Application of synthetic and biological materials in articular cartilage repair / 中国组织工程研究

BACKGROUND:The repair of articular cartilage injury remains a difficult problem to be solved urgently in clinical practice.Utilizing synthetic or biological materials to promote cartilage regeneration has been a research hotspot. OBJECTIVE:To review the research progress of synthetic and biological materials in articular cartilage repair. METHODS:PubMed and CNKI databases were searched for articles about the progress of synthetic and biological materials utilized in articular cartilage repair."Collagen,gelatin,silk,chitosan,alginate,PEG,PCL,PLA,cartilage tissue engineering,cartilage tissue engineering materials"were used as English and Chinese search terms,respectively.After preliminary screening based on the inclusion and exclusion criteria,98 articles with high quality and relevance were retained for review. RESULTS AND CONCLUSION:Natural materials,including collagen,gelatin,silk,chitosan,and alginate,have good biocompatibility and degradability.Synthetic materials,containing polyethylene glycol,polycaprolactone,and polylactic acid,have good mechanical properties.Modification and composition of materials can overcome the inherent defects in materials and show better cartilage repair ability.Studies about multi-layer scaffolds based on hierarchical structure are rare,and it is more targeted at osteochondral injury repair rather than simple cartilage injury repair.At present,scaffold research is focused on the synthetic research and development stage,and the corresponding clinical trials are few,so it is necessary to pay attention to clinical transformation in the future.

Preparation methods,advantages,and disadvantages of cartilage scaffold materials / 中国组织工程研究

BACKGROUND:Scaffold materials serve as platforms that provide space and structure,playing a crucial role in the regeneration of cartilage tissue.Scholars from around the world are exploring different approaches to fabricate more ideal scaffold materials. OBJECTIVE:To review the design principles and preparation methods of cartilage scaffolds,and to further explore the advantages and limitations of various preparation methods. METHODS:Literature searches were conducted on the databases of CNKI,WanFang Data,PubMed,and FMRS from 1998 to 2023.The search terms were"cartilage repair,cartilage tissue engineering,cartilage scaffold materials,preparation"in Chinese and English.A total of 57 articles were ultimately reviewed. RESULTS AND CONCLUSION:(1)The articular cartilage has a unique structure and limited self-repair capacity after injury.Even if self-repair occurs,the newly formed cartilage is typically fibrocartilage,which is far inferior to normal articular cartilage in terms of structure and mechanical properties.It is difficult to maintain normal function and often leads to degenerative changes.Currently,the design and fabrication of scaffold materials for cartilage repair need to consider the following aspects:biocompatibility and biodegradability,suitable pore structure and porosity,appropriate mechanical properties,and bioactivity.(2)Research on the preparation of cartilage scaffolds has made significant progress,continuously introducing new preparation methods and optimization strategies.These methods have their advantages and disadvantages,providing more possibilities for customized preparation and functional design of cartilage scaffolds according to specific requirements.

Advantages and features of nanocomposite hydrogel in treatment of osteoarthritis / 中国组织工程研究

BACKGROUND:Nanocomposite hydrogel has great research prospects and application potential in the treatment of osteoarthritis. OBJECTIVE:To review the research progress of nanocomposite hydrogel in osteoarthritis and cartilage repair. METHODS:Databases such as CNKI and PubMed were searched.The English key words were"nanocomposite hydrogel,nanogel,osteoarthritis,cartage,physical encapsulation,electrostatic interaction,covalent crosslinking",and the Chinese key words were"nanocomposite hydrogel,nanogel,osteoarthritis,cartage,physical encapsulation,physical encapsulation,electrostatic effect,covalent cross-linking".After an initial screening of all articles based on inclusion and exclusion criteria,71 articles with high correlation were retained for review. RESULTS AND CONCLUSION:In cell or animal experiments,nanocomposite hydrogel has the effect of improving osteoarthritis.Nanocomposite hydrogel can promote cartilage repair,improve the internal environment of osteoarthritis,and achieve the therapeutic purpose of osteoarthritis by improving the mechanical environment between joints,carrying targeted drugs,and promoting the chondrogenesis of seed cells.At present,the research of nanocomposite hydrogel in osteoarthritis disease still has a huge space to play.It is expected to open up a new way for the clinical treatment of osteoarthritis by continuing to deepen the research of material preparation and actively carrying out cell and animal experiments.

