Promise and Limitations of Microalgal Nanoparticles in Cancer Therapy

Nanoparticles (NPs), sized 1–100 nm, exhibit unique physical, chemical, and biological properties not seen in bulk materials. Their high surface area, quantum effects, and enhanced reactivity make them valuable in drug delivery, imaging, and cancer therapeutics.

Traditional NP synthesis often involves toxic chemicals or energy-intensive methods, limiting clinical use. Green synthesis, using biological systems like microalgae, offers a safer, eco-friendly alternative. Microalgae are rich in enzymes, metabolites, and bioactive compounds, enabling the reduction of metal ions into biogenic nanoparticles under mild conditions. These NPs are highly biocompatible and can selectively target cancer cells.

Microalgal species such as Chlorella, Spirulina, Scenedesmus, and Dunaliella salina have been used to produce metallic nanoparticles, including silver (AgNPs) and gold (AuNPs). Synthesis involves incubating microalgal biomass with metal salts, where secreted metabolites mediate reduction, indicated by a color change. Nanoparticles can form intracellularly or extracellularly through stages of activation (nucleation), growth (aggregation), and termination (stabilization). Characterization techniques include TEM, UV-Vis spectroscopy, EDX, and FTIR.

NP properties—size, shape, and surface charge can be tailored by adjusting synthesis parameters. This fine-tuning influences biological activity, allowing selective cytotoxicity against cancer cells while sparing healthy tissue. Mechanisms include ROS generation, membrane disruption, and apoptosis induction. Due to their nanoscale size, these NPs exploit the enhanced permeability and retention (EPR) effect to accumulate in tumors, and surface functionalization with targeting ligands or drugs further enhances therapeutic efficacy.

source: https://www.azonano.com/news.aspx?newsID=41525