Mechanical, Thermal, and Rheological Properties of Fish-Porcine Gelatin Microparticle composites

Driven by the increasing demand for the bio-fabrication of complex hydrogels using 3D extrusion and embedded printing, this research focuses on creating hydrogels with tunable mechanical, swelling, and thermal characteristics suitable for tissue engineering applications. This study presents an approach to engineering composite hydrogels by incorporating pre-crosslinked porcine gelatin microparticles into a methacrylated fish gelatin matrix at varying ratios. Methacrylation of both gelatin types was confirmed using NMR, while Mastersizer analysis provided detailed microparticle size and distribution data, ensuring precise control over the hydrogel structure. SEM imaging revealed the pore architecture essential for tissue integration, while further characterization explored the hydrogels’ swelling behavior, mechanical properties, and thermal stability via mass swelling ratios, compression testing, TGA, DTG, and DSC analysis. Remarkably, these composite hydrogel formulations displayed significantly improved shear-thinning behavior, a key property for extrusion-based 3D printing, along with rapid and effective photo-crosslinking under UV light (365 and 405 nm), ensuring compatibility with digital light processing (DLP) printing. Moreover, microparticle inclusion offers an innovative potential for these hydrogels to function as support baths in embedded printing applications, further expanding their utility. These findings demonstrate that the developed composite hydrogels have the potential to meet fabrication requirements while offering a level of tunability and functionality that single-component hydrogels cannot achieve. This advancement underscores the potential of these materials as a foundational platform in tissue engineering, opening new avenues for creating complex, biocompatible structures with customizable properties.