Effect of collagen hydrolysate on chondrocyte-seeded agarose constructs

The mechanical properties of engineered cartilage are strongly dependent on collagen content, but the collagen to glycosaminoglycan ratio in engineered cartilage is often much lower than that of the native tissue. Therefore culture medium supplements which increase collagen production by chondrocytes are of interest. It had previously been reported that collagen hydrolysate stimulated type II collagen biosynthesis in short-term, high density monolayer chondrocyte cultures. It was hypothesized that collagen hydrolysate added to the culture medium of three dimensional chondrocyte-agarose constructs would enhance their mechanical properties. Porcine articular chondrocytes were embedded in 2% agarose and cultured for up to 6 weeks with and without 1 mg/ml collagen hydrolysate. The instantaneous compressive modulus and equilibrium compressive modulus were significantly lower in the collagen hydrolysate-treated constructs, consistent with the finding of lower collagen and GAG content. Contrary to our hypothesis, our results indicate that 1 mg/ml collagen hydrolysate may actually inhibit macromolecule biosynthesis and be detrimental to the mechanical properties of long term chondrocyte-agarose constructs.