Development and characterization of antibacterial 3D porous hydroxyapatite-gelatin-PVA scaffolds containing zinc oxide nanoparticles

Abstract

There is still a need to develop hydroxyapatite (HAp)/gelatin-based porous scaffolds to provide a hybrid system with structural and biochemical properties equivalent to those of bone. Here, we fabricated and characterized 3D hybrid scaffolds composed of HAp nanoparticles synthesized in situ in gelatin and PVA solutions and loaded with combustionally synthesized (10 wt%) zinc oxide nanoparticles (ZnO NPs) to ensure their homogeneous embedding in the polymer matrices. The phase analysis, composition, morphological and microstructural properties of ZnO NPs and freeze-dried hybrid scaffolds were studied. The compressive strength, porosity, swelling capacity, degradation rate, and antibacterial activity of the hybrid scaffolds were measured. The fabricated 3D scaffolds showed high porosity of up to 78 % with a pore size of about 50–300 μm, good mechanical strength in the range of about 55 kPa, high swelling capacity of up to 505 %, and long-term degradation rate of about 22–25 % for up to 35 days. ZnO NPs have a pure phase and a quasi-spherical shape with a size of about 78 ± 25 nm structure and there are no significant differences between the physicochemical properties of ZnO-free scaffolds and ZnO-loaded scaffolds. Incorporation of ZnO NPs into the scaffolds enhanced their antibacterial response against pathogenic Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). This work provides advanced 3D porous hybrid bone scaffolds with favorable mechanical performance and antibacterial activity for bone repair and regeneration.