A composition including a peptide sequence of the formula βX1-X2, the peptide sequence corresponding to an amino acid sequence of a fibrin beta chain fragment of a Bbeta chain of fibrinogen, wherein X1 represents an N-terminal end of the peptide sequence, and X2 represents a C-terminal end of the peptide sequence, wherein the peptide sequence includes additional amino acids between X1 and X2, wherein the peptide sequence may contain a non-naturally occurring amino acid residue, wherein the peptide sequence is other than a wild-type β15-42 monomer sequence per se, and wherein the peptide sequence is other than (β15-66)2 dimer having two chains with each chain limited to wild type amino acids β15-65 and each chain further including a non-naturally occurring Gly at position 66 of each chain. Methods for treatment and pharmaceutical combinations may include a polypeptide agent such as Thymosin beta 4. In such methods and combinations, a dimer of the peptide sequence may include amino acids 15-66 of the fibrin beta chain.