Development of Adaptable 3D-Bioprinted Scaffold for Tissue Regeneration

Abstract

3D printing is an additive manufacturing technique that can transform 3D virtual models into physical objects by layer-by-layer deposition of materials that can undergo rapid liquid-to-solid transformation after dispensing. Hydrogels are one of the most interesting and challenging classes of material systems that can be employed as inks, and hydrogel-based 3D printing has been exploited in tissue engineering and regenerative medicine. Here, hydrogel bio-inks using k-Carrageenan (kC) and poly(vinyl alcohol) (PVA) have been formulated with the objective of tuning the printability properties of bio-ink. The kC allows the systems to undergo rapid sol-to-gel transitions upon cooling from 60 °C and above to body temperature, while the need to introduce PVA is related to optimizing the viscosity of the ink solution to enable 3D printing with a continuous filament and to introduce interconnected porosity in the scaffold. ?-radiation-induced chemical modification of kC polymer powder is successfully used here as a mean to induce noticeable modifications in the polymer molecular weight distribution and polymer structure and to optimize the printing properties of bio-ink formulations. The study aims to develop hydrogel formulations with viscoelastic properties and sol-gel transitions suitable for use as bioinks for 3D printing scaffolds with adipose stem cell spheroids for cartilage or bone tissue reconstruction.