New perspectives for articular cartilage repair treatment through tissue engineering: A contemporary review

In this paper review we describe benefits and disadvantages of the established methods of cartilage regeneration that seem to have a better long-term effectiveness.We illustrated the anatomical aspect of the knee joint cartilage, the current state of cartilage tissue engineering, through mesenchymal stem cells and biomaterials,and in conclusion we provide a short overview on the rehabilitation after articular cartilage repair procedures.Adult articular cartilage has low capacity to repair itself,and thus even minor injuries may lead to progressive damage and osteoarthritic joint degeneration, result-ing in significant pain and disability. Numerous efforts have been made to develop tissue-engineered grafts or patches to repair focal chondral and osteochondral defects, and to date several researchers aim to implement clinical application of cell-based therapies for cartilage repair. A literature review was conducted on PubM ed, Scopus and Google Scholar using appropriate keywords, examining the current literature on the wellknown tissue engineering methods for the treatment of knee osteoarthritis.

Functionalized Hydrogels for Articular Cartilage Tissue Engineering

Articular cartilage(AC)is an avascular and flexible connective tissue located on the bone surface in the diarthrodial joints.AC defects are common in the knees of young and physically active individuals.Because of the lack of suitable tissue-engineered artificial matrices,current therapies for AC defects,espe-cially full-thickness AC defects and osteochondral interfaces,fail to replace or regenerate damaged carti-lage adequately.With rapid research and development advancements in AC tissue engineering(ACTE),functionalized hydrogels have emerged as promising cartilage matrix substitutes because of their favor-able biomechanical properties,water content,swelling ability,cytocompatibility,biodegradability,and lubricating behaviors.They can be rationally designed and conveniently tuned to simulate the extracel-lular matrix of cartilage.This article briefly introduces the composition,structure,and function of AC and its defects,followed by a comprehensive review of the exquisite(bio)design and(bio)fabrication of func-tionalized hydrogels for AC repair.Finally,we summarize the challenges encountered in functionalized hydrogel-based strategies for ACTE both in vivo and in vitro and the future directions for clinical translation.

A Novel Biomaterial for Cartilage Repair Generated by Self-Assembly: Creation of a Self-Organized Articular Cartilage-Like Tissue

Recently, attention has been drawn to tissue engineering and other novel techniques aimed at reconstruction of the joint. Regarding articular cartilage tissue engineering, three-dimensional materials created in vitro by cultivation of autologous chondrocytes or mesenchymal stem cells with a collagen gel have been implanted to replace defective parts of the articular cartilage in limited cases with the diseases such as trauma or arthritis. However, several passages of chondrocyte culture are required to obtain a sufficient number of cells for tissue engineering. Additionally, several other problems arise including dedifferentiation of chondrocytes during cell culture, which need to be solved from a viewpoint of cellular resources. The purpose of our study is to create a novel biomaterial possessing functions and structures comparable to native hyaline articular cartilage by utilizing the physicochemical properties of the cartilage matrix components themselves, in other words, employing a self-assembly technique instead of using chondrocytes to produce cartilage matrices eventually leading to articular cartilage tissue formation. We verified the conditions and accuracy of the self-organization process and analyzed the resulting micro structure using electron beam microscopy in order to study the technique involved in the self-organization which would be applicable to creation of cartilage-like tissue. We demonstrated that self-assembly of several cartilage components including type II collagen, proteoglycan and hyaluronic acid could construct self-assembled cartilage-like tissues characterized by nano composite structures comparable to human articular cartilage and by low friction coefficients as small as those of native cartilage.

Research Progress of Osteochondral Composite Scaffolds in Tissue Engineering Cartilage Repair

Repair and regeneration of articular cartilage has always been a major challenge in the medical field due to its peculiar structure(e.g.sparsely distributed chondrocytes,no blood supply).Cartilage tissue engineering is one promising strategy for cartilage repair,however,one critical issue for cartilage tissue engineering is the integration between tissue-engineered and native cartilage.In recent years,osteochondral tissue engineering has attracted growing interest for overcoming this problem.Herein,we review the development of osteochondral tissue engineering.Firstly,currently used seed cells in osteochondral tissue engineering will be described.Secondly,several types of scaffolds and their(dis)advantage for osteochondral tissue engineering will be introduced.Thirdly,the growth factors currently used in osteochondral tissue engineering will be presented and discussed.

