RESUMEN
Diverse developments in the field of tissue engineering have stimulated much research on tissue production. However, studies on fat tissue still remain insufficient. The purpose of this study is to examine if alginate gel and collagen gel can be used as a three-dimensional scaffold for the culture of preadipocytes, and if these gels can induce preadipocytes to differentiate into mature adipocytes. The preadipocytes harvested from rat epididymal fat pads were three-dimensionally cultured in 1%, 2% alginate gel and collagen gel for 14 days. The morphology, number, and activity of preadipocytes were examined during the experimental period. The results were as follows; 1. The preadipocytes of monolayer culture were spindle shape with rich cytoplasm. The preadipocytes of collagen gel were multipolar or star-like in shape and there was no oil-red 0 stained cell until 14 days. However, the preadipocytes in alginate gel were round and some of cells transformed into mature fat cells which were stained by oil-red 0 after 14 days. 2. The number of preadipocytes in collagen gel continuously increased for 14 days, and significantly increased compared to that of preadipocytes in monolayer culture after 7 days. However, the number of preadipocytes in alginate gel significantly decreased compared to that of preadipocytes in monolayer culture and collagen gel for 14 days, and there was no difference between 1% and 2% alginate gel groups in the number of preadipocytes. 3. The activity of preadipocytes in collagen gel was decreased until 7 days, but not significantly different after 10 days, when compared with that of preadipocytes in monolayer culture. And the activity of preadipocytes in alginate gel was decreased than that of preadipocytes in monolayer culture until 10 days, was higher than that of preadipocytes in collagen gel until 7 days, but was not significantly different compared with that of preadipocytes in monolayer culture and collagen gel on the 14th day. There was no difference between 1% and 2% alginate gel groups in activity of preadipocytes for 14 days. The results suggest that collagen gel are adequate three-dimensional scaffolds in which the proliferation of preadipocytes can be induced, and that alginate gel can be used as a three-dimensional scaffold that has the ability to induce differentiation of preadipocyte although the proliferation of preadipocytes is inhibited.