The methods and compositions described herein address the need in the art by providing peptides and polypeptides comprising a growth factor binding domain. In some embodiments, the peptides have an amino acid sequence that is at least 80% identical to one of SEQ ID NOS:1-7, 13-15, 49-50, or 66-70, or a fragment thereof; wherein the peptide is less than 300 amino acids in length.