Repair effect of articular cartilage defects by nitric oxide synthase inhibitor

Objective To discuss repairing effects of articular cartilage defects by nitric oxide synthase inhibitor (S methylisothiourea, SMT), and explore the role of nitric oxide in cartilage repair. Methods Full-thickness defects of cartilage were created in the intercondylar trochlear groove of femur of thirty-six adult New Zealand white rabbits, and were divided into three gorups. Twenty-four defects were untreated as the control, twenty-four were filled with fibrin glue and impregnated with rhBMP AS rhBMP group, the rest twenty-four were filled with fibrin glue and impregnated with rhBMP, and hypodermic injection with SMT as SMT group. The animals were sacrified at sixteen weeks postoperatively, and the gross appearance of the defect was estimated. The repair tissue was examined histologically and was evaluated according to the grading scale of histology. The amount of released NO and the activities of nitric oxide synthase(NOS) were examined by chemical colorimetry. The distribution of type-Ⅰ , Ⅱ

Expression of Transforming Growth Factor β_(1) in Mesenchymal Stem Cells: Potential Utility in Molecular Tissue Engineering for Osteochondral Repair

The feasibility of using gene therapy to treat full-thickness articular cartilage defects was investigated with respect to the transfection and expression of exogenous transforming growth factor(TGF)-β_(1)genes in bone marrow-derived mesenchymal stem cells(MSCs)in vitro.The full-length rat TGF-β_(1)cDNA was transfected to MSCs mediated by lipofectamine and then selected with G418,a synthetic neomycin analog.The transient and stable expression of TGF-β_(1)by MSCs was detected by using immunohistochemical staining.The lipofectamine-mediated gene therapy efficiently transfected MSCs in vitro with the TGF-β_(1)gene causing a marked up-regulation in TGF-β_(1)expression as compared with the vector-transfected control groups,and the increased expression persisted for at least 4 weeks after selected with G418.It was suggested that bone marrow-derived MSCs were susceptible to in vitro lipofectamine mediated TGF-β_(1)gene transfer and that transgene expression persisted for at least 4 weeks.Having successfully combined the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology,an innovative concept,i.e.molecular tissue engineering,are put forward for the first time.As a new branch of tissue engineering,it represents both a new area and an important trend in research.Using this technique,we have a new powerful tool with which:(1)to modify the functional biology of articular tissue repair along defined pathways of growth and differentiation and(2)to affect a better repair of full-thickness articular cartilage defects that occur as a result of injury and osteoarthritis.

Morphological MRI and T2 mapping of cartilage repair tissue after mosaicplasty with tissue-engineered cartilage in a pig model

The aim of this study was to evaluate the efficacy of mosaicplasty with tissue-engineered cartilage for the treatment of osteochondral defects in a pig model with advanced MR technique. Eight adolescent miniature pigs were used. The right knee underwent mosaicplasty with tissue-engineered cartilage for treatment of focal osteochondral defects, while the left knee was repaired via single mosaicplasty as controls. At 6, 12, 18 and 26 weeks after surgery, repair tissue was evaluated by magnetic resonance imaging （MRI） with the cartilage repair tissue （MOCART） scoring system and T2 mapping. Then, the results of MRI for 26 weeks were compared with findings of macroscopic and histologic studies. The MOCART scores showed that the repaired tissue of the tissue-engineered cartilage group was statistically better than that of controls （P 〈 0.001）. A significant correlation was found between macroscopic and MOCART scores （P 〈 0.001）. Comparable mean T2 values were found between adjacent cartilage and repair tissue in the experimental group （P 〉 0.05）. For zonal T2 value evaluation, there were no significant zonal T2 differences for repair tissue in controls （P 〉 0.05）. For the experimental group, zonal T2 variation was found in repair tissue （P 〈 0.05）. MRI, macroscopy and histology showed better repair results and bony incorporation in mosaicplasty with the tissue-engi- neered cartilage group than those of the single mosaicplasty group. Mosaicplasty with the tissue-engineered cartilage is a promising approach to repair osteochodndral defects. Morphological MRI and T2 mapping provide a non-invasive method for monitoring the maturation and integration of cartilage repair tissue in vivo.

