Inorganic nanoparticles for natural product delivery: a review

The therapeutic potential of plant-based natural products is well known, yet it is actually limited by poor water solubility, low bioavailability and rapid metabolism. These issues can be solved by formulation with silica, gold, iron and silver nanoparticles. This manuscript discusses the synthesis and toxicity of inorganic nanoparticles used for therapeutic applications. The use of silver nanoparticles in the 0.4–30 µg dose range is optimal without any severe short-term toxicity. The bio-distribution of gold nanoparticles are controlled by their size; for instance, 5–15 nm particles show broader organ distribution, whereas 50–100 nm particles were mainly found in the liver and spleen. Curcumin-loaded silver nanoparticles decrease four times the minimum effective concentration against gram-positive and gram-negative bacteria. Mesoporous silica nanoparticles enhance the solubility of resveratrol up to about 95%. Mesoporous silica nanoparticles delivered 2.68 fold higher paclitaxel concentrations in lungs as compared to the free drug.