Anticancer effects of biomimetic green-synthesized silver nanoparticles coated lactobacilli species against various cancer cell lines.

Masking drugs by entrapping them in the immune-evasive materials facilitates targeted delivery to specific parts of the body. Cancers, including lung cancer and ascitic tumors, remain significant threats to human life, with limited effective treatment options. In the present study, to specifically target lung cancer and Dalton's lymphoma ascitic (DLA) cells, we synthesized green silver nanoparticles (NS-AgNps) using Nigella sativa (NS) seeds extract, with thymoquinone as the reducing and capping agent, confirmed by GC-MS analysis. The nanoparticles were characterized through various photophysical techniques at different stages of fabrication. Lactobacillus spp., isolated from prebiotic and probiotic tablets and identified through biochemical tests, were coated with synthesized NS-AgNps to form lactobacillus coated-Nigella sativa-silver nanoparticles (L-NS-AgNps). The successful coating was confirmed by scanning electron microscopy. The anticancer activity of L-NS-AgNps was evaluated against A549 (human lung carcinoma cells) and DLA cells using MTT and Trypan blue assays. L-NS-AgNPs exhibited dose-dependent cytotoxicity with a maximum of 54% cell death at 3 µg/ml and an LC50 of 3.005 µg/ml for A549 cells, and 58% cell death in DLA cells. Biocompatibility was assessed both in vitro and in vivo using fibroblast cell lines (V79) and zebrafish embryos, respectively. The nanoparticles showed high biocompatibility, maintaining over 95% viability in V79 fibroblasts and causing no developmental abnormalities in zebrafish embryos at a concentration up to 3 µg/ml. These findings suggest that our L-NS-AgNPs hold strong potential as a novel and safe therapeutic agent for cancer treatment.

Supplementary information: The online version contains supplementary material available at 10.1007/s13205-025-04393-4.