Microalgae are complex photosynthetic organisms found in marine and freshwater environments that produce valuable metabolites. Microalgae-derived metabolites have gained remarkable attention in different industrial biotechnological processes and pharmaceutical and cosmetic industries due to their multiple properties, including antioxidant, anti-aging, anti-cancer, phycoimmunomodulatory, anti-inflammatory, and antimicrobial activities. These properties are recognized as promising components for state-of-the-art cosmetics and cosmeceutical formulations. Efforts are being made to develop natural, non-toxic, and environmentally friendly products that replace synthetic products. This review summarizes some potential cosmeceutical applications of microalgae-derived biomolecules, their mechanisms of action, and extraction methods.

The COVID-19 pandemic has been one of the biggest challenges worldwide. The psychological disorders associated with the pandemic causing depression, insomnia, post-traumatic stress disorder (PTSD) and anxiety reduce emotional stability. Different antidepressant drugs with several mechanisms of action are used with a prescription. The excretion of the compounds and their metabolites reach municipal wastewaters and enter sewage treatment plants with a low rate of remotion of pharmaceutical compounds and the releasing on the environment. Several effects on aquatic species exposed to antidepressants have been reported as the impact in gene transcription, reproduction cycles, predator defense, and motility. The aim of this work is to resume the common antidepressants detected in wastewater around the world and show the increment of its use during SARS-CoV-2 crisis.

Carbon dots (CDs) have attracted significant research attention worldwide due to their unique properties and advantageous attributes, such as superior optical properties, biocompatibility, easy surface functionalization, and more. Moreover, biomass-derived CDs have attracted much attention because of their additional advantages related to more environmentally friendly and lower-cost synthesis. In this respect, chitosan has been recently explored for the preparation of CDs, which in comparison to other natural precursors exhibited additional advantages. Beyond the benefits related to the eco-friendly and abundant nature of chitosan, using it as a nanomaterial precursor offers additional benefits in terms of structure, morphology, and dopant elements. Furthermore, the high content of nitrogen in chitosan allows it to be used as a single carbon and nitrogen precursor for the preparation of N-doped CDs, significantly improving their fluorescent properties and, therefore, their performances. This review addresses the most recent advances in chitosan-based CDs with a special focus on synthesis methods, enhanced properties, and their applications in different fields, including biomedicine, the environment, and food packaging. Finally, this work also addresses the key challenges to be overcome to propose future perspectives and research to unlock their great potential for practical applications.

Microalgae and cyanobacteria are photosynthetic microorganisms’ sources of renewable biomass that can be used for bioplastic production. These microorganisms have high growth rates, and contrary to other feedstocks, such as land crops, they do not require arable land. In addition, they can be used as feedstock for bioplastic production while not competing with food sources (e.g., corn, wheat, and soy protein). In this study, we review the macromolecules from microalgae and cyanobacteria that can serve for the production of bioplastics, including starch and glycogen, polyhydroxyalkanoates (PHAs), cellulose, polylactic acid (PLA), and triacylglycerols (TAGs). In addition, we focus on the cultivation of microalgae and cyanobacteria for wastewater treatment. This approach would allow reducing nutrient supply for biomass production while treating wastewater. Thus, the combination of wastewater treatment and the production of biomass that can serve as feedstock for bioplastic production is discussed. The comprehensive information provided in this communication would expand the scope of interdisciplinary and translational research.

PFAS are a very diverse group of anthropogenic chemicals used in various consumer and industrial products. The properties that characterize are their low degradability as well as their resistance to water, oil and heat. This results in their high persistence in the environment and bioaccumulation in different organisms, causing many adverse effects on the environment as well as in human health. Some of their effects remain unknown to this day. As there are thousands of registered PFAS, it is difficult to apply traditional technologies for an efficient removal and detection for all. This has made it difficult for wastewater treatment plants to remove or degrade PFAS before discharging the effluents into the environment. Also, monitoring these contaminants depends mostly on chromatography-based methods, which require expensive equipment and consumables, making it difficult to detect PFAS in the environment. The detection of PFAS in the environment, and the development of technologies to be implemented in tertiary treatment of wastewater treatment plants are topics of high concern. This study focuses on analyzing and discussing the mechanisms of occurrence, migration, transformation, and fate of PFAS in the environment, as well the main adverse effects in the environment and human health. The following work reviews the recent advances in the development of PFAS detection technologies (biosensors, electrochemical sensors, microfluidic devices), and removal/degradation methods (electrochemical degradation, enzymatic transformation, advanced oxidation, photocatalytic degradation). Understanding the risks to public health and identifying the routes of production, transportation, exposure to PFAS is extremely important to implement regulations for the detection and removal of PFAS in wastewater and the environment.

Bionanocomposites based on natural bioactive entities have gained importance due to their abundance; renewable and environmentally benign nature; and outstanding properties with applied perspective. Additionally, their formulation with biological molecules with antimicrobial, antioxidant, and anticancer activities has been produced nowadays. The present review details the state of the art and the importance of this pyrrolic compound produced by microorganisms, with interest towards Serratia marcescens, including production strategies at a laboratory level and scale-up to bioreactors. Promising results of its biological activity have been reported to date, and the advances and applications in bionanocomposites are the most recent strategy to potentiate and to obtain new carriers for the transport and controlled release of prodigiosin. Prodigiosin, a bioactive secondary metabolite, produced by Serratia marcescens, is an effective proapoptotic agent against bacterial and fungal strains as well as cancer cell lines. Furthermore, this molecule presents antioxidant activity, which makes it ideal for treating wounds and promoting the general improvement of the immune system. Likewise, some of the characteristics of prodigiosin, such as hydrophobicity, limit its use for medical and biotechnological applications; however, this can be overcome by using it as a component of a bionanocomposite. This review focuses on the chemistry and the structure of the bionanocomposites currently developed using biorenewable resources. Moreover, the work illuminates recent developments in pyrrole-based bionanocomposites, with special insight to its application in the medical area.