Abstract
Photoinduced network formation is an attractive strategy for designing water-insoluble gelatin fibres as medical device building blocks and for enabling late-stage property customisation. However, mechanically competent, long-lasting filaments are still hard to realise with current photoactive, e.g. methacrylated, gelatin systems due to inherent spinning instability and restricted coagulation capability. To explore this challenge, we present a multiscale approach combining the synthesis of 4-vinylbenzyl chloride (4VBC)-functionalised gelatin (Gel-4VBC) with a voltage-free spinning and UV-curing process so that biopolymer networks in the form of either individual fibres or nonwovens could be successfully manufactured. In comparison with state-of-the-art methacrylated gelatin, the mechanical properties of UV-cured Gel-4VBC fibres were readily modulated by adjustment of coagulation conditions, so that an ultimate tensile strength and strain at break of 25 ± 4–74 ± 3 MPa and 1.7 ± 0.3–8.6 ± 0.5% were measured, respectively. The sequential functionalisation/spinning route proved to be highly scalable, so that one-step spun-laid formation of fibroblast-friendly nonwoven fabrics was successfully demonstrated with wet-spun Gel-4VBC fibres. The presented approach could be exploited to generate a library of gelatin building blocks tuneable from the molecular to the macroscopic level to deliver computer-controlled extrusion of fibres and nonwovens according to defined clinical applications.
Highlights
As derived from the partial denaturation of collagen, gelatin has significant potential as a building block for economically attractive manufacture of medical devices, due to its biocompatibility, wide availability and low cost
Sample nomenclature for the wet-spun and UV-cured fibre samples is as follows: ‘4-vinylbenzyl chloride (4VBC)-polyethylene glycol (PEG)’ indicates fibres whereby 4VBCfunctionalised gelatin was dissolved in 17.4 mM acetic acid (15 wt % gelatin) and wet-spun into 0.1 M PBS supplemented with 20% w/v PEG. ‘4VBC-NaCl’ indicates fibres prepared by dissolving 4VBC-functionalised gelatin (15 wt%) in 17.4 mM acetic acid followed by wet spinning into an aqueous solution containing 20% w/v NaCl
‘methacrylic anhydride (MA)-EtOH’ identifies fibres prepared with 30 wt% solution of MA-functionalised gelatin in acetic acid and wet-spun into ethanol at - 20% (w/v) NaCl (20 °C); ‘Native-PEG’ is the fibre control made of 15 wt% native gelatin in 17.4 mmol acetic acid and wet-spun into PEG-supplemented PBS bath; ‘Native-NaCl’ is the fibre control prepared by wet spinning the native gelatin solution into the aqueous solution containing 20% w/v NaCl
Summary
As derived from the partial denaturation of collagen, gelatin has significant potential as a building block for economically attractive manufacture of medical devices, due to its biocompatibility, wide availability and low cost. Once grafted onto the amino acid residues of the polypeptide, covalently coupled photoactive moieties can induce the formation of covalent crosslinks when exposed to a photoinitiator and a specific wavelength of light This photoinduced network formation approach enables in situ crosslinking to occur at a much faster rate than typical chemical crosslinking reactions [19, 34,35,36], combined with cellular tolerability. To mediate fibre-forming capability and minimise toxicity issues, wet spinning of collagenbased polypeptides into polyethylene glycol (PEG)supplemented aqueous solutions has been shown to enhance the thermal and mechanical properties of the fibres as well as cell infiltration and tissue in growth [40,41,42]. These absorbance values were used in conjunction with Eq 1 and 2 to determine the molar content of remaining lysines (per gram of gelatin) and the degree of gelatin functionalisation, respectively: ÀÁ
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
