In vitro study of stem cell homing towards transgenic graft

• Main Author: JP Dhephekka
• Other Authors: Wang Dongan
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Science
• Online Access: http://hdl.handle.net/10356/54068
• Institution: Nanyang Technological University

The escalating incidences of cartilage wear and tear could be attributed to factors such as ageing or cartilage injury. Due to the shortcomings of current cartilage repair treatments, a novel living hyaline cartilage graft (LhCG) was engineered earlier to serve as an implantable cartilage graft. Despite being biomaterial free, the cell densities of the LhCG are often insufficient to achieve optimal cartilage regeneration. In this project, a transgenic LhCG construct containing mouse stromal derived factor-1 (mSDF-1) adenoviral vector was fabricated to enable the secretion of the potent chemokine, mSDF-1 into the surrounding media over 72 hours. Transwell migration analysis using mouse mesenchymal stem cells (mMSCs), mouse endothelial progenitor outgrowth cells (mEPOCs) and mouse induced pluripotent stem cells (miPSCs) were performed with the collected mSDF-1 media to determine its ability to attract the various stem/progenitor cells towards itself. The results demonstrated that the concentration of mSDF-1 secreted by the transduced constructs increased steadily over 72 hours. Furthermore, an increasing migratory effect was observed in the mMSCs and the mEPOCs as the mSDF-1 concentration increased, but the number of mEPOCs recruited was significantly lower than the mMSCs. The miPSCs however failed to demonstrate a significant amount of migration towards the mSDF-1 source, probably suggesting that they do not respond to mSDF-1. Hence, the elevated migration of the mMSCs towards the mSDF-1 produced by the transduced LhCG constructs compared to mEPOCs suggests that the graft could be capable of maintaining the chondrogenic phenotype and can be utilized to increase its overall cell density. Furthermore, by implanting the transduced constructs, the dual outcomes of replacing the damaged cartilage and promoting the homing of MSCs to the site of implantation via SDF-1 secretion by the construct could possibly enhance the cartilage regeneration process.