From waste to value

: fish bone derived collagen to prepared 3D cell models

Abstract

Three-dimensional (3D) cell culture systems have been developed as superior models to two-dimensional (2D) cell cultures. The use of 3D systems has been shown to improve cellular morphology, proliferation and signalling, replicating the extracellular matrix (ECM) in a more accurate manner. Hydrogels are particularly well-suited to these three-dimensional systems. Agarose, a biocompatible polysaccharide, provides structural support, while collagen enhances bioactivity and cell adhesion. Agarose-collagen hydrogels thus represent an optimal matrix for three-dimensional cell culture applications, combining the mechanical integrity of agarose with the biofunctionality of collagen. Considering the increasing focus on sustainability, fish bone-derived collagen represents a promising alternative to common type I collagen. This approach aligns with the principles of a circular economy, whereby waste from fish processing is transformed into valuable biomaterials. The present study evaluates collagen extracted from fish bones through three methods: a shorter extraction at a higher temperature, yielding smaller peptides, with some bones pre-treated with ultrasound (US) and others without (NUS); and a longer extraction at a lower temperature (4ºC) to better preserve the collagen structure. The biocompatibility, stability, mechanical properties and potential for spheroid growth from human osteosarcoma cell lines of hydrogels containing collagen extracts at concentrations of 0.02% and 0.04% were evaluated. The 4°C method preserved collagen’s native structure best, resulting in hydrogels with greater stability and cell viability. Conversely, US extraction yielded higher collagen amounts but produced fragmented peptides that led to rapid collagen release and limited spheroid support. NUS extraction offered a middle ground, achieving a balance between stability and bioactivity. Additionally, higher collagen concentrations (0.04%) increased the stability and mechanical resilience without enhancing cellular growth, while lower concentrations (0.02%) supported spheroid culture effectively. This study highlights fish bone collagen as a sustainable material for 3D cell culture and the valorisation of fish waste in tissue engineering.

Date of Award	29 Jan 2025
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Clara Piccirillo (Supervisor) & Alessandra Quarta (Co-Supervisor)