Analytical approaches to uptake and release of hydrogel-associated FGF-2.

Strategies to control the delivery of growth factors are critically important in the design of advanced biomaterials. In this study we investigated the binding and release of fibroblast growth factor 2 (FGF-2) to/from a biohybrid hydrogel matrix by four independent analytical methods: radioisotope and fluorescence labeling, amino acid analysis and Enzyme-Linked Immunosorbent Assays (ELISA). The compared analyses provided qualitatively similar uptake characteristics while the results of the FGF-2 quantification strongly depended on the particular experimental conditions. The release kinetics of FGF-2 from the gels could be monitored sensitively by (125)I labeling and by ELISA-techniques. The latter method was concluded to be advantageous since it permits the application of unmodified ("native") growth factors.