In vitro assessment of the biological activity of basic fibroblast growth factor released from various polymers and biomatrices

The kinetics of controlled release of basic fibroblast growth factor (bFGF) from polymers (sutures, polycarbonate, Hydron, and Elvax), biopolymers (alginate), and biomatrices (lens capsules), and conditions for storage of bFGF (temperature, plastic type, heparin) were evaluated in vitro. Tissue culture proliferation bioassays with 3T3 fibroblasts, showed that only lens capsules with bFGF had a sustained release of bFGF for up to three weeks. The other materials released all of the 'bound' bFGF with two hours or produced an inflammatory response in vivo. Therefore, the lens tissue had the most potential for controlled long-term delivery of bFGF in vivo. These studies emphasise the importance of in vitro analysis of release kinetics of growth factors from a range of materials as a basis for potential in vivo applications.