Applicable techniques for subchondral separation of femoral head necrosis treated by tissue engineering / 中国组织工程研究

BACKGROUND:The appearance of the crescent sign in femoral head necrosis is a"turning point"in the progression of the disease,and repairing and stabilizing the bone-cartilage interface is particularly important in preventing further progression and collapse of the femoral head.Tissue engineering offers potential advantages in the simultaneous repair and integration of the bone-cartilage interface. OBJECTIVE:To review potentially suitable techniques addressing the subchondral separation in femoral head necrosis. METHODS:Relevant articles from January 1970 to April 2023 were searched in PubMed,Web of Science,and China National Knowledge Infrastructure(CNKI)using English search terms"femoral head necrosis,avascular necrosis of femoral head,osteonecrosis of femoral head"and Chinese search terms"femoral head necrosis,subchondral bone,cartilage,integration of cartilage and subchondral bone".A total of 114 articles were included for review and analysis. RESULTS AND CONCLUSION:(1)Structural defects,ischemic and hypoxic environment,inflammatory factors,and stress concentration may cause subchondral separation in osteonecrosis of the femoral head.Subchondral bone collapse and failure of hip-preserving surgery may be associated.Integration of tissue engineering scaffolds with the bone-cartilage interface is one potential approach for treating subchondral separation in osteonecrosis of the femoral head.(2)Current literature suggests that multiphase scaffolds,gradient scaffolds,and composite materials have shown improvements in promoting cell adhesion,proliferation,and deposition of bone and cartilage matrix.These advancements aid in the integration of scaffolds with the bone-cartilage interface and have implications for the treatment of subchondral separation in osteonecrosis of the femoral head.(3)Surface modifications of scaffolds can enhance interface integration efficiency,but they have their advantages and disadvantages.Scaffolds providing different environments can induce differentiation of mesenchymal stem cells and facilitate integration between different interfaces.(4)Future scaffolds for subchondral separation in osteonecrosis of the femoral head are expected to be composite materials with gradient and differentiated biomimetic structures.Surface modifications and stem cell loading can promote integration between the bone-cartilage interface and scaffolds for therapeutic purposes,but further experimental verification is still needed.Challenges include synchronizing scaffold degradation rate with repair progress and ensuring stability between different interfaces.

Bone/cartilage immunomodulating hydrogels: construction strategies and applications / 中国修复重建外科杂志

OBJECTIVE@#To review the research progress in the construction strategy and application of bone/cartilage immunomodulating hydrogels.@*METHODS@#The literature related to bone/cartilage immunomodulating hydrogels at home and abroad in recent years was reviewed and summarized from the immune response mechanism of different immune cells, the construction strategy of immunomodulating hydrogels, and their practical applications.@*RESULTS@#According to the immune response mechanism of different immune cells, the biological materials with immunoregulatory effect is designed, which can regulate the immune response of the body and thus promote the regeneration of bone/cartilage tissue. Immunomodulating hydrogels have good biocompatibility, adjustability, and multifunctionality. By regulating the physical and chemical properties of hydrogel and loading factors or cells, the immune system of the body can be purposively regulated, thus forming an immune microenvironment conducive to osteochondral regeneration.@*CONCLUSION@#Immunomodulating hydrogels can promote osteochondral repair by affecting the immunomodulation process of host organs or cells. It has shown a wide application prospect in the repair of osteochondral defects. However, more data support from basic and clinical experiments is needed for this material to further advance its clinical translation process.

