Polydopamine-coated regenerated cellulose-bioceramic composite scaffolds for enhanced bone tissue engineering

Bone tissue engineering seeks innovative solutions to address the limitations of traditional bone grafts, such as donor site morbidity and limited availability. In this study, we developed composite scaffolds using regenerated cellulose blended with hydroxyapatite/cellulose nanocrystals (HC), synthesized via an in-situ regeneration process. To enhance cellular attachment and integration, the scaffolds were coated with polydopamine (PDA), a bio-inspired polymer known for its adhesive properties and ability to promote cell adhesion. Physical and mechanical characterization revealed that the scaffolds exhibited excellent porosity (>91 %), a critical feature for facilitating nutrient diffusion and tissue ingrowth. Energy dispersive spectroscopy (EDS) confirmed the presence of hydroxyapatite with a Ca/P ratio of 1.67, closely matching the stoichiometric composition of natural bone. Mechanical testing demonstrated that increasing HC content improved the compressive modulus, reaching 0.82 MPa in scaffolds containing 10 % HC (SHC10). Importantly, the scaffolds showed no cytotoxicity toward osteoblast cells (BMT001), exhibiting robust viability and biocompatibility. These findings suggest that PDA-coated regenerated cellulose-bioceramic scaffolds represent a promising alternative for bone tissue engineering applications, offering both structural integrity and biological functionality. Future work will explore their performance in preclinical models to validate their translational potential.