# UV-Crosslinking Effects on the Physicochemical and Rheological Properties of Fish Collagen Ink for 3D Bioprinting

## TL;DR

This paper explores using UV-crosslinked fish collagen as a safer bioink for 3D bioprinting, improving its stability and suitability for tissue engineering.

## Contribution

The study introduces UV-crosslinked fish collagen as a novel, sustainable bioink with enhanced structural properties for 3D bioprinting.

## Key findings

- UV crosslinking significantly improved the structural integrity and stability of printed fish collagen scaffolds.
- UV treatment enhanced thermal behavior, degradation resistance, and surface roughness of the bioink.

## Abstract

Three-dimensional bioprinting revolutionized tissue and organ replacement by enabling the precise deposition of living cells and biomaterials, making it ideal for biomedical applications. Natural polymers are commonly used as bioink for their biocompatibility and bioactivity. Among them, type I collagen, the most abundant protein of extracellular matrix, is commonly used as bioink. However, mammalian-derived collagens raise concerns related to zoonotic disease transmission, religious restrictions, and immunogenicity. Fish-derived collagen represents a safer and more sustainable alternative, although its rapid degradation and limited mechanical properties remain significant challenges. In this study, the printability of a novel fish collagen ink was assessed for micropatterned scaffolding by extrusion. In order to overcome material-related challenges, the effect of UV-induced crosslinking was investigated. Morphological, rheological, and physicochemical characterizations—including thermal behavior, degradation resistance, exposed chemical groups, and roughness—were performed before and after UV treatment. Results demonstrated that UV crosslinking significantly improved the structural integrity and stability of the printed scaffolds. These findings support the potential of UV-crosslinked fish collagen as biomaterial ink for regenerative medicine and tissue engineering applications.