New strategies and problems of affinity peptide in cartilage tissue engineering / 中国组织工程研究

BACKGROUND: With the development of cartilage tissue engineering, affinity peptides have attracted some attention because of their special affinity to some key factors of cartilage tissue engineering. OBJECTIVE: To review the screening and identification of various affinity peptides and their application in cartilage tissue engineering. METHODS: The articles related to affinity peptides in CNKI, Wanfang, and PubMed were searched by computer from January 2000 to May 2020. “Affinity peptides, cartilage tissue engineering, mesenchymal stem cell, scaffold” in English and Chinese were used as key words. Finally, 66 articles were included for analysis. RESULTS AND CONCLUSION: Many polypeptides with specific amino acid sequence can bind with some cells, factors and molecules, and have affinity. According to different targets, they can be divided into cell affinity peptide, factor affinity peptide and extracellular matrix molecular affinity peptide. Affinity peptides have been used in cartilage tissue engineering through screening and identification to enhance the repair effect of tissue engineering by adhering fine cells, recruitment factors and molecules. In many strategies of biomimetic cartilage multilayer scaffolds, affinity peptides that interact with specific molecules play an important role in simulating the environment of normal cartilage. At the same time, with the development of cartilage tissue engineering technology, especially the application of computer-aided technology, it provides a new strategy for the use of affinity peptides. However, the residence time, degradation rate and degradation pathway of affinity peptides in vivo are relatively few, which need to be further understood.

Legal Aspects of Articular Cartilage Tissue Engineering Experimentation: A Review on Malaysian Acts, Regulations and Guidelines

@#Presently, there is no specific federal legislation governing articular cartilage tissue engineering (ACTE) experimentation practices in Malaysia. However, there are related regulations and guidelines provided by government agencies to oversee and guide such practices. The rules and regulations provided in the documents have the essential aim of safeguarding public health through ensuring that non-clinical studies reach a certain quality, efficient and safe for human use. There are themes identified when scrutinising relevant documents which includes, the need for authorised personnel and the establishment of facilities in conducting such experiments, the aspect of cell-scaffold construct development, the use of human materials, the aspect of biosafety, animal care and use during the experiments, and considerations on the impact on the environment. The individual laboratory or facility shall adopt and adapt these standards as deemed appropriate by the ACTE researchers to ensure that non-clinical studies are conducted in a proper and ethical manner.

Preparation and evaluation of carboxymethyl chitosan/sodium alginate hydrogel for cartilage tissue engineering / 华西口腔医学杂志

OBJECTIVE@#This study aimed to optimize the preparation of carboxymethyl chitosan/sodium alginate (CMCS/OSA) compound hydrogels. This study also aimed to investigate the applicability of the hydrogels in cartilage tissue engi-neering.@*METHODS@#Three groups of CMCS/OSA composite hydrogels with amino-to-aldehyde ratios of 2∶1, 1∶1 and 1∶2 were prepared. The microstructure, physical properties, and cell biocompatibility of the three groups of CMCS/OSA com-posite hydrogels were evaluated. Samples were subjected to scanning electron microscopy, rheological test, adhesion tension test, swelling rate test, and cell experiments to identify the CMCS/OSA composite hydrogel with the cross-linking degree that can meet the requirements for scaffolds in cartilage tissue engineering.@*RESULTS@#The experimental results showed that the CMCS/OSA hydrogel with a amine-to-aldhyde ratio of 1∶1 had good porosity, suitable gelling time, strong adhesive force, stable swelling rate, and good cellular biocompatibility.@*CONCLUSIONS@#The CMCS/OSA compound hydrogel prepared with a 1∶1 ratio of amino and aldehyde groups has potential applications in cartilage tissue engineering.

Development of cartilage extracellular matrix in cartilage tissue engineering / 华西口腔医学杂志

Cartilage tissue engineering, an effective way to repair cartilage defects, requires an ideal scaffold to promote the regeneration performance of stem cells. Cartilage extracellular matrix (CECM) can imitate the living environment of cartilage cells to the greatest extent. CECM not only exhibits good biocompatibility with chondrocytes and stem cells, which can meet the basic requirements of scaffolds, but also promotes chondrocytes to secrete matrix and induce stem cells to differentiate into chondrocytes; as such, this matrix is a better scaffold and has more advantages than existing ones. The promotion and induction effects could be related to various cartilage-related proteins inside. However, the practical application of this technique is hindered by problems, such as poor mechanical properties and insufficient cell penetration of CECM. Association with other materials can compensate for these inadequacies to a certain degree, and finding a combination mode with optimized performance is the application trend of CECM. This review focuses on research of CECM materials in cartilage tissue engineering.

