RGD peptides grafted on polymethylmethacrylate to improve osteoblast adhesion. Furthermore, we show the potential advantage of immobilizing and incorporating collagen I on titanium implant surfaces. These techniques or a combination of them will help to create improvements, for example, of dental implants in the near future. They will also help to promote bone and dentin regeneration. Received: 12 October 1999 / Accepted: 15 March 2000     

构建无外源性支架材料组织工程真皮的研究

目的:探讨运用组织工程方法构建不含有任何外源性支架材料的组织工程真皮组织.方法:以青少年包皮环切术后皮肤组织作为细胞来源,用消化法获得真皮成纤维细胞,用本实验室设计的组织工程皮肤培养系统构建组织工程真皮:在培养液中加入10 ng/ml的bFGF和50 ug/ml的Vitamin C,持续培养4周即形成组织工程真皮.免疫组化检测构建的真皮中细胞外基质(Ⅰ型胶原)的形成情况.结果:所构建的组织工程真皮含有多层细胞,细胞状态良好,染色结果显示形成了大量成熟的细胞外基质,Ⅰ型胶原呈强阳性表达.结论:本实验成功构建了不含外源性的组织工程真皮组织,可以用于下一步构建含有表皮的全层皮肤和动物实验.     

智能化组织工程支架材料研究进展

作为组织工程中的三大要素之一,合适的生物支架对于种子细胞的生长和分化具有重要的意义。目前,改良生物支架的研究多集中于支架材料智能化的开发。比起传统的生物材料,智能化生物支架材料除了自身的优良机械性能外,还能更好地引导细胞分化和控制生长因子的释放。下面就组织工程支架材料的智能化研究进展作一综述。     

骨组织工程学支架材料研究进展

支架材料是骨组织工程学中之关键环节，支架材料的发展状况将严重制约骨组织工程乃至组织工程学的发展。本文介绍了骨组织工程学中研究比较集中的数种支架材料的优缺点及其目前研究状况。     

软骨组织工程支架材料的研究进展

支架材料的研究是组织工程研究的一个重要方面。支架材料作为种子细胞的暂时细胞外基质替代物,对细胞的黏附、增殖和分化等均有不可低估的影响。选择适合的支架材料对组织再生有重要意义。本文对目前软骨组织工程常用支架材料(包括天然和人工)的特点和研究进展作一综述。     

Reconstructive materials and bone tissue engineering in implant dentistry

Periodontal function for natural teeth and dental implants depends strongly on the mechanical integrity of the bone in the maxilla and mandible. Ongoing healthy bone remodeling around a natural tooth or implant is critical for longevity. Chemical factors that influence bone remodeling have been explored with the goal of enhancing the growth and maintenance of good quality bone. Less, but increasing, effort has been directed at understanding mechanical signals and factors, including those affected by implant/prosthesis materials that transmit loads directly to the surrounding bone. This article reviews research on the effects of synthetic materials and resulting mechanical stimuli on bone tissue engineering in dentistry.     

New clinical materials and techniques in guided tissue regeneration

AIM: To review the evidence on using Guided Tissue Regeneration (GTR) techniques and materials in various clinical circumstances. METHOD: Literature review. MAIN OUTCOME MEASURES: The success of GTR techniques and materials in halting or reversing the destruction of tooth attachment apparatus caused by progressive periodontal disease. RESULTS: GTR and osseous grafting are the two techniques with the most clinical and histological documentation of periodontal regeneration. CONCLUSIONS: GTR materials, whether non-resorbable or bioabsorbable, give similar clinical results. GTR procedures have been demonstrated to be clinically effective in treating infrabony osseous defects, recession defects, preserving alveolar bone in recent extraction sites and in some types of furcation defects. GTR procedures are technique sensitive and are adversely affected by poor home oral hygiene care, poor follow-up professional maintenance care and smoking.     

纳米级支架材料在骨组织工程中的应用

骨组织工程研究领域中，支架材料与细胞的相互作用是主要的研究课题。支架材料表面的微观结构对细胞的生物调控作用非常重要。纳米材料因具有一些独特的效应，有利于细胞的黏附、增殖和功能的增强，因而作为骨组织工程支架有着良好的应用前景。目前用于骨组织工程的纳米支架材料主要有纳米复合材料和纳米纤维材料。作者就纳米支架材料与细胞作用的机制以及近年来其在骨组织工程中的应用研究现状作一综述。     

Connective tissue organization of healthy human gingiva

Healthy human gingival connective tissue appears to be arranged in two patterns of organization at the ultrastructural level: Pattern I (PI) and Pattern II (PII). PI is a dense pattern of organization mainly constituted of large, dense bundles of thick collagen fibers, whereas PII is a loose pattern of organization, mainly constituted of short, thin collagen fibers mixed with a fine reticular network, especially located under or around basement membranes. Ultrastructural immunoperoxidase labelling of types I, III, and IV collagen demonstrates that gingival connective tissue is made of an intricate pattern of type I and III collagen where type I collagen fibers are preferentially organized in large dense bundles in PI, whereas a fibrous and fibrillar type III collagen network is predominant in PII. Type IV collagen, which does not exist in fibrous or fibrillar form, appears to be the main collagenous component of the basement membranes.     

