The Effect of Fibroblast Growth Factor and Transforming Growth Factor-β on Porcine Chondrocytes and Tissue-Engineered Autologous Elastic Cartilage

Abstract

Elastic cartilage responds mitogenically in vitro to transforming growth factor-beta (TGF-beta) and basic fibroblast growth factor (basic FGF). We studied the effects of these growth factors separately or in a combination on porcine auricular chondrocytes in vitro and on the autologous elastic cartilage produced. Cells were harvested from the elastic auricular cartilage of 16- to 18-kg Yorkshire swine. Viability and quantification of the cells was determined. Cells were plated at equal concentration and studied in vitro in one of four identical media environments except for the growth factors: Group I contained Ham's F-12 with supplements but no growth factors, Group II also contained basic-FGF, Group III also contained TGF-beta, and Group IV also contained a combination of both growth factors. After 3 weeks in vitro, the cells were chemically dissociated with 0.25% trypsin. Cell suspensions composed of 3 x 10(7) cells/cc in 30% Pluronic F-127/Ham's F-12 were injected subcutaneously. Implants were harvested at 6, 8, 10, and 12 weeks of in vivo culture and then were examined with histologic stains. After 3 weeks of in vitro culture the total number of cells was as follows: Group I, 1.8 x 10(8); Group II, 3.5 x 10(8); Group III, 1.3 x 10(8); Group IV, 2.5 x 10(8). After 8 weeks of in vivo autologous implantation, the average weight (g) and volume (cm3) of each group was as follows: Group I, 0.7 g/0.15 cm3; Group II, 1.5 g/0.8 cm3; Group III, 0.6 g/0.1 cm3; Group IV, 1.2 g/0.3 cm3. Histologically, Groups I, II, and IV generated cartilage similar to native elastic cartilage, but Group III specimens demonstrated fibrous tissue ingrowth. Basic FGF produced the most positive enhancement on the quantity and quality of autologous tissue engineered elastic cartilage produced in this porcine model both in vitro and in vivo.

Expansion of the Number of Human Auricular Chondrocytes: Recycling of Culture Media Containing Floating Cells

“…6,7,9 This adjunctive tissue culture technique has the potential to bring us a step closer to generating human cartilage grafts for the reconstruction of external ears.…”

“…6 The application of growth factors has been useful. Basic fibroblast growth factor (bFGF), transforming growth factor b (TGF-b), and insulin-like growth factor I (IGF-I) have demonstrated positive influences on the in vitro cell number and in vivo growth of engineered pediatric human auricular cartilage 8,9 and, fortunately, safety issues regarding hypothetical effects of these growth factors on cell cycle and cellular DNA pattern are reassuring. 10 However, the advantageous use of growth factors still fails to provide adequate speed of cell replication.…”

Tissue engineered cartilage: Utilization of autologous serum and serum-free media for chondrocyte culture

“…Only a limited supply of donor cartilage is available, yet the generation of a large number of new cells in a practical time limit will be required. Various methods have been successfully developed to increase the yield of cultured chondrocytes [6][7][8][9]. These methods utilize the addition of animal serum (FBS: fetal bovine serum) and/or growth factors to the culture media as nutrients.…”

Effect of Local Environment, Fibrin, and Basic Fibroblast Growth Factor Incorporation on a Canine Autologous Model of Bioengineered Cartilage Tissue

“…In addition, it has been reported that the sustained release of b-FGF immobilized to gelatin is consistent with the gelatin degradation rate [Tabata et al, 1999]. Reportedly, b-FGF promotes chondrocyte growth at 10 ng/ml in vitro [Arevalo-Silva et al, 2000, 2001. b-FGF most strongly induced vascularization at 1 mg/ml in vivo [Tabata et al, 1994].…”