Compositions comprising human brain natriuretic peptide (BNP) fragments

A composition comprising:

• at least two human brain natriuretic peptide (BNP) fragments, wherein each of the human BNP fragments of said composition is cross-linked to at least one of the other human BNP fragments of said composition, wherein said composition comprises a first human BNP fragment and a second human BNP fragment, and wherein the first human BNP fragment has an amino acid sequence consisting of amino acid residues selected from the group consisting of residues 1-13, 1-17, 3-13 and 3-17 of human BNP, and the second human BNP fragment has an amino acid sequence consisting of residues 18-30 or 18-32 of human BNP.