The invention provides fibrin-based, biocompatible materials useful in promoting cell growth, wound healing, and tissue regeneration. These materials are provided as part of several cell and tissue scaffolding structures that provide particular application for use in wound-healing and tissue regenerating. Methods for preparing these compositions and using them are also disclosed as part of the invention. A variety of peptides may be used in conjunction with the practice of the invention, in particular, the peptide IKVAV, and variants thereof. Generally, the compositions may be described as comprising a protein network (e.g., fibrin) and a peptide having an amino acid sequence that comprises a transglutaminase substrate domain (e.g., a factor XIIIa substrate domain) and a bioactive factor (e.g., a peptide or protein, such as a polypeptide growth factor), the peptide being covalently bound to the protein network. Other applications of the technology include their use on implantable devices (e.g., vascular graphs), tissue and cell scaffolding. Other applications include use in surgical adhesive or sealant, as well as in peripheral nerve regeneration and angiogenesis.