Curcumin, a component of turmeric and an approved food additive has been shown to possess a wide spectrum of biological activity in particular antimicrobial, anti-cancer and antioxidant. Research in experimental models of several diseases, including cancer, diabetes, atherosclerosis and gastrointestinal diseases, has revealed significant preventive and/or healing effects of curcumin. There is ample evidence to support its use as functional food ingredient. However, the poor aqueous solubility of curcumin creates an obstacle on the way to deliver its bioactivity in food systems. Reducing particle size to sub-micrometer and nano scales was shown to enhance solubility and bioavailability of poorly water-soluble compounds, including curcumin. In this work, we present a methodology for preparing a series of water-dispersible curcumin nanoparticles by ligand–capping technique using a set of stabilizing compounds, and asses the influence of ligands on solubility, stability and biological activity of these particles.
The particles were produced by antisolvent precipitation. The initial set of twenty potential stabilizing ligands including polymers, amino acids, other charged organic molecules and natural phenolic compounds was evaluated by high-throughput screening assay for their ability to facilitate self-assembly and to stabilize curcumin nanoparticles in aqueous medium. The promising ligands chosen from the screening were used for further optimization of nanoparticle assembly and preparing of particles with improved yield, solubility and colloidal stability. The analysis by means of Scanning Electron Microscopy and the Dynamic Light Scattering (DLS) showed that particles prepared by this method had smaller size (150-200 nm) and higher monodispersity (polydispersity index 0.2-0.4) compared to the particles prepared by simple antisolvent precipitation (size 900-1200 nm and polydispersity index 0.6-0.8). Furthermore, the DLS revealed that ligand-protected nanoparticles had higher colloidal stability. The antimicrobial activity tests with E. coli revealed that MIC of curcumin nanoparticles prepared by this method was 400 mM. The reported approach may be implemented also with other poorly water-soluble bioactive materials.
Principal investigator: Dr. Victor Rodov vrodov@agri.gov.il
