Microalgae oil-based drug delivery systems: Fabrication and applications

Microalgae cells in general have a high content of lipids and can be the sustainable source of microalgae oil. To pursue new and high-value applications of microalgae oil will be beneficial to the microalgae industry. The purpose of this chapter is to introduce the capability of microalgae oil to form vesicles/carriers or nanoemulsions in aqueous phase with the potential of being applied as drug and/or nutritious supplement delivery systems. Three fabrication methods are adopted, and the formation of vesicles/carriers or nanoemulsions from microalgae oil is confirmed. By using a mechanical dispersion method, vesicles with well controlled sizes and high physical stability can be fabricated from microalgae oil. The applicability of the fabrication method is revealed by using microalgae oils with different fatty acid compositions as the raw materials. Encapsulation ability of the microalgae oil-based vesicles is then demonstrated by using lutein as the model nutritious supplement. With the probe sonication method, stable microalgae oil-based carriers can be easily prepared even at a low temperature of 20°C. Encapsulation capability of the microalgae oil-based carriers is then shown by using vitamin E acetate as the model compound. Microalgae oil-based nanoemulsions with high physical stability can be fabricated by adopting a homogenization-extrusion method with the potential of being scaled up. The effects of the extrusion operation on the size distribution of the nanoemulsions are discussed, and the encapsulation ability of the nanoemulsions for lutein is demonstrated. All the results suggest that microalgae oil can be considered as a functional microalgae-based biomaterial with a great potential of forming vesicles/carriers or nanoemulsions for drug and/or nutritious supplement delivery applications.