Methods and Technical Issues for Optimizing the Production of Hydrogels Containing Decellularized Wharton's Jelly

Bioinspired scaffolds, designed to mimic natural tissue and provide biological cues for tissue regeneration, are becoming increasingly important in the field of tissue engineering. We previously developed hydrogel scaffolds based on alginate and decellularized Wharton's jelly (DWJ) from an umbilical cord. These scaffolds have proven to be highly effective in promoting the recovery of the lost discogenic phenotype in degenerated intervertebral disc (IVD) cells obtained from patients undergoing discectomy. This prompted us to refine the various steps of the protocol to optimize the development of stable DWJ-based scaffolds with anatomically shaped geometries such as millimeter-scale cylinders (millicylinders) suitable for use in articular cartilage tissue engineering. Particular attention was paid to the handling of the materials used, the reproducibility of data, and the adaptability of the developed system to different experimental needs/conditions, including the transmission of mechanical stimuli and the evaluation of the reactivity of the combined cells. Here, we report the characterization of both the physicochemical properties of the hydrogel produced and its specific biological effects by using IVD cells and macrophages as experimental models. The detailed description of the various steps provides a protocol that aims to facilitate the development of DWJ-based hydrogels that may provide new strategies for addressing joint degeneration.