Abbreviations: BSS ophthalmic balanced salt solution; DMEM Dulbecco's Modified Eagle's Medium; EGF epidermal growth factor; FBS fetal bovine serum; FDA fluorescein diacetate; PBS phosphate buffered saline; PCL polycaprolactone; pSi nanostructured porous silicon; SEM scanning electron microscopy; TEM transmission electron microscopy. To investigate loading of large-molecule biologics, murine BALB/c 3T3 cells, responsive to epidermal growth factor, insulin and transferrin, were seeded on composite materials. The cells showed significantly more proliferation at 48 h when seeded on composites loaded with these biologics, than on unloaded composites. No cell proliferation was observed on PCL alone, indicating the biologics had loaded into the pSi microparticles. Drug release, measured by ELISA for insulin, indicated a burst followed by a slower, continuous release over six days. When implanted under the rat conjunctiva, the most promising composite material did not cause significant neovascularization but did elicit a macrophage and mild foreign body