Gelatin/chitosan/hyaluronan ternary complex scaffold containing basic fibroblast growth factor for cartilage tissue engineering

Abstract

Gelatin, chitosan and hyaluronan with a weight ratio of 82.6%, 16.5% and 0.1% were chosen as a scaffold material to mimic the composition of natural cartilage matrix for cartilage tissue engineering. Water soluble carbodiimide was added into the biomacromolecule solution with a concentration of 5% to crosslink the complex. Following a freeze-drying procedure, a porous scaffold (control) was then prepared. To enhance chondrogenesis, heparin was covalently immobilized onto the scaffold by carbodiimide chemistry, through which basic fibroblast growth factor (bFGF) was further incorporated by a bioaffinity force. Incubation in phosphate buffered saline (PBS, pH 7.4) at 37 °C caused the weight loss of all kinds of the scaffolds, which could be brought by both the degradation and dissolution of the biomacromolecules. Compared with the control, however, the heparinized scaffold showed stronger ability to resist the weight loss, implying that a higher crosslinking degree was achieved by incorporation of the heparin. Rabbit auricular chondrocytes were seeded onto the ternary complex scaffold containing bFGF to assess cell response. Chondrocytes could adhere and proliferate in all kinds of the scaffold, regardless of the existence of bFGF. No significant difference on glycosaminoglycan (GAG) secretion was recorded between these scaffolds after cultured for 7 and 21 days too, although the absolute value from the Scaffold-heparin-bFGF was somewhat higher. However, chondrocytes seeded in the Scaffold-heparin-bFGF indeed showed significant higher viability than that on the control scaffold. These results reveal that the ternary complex scaffolds, in particular the one containing bFGF, are a potential candidate for cartilage tissue engineering.