A comparison of human umbilical cord matrix stem cells and temporomandibular joint condylar Chondrocytes for tissue engineering temporomandibular joint condylar cartilage

The temporomandibular joint ( TMJ) presents many problems in modern musculoskeletal medicine. Patients who suffer from TMJ disorders often experience a major loss in quality of life due to the debilitating effects that TMJ disorders can have on everyday activities. Cartilage tissue engineering can lead to replacement tissues that could be used to treat TMJ disorders. In this study, a spinner flask was used for a period of 6 days to seed polyglycolic acid ( PGA) scaffolds with either TMJ condylar chondrocytes or mesenchymal- like stem cells derived from human umbilical cord matrix ( HUCM). Samples were then statically cultured for 4 weeks either in growth medium containing chondrogenic factors or in control medium. Immunohistochemical staining of HUCM constructs after 4 weeks revealed a strong presence of collagen I and minute amounts of collagen II, whereas TMJ constructs revealed little collagen I and no collagen II. The HUCM constructs were shown to contain more GAGs than the TMJ constructs quantitatively at week 0 and histologically at week 4. Moreover, the cellularity of HUCM constructs was 55% higher at week 0 and nearly twice as high after 4 weeks, despite being seeded at the same density. The increased level of biosynthesis and higher cellularity of HUCM constructs clearly demonstrates that the HUCM stem cells outperformed the TMJ condylar cartilage cells under the prescribed conditions. HUCM stem cells may therefore be an attractive alternative to condylar cartilage cells for TMJ tissue engineering applications. Further, given the availability and ease of obtaining HUCM stem cells, these findings may have far- reaching implications, leading to novel developments in both craniofacial and orthopaedic tissue replacement therapies.