Biofunctional nanofibrous substrate comprising immobilized antibodies and selective binding of autologous growth factors

Abstract

The immobilization of biomolecules at the surface of different biomedical devices has attracted enormous interest in order to enhance their biological functionality at the cellular level. This work aims to develop a biofunctional polymeric substrate capable of selectively binding growth factors (GFs) of interest from a pool of proteins present in a biological fluid: platelet lysate (PL). To achieve this goal, the surface of electrospun PCL nanofibers needs to be activated and functionalized to be able to insert chemical groups for the immobilization of antibodies. After determining the maximum immobilization capacity of each antibody, TGF-β1 (12 μg mL(-1)), bFGF (8 μg mL(-1)), and VEGF (4 μg mL(-1)), the next step was to confirm their bioavailability using recombinant proteins. The binding efficiency of PL-derived GFs was of 84-87% for TGF-β1, 55-64% for bFGF, and 50-59% for VEGF. Cellular assays confirmed the biological activity of the bound VEGF (both recombinant and PL-derived). Multiple antibodies (i.e., bFGF and VEGF) were also immobilized over the same structure in a mixed or side-by-side fashion. Using both autologous biological fluids and cells, it is possible to use this platform to implement very effective and personalized therapies that can be tailored to specific medical conditions.