CULTURING PERIOSTEUM IN-VITRO - THE INFLUENCE OF DIFFERENT SIZES OF EXPLANTS

Periosteal transplantation is being used clinically to repair articula r defects. Isolated cells and very small periosteal explants can be gr own in tissue culture, but it will be necessary to test larger sizes f or tissue engineering to be applied to clinical transplantation of per iosteum. This study was conducted to assess the chondrogenic potential of different sizes of periosteal explants in agarose culture. Ninety- six rabbit tibial periosteal explants in three different sizes (small 1.5 x 2, medium 3 x 2, and large 4 x 6 mm, 32 pieces per size) were cu ltured in agarose suspension for 6 wk and given TGF-beta 1 (10 ng/mL) for the first 2 wk, Tissue growth, as indicated by normalized final we t weights of the explants after 6 wk in culture, was inversely proport ional to explant size. Cartilage formation was observed in all explant s. Histomorphometry revealed that cartilage formation was significantl y better for the smaller explants (80% cartilage), but similar in the medium and larger explants (60% cartilage). Similar proportions of typ e II collagen were present in the different-sized explants, This study demonstrates that various sizes of periosteal explants can be grown i n culture. Abundant cartilage was produced even by the large explants, (C) 1998 Elsevier Science Inc.