Elastomeric polypentapeptides cross-linked into matrixes and fibers.
Microbially prepared polypentapeptides were cross-linked by two chemical methods. In one chemical approach, (GVGIP)(260) where G = glycine, V = valine, I = isoleucine, and P = proline with no functional groups in its side chains, was cross-linked using dicumyl peroxide, and reaction conditions were systematically examined. Successful cross-linking was obtained even under severe conditions for proteins, i.e., 3 h at 120 degrees C, without having significant side reactions. In the second chemical approach, two separate polymers, (GVGVP GVGVP GXGVP GVGVP GVGVP GVGVP)(n) where X is either E (the carboxylic acid containing glutamic acid residue) or K (the lysine residue with an epsilon-amino function), were mixed and cross-linked using a carbodiimde reagent. The reaction temperature was found to affect the equilibrium swelling behavior of the resulting cross-linked hydrogels. In hydrogels cross-linked at a temperature above their hydrophobic folding and assembling transition temperature, 3D continuous filamentous microstructures were observed. Chemically cross-linked hydrogel fibers were also prepared and their anisotropy in swelling was confirmed. Uniaxial tensile moduli and equilibrium weight swelling ratios of the chemically cross-linked samples were compared to those of (GVGVP)(251) and (GVGIP)(260), gamma-irradiation cross-linked at different Mrad doses.
Lee
J
J
Chemical Engineering and Materials Science, The University of Minnesota, Minneapolis, Minnesota 55455, USA. jong@cems.umn.edu
Macosko
C W
CW
Urry
D W
DW
D000595:Amino Acid Sequence; D016880:Anisotropy; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D020724:Elastomers / Q000737:chemistry*; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013718:Tensile Strength; D013816:Thermodynamics
D001672:Biocompatible Materials; D020724:Elastomers; D020100:Hydrogels; D010455:Peptides