Sol-gel synthesis of amorphous calcium phosphate nanoparticles in brown rice substrate and assessment of their cytotoxicity and antimicrobial activities

Objective: This study intended to perform a synthesizing procedure for amorphous calcium phosphate (ACP) through a green template by the usage of brown rice (BR). Materials and Methods: ACP nanoparticles were obtained by application of a sol-gel method and comprehensively characterized using X-ray powder diffraction (XRD), zeta potential, fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), and atomic force microscopy (AFM). Cytotoxic activity of ACP was evaluated in human epithelial type 2 (HEp-2) cell lines. The antibacterial effects of nanoparticles were appraised against Gram-positive Streptococcus mutans and Enterococcus faecalis. Results: The procedures for the evaluation of the characterization outcomes, dispersion, and stability of our product were confirmed by observing the smooth and uniformed surfaces of ACP. The zeta potential value of the synthesized sample was -22 mV, which indicates its acceptable stable condition caused by electrostatic repulsion. The cytotoxicity of the ACP nanoparticles was investigated in HEp-2 cells, and results showed no cytotoxicity for the synthesized nanoparticles. Also, the obtained minimum inhibitory concentration (MIC) of ACP nanoparticles in opposition to S. mutans and E. faecalis was 15 and 20 μg/ml, respectively, indicating the resistance of E. faecalis in comparison to S. mutans and MBC for synthesized nanoparticles against S. mutans and E. faecalis strains was 20 and 25 μg/ml. Conclusion: The present study showed that this compound has no toxicity on the examined cell line. Also, the antibacterial properties of the synthesized ACP were approved by the obtained data, which enables the application of this material for therapeutic purposes in the pharmaceutical industry.