title: Expanding functionality of recombinant human collagen through engineered non-native cysteines.
abstract: Collagen is the most abundant protein in extracellular matrices and is commonly used as a tissue engineering scaffold. However, collagen and other biopolymers from native sources can exhibit limitations when tuning mechanical and biological properties. Cysteines do not naturally occur within the triple-helical region of any native collagen. We utilized a novel modular synthesis strategy to fabricate variants of recombinant human collagen that contained 2, 4, or 8 non-native cysteines at precisely defined locations within each biopolymer. This bottom-up approach introduced capabilities using sulfhydryl chemistry to form hydrogels and immobilize bioactive factors. Collagen variants retained their triple-helical structure and supported cellular adhesion. Hydrogels were characterized using rheology, and the storage moduli were comparable to fibrillar collagen gels at similar concentrations. Furthermore, the introduced cysteines functioned as anchoring sites, with TGF-β1-conjugated collagens promoting myofibroblast differentiation. This approach demonstrates the feasibility to produce custom-designed collagens with chemical functionality not available from native sources.
authors.affiliation: Department of Biomedical Engineering and ‡Department of Chemical Engineering and Materials Science, University of California , Irvine, California 92697, United States.
authors.forename: Richard
authors.initials: R
authors.lastname: Que
authors.forename: Ali
authors.initials: A
authors.lastname: Mohraz
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Da Silva
authors.forename: Szu-Wen
authors.initials: SW
authors.lastname: Wang
mesh_terms: D002448:Cell Adhesion / Q000502:physiology; D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D024022:Fibrillar Collagens / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry* / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D024022:Fibrillar Collagens; D020100:Hydrogels; D011994:Recombinant Proteins; D053773:Transforming Growth Factor beta1; D003545:Cysteine