RGD多肽耦联活化小牛松质骨骨组织工程材料的研究

目的：利用肽羧合剂EDC[1-乙基-3-（3-二甲基氨丙基）-碳二亚胺盐酸盐]将粘附蛋白类八肽（谷氨酸-脯氨酸-精氨酸-甘氨酸-天冬氨酸-天冬酰胺-酪氨酸-精氨酸）耦联到经紫外线辐照活化的小牛松质骨片上,制备出用于骨缺损性疾病的骨修复与重建的组织工程新方法,为口腔医学中牙齿和颌骨缺损性疾病的治疗提供骨移植的新型材料。方法：采用125I-RGD放射性示踪技术、碳二亚胺羧合、紫外线辐照活化的小牛松质骨的羧基及蛋白质染色技术。结果：牢固地将RGD耦联到小牛松质骨上。结论：随着骨组织工程研究的发展和这一新材料的深入研究,将改变骨缺损临床采用羟基磷灰石或骨水泥等材料将缺损部位封闭,从而使其丧失功能的治疗方法,引领骨移植临床应用的到来。     

Cytotoxic effects of restorative materials on early passage cultured cells derived from human gingiva (in vitro)

This study evaluated the cytotoxic effects of three common restorative materials on early passage cultured cells derived from human gingiva (HG cells). Other early passage cultured cells derived from human dental pulp tissues (HP cells) and L cells established obtained from mouse subcutaneous tissues, were also examined. Cytotoxicity was assessed according to the uptake of neutral red and dye exclusion with nigrosin. The cytotoxicity was in the order of glass ionomer cement (highest), light cured composite resin and dental amalgam. HG cells were the least sensitive to the materials tested. Both filtration of extracts and addition of serum into the extract affected the cytotoxicity. Glass ionomer cement increased the acidity of the extract, but the two other materials did not. Dissolution of metal ions, aluminium, tin, copper, mercury and zinc occurred from the materials. The extract of the composite resin had a different absorbance. This study disclosed differences in the cellular reaction to the restorative materials. Thus, utilization of early passage cultured cells is necessary for biological evaluation of the dental materials in vitro.     

Fabrication of precise cylindrical three-dimensional tissue engineering scaffolds for in vitro and in vivo bone engineering applications

It is sometimes necessary to form highly porous polymeric tissue engineering scaffolds into various shapes and sizes. Ideally, in these cases, the three-dimensional morphology should be maintained to the outer margins of the scaffold so as to provide optimum function. Many biodegradable polymeric scaffolds are soft and delicate, however, and their poor physical strength presents a challenge when cutting these materials into the required shapes. We describe a simple device that can be used quickly and accurately to cut cylindrical shapes from such delicate polymeric scaffold materials, which maintain their morphological features to the margins of the shapes produced. We demonstrate that the device can be used to create scaffolds with reproducible dimensions having an SD in mass of less then 6%. The in vitro utility of scaffolds cut with the device was established through demonstrating bone marrow-derived cell invasion into fibrin-filled scaffolds that fit precisely into the wells of 24-well plates. We also demonstrate the in vivo utility of precise cylindrically shaped scaffolds by observing rapid bone invasion into 2.4-mm diameter scaffolds that have been placed into drill hole defects in the distal femur of young rats. When scaffolds are filled with fibrin before implantation as part of a bone tissue engineering strategy, less blood fills the defect site and the fibrin is gradually remodeled and replaced by bone. The ability to cut precise cylindrical scaffolds in the millimeter size range has allowed for the creation of a new small animal model that may prove useful for screening tissue engineering scaffolds for further study.     

组织工程技术在口腔种植中的应用

口腔种植学和组织工程学是近年来发展迅速的两门学科,随着这两门学科的交叉发展,将组织工程技术应用于口腔种植学领域取得了较大的进展。本文就目前组织工程技术在口腔种植中的应用的研究进展作一综述。