Redefining 3D cell culture: Human methacryloyl platelet lysates hydrogels for reliable, consistent, and ethical applications

The transition to human-derived biomaterials is critical for advancing ethical and clinically relevant three-dimensional (3D) cell culture systems. In this study, we evaluate the performance of human methacryloyl platelet lysates (hPLMA), a xeno-free, human-derived hydrogel, benchmarking it against Matrigel, the gold standard in the field, and a widely used but animal-derived matrix with an unethical tumor origin. Human adipose-derived stem cells (hASCs) were encapsulated in both materials and cultured for 14 days. Both materials support high viability and proliferation for 7 days. However, hPLMA promotes consistent cell growth and intricate networks, while Matrigel induces rapid spreading, leading to massive cell clusters and ultimately the degradation of the hydrogel after 7 days. Although macrophage culture in both materials show low cytokine levels, the transcriptomic profile of hASCs in Matrigel reveal a constant high expression of immune-related genes, especially after 5 days. In contrast, hASCs in hPLMA have lower expression of immune response genes and higher expression of genes associated with cell migration, adhesion, and matrix organization, showing hPLMA's ability to mimic the natural cell environment. These results position hPLMA as a robust, xeno-free platform not only for 3D cell culture applications such as drug screening, organ-on-chip and tissue models, but also as a promising candidate for therapeutic applications, including tissue engineering and regenerative medicine. Ultimately, its human origin enhances physiological relevance while minimizing immune activation, supporting its translation towards clinical use.