Photomediated Solid-State Cross-Linking of an Elastin−Mimetic Recombinant Protein Polymer

Abstract

Solid-state cross-linking of elastin-mimetic fibers was investigated. Through available lysine residues, an elastin-mimetic protein polymer, poly((Val-Pro-Gly-Val-Gly)4(Val-Pro-Gly-Lys-Gly))39, was modified to incorporate an acrylate moiety. The degree of acrylate functionalization could be varied by changing the reactant ratio of anhydride to elastin. Acrylate modified elastomeric (AME) proteins were associated with lower inverse transition temperatures than the unmodified recombinant protein. The inverse transition temperature in turn dictated the temperature for fiber formation. Fibers and fabric samples of AME were prepared by electrospinning at appropriate temperatures and cross-linked by visiblelight-mediated photoirradiation. Fibers in the diameter range of 300 nm-1.5 µm were produced. Fabrics were found to have an average pore size of 78 µm. The occurrence of cross-linking was confirmed by 13 C solid-state NMR with a commensurate increase in modulus.

Elastin as a biomaterial for tissue engineering

“…The coacervation temperature of this peptide is about 75°C. When functionalising this sequence with methacrylate to facilitate site-specifi c solid-state photo-crosslinking, the coacervation temperature was reduced (up to 50°C), but no appreciable effect on fi bre morphology was observed [168]. Lee et al constructed (Gly-Val-Gly-Val-Pro) n where the bold Val residue was replaced with either Glu or Lys per 6 pentapeptides.…”

Peptide-based biopolymers in biomedicine and biotechnology

“…Also, because ELPs can be designed at the molecular level and genetically synthesized, unique properties can be introduced by incorporating other biologically active peptide sequences. Examples can be found of ELP hydrogels that are formed by irradiation [246][247][248], photoinitiation [249], amine-reactive chemical crosslinking [37,68,[250][251][252][253][254][255][256][257][258][259][260], and enzymatic crosslinking by tissue transglutaminase [261]. The hydrogels have been successfully used for cartilage and intervertebral disc tissue repair, small-diameter vascular grafts, urinary bladders, stem cell matrices, neural guides, stem cell sheets, and post-surgical wound treatment [250][251][252][253][254][255][256][262][263][264].…”

Single step fabrication of antimicrobial fibre mats from a bioengineered protein-based polymer

“…In addition, the extensive crosslinking within the VPGXG may preclude its proper folding leading to a loss of properties. Other fibre stabilization procedures involve blending the ELR with other polymers such as polycaprolactone [15] and methacrylate [16]. Nevertheless, these approaches may exert a negative impact in the bioactivity and mechanical properties of the ELR fibres.…”