Fabrication and characterization of microalgae extract loaded chitosan/alginate-based nanoparticles with ultraviolet protection features

Microalgae are constantly exposed to ultraviolet rays because they are usually found in areas with high sunlight exposure. Several studies have addressed the harmful impact of increased ultraviolet radiation on various microalgae. However, some microalgae have a great ability to overcome or counteract different stresses such as intense solar ultraviolet radiation, this has been happening over the years and with the evolution of microalgae, some examples of defense and/or tolerance mechanisms are DNA repair, synthesis of antioxidants, and enzymatic/non-enzymatic compounds, such as mycosporine-like amino acids and scytonemin to counteract the harmful effects of ultraviolet radiation. This characteristic has not only been investigated to learn more about microalgae, but also for applications such as product creation, since they grow rapidly and are considered the most promising and sustainable sources of biomass. Due to their performance under optimal conditions, they have been widely studied for different bioproducts. Which is why microalgae extracts, by showing resistance to both types of rays, show great potential as sunscreens and this gives a very strong advantage to future bioproducts. This study deals with the application of microalgae extracts for the creation of polymeric nanoparticles based on chitosan and alginate. The synthesis of nanoparticles with a size of 500 nm and a polydispersity index of 0.1 was successfully achieved, indicating the uniformity of these nanoparticles. Different characterization techniques were used for the analysis of these nanoparticles, including UV-Visible spectrophotometry (UV-Vis), Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). All these techniques allow us to see different aspects of the nanoparticles confirming their structure, uniformity, and composition for further effective utilization.