Development of CRISPR technology and its application in bone and cartilage tissue engineering / 南方医科大学学报

The CRISPR/Cas9 system, consisting of Cas9 nuclease and single guide RNA (sgRNA), is an emerging gene editing technology that can perform gene reprogramming operations such as deletion, insertion, and point mutation on DNA sequences targeted by sgRNA. In addition, CRISPR/dCas9 (a mutant that loses Cas9 nuclease activity) still retains the ability of sgRNA to target DNA. The fusion of dCas9 protein with transcriptional activator (CRISPRa) can activate the expression of the target gene, and fusion transcriptional repressors (CRISPRi) can also be used to suppress target gene expression. Efficient delivery of the CRISPR/Cas9 system is one of the main problems limiting its wide clinical application. Viral vectors are widely used to efficiently deliver CRISPR/Cas9 elements, but non-viral vector research is more attractive in terms of safety, simplicity, and flexibility. In this review, we summarize the principles and research advances of CRISPR technology, including CRISPR/ Cas9 delivery vectors, delivery methods, and obstacles to the delivery, and review the progress of CRISPR-based research in bone and cartilage tissue engineering. Finally, the challenges and future applications of CRISPR technology in bone and cartilage tissue engineering are discussed.

Construction of tissue engineered cartilage based on acellular cartilage extracellular matrix oriented scaffold and chondrocytes / 中国修复重建外科杂志

Objective: To observe the feasibility of acellular cartilage extracellular matrix (ACECM) oriented scaffold combined with chondrocytes to construct tissue engineered cartilage.

Dopamine modified and cartilage derived morphogenetic protein 1 laden polycaprolactone-hydroxyapatite composite scaffolds fabricated by three-dimensional printing improve chondrogenic differentiation of human bone marrow mesenchymal stem cells / 中国修复重建外科杂志

Results: The scaffolds in 3 groups were all showed a cross-linked and pore interconnected with pore size of 400-500 μm, porosity of 56%, and fiber orientation of 0°/90°. For dopamine modification, the scaffolds in groups B and C were dark brown while in group A was white. Similarly, water static contact angle was from 76° of group A to 0° of groups B and C. After cultured for 24 hours, the cell adhesion rate of groups A, B, and C was 34.3%±3.5%, 48.3%±1.5%, and 57.4%±2.5% respectively, showing significant differences between groups ( P<0.05). Live/Dead staining showed good cell activity of cells in 3 groups. MTT test showed that hBMSCs proliferated well in 3 groups and the absorbance ( A) value was increased with time. The A value in group C was significantly higher than that in groups B and A, and in group B than in group A after cultured for 4, 7, 14, and 21 days, all showing significant differences ( P<0.05). The mRNA relative expression of collagen type Ⅱ and Aggrecan increased gradually with time in 3 groups. The mRNA relative expression of collagen type Ⅱafter cultured for 7, 14, and 21 days, and the mRNA relative expression of Aggrecan after cultured for 14 and 21 days in group C were significantly higher than those in groups A and B, and in group B than in group A, all showing significant differences ( P<0.05).

Application of cell sheet technology in bone and cartilage tissue engineering / 中国修复重建外科杂志

Objective: To review the progress of cell sheet technology and its application in bone and cartilage engineering.

