Ciprofloxacin-loaded chitosan-based nanocomposite hydrogel containing silica nanoparticles as a scaffold for bone tissue engineering application

Considering the nanocomposite structure of natural bone, three-dimensional (3D) nanocomposite hydrogels based on osteoconductive (nano-)materials and polymeric biomaterials are promising scaffolds in bone tissue engineering (TE). Therefore, a novel scaffold composed of chitosan (CS), poly(2-hydroxyethyl methacrylate) (PHEMA), and SiO₂ nanoparticles (NPs) was fabricated for bone TE application. Firstly, SiO₂ NPs were synthesized, and then modified. The modified NPs, CS, and HEMA monomer was copolymerized via free radical polymerization method in the presence of a crosslinker to afford a nanocomposite hydrogel (CS-cl-PHEMA/SiO₂) followed by loading of ciprofloxacin (Cip) as an antibiotic drug. Drug encapsulation efficiency was obtained approximately 20% for the scaffold, and in vitro drug release study revealed that the scaffold had a pH-dependent drug release profile. Applicability of the scaffold in bone TE was examined in terms of numerous physicochemical and biological features. Maximum swelling of scaffold was obtained as 312% after 5 h, and then reached equilibrium. The scaffold exhibited proper in vitro biodegradation, especially in acidic pH. Hemolysis assay revealed that the scaffold was hemocompatible up to 400 µgmL⁻¹ with hemolytic rate of 4.9%. MTT-assay results revealed that the scaffold do not had any toxic effects on the cells and can improve the proliferation of osteoblast cells.