Bioinspired mineralized cryogel scaffolds with sequential methacrylated gelatin cross-linking and hyaluronic acid...

Owing to their highly porous architecture, cryogels have emerged as promising scaffolds for biomedical applications, particularly in the field of bone tissue engineering. However, their inherent mechanical fragility and biological inertness significantly constrain their broader applications. In this study, we developed a mineralized, dual-crosslinked cryogel based on ultra-high molecular weight polyethylene (UHMWPE) through sequential surface modifications strategy. This approach involved: (i) grafting of polydopamine (PDA) to introduce reactive groups; (ii) photocrosslinking of methacrylated gelatin (GelMA); (iii) conjugation of hyaluronic acid (HA); and (iv) deposition of a hydroxyapatite (HAp) layer via incubation in simulated body fluid (SBF). Collectively, these modifications substantially enhanced both the mechanical robustness and bioactivity of the cryogel. The engineered cryogels exhibited a 34.8-fold increase in compressive modulus (reaching 4.5 MPa) compared to the unmodified controls, along with markedly reduced water contact angles, demonstrating significantly improved mechanical strength and surface hydrophilicity. In vitro assessments further confirmed enhanced cellular responses, including promoted adhesion, migration, and osteogenic differentiation of rabbit bone marrow mesenchymal stem cells (rBMSCs) without exogenous inductive factors. This multi-scale modification approach presents an innovative paradigm for the design of high-performance scaffolds for bone tissue engineering.