Collagen Scaffolds in Cartilage Tissue Engineering and Relevant Approaches for Future Development

BACKGROUND: Cartilage tissue engineering (CTE) aims to obtain a structure mimicking native cartilage tissue through the combination of relevant cells, three-dimensional scaffolds, and extraneous signals. Implantation of ‘matured’ constructs is thus expected to provide solution for treating large injury of articular cartilage. Type I collagen is widely used as scaffolds for CTE products undergoing clinical trial, owing to its ubiquitous biocompatibility and vast clinical approval. However, the long-term performance of pure type I collagen scaffolds would suffer from its limited chondrogenic capacity and inferior mechanical properties. This paper aims to provide insights necessary for advancing type I collagen scaffolds in the CTE applications. METHODS: Initially, the interactions of type I/II collagen with CTE-relevant cells [i.e., articular chondrocytes (ACs) and mesenchymal stem cells (MSCs)] are discussed. Next, the physical features and chemical composition of the scaffolds crucial to support chondrogenic activities of AC and MSC are highlighted. Attempts to optimize the collagen scaffolds by blending with natural/synthetic polymers are described. Hybrid strategy in which collagen and structural polymers are combined in non-blending manner is detailed. RESULTS: Type I collagen is sufficient to support cellular activities of ACs and MSCs; however it shows limited chondrogenic performance than type II collagen. Nonetheless, type I collagen is the clinically feasible option since type II collagen shows arthritogenic potency. Physical features of scaffolds such as internal structure, pore size, stiffness, etc. are shown to be crucial in influencing the differentiation fate and secreting extracellular matrixes from ACs and MSCs. Collagen can be blended with native or synthetic polymer to improve the mechanical and bioactivities of final composites. However, the versatility of blending strategy is limited due to denaturation of type I collagen at harsh processing condition. Hybrid strategy is successful in maximizing bioactivity of collagen scaffolds and mechanical robustness of structural polymer. CONCLUSION: Considering the previous improvements of physical and compositional properties of collagen scaffolds and recent manufacturing developments of structural polymer, it is concluded that hybrid strategy is a promising approach to advance further collagen-based scaffolds in CTE.

Effect of cartilage tissue engineering scaffolds PVA/ι-CA on biological behavior and biocompatibility of ATDC-5 cells / 吉林大学学报(医学版)

Objective: To investigate the effect of cartilage tissue engineering scaffold PVA/ι-CA on the biological behavior of the ATDC-5 cells,and to evaluate its feasibility on constructing tissue engineering cartilage. Methods:The polyvinyl alcohol (PVA)and carrageenan were used to make the composite scaffold material PVA/ι-CA according to a certain proportion by physical blending technology and repeated freezing thawing method,and the porosity and pore size of PVA/ι-CA were detected.The ATDC-5 cells were seeded into the composite scaffold and its growth was observed; the expressions of collagen type Ⅱ in the ATDC-5 cells were tested by immunohistochemical staining and immunofluorescence staining; the morphology of the ATDC-5 cells was confirmed by Toluidine blue staining.The growth and secretion of extracellular matrix of the ATDC-5 cells were observed under scanning electron microscope (SEM);the proliferative rates of ATDC-5 cells in composite scaffold materials in negative control group (added with DMEM culture media)and experimental group (added with DMEM contain scaffold)were determined by MTT assay.The composite scaffolds were implanted subcutaneously in the SD rats.The histocompatibility and vascularization in vivo of the composite scaffolds were evaluated.Results:The average porosity of cartilage tissue engineering scaffold PVA/ι-CA was (86.88±3.88)%,and the average pore size was 20-40 μm.The HE staining results showed that the ATDC-5 cells grew well with the polygon and plumpness morphology. All the samples were stained positive for collagen type Ⅱ by immunohistochemistry and immunofluorescence staining,which verified the normal phenotype of chondrocytes on the scaffolds. All the sample were stained positive for toluidine blue staining,which verified ECM deposition of the ATDC-5 cells on the scaffolds.The number of the positive cells was significantly increased with the prolongation of time.After cultured for 7 d,few of the ATDC-5 cells presented polygonal;after cultured for 14 d,the ATDC-5 cells distributed more densely,and contacted with each other on the scaffold;after cultured for 21 - 28 d,the ATDC-5 cells filled the interconnected pores of the scaffolds,synthesizing a significant amount of neo-formed ECM.The proliferation of ATDC-5 cells in PVA/ι-CA grew fast during 7-14 d,and it became slow during 21-28 d;the difference was not statistically significant compared with control group (P >0.05).The subcutaneous implantation results showed the inflammatory reactions were slight at the early stage and eviated gradually,there was an increasing angiogenesis at the late stage,and the degradation and absorption of the meterial were slight.Conclusion:PVA/ι-CA composite material will be an ideal material for the cartilage tissue engineering.

