Bioinspired conductive and antibacterial hydrogel bionanocomposite based on tragacanth gum, polyaniline and osteoconductive SiO2 nanoparticles as a scaffold for bone tissue engineering application

Tissue engineering (TE) has developed as an interdisciplinary field to replace, repair, or improving the function of failed or fractured bones. Hydrogels, due to their inherent biological and physicochemical features, have gained attention as scaffolds that support cell adhesion, proliferation, and differentiation. This study aimed to develop a novel hydrogel bionanocomposite for bone TE. Silica nanoparticles (SiO 2 NPs) were synthesized via stober approach, and subsequently, modified with a silane coupling agent. Tragacanth gum/polyaniline (TG/PANI) composite was fabricated through chemical oxidation polymerization method, and then copolymerized with 2-hydroxyethyl methacrylate (HEMA) monomer and methacrylate-modified SiO 2 NPs in the presence of a crosslinker to afford a TG/PANI- cl -PHEMA/SiO 2 hydrogel bionanocomposite. Physicochemical properties, including swelling behavior, degradability, protein adsorption capacity, and in vitro drug release behavior were assessed along with biological tests such as, hemocompatibility, antibacterial activity, cytocompatibility and proliferation of MG-63 osteoblast-like cells via MTT-assay. The resulting scaffold exhibited a well-defined, and porous three dimensional (3D) structure with dispersed spherical SiO 2 NPs. It demonstrated proper swelling ratio (371.5 ± 12.1%) and pH-dependent ciprofloxacin (Cip) release behavior. The developed scaffold showed higher cell viability value (139 ± 3.2%) than control groups (100 ± 3.5%) that confirmed cells proliferation potential of the scaffold at prolonged times. Finally, future studies should explore in vivo performance and long-term functionality of the scaffold.