Biomaterials for repair and regeneration of the cartilage tissue

The repair and regeneration of the diseases and damaged cartilage tissue are one of the most challenging issues in the field of tissue engineering and regenerative medicine. As the cartilage is a non-vascularized and comparatively acellular connective tissue, its ability to the self-restoration is limited to a large extent. Although there is a countless deal of experimental documents on this field, no quantifiable cure exists to bring back the healthy organization and efficacy of the impaired articular cartilage. Tissue reformative approaches have been of excessive curiosity in restoring injured cartilage. Bioengineering of the cartilage has progressed from the cartilage focal damages treatment to bioengineering tactics progress aiming the osteoarthritis procedures. The main focus of the present study is on the diverse potential development of strategies such as various categories of biomaterials applied in the reconstruction of the cartilage tissue.

Study on the Microstructure of Human Articular Cartilage/Bone Interface

For improving the theory of gradient microstructure of cartilage/bone interface, human distal femurs were studied. Scanning Electron Microscope （SEM）, histological sections and MicroCT were used to observe, measure and model the micro- structure of cartilage/bone interface. The results showed that the cartilage/bone interface is in a hierarchical structure which is composed of four different tissue layers. The interlocking of hyaline cartilage and calcified cartilage and that of calcified car- tilage and subchondral bone are in the manner of＂protrusion-pore＂ with average diameter of 17.0 gm and 34.1 lam respectively. In addition, the cancellous bone under the cartilage is also formed by four layer hierarchical structure, and the adjacent layers are connected by bone trabecula in the shape of H, I and Y, forming a complex interwoven network structure. Finally, the simplified structure model of the cartilage/bone interface was proposed according to the natural articular cartilage/bone interface. The simplified model is a 4-layer gradient biomimetic structure, which corresponds to four different tissues of natural cartilage/bone interface. The results of this work would be beneficial to the design of bionic scaffold for the tissue engineering of articular cartilage/bone.

Molecular Tissue Engineering: Applications for Modulation of Mesenchymal Stem Cells Proliferation by Transforming Growth Factor β_1 Gene Transfer

The effect of transforming growth factor β 1 (TGF β 1 ) gene transfection on the proliferation of bone marrow derived mesenchymal stem cells (MSC S ) and the mechanism was investigated to provide basis for accelerating articular cartilage repairing using molecular tissue engineering technology. TGF β 1 gene at different doses was transduced into the rat bone marrow derived MSCs to examine the effects of TGF β 1 gene transfection on MSCs DNA synthesis, cell cycle kinetics and the expression of proliferating cell nuclear antigen (PCNA). The results showed that 3 μl lipofectamine mediated 1 μg TGF β 1 gene transfection could effectively promote the proliferation of MSCs best; Under this condition (DNA/Lipofectamine=1μg/3μl), flow cytometry and immunohistochemical analyses revealed a significant increase in the 3 H incorporation, DNA content in S phase and the expression of PCNA. Transfection of gene encoding TGF β 1 could induce the cells at G0/G1 phase to S1 phase, modulate the replication of DNA through the enhancement of the PCNA expression, increase the content of DNA at S1 phase and promote the proliferation of MSCs. This new molecular tissue engineering approach could be of potential benefit to enhance the repair of damaged articular cartilage, especially those caused by degenerative joint diseases.