Polycaprolactone Triol–Citrate Scaffolds Enriched with Human Platelet Releasates Promote Chondrogenic Phenotype and Cartilage Extracellular Matrix Formation

In this paper we report the differentiating properties of platelet-rich plasma releasates (PRPr) on human chondrocytes within elastomeric polycaprolactone triol–citrate (PCLT–CA) porous scaffold. Human-derived chondrocyte cellular content of glycosaminoglycans (GAGs) and total collagen were determined after seeding into PCLT–CA scaffold enriched with PRPr cells. Immunostaining and real time PCR was applied to evaluate the expression levels of chondrogenic and extracellular gene markers. Seeding of chondrocytes into PCLT–CA scaffold enriched with PRPr showed significant increase in total collagen and GAGs production compared with chondrocytes grown within control scaffold without PRPr cells. The mRNA levels of collagen II and SOX9 increased significantly while the upregulation in Cartilage Oligomeric Matrix Protein (COMP) expression was statistically insignificant. We also report the reduction of the expression levels of collagen I and III in chondrocytes as a consequence of proximity to PRPr cells within the scaffold. Interestingly, the pre-loading of PRPr caused an increase of expression levels of following extracellular matrix (ECM) proteins: fibronectin, laminin and integrin β over the period of 3 days. Overall, our results introduce the PCLT–CA elastomeric scaffold as a new system for cartilage tissue engineering. The method of PRPr cells loading prior to chondrocyte culture could be considered as a potential environment for cartilage tissue engineering as the differentiation and ECM formation is enhanced significantly.

Electrospun Fibrous Silk Fibroin/Poly(L-Lactic Acid) Scaffold for Cartilage Tissue Engineering

For successful tissue engineering of articular cartilage, a scaffold with mechanical properties that match those of natural cartilage as closely as possible is needed. In the present study, we prepared a fibrous silk fibroin (SF)/poly(L-lactic acid) (PLLA) scaffold via electrospinning and investigated the morphological, mechanical, and degradation properties of the scaffolds fabricated using different electrospinning conditions, including collection distance, working voltage, and the SF:PLLA mass ratio. In addition, in vitro cell-scaffold interactions were evaluated in terms of chondrocyte adhesion to the scaffolds as well as the cytotoxicity and cytocompatibility of the scaffolds. The optimum electrospinning conditions for generating a fibrous SF/PLLA scaffold with the best surface morphology (ordered alignment and suitable diameter) and tensile strength (~1.5 MPa) were a collection distance of 20 cm, a working voltage of 15 kV, and a SF:PLLA mass ratio of S50P50. The degradation rate of the SF/PLLA scaffolds was found to be determined by the SF:PLLA mass ratio, and it could be increased by reducing the PLLA proportion. Furthermore, chondrocytes spread well on the fibrous SF/PLLA scaffolds and secreted extracellular matrix, indicating good adhesion to the scaffold. The cytotoxicity of SF/PLLA scaffold extract to chondrocytes over 24 and 48 h in culture was low, indicating that the SF/PLLA scaffolds are biocompatible. Chondrocytes grew well on the SF/PLLA scaffold after 1, 3, 5, and 7 days of direct contact, indicating the good cytocompatibility of the scaffold. These results demonstrate that the fibrous SF/PLLA scaffold represents a promising composite material for use in cartilage tissue engineering.

