Hydroxyapatite Doped with Alpinia galanga (L.) Willd. Rhizome Extract Exhibits Potential Antioxidant and Antibacterial Features

The study focused on doping of hydroxyapatite (HAp) with Alpinia galanga (L.) Willd. rhizome extract (Agr) to impart antioxidant and antimicrobial features to HAp by a green approach. The HAp was synthesized by solgel method using ortho-phosphoric acid and calcium nitrate tetrahydrate as precursors. The HAp was doped with Agr by the wet-precipitation method. The X-ray diffraction (XRD) showed that HAp and HAp-Agr biocomposite were crystalline. The FTIR study validated the successful impartation of Agr into HAp by confirming the presence of functional groups as alcoholic, phosphate, and carbonate groups in HAp-Agr biocomposite. The field emission scanning electron microscope analysis showed that HAp and HAp-Agr biocomposite were irregular and agglomerated. Moreover, energy dispersive X-ray (EDX) analysis showed the entrapment of phytomolecules of Agr into HAp- Agr biocomposite. The Zeta potential analysis revealed that HAp and HAp-Agr biocomposite were stable with −24.6 and -10.7 mV, respectively. The hydrodynamic size distribution of HAp and HAp-Agr biocomposite were 191.5 and 280.7 d. nm, respectively. The HAp-Agr biocomposite exhibited potential antioxidant activity, and its IC50 value (concentration required to scavenge 50% of free radicals) was 133.92 ± 4.08 and 141.24 ± 6.79 μg/mL in DPPH and ABTS assays, respectively. The HAp-Agr biocomposite exhibited a broad range of antibacterial activity against Gram-ve and Gram+ve bacteria by broth-dilution technique. This work highlighted that the as-synthesized HAp-Agr biocomposite had notable antioxidant and antibacterial characteristics and highly apt for biomedical application.