光固化水凝胶负载骨髓间充质干细胞修复大鼠颅骨缺损

目的探讨新型甲基丙烯酸酐化明胶(gelatin methacryloyl,GelMA)/骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)复合水凝胶应用于大鼠颅骨缺损区的成骨性能,为骨再生生物材料的应用提供实验依据。方法本研究经南京大学动物伦理委员会批准。通过组合光引发剂苯基(2,4,6-三甲基苯甲酰基)磷酸锂[lthium phenyl(2,4,6-trimethylbenzoyl)phosphinate,LAP]、GelMA、BMSCs构建光固化复合生物水凝胶GelMA/BMSCs,扫描电子显微镜(scanning electron microscope,SEM)和能量色散X射线光谱仪(energy disper-sive X-ray spectroscopy,EDX)检测GelMA凝胶表面微观形态及元素构成,电子万能试验机测试凝胶压缩强度。将GelMA/BMSCs水凝胶在体外培养1、2、5 d后,通过CCK-8检测水凝胶包封的BMSCs细胞增殖活性,利用共聚焦显微成像技术观察其存活情况和细胞形态;在大鼠颅骨制备5 mm临界骨缺模型,经复合水凝胶治疗的为GelMA/BMSCs组,不做任何处理的为对照组。分别于术后第4、8周拍摄Micro-CT测算骨缺损面积和新生骨指标,第8周处死大鼠取缺损区颅骨样本进行H&E染色、Van Gieson染色和Goldner染色评价新生骨的质量。结果SEM观察到固化的GelMA内部呈现3D海绵状大孔凝胶网络,大孔形貌均匀,孔隙率为73.41%,孔径为(28.75±7.13)μm;EDX结果显示C和O均匀分布在水凝胶的网状大孔结构上;水凝胶压缩强度为152 kPa,GelMA/BMSCs培养第5天,镜下细胞形态铺展,从卵圆形变为梭形,CCK-8检测结果显示细胞增殖159.4%。术后第4周,Micro-CT三维重建图像显示对照组的骨缺损范围未见明显缩小,GelMA/BMSCs组骨缺损内部可见大量新骨生成;术后第8周,对照组骨缺损仍无明显变化,仅可见少量新生骨,GelMA/BMSCs组颅骨缺损基本愈合;第4周与第8周的定量分析发现,GelMA/BMSCs组大鼠颅骨缺损处新生骨量(new bone vol-ume,BV)、骨体积分数(new bone volume/total bone volume,BV/TV)、骨表面积(bone surface,BS)、骨表面积组织体积比(bone surface/total bone volume,BS/TV)均优于对照组(P<0.05)。第8周组织学染色结果显示GelMA/BMSCs组骨缺损处形成连续且致密的骨组织,而对照组仅在缺损边缘可见少量不连续新骨生成,缺损处主要为纤维结缔组织。结论光固化水凝胶的干细胞疗法具有良好生物安全性,在诱导大鼠颅骨缺损区新骨形成的同时促进骨成熟,具有潜在的临床转化前景。

Repair of articular cartilage defects in rabbits through tissue-engineered cartilage constructed with chitosan hydrogel and chondrocytes

Objective： In our previous work, we prepared a type of chitosan hydrogel with excellent biocompatibility. In this study, tissue-engineered cartilage constructed with this chitosan hydrogel and costal chondrocytes was used to repair the articular cartilage defects. Methods： Chitosan hydrogels were prepared with a crosslinker formed by combining 1,6-diisocyanatohexane and polyethylene glycol. Chitosan hydrogel scaffold was seeded with rabbit chondrocytes that had been cultured for one week in vitro to form the preliminary tissue-engineered cartilage. This preliminary tissue-engineered cartilage was then transplanted into the defective rabbit articular cartilage. There were three treatment groups： the experimental group received preliminary tissue-engineered cartilage; the blank group received pure chitosan hydrogels; and, the control group had received no implantation. The knee joints were harvested at predetermined time. The repaired cartilage was analyzed through gross morphology, histologically and immunohistochemically. The repairs were scored according to the international cartilage repair society （ICRS） standard. Results： The gross morphology results suggested that the defects were repaired completely in the experimental group after twelve weeks. The regenerated tissue connected closely with subchondral bone and the boundary with normal tissue was fuzzy. The cartilage lacuna in the regenerated tissue was similar to normal cartilage lacuna. The results of ICRS gross and histological grading showed that there were significant differences among the three groups （P〈0.05）. Conclusions： Chondrocytes implanted in the scaffold can adhere, proliferate, and secrete extracellular matrix. The novel tissue-engineered cartilage constructed in our research can completely repair the structure of damaged articular cartilage.

