The present invention is directed to tissue-engineering scaffolds containing both a microporous scaffold made from a biocompatible material suitable for use in tissue-engineering scaffolds and a nanofibrous, nanoporous hydrogel formed from a self-assembling peptide, where at least a portion of the hydrogel is disposed within the pores of the microporous scaffold, thus providing tissue-engineering scaffolds having average pore diameters in the nanometer range and that provide both mechanical properties suitable for implantation into a body of a mammal and excellent tissue response once implanted in the body.