Synthesis of carob honey loaded chitosan nanoparticles and determination of its antimicrobial potential and cytotoxic effect on breast cancer cell line

Embedding natural products into chitosan nanoparticles (CNP) is an effective way to produce a novel combination with better antimicrobial and anticancer activities. Therefore, this study aims to incorporate carob honey (CH) into CNP, determine its potential antimicrobial along with antiproliferative activities, by well diffusion and MTT cell viability assays, respectively. Successful loading of CH in CNP was confirmed after due characterization. The nanoparticles, synthesized by ionic gelation method, produced a small (101.3 ± 4.13 nm), stable (+27.27 ± 0.95 mV), and monodispersed (0.2265 ± 0.0027) CH-loaded CNP (CHCNP). The best antibacterial activity occurred in <i>Klebsiella pneumoniae (K. pneumoniae) (</i>23 ± 0 mm to 16 ± 1.7 mm) followed by <i>Escherichia coli (E. coli)</i> (18 ± 2.0 mm to 10 ± 1 mm). Meanwhile, <i>Aspergillus niger (A. niger)</i> and <i>Aspergillus flavus (A. flavus)</i> were evenly inhibited with inhibition zones in the range of 15 ± 3 mm to 7 ± 0.8 mm and 15 ± 5 mm to 9 ± 1.4 mm, respectively. CHCNP showed a remarkable cytotoxic effect on MDA-MB-231 according to concentration and time, with IC₅₀ of 25 ± 5 to 18 ± 2.6 μg/mL within 24-72 h. These findings demonstrated the feasibility of loading CH in CNP to form a nanoformulation that could potentially serve as a target-specific therapeutic agent in the treatments of microbial infections and breast cancer. However, there is a need for further research on the safety, dosage optimization, <i>in vivo</i> studies and mechanisms of action of the nanoparticles.