Harnessing Plant-Based Nanoparticles for Targeted Therapy: A Green Approach to Cancer and Bacterial Infections

This study investigates the antioxidant, antimicrobial, and antitumor activities of Dandelion (Taraxacum officinale) and Sweet Wormwood (Artemisia annua) extracts, along with the synergistic effects of green-synthesized gold and silver nanoparticles. Nanoparticle bioreduction was achieved using aqueous and ethanolic plant extracts (100 mg/mL), allowing a comparative solvent analysis. The physicochemical properties of the nanoparticles were characterized using UV-Visible Spectroscopy, Fluorescence Spectroscopy, SEM, DLS, HRTEM, and Zeta Potential Analysis. UV-Visible Spectroscopy provided insights into the optical properties and aggregation state, Fluorescence Spectroscopy helped detect surface modifications, SEM and HRTEM enabled detailed visualization of morphology and structural integrity, while DLS assessed hydrodynamic size and stability. However, each technique has limitations: UV-Visible Spectroscopy cannot provide exact nanoparticle size, SEM may introduce artifacts due to sample preparation, and DLS results can be influenced by particle aggregation. These techniques collectively revealed differences in size, morphology, stability, and biological interactions based on the solvent composition of the nanoparticles, with nanoparticle structure and activity varying significantly even at low ethanol concentrations (3–5%). Biological assays demonstrated that gold nanoparticles from Dandelion exhibited strong antibacterial effects against Staphylococcus aureus, while silver nanoparticles from both plants effectively targeted Escherichia coli. The antitumor potential of nanoparticles exhibited dependence on the plant source and solvent type, showing enhanced cytotoxicity at higher concentrations. Silver nanoparticles from Dandelion (AgNPsEETOH3%-D) displayed significant cytotoxicity against LoVo (colon, p = 4.58e-3) and MDA-MB-231 (breast cancer, p = 7.20e-5) cancer cells, with selectivity indices (SI) surpassing Cis-Pt and DOX at 24 and 48 hours. Gold nanoparticles from aqueous Dandelion extracts (AuNPsEaq-D) had an SI of 2.16 (LoVo, p = 1.82e-3) and 8.41 (MDA-MB-231, p = 1.01e-8), suggesting improved therapeutic selectivity. While some formulations exhibited moderate cytotoxicity and lower selectivity (SI < 1.5), MTT assays confirmed strong biological activity, reinforcing the potential of these nanoparticles in cancer therapy. Further in vivo studies, pharmacokinetic profiling, and combination therapies are needed to enhance selectivity and clinical applicability.