纳米复合水凝胶在骨关节炎治疗中的优势与特征

背景:纳米复合水凝胶在骨关节炎治疗中有很大的研究前景和应用潜力。目的:综述纳米复合水凝胶在骨关节炎及软骨修复中的研究进展。方法:检索中国知网和PubMed等数据库,英文检索词为“nanocomposite hydrogel,nanogel,osteoarthritis,cartilage,physical encapsulation,electrostatic interaction,covalent crosslinking”,中文检索词为“纳米复合水凝胶,纳米水凝胶,骨关节炎,软骨,物理包覆,物理包载,静电作用,共价交联”。根据纳入与排除标准对所有文章进行初筛后,保留相关性较高的71篇文章进行综述。结果与结论:在细胞或动物实验中,纳米复合水凝胶具有改善骨关节炎的效果。纳米复合水凝胶可以从改善关节间力学环境、搭载靶向药物、促进种子细胞软骨化等方面加速软骨修复,改善骨关节炎症内环境,达到治疗骨关节炎的目的。目前纳米复合水凝胶在骨关节炎疾病中的研究仍有巨大的发挥空间,继续深入材料制备研究,积极开展细胞、动物实验将有望为临床治疗骨关节炎开辟新途径。

生物支架材料及打印技术修复骨缺损

背景:近年来随着生物支架材料和生物打印技术的发展,组织工程骨成为了骨缺损修复的研究热点。目的:简述当前骨缺损的治疗方式,总结制备组织工程骨支架的生物材料及生物打印技术,探讨生物材料和打印技术在组织工程中的应用及目前面临的挑战。方法:以“bone defect,tissue engineering,biomaterials,3D printing technology,4D printing technology,bioprinting,biological scaffold,bone repair”或“骨缺损,组织工程,生物材料,3D打印技术,4D打印技术,生物打印,生物支架,骨修复”等作为检索词,应用计算机在中国知网、PubMed、Web of Science数据库检索2009-01-01/2022-12-01发表的相关文献,最后经第一作者筛除并追加收录优质参考文献,共纳入93篇文章进行综述。结果与结论:骨缺损的治疗方式主要有骨移植、膜引导再生技术、基因治疗、骨组织工程技术等,最佳的治疗方式仍没有定论。骨组织工程技术是治疗骨缺损的新兴技术,通过构建能促进成骨细胞增殖分化及增强骨形成能力的三维结构,成为当前研究的重点热点技术。生物支架材料多种多样,各具特点,有利有弊,单一的生物材料无法满足组织工程骨对支架的需求,通常将多种材料复合互补使支架在满足力学性能需求的同时兼顾生物性能。生物打印技术能对支架的孔隙进行调节、构建复杂的空间结构,更利于细胞的黏附增殖和分化。新兴的4D打印技术引入“时间”作为第四维度,使制备的支架具有动态性,随着智能材料的同步发展,4D打印技术为未来骨缺损高效修复提供了可能。

