• A ready-to-use sodium alginate@paper material was successfully prepared via freeze-drying with polyethylene glycol-diamine as a crosslinker, eliminating the need for hydrogel preparation before use.
• The ready-to-use material exhibited no cytotoxicity and supported uniform adhesion and interaction of HEK 293 cells, comparable to freshly prepared material.
• The material maintained its structural integrity, porosity, and cytocompatibility after storage for up to 120 days at room temperature, demonstrating excellent stability.
• This ready-to-use material offers a convenient and stable platform for three-dimensional cell culture, potentially advancing CiGiP technology.