Preparation of protamine-adsorbed calcium phosphate powders and their antibacterial property

Abstract

ABSTRACT Calcium phosphates are key biomaterials in bone regeneration and dental treatment fields. Biomaterials must exhibit antibacterial properties to ensure protection against microbial infection in implantation frameworks. Various starting calcium phosphate and protamine-adsorbed calcium phosphate powders were prepared in this study to develop novel antimicrobial biomaterials exhibiting the biocompatibility of calcium phosphates and the antimicrobial property of protamine, and their properties were examined. Specifically, hydroxyapatite (HAp) and its precursors – amorphous calcium phosphate (ACP) and octacalcium phosphate (OCP) – were synthesized using the conventional wet process. Moreover, three types of protamine-adsorbed calcium phosphate powders (ACP-Protamine, OCP-Protamine, and HAp-Protamine) were prepared via adsorption of protamine (25.2, 5.28, and 19.2 mg·g−1, respectively) on the starting calcium phosphate powders in water for 48 h. The antimicrobial property of the protamine-adsorbed calcium phosphate powders against Staphylococcus aureus, a representative bacterium that causes implantation-related infection of biomaterials, was evaluated. All the examined protamine-adsorbed calcium phosphate powders exhibited antibacterial properties and, therefore, show promise as effective antimicrobial biomaterials.