Fabrication of Drug-Loaded Calcium Phosphate Nanoparticles: An Investigation of Microbial Toxicity

Calcium phosphate (CaP) nanomaterials are considered as potential biomaterial for drug delivery systems because of their excellent biocompatible features. In the present study, amino glycoside antibiotics, such as kanamycin and gentamycin-loaded CaP nanoparticles, were successfully synthesized by the precipitation method. Physicochemical properties were analyzed by XRD, FTIR, FE-SEM, EDX, and light-scattering (DLS) measurements. The average size of CaP nanoparticles ranges from 20 to 100 nm, as measured by DLS analysis. The crystallinity of the prepared nanoparticles was confirmed by XRD analysis, which revealed that the CaP nanoparticles were in crystalline and hydroxyapatite (HA) phase with tricalcium phosphate (TCP). The FTIR spectrum confirmed the presence of phosphate and surface hydroxyl groups. In vitro release study of drug-loaded CaP (D-CaP) nanoparticles was performed, and the drug release from nanoparticles was sustained over 5 days, with an entrapment efficiency of 52.05 ± 3% and 65.3 ± 4%, respectively. The antibacterial activity of D-CaP nanoparticles was evaluated against Bacillus cereus (KACC 14394), Staphylococcus aureus (KCTC 1916) Escherichia coli (KACC 10005), and Salmonella typhi (KCCM 40253) by the well diffusion and minimum inhibitory concentration (MIC) methods. We found the bactericidal effect of D-CaP nanoparticles in a dose-dependent manner by MTT assay. In addition, the interaction of D-CaP nanoparticles against bacterial pathogens was demonstrated by Bio-TEM analysis, providing clear evidence of the disruption of bacterial cell membranes. The results of the present study suggest that D-CaP nanoparticles can be useful for the treatment of bacterial infection in the bone as well as in the biomedical field.