Fish collagen derived bioink for extrusion 3D printing

Three-dimensional (3D) bio-printing has revolutionized the creation of functional tissues and organ substitutes, surpassing conventional 3D scaffold fabrication1. This method uses computer-aided design to layer living and non-living materials precisely, making it ideal for tissue engineering, regenerative medicine, pharmacokinetics, and biological research2. Bioinks, essential for 3D bio-printing, embed cells within scaffolds and must protect them during printing while supporting their growth and differentiation3. Hydrogels, particularly natural polymers like collagen, gelatin, alginate, hyaluronic acid, chitosan, dextran, and fibrin, are commonly used for their biocompatibility and ability to support cell proliferation4. Collagen, the most abundant extracellular matrix protein, is crucial for tissue integrity and cell function5. Type-I collagen derived from land animals is the most commonly used but several drawbacks limited its use6. Fish collagen offers a safer alternative, mitigating concerns related to prion transmission, religious restrictions, and allergies associated with mammalian collagen sources7. However, its rapid degradation and poor mechanical strength are limitations to overcome. In this study, a fish collagen bioink developed by Typeone Biomaterials S.r.l. according to a proprietary process has been studied for evaluating its printability by extrusion for the development of micropatterned 3D scaffolds. In order to improve the bioink mechanical strength and stability during time, the UV crosslinking of the bioink has been investigated and optimised in terms of time and UV intensity. The thermal stability, rheological and viscoelastic properties and morphology of simple 3D printed constructs have been studied and correlated with printability properties. Finally, several scaffolds have been 3D printed and UV cross-linked.