Original Article In Vitro Healing of Avascular Meniscal Injuries with Fresh and Frozen Plugs Treated with TGF-β1 and IGF-1 in Sheep
Iñigo Izal, Purificación Ripalda, Carlos A Acosta and Francisco Forriol
Orthopaedic Research Laboratory, University of Navarra, Pamplona, Spain and Research Area, Fremap, Majadahonda, Spain.
Received 10 Oct 2007; Accepted with revision 16 Dec 2007; Available online 1 January 2008
Abstract: We studied the effect of freezing and inserting meniscal plugs in lesions generated in the avascular area of sheep menisci maintained in vitro, and whether the healing process can be improved by adding growth factors TGF-β1 and IGF-1. Thirty six menisci obtained from healthy 3 months-old sheep were cultured in 6 well plates and holes were perforated in the avascular area. Meniscal plugs, either fresh or frozen at -20ºC for 1 month, were used to fill in the lesions, and then cultured in the presence or absence of TGF-β1 or IGF-1 for 8 weeks. Samples stained with Massons trichrome were analyzed to evaluate the attachment of the plug and the cell density of the tissue. BrdU immunohistochemistry was performed to identify the proliferation of meniscal cells. Both growth factors improved considerably the cell density of implanted plugs. TGF-β1 increased significantly the attachment of both fresh and frozen plugs, but it had no effect on meniscal cell proliferation. In contrast, IGF-1 had no effect on the attachment, but did increase significantly the number of proliferating cells in the surface of the host meniscus and the inserted plug. In conclusion, frozen plugs can survive if treated with either TGF-β1 or IGF-1. The combination of TGF- β1 and IGF-1 could aid in the repairing of the avascular meniscal injuries, as they are capable of promoting the attachment of tissue, and increasing the proliferation of meniscal cells. (IJCEP710006).