Objective: To evaluate both the potential for transferring genes to periosteal cells using an adeno-associated virus (AAV) vector and the potential for gene expression after transplantation of those cells to a cartilage defect in vivo.
Methods: Periosteum was obtained from the tibia of 6-week-old rabbits and enzymatically digested. The isolated periosteum derived cells were cultured and the subconfluence cells were infected with a recombinant AAV expressing the LacZ gene (AAV-LacZ). Collagen gel containing the LacZ transferred, periosteum derived cells was transplanted into a full thickness articular cartilage defect in 10 rabbits.
Results: Infected cells still growing on the plate continued to express LacZ at least 12 weeks after AAV infection, with the highest percentage of LacZ positive cells reaching 74.4%. The LacZ positive cells were recognized at the transplant sites in 8 out of 10 knees.
Conclusion: Gene expression in periosteum derived cells was sustained in vitro for at least 12 weeks using the AAV vector, and for 2 weeks ex vivo after transplantation into a cartilage defect.