Poly(methacrylic acid)/gelatin interpenetrating network hydrogels reinforced by nano-structured hydroxyapatite particles—improved drug delivery systems

Abstract

Novel poly(methacrylic acid)/gelatin (PMAG) interpenetrating networks reinforced by different amounts of nanostructured particles of hydroxyapatite (HA) (HA/polymer weight ratios from 0% to 40%) were synthesized. The introduction of HA significantly enhanced mechanical properties, but slightly reduced swelling ability, pH sensibility and porosity. The increase of HA/polymer ratio to 40% increased the compressive strength from 29.83 (pure PMAG hydrogel) to 68.16 kPa. Drug release behavior investigated in simulated physiological conditions, using ciprofloxacin (hydrophilic) and oxaprozin (hydrophobic), demonstrated different drug release kinetics. In vitro antimicrobial testing demonstrated bactericidal and fungicidal activity of the drug-loaded hydrogels against E. coli, S. aureus and C. albicans.