Envisaging marine diatom Thalassiosira weissflogii as a SMART drug delivery system for insoluble drugs

In this study, naturally occurring diatoms frustules of Thalassiosira weissflogii were utilized as a drug delivery system. The amount of curcumin (model drug) loaded onto the frustules was found to be 79.05 +/- 4%. The drug release kinetics data suggest that the rate of drug release was faster in physiological conditions compared to acidic conditions. The surface charge of -3.05 supports the adsorption of curcumin to the void pores of biosilica. The experimental results were further characterized using dynamic light scattering (DLS), Zeta potential (zeta), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and Fourier-transform infrared spectroscopy (FT-IR). The cell viability assay suggests that curcumin-loaded biosilica do not have any toxic effect on HEK 293 (normal) whereas showed toxic effect against ACHN (cancer) cell lines. The biological activity of the test compound exhibits broad-spectrum antibacterial action against Escherichia coli, Streptococcus pneumonia, Staphylococcus aureus, Bacillus subtilis, and Aeromonas. This work exhibits that the live marine diatoms can be a promising tool for drug delivery application owing to their stability, biocompatibility, cellular uptake, non-toxic and drug release profiles.

Automated summary

This study utilized naturally occurring diatoms frustules as a drug delivery system and successfully loaded curcumin onto the frustules. The research found that drug release was faster in physiological conditions compared to acidic conditions, and the frustules had good adsorption capacity. Experimental results further characterized the frustules' properties and drug release mechanism. The curcumin-loaded frustules were non-toxic to normal cells but showed toxicity against cancer cells, and exhibited broad-spectrum antibacterial activity. These findings demonstrate that diatoms can be a promising tool for drug delivery applications.