Embedded Bioprinting of Tissue-like Structures Using κ-Carrageenan Sub-Microgel Medium

3D bioprinting in a microgel-based suspension bath has provided a versatile platform for fabricating complex 3D structures using soft hydrogels, but it is still limited by the low print resolution and accuracy, hindering the practical applications of the printed products in tissue engineering. The present microgel baths often exhibit large sizes and poor dispersions, resulting in a big diameter and irregular morphology of the printed filaments. Therefore, it poses a significant challenge in preparing a microgel bath with a small particle size and uniform morphology.

This protocol offers the fabrication of a homogenous and biocompatible cationic cross-linked kappa-carrageenan sub-microgel bath for high-fidelity bioprinting through an easy-to-operate mechanical grinding strategy. Since kappa-carrageenan sub-microgels exhibit a uniform methodology with a small particle size of 565 nanometer, and a low germ state of 0.35%enabling precise tissue and organ construction with remarkable fidelity and high resolution. Begin by adding 1.75 grams of kappa-carrageenan powder to 500 milliliters of PBS in a 1000 milliliter glass bottle.