Methacrylated-κ-carrageenan/hydroxyapatite composite bioinks for extrusion-based bioprinting: Physicochemical, rheological, mechanical, and in vitro biological investigations

Abstract

Composite hydrogels are of interest in modulating the rheological properties of bioinks for extrusion-based 3D-bioprinting. In this study, new composite bioinks composed of different levels of methacrylated κ-carrageenan (κ-Car-L-MA, κ-Car-M-MA, and κ-Car-H-MA) and hydroxyapatite (HAp) were prepared and evaluated for extrusion-based 3D-bioprinting applications, focusing on printability, mechanical and physicochemical properties. The methacrylation degree and incorporation of HAp were found to significantly affect the printing performance of bioinks. Semi-quantitative printability assessment revealed that κ-Car-M-MA and κ-Car-M-MA-HAp bioinks exhibited optimal printability. The mechanical behavior of the bioinks appeared to depend on the methacrylation degree, which affects compressive modulus and toughness. Bioprinting studies were conducted to create a bilayer model using human adipose-derived stem cells and an almost two-fold increase in cell viability in the printed constructs was observed on the seventh day of culture. The findings suggest that the developed bioink composition demonstrates significant potential for 3D-bioprinting-based biomedical applications.