丝素蛋白/明胶/壳聚糖三维多孔软骨组织支架的制备及体外评价

背景:软骨缺损是骨科医生面临的主要临床挑战之一,组织工程是一种结合了工程学和细胞生物学知识的跨学科方法,为软骨缺损的修复提供了新思路与途径。目的:基于丝素蛋白、明胶和壳聚糖制备多组分复合支架,通过评估其理化性质和生物学性能,筛选能够适合软骨再生的三维多孔支架。方法:以丝素蛋白、明胶和壳聚糖为基础材料,通过真空冷冻干燥法制备4组多孔支架,分别为明胶/壳聚糖支架、丝素蛋白/壳聚糖支架、丝素蛋白/明胶支架和丝素蛋白/明胶/壳聚糖支架,通过扫描电镜、X射线衍射、孔隙率、吸水膨胀率和生物降解率及力学性能等检测筛选出合适的软骨支架。然后将软骨支架与骨关节炎患者软骨细胞共培养,通过细胞黏附率、活死染色和增殖活性等检测体外评估多孔支架用于软骨损伤修复的可行性。结果与结论:①4组支架均具有多孔结构,综合物理性能检测结果得出丝素蛋白/明胶/壳聚糖支架更符合软骨缺损修复的要求,该支架的孔径为(176.00±53.68)μm,孔隙率为(80.15±2.57)%,吸水溶胀率为(3712±358)%,体外浸泡于含溶菌酶的PBS中28 d后的生物降解速率为(46.87±3.25)%,且具有良好的机械性能;②软骨细胞可在丝素蛋白/明胶/壳聚糖支架上良好黏附,且随着时间的延长,细胞黏附率增加;CCK8和活/死细胞双染检测结果显示,丝素蛋白/明胶/壳聚糖支架具有良好的生物相容性和较低的细胞毒性;③结果表明,丝素蛋白/明胶/壳聚糖支架具有高度水合3D结构、合适的孔径和孔隙率、良好的生物降解性能和优越的机械性能,可以为营养物质的转运和软骨细胞的附着、增殖提供良好的网状骨架和微环境。

可视化分析关节软骨修复领域的研究热点与趋势

背景:由于关节软骨的自我修复能力非常有限,自然退变或创伤等引起的关节软骨缺损往往无法自行修复,进而引发或加重骨关节炎,甚至导致严重残疾,因此关节软骨损伤的修复治疗已成为临床上亟待解决的问题。目的:运用文献计量学方法分析归纳关节软骨修复领域的研究热点及发展趋势。方法:从Web of Science核心合集中检索2000-2023年关节软骨修复的相关文献,运用VOSviewer、Citespeace和Bibliometrix R-package进行文献计量与可视化分析。结果与结论:关节软骨修复领域年度发文量总体呈现上升趋势,美国、中国、德国是发文量前三的国家,研究机构集中于大学和医院,哈佛大学、纽约特种外科医院、上海交通大学是发文量前三的机构。《AMERICAN JOURNAL OF SPORTS MEDICINE》是出版该领域研究文献最多的期刊,《BIOMATERIALS》则是该领域被引次数最多的期刊。“Injectable hydrogels for cartilage and bone tissue engineering”是近10年间发表的被引次数最多的文献,发文量最多的作者是Madry Henning,该领域的活跃作者相互之间形成了多个结构稳定的研究团队,不同团队间的合作有待进一步加强。关节内注射、胫骨高位截骨、水凝胶、药物递送、炎症、软骨再生及支架是当前该领域研究的热点内容,3D打印技术、生物墨水、蚕丝蛋白、可注射水凝胶、外泌体等在关节软骨修复中的应用可能是该领域研究前沿。整合各种创新技术和方法以实现更有效、持久且功能性的关节软骨再生和修复,并通过开展更多高质量的临床研究以促进相关技术和方法的临床转化可能是该领域未来的研究趋势。

可降解新型聚乳酸膜在引导骨组织再生中的应用

目的探索一种可降解新型聚乳酸膜(PDLLA/PLLA)在引导骨组织再生中的应用效果。方法新西兰大白兔24只,体重2.5~3.0 kg,在动物一侧下颌骨体部近下颌骨下缘处制备10 mm×5 mm×3 mm箱状骨缺损,然后将动物随机分为实验组、对照组和空白组,每组8只。实验组动物骨缺损处填Bio-oss骨粉后将PDLLA/PLLA覆盖于缺损表面,对照组动物骨缺损处填Bio-oss骨粉后将Guidor聚乳酸可吸收膜覆盖于缺损表面,空白组动物不作处理。术后8、12周采集缺损处标本,进行大体观察、Micro-CT检查和组织病理学观察。结果实验期间各组实验动物均未发生炎症和排异反应,各组创口愈合良好,成骨活跃。大体观察显示,术后8周实验组动物成骨量较多,材料降解较少,对照组动物成骨量较实验组少,材料降解完全;术后12周实验组动物和对照组动物成骨量相当,实验组材料进一步降解,空白组动物成骨量少于实验组和对照组。术后8、12周,Micro-CT可以观察到实验组和对照组缺损区域新生骨明显多于空白组。术后8、12周,实验组动物和对照组动物新生骨相对骨体积分数(BV/TV)、骨密度(BMD)和骨小梁数量(Tb.N)均显著高于空白组动物(P<0.05),且术后8周实验组动物新生骨BV/TV高于对照组(P<0.05);但在术后12周时实验组与对照组新生骨BV/TV、BMD和Tb.N比较,差异无统计学意义(P>0.05)。组织切片观察显示,术后8周实验组动物新生骨小梁周边细胞生长活跃,并可见少量成骨细胞及破骨细胞;术后12周实验组动物骨小梁周围可见大量成骨细胞及破骨细胞,骨缺损部位骨组织密度接近周边正常骨组织。结论与对照组和空白组相比,PDLLA/PLLA呈现出了良好的生物相容性和骨传导性,可以明显促进缺损处愈合。

