Bioactive and Antibacterial Gallic Acid Incorporated 3D-Printed Hydroxyapatite/Gelatin/Carboxymethyl Cellulose...

This study reports the development of 3D-printed gallic acid (GA) incorporated nano-hydroxyapatite /carboxymethyl cellulose/gelatin (GA/HAp/CMC/GEL) scaffolds for bone tissue engineering with combined bioactive and antibacterial functionality. Rheological studies indicated shear thinning behavior of all the hydrogels. After 3D printing, the samples were cross-linked by 100 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride. The scaffolds exhibited a well-defined, interconnected pore architecture. Mechanical testing revealed that GA increased ultimate compressive strength and ductility. All scaffolds showed apatite-forming ability in simulated body fluid, with cauliflower-like mineral layers. X-ray diffraction analysis indicated that HaP peaks sharpness was consistent for all scaffolds. Although MC3T3-E1 pre-osteoblasts cultured on GA-containing scaffolds exhibited significantly increased metabolic activity, Alizarin red staining due to MC3T3-E1 pre-osteoblast mineralization was reduced after incorporation of GA, which requires further investigation. 0.20% GA scaffold achieved up to 62.0% and 78.1% reduction in Escherichia coli and Staphylococcus aureus viability, respectively. Overall, GA-loaded HAp/CMC/GEL scaffolds combine bioactivity, cytocompatibility, tunable mechanics, and concentration-dependent antibacterial activity, indicating their promise as multifunctional candidates for bone tissue engineering.