BACKGROUND: Cartilage injury and defect have always been a challenge to orthopedic and plastic surgeons. Tissue engineering technology provides a novel promising approach to repair cartilage defects. Adipose-derived stem cells (ADSCs) are a great source of seed cells for cartilage tissue engineering due to the sufficient storage, easy harvest, high yield, easy isolation, strong proliferation and multilineage differentiation capability.
OBJECTIVE: To analyze the factors that influence the construction of tissue-engineered cartilage using ADSCs as seed cells, to summarize the methods that verify a successful differentiation towards chondrocytes from ADSCs, to discuss some issues on the ADSCs based cartilage tissue engineering, and to look forward the future of cartilage tissue engineering.
METHODS: On June 5, 2017, we searched in PubMed using the following strategy “(((adipose stem cell[Title]) OR adipose-derived stem cell[Title]) OR adipose-derived mesenchymal stem cell[Title]) AND chondrogenic differentiation[Title]”. On August 4, 2017, we searched in SinoMed using the following strategy “(“adipose-derived stem cell”[Title]) AND “cartilage”[Title]” in Chinese. We first selected literatures related to ADSC differentiation into chondrocyte or cartilage tissue engineering using ADSCs as seed cells according to their titles and abstracts. We then read the titles of the references of the selected literatures and reselected the articles associated with the same topic from the references and removed the repetitive literatures.
RESULTS AND CONCLUSION: There were 35 eligible literatures in PubMed, among which 30 were published in recent 5 years. There were 71 eligible literatures in SinoMed, among which 9 were reviews and 22 were published in recent 5 years. Finally, 60 literatures were included for this review. Growth factors such as transforming growth factor β, bone morphogenetic protein, insulin-like growth factor can facilitate the ADSCs differentiation towards chondrocytes. The combination of several growth factors and gene modification of ADSCs utilizing the above-mentioned growth factor genes for a long-term stable release are in the spotlight of current research. Traditional induction medium recipe consisting of dexamethasone, insulin, vitamin C and several growth factors is still the mainstream in the current market. Cell culture methods such as coculture, microsphere, scaffold, and dynamic three-dimensional culturing system can promote the efficiency and quality of the construction of tissue engineered cartilage. However it is essential to find an ideal scaffold material. Furthermore, other factors including ADSCs source, culture conditions, miRNA, platelet rich plasma, parathyroid hormone related peptides can also affect the ADSCs differentiation towards chondrocytes. Besides the morphological changes of induced ADSCs, the chondrogenic differentiation can also be verified through dyeing or the detection of specific genes and proteins such as Sox9, Collagen II, chondroitin sulfate, and keratansulfate. The future research interest will focus on the specific marker of ADSCs, the sequence and dose of exogenous growth factors for combined utility, gene-modified ADSCs and scaffold materials.