A recombinant human transforming growth factor -β monomer selected from TGF-β1, TGF-β2, and TGF-β3, comprising: (i) a cysteine to serine substitution at an amino acid residue corresponding to residue 77 of SEQ ID NO: 2; (ii) a deletion of the α3 helix corresponding to amino acid residues 52-71 of SEQ ID NO: 2; and (iii) at least one amino acid substitution relative to a wild-type TGF-β monomer that increases net charge of the recombinant TGF-β monomer, wherein (a) for a TGF-β2 monomer, the at least one amino acid substitution is selected from a leucine to arginine substitution at an amino acid residue corresponding to residue 51 and an alanine to lysine substitution at an amino acid residue corresponding to residue 74 of SEQ ID NO: 2; (b) for a TGF-β1 monomer, the at least one amino acid substitution is selected from an isoleucine to arginine substitution at an amino acid residue corresponding to residue 51, an alanine to lysine substitution at an amino acid residue corresponding to residue 74 and an alanine to serine substitution at an amino acid residue corresponding to residue 75 of SEQ ID NO: 1; or (c) for a TGF-β3 monomer, the at least one amino acid substitution is selected from a leucine to glutamate substitution at an amino acid residue corresponding to residue 51, an alanine to glutamate substitution at an amino acid residue corresponding to residue 72 and an alanine to aspartate substitution at an amino acid residue corresponding to residue 74 of SEQ ID NO: 3, wherein wild-type TGF-β1, TGF-β2, and TGF-β3 monomers have the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3, respectively. (i) a cysteine to serine substitution at an amino acid residue corresponding to residue 77 of SEQ ID NO: 2; (ii) a deletion of the α3 helix corresponding to amino acid residues 52-71 of SEQ ID NO: 2; and (iii) at least one amino acid substitution relative to a wild-type TGF-β monomer that increases net charge of the recombinant TGF-β monomer, wherein (a) for a TGF-β2 monomer, the at least one amino acid substitution is selected from a leucine to arginine substitution at an amino acid residue corresponding to residue 51 and an alanine to lysine substitution at an amino acid residue corresponding to residue 74 of SEQ ID NO: 2; (b) for a TGF-β1 monomer, the at least one amino acid substitution is selected from an isoleucine to arginine substitution at an amino acid residue corresponding to residue 51, an alanine to lysine substitution at an amino acid residue corresponding to residue 74 and an alanine to serine substitution at an amino acid residue corresponding to residue 75 of SEQ ID NO: 1; or (c) for a TGF-β3 monomer, the at least one amino acid substitution is selected from a leucine to glutamate substitution at an amino acid residue corresponding to residue 51, an alanine to glutamate substitution at an amino acid residue corresponding to residue 72 and an alanine to aspartate substitution at an amino acid residue corresponding to residue 74 of SEQ ID NO: 3, (a) for a TGF-β2 monomer, the at least one amino acid substitution is selected from a leucine to arginine substitution at an amino acid residue corresponding to residue 51 and an alanine to lysine substitution at an amino acid residue corresponding to residue 74 of SEQ ID NO: 2; (b) for a TGF-β1 monomer, the at least one amino acid substitution is selected from an isoleucine to arginine substitution at an amino acid residue corresponding to residue 51, an alanine to lysine substitution at an amino acid residue corresponding to residue 74 and an alanine to serine substitution at an amino acid residue corresponding to residue 75 of SEQ ID NO: 1; or (c) for a TGF-β3 monomer, the at least one amino acid substitution is selected from a leucine to glutamate substitution at an amino acid residue corresponding to residue 51, an alanine to glutamate substitution at an amino acid residue corresponding to residue 72 and an alanine to aspartate substitution at an amino acid residue corresponding to residue 74 of SEQ ID NO: 3,