Multifunctional scaffold applied on bone regeneration: Assessment of bioactivity, biocompatibility, and antibacterial properties

Bone defects resulting from injuries or pathologies necessitate advanced filler materials that provide structural support and promote localized tissue repair. This study presents the development of a composite scaffold based on synthetic nano-hydroxyapatite (HA), sodium alginate (ALG), and calcium phosphate/carbonate cements (CPC) loaded with ciprofloxacin (CIP). The physicochemical behavior was assessed under simulated physiological conditions, revealing a pH-responsive performance: the scaffold maintains initial stability and high swelling at pH 7.4, while undergoing accelerated degradation at pH 4.2 in a simplified in vitro model. Optical microscopy with crossed polarizers revealed birefringent domains that reinforce the matrix structure. Bioactivity assays in simulated body fluid (SBF) demonstrated the progressive growth of an apatite-like mineral layer, with extensive surface coverage achieved after 28 days, as validated by FE-SEM, XRD, and FT-IR analysis. Furthermore, the system ensures localized CIP release with in vitro antibacterial activity against common osteomyelitis-associated bacterial strains while maintaining a hemolysis rate below 1%, confirming a favorable in vitro hemocompatibility profile under the tested conditions. These findings establish a multifunctional platform as a potential local delivery scaffold for bone-filling applications