3D-Printed Alginate Dialdehyde (ADA)–Gelatin (GEL) Hydrogels with Gallic Acid (GA) for Enhanced Multifunctional Properties

This study investigates the incorporation of gallic acid (GA) into alginate dialdehyde–gelatin (ADA–GEL) at GA concentrations (0.125%, 0.25%, and 0.5%). Spectroscopic analyses confirmed GA integration within the matrix, with Raman spectroscopy revealing GA vibrational bands (C–OH and C═C). Thermal and structural assessments indicated preservation of the polymer framework after GA incorporation, while scanning electron microscope (SEM) analysis showed increased surface roughness, suggesting network modification. GA functionalization enhanced phenolic content and antioxidant activity (∼96% DPPH radical scavenging) in films without significantly affecting swelling or degradation behavior, demonstrating maintained structural integrity. At 0.125% and 0.25% GA, improved rheological properties enabled successful three-dimensional (3D) printing of scaffolds with controlled pore size (∼0.6 mm). The printed scaffolds exhibited good cytocompatibility toward MC3T3-E1 preosteoblasts, while the films demonstrated antibacterial activity against Staphylococcus aureus, a pathogen associated with chronic bone infections. Overall, ADA–GEL–GA represents a promising biomaterial for bone tissue regeneration, combining structural stability, printability, and bioactive functionality.