Biomimetic wet-stable fibres via wet spinning and diacid-based crosslinking of collagen triple helices

TL;DR

This study develops wet-stable collagen fibres via wet spinning and diacid crosslinking, retaining triple helix structure and enhancing mechanical properties, suitable for bone regeneration applications.

Contribution

It introduces a novel diacid-based crosslinking method that preserves collagen triple helices and improves fibre stability and strength for biomedical use.

Findings

Nearly complete triple helix retention in wet fibres

Fibre stability maintained after 1-week PBS incubation

Enhanced tensile properties with diacid crosslinking

Abstract

One of the limitations of electrospun collagen as bone-like fibrous structure is the potential collagen triple helix denaturation in the fibre state and the corresponding inadequate wet stability even after crosslinking. Here, we have demonstrated the feasibility of accomplishing wet-stable fibres by wet spinning and diacid-based crosslinking of collagen triple helices, whereby fibre ability to act as bone-mimicking mineralisation system has also been explored. Circular dichroism (CD) demonstrated nearly complete triple helix retention in resulting wet-spun fibres, and the corresponding chemically crosslinked fibres successfully preserved their fibrous morphology following 1-week incubation in phosphate buffer solution (PBS). The presented novel diacid-based crosslinking route imparted superior tensile modulus and strength to the resulting fibres indicating that covalent functionalization of distant collagen molecules is unlikely to be accomplished by current state-of-the-art carbodiimide-based crosslinking. To mimic the constituents of natural bone extra cellular matrix (ECM), the crosslinked fibres were coated with carbonated hydroxyapatite (CHA) through biomimetic precipitation, resulting in an attractive biomaterial for guided bone regeneration (GBR), e.g. in bony defects of the maxillofacial region.