软骨支架材料的制备方法及优缺点

背景:软骨组织工程支架材料是提供空间和结构的平台,对软骨组织的再生至关重要,国内外学者均在尝试采用不同方式制备更理想的软骨组织工程支架材料。目的:综述软骨支架材料的设计原则和制备方式,并进一步探讨各种制备方法的优缺点。方法:应用计算机检索中国知网、万方、PubMed和FMRS数据库1998-2023年发表的与软骨组织工程中支架材料有关的文献,中文检索词包括“软骨修复,软骨组织工程,软骨支架材料,制备方法”,英文检索词包括“Cartilage repair,cartilage tissue engineering,cartilage scaffold materials,preparation”,最终选择57篇文献进行综述。结果与结论:①关节软骨结构特殊,其损伤后的自我修复能力较差,即使发生自我修复其新生的软骨通常为纤维软骨,无论是结构还是力学性能都远远不如正常关节软骨,难以维系正常的功能,通常很快就会发生退行性病变。目前设计制备软骨修复的支架材料需要考虑以下内容:生物相容性和生物降解性、适宜的孔隙结构和孔隙率、合适的力学性能及生物活性。②软骨支架制备的研究取得了显著进展,不断涌现出新的制备方法和优化策略,这些方法各有优劣,可以根据具体需求选择合适的方法为软骨支架的定制化制备和功能性设计提供了更多可能性。

三维动静态培养软骨源性微组织的细胞行为及软骨形成能力

背景:与传统二维培养相比,三维培养软骨微组织具有更大的优势,但仍需进一步探索更有利的三维培养方式。目的:评价2种三维培养方式下微组织的细胞行为及促软骨形成能力。方法:通过化学脱细胞方法和组织粉碎方法制备软骨源性微载体,采用DNA定量和核染色验证脱细胞是否成功,通过组织学染色观察脱细胞前后基质保留情况,采用扫描电子显微镜和CCK-8方法对微载体进行表征;通过三维静态培养法和三维动态培养法将软骨源性微载体与人脂肪间充质干细胞结合构建软骨源性微组织,利用扫描电子显微镜、活死染色、RT-qPCR等手段检测两组微组织的细胞活力及成软骨能力。结果与结论:①成功制备软骨源性微载体,与脱细胞前相比,脱细胞后DNA含量显著降低(P<0.001);扫描电子显微镜观察微载体表面有胶原包绕,保持天然软骨细胞外基质特征;CCK-8法检测表明微载体无细胞毒性且能够促进细胞增殖;②扫描电子显微镜及活死染色结果显示,相比三维静态组,三维动态组微组织细胞具有更舒展的形态,细胞与细胞间、细胞与基质间、基质与基质间形成广泛的连接;③RT-qPCR结果表明两组微组织SOX9、蛋白聚糖、Ⅱ型胶原表达在培养7 d或14 d时均增高;14 d时三维动态组各基因相对表达量均显著高于三维静态组(P<0.05);21 d时三维静态组各基因表达均显著高于三维动态组(P<0.001);④结果表明,与三维静态培养微组织相比,三维动态培养微组织可在更短时间实现软骨相关基因的高表达,显示出更好的细胞活性和成软骨能力。