In vitro and in vivo evaluation of the developed PLGA/HAp/Zein scaffolds for bone-cartilage interface regeneration / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the effect of electronspun PLGA/HAp/Zein scaffolds on the repair of cartilage defects.</p><p><b>METHODS</b>The PLGA/HAp/Zein composite scaffolds were fabricated by electrospinning method. The physiochemical properties and biocompatibility of the scaffolds were separately characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and fourier transform infrared spectroscopy (FTIR), human umbilical cord mesenchymal stem cells (hUC-MSCs) culture and animal experiments.</p><p><b>RESULTS</b>The prepared PLGA/HAp/Zein scaffolds showed fibrous structure with homogenous distribution. hUC-MSCs could attach to and grow well on PLGA/HAp/Zein scaffolds, and there was no significant difference between cell proliferation on scaffolds and that without scaffolds (P>0.05). The PLGA/HAp/Zein scaffolds possessed excellent ability to promote in vivo cartilage formation. Moreover, there was a large amount of immature chondrocytes and matrix with cartilage lacuna on PLGA/HAp/Zein scaffolds.</p><p><b>CONCLUSION</b>The data suggest that the PLGA/HAp/Zein scaffolds possess good biocompatibility, which are anticipated to be potentially applied in cartilage tissue engineering and reconstruction.</p>

Polyvinyl alcohol and its composite materials for tissue engineering scaffolds / 中国组织工程研究

BACKGROUND:Polyvinyl alcohol is a biocompatible and biodegradable polymer. It is widely used in clinical areas because of its water-soluble, film forming, emulsification, adhesiveness, tasteless, and nontoxic. OBJECTIVE:To review the applications of polyvinyl alcohol and its composite materials in bone, cartilage, skin, vessels and other tissue engineering scaffolds. METHODS:A computer-based online search of CNKI database from January 2000 to December 2011, PubMed database and Elsevier (ScienceDirect) database from January 1980 to December 2012, was performed by the first author with key words of“poly(vinyl alcohol), composite material, tissue engineering scaffold”both in Chinese and English. Literatures concerning polyvinyl alcohol and its composite materials in bone, cartilage, skin, vessels and other tissue engineering scaffolds were included, and repetitive research was excluded. RESULTS AND CONCLUSION:Although there are not enough strength, complications and other shortcomings in vivo, due to its good biocompatibility and biodegradable properties, polyvinyl alcohol and its composite materials have made great progress in tissue engineering applications from the laboratory to the pre-clinical research. But its long-term effects need further research. It wil be a main research aim of scaffold materials in the future to improve the interaction of cel s with the scaffold materials by surface modification, to prepare biomimetic materials by cel microenvironment simulation, to improve the hydrophilicity, the adhesion of cel s, and cel differentiation and proliferation, to bionic the structure and function of the natural extracel ular matrix by building three-dimensional porous structure and control ing the release of cel growth factors, to meet the need of tissue regeneration by congruity or harmony of degradation and mechanical strength.

Cartilage tissue engineering of TGF-β3 combined with IGF-1-induced bone marrow mesenchymal stem cells derived chondrocytes / 中华医学美学美容杂志

Objective To investigate the effect of IGF-1 on the TGF-β3 induced chondrogenesis of MSCs encapsulated in alginate beads and its application in cartilage tissue engineering.Methods MSC chondrogenesis in alginate beads was induced by TGF-β3 and/or IGF-1.Collagen type Ⅱ,aggrecan and Sox-9 expression was evaluated by immunostaining,RT-PCR and Western blot,respectively.Scanning electron microscope and laser confocal microscope were used to observe the differentiated chondrocytes when cultured on the chitosan-based scaffold.Results TGF-β3 with IGF-1 induced MSCs in alginate beads to express the higher level of collagen type Ⅱ,aggrecan and Sox-9 than any other growth factor alone (P＜0.05).The correlation coefficient between Sox9 and collagen type Ⅱ or aggrecan was 0.95 and 0.91,respectively.The chitosan-based scaffold supported the cell's adhesion,migration and proliferation.Conlusion IGF-1 enhances the TGF-β3-induced MSC chondrogenesis via upregulating Sox9 expression.The chitosan-based scaffold is biocompatible with the differentiated chondrocytes.