The skin, being the largest organ of the human body, serves as the primary barrier against external insults, including UV radiation, pollutants, and microbial pathogens. However, prolonged exposure to these environmental stressors can lead to the generation of reactive oxygen species (ROS), causing oxidative stress, inflammation, and ultimately, skin aging and diseases. Antioxidants play a crucial role in neutralizing ROS and preserving skin health by preventing oxidative damage. In recent years, nanotechnology has emerged as a powerful tool for enhancing the delivery of antioxidants onto the skin. In particular, liposomal formulations have offered unique advantages such as improved stability, controlled release, and enhanced penetration through the skin barrier. This has led to a surge in research focused on developing liposomal-based antioxidant delivery systems tailored for skin health applications. Through a comprehensive analysis of the literature from the 2019–2024 period, this review provides an overview of emerging trends in the use of liposomal delivery systems developed for antioxidants aimed at improving skin health. It explores the latest advancements in liposomal formulation strategies, vesicle characterization, and their applications in delivering antioxidants to combat oxidative stress-induced skin damage and other associated skin pathologies. A comparison of various delivery systems is conducted for the most common antioxidants. Finally, a brief analysis of lipid nanovesicles used in the cosmeceutical industry is provided.
The skin, being the largest organ of the human body, serves as the primary barrier against external insults, including UV radiation, pollutants, and microbial pathogens. However, prolonged exposure to these environmental stressors can lead to the generation of reactive oxygen species (ROS), causing oxidative stress, inflammation, and ultimately, skin aging and diseases. Antioxidants play a crucial role in neutralizing ROS and preserving skin health by preventing oxidative damage. In recent years, nanotechnology has emerged as a powerful tool for enhancing the delivery of an-tioxidants onto the skin. In particular, liposomal formulations have offered unique advantages such as improved stability, controlled release, and enhanced penetration through the skin barrier. This has led to a surge in research focused on developing liposomal-based antioxidant delivery systems tailored for skin health applications. Through a comprehensive analysis of the literature from the 2019-2024 period, this review provides an overview of emerging trends in the use of liposomal delivery systems developed for antioxidants aimed at improving skin health. It explores the latest advancements in liposomal formulation strategies, vesicles characterization and their applications in delivering antioxidants to combat oxidative stress-induced skin damage and other associated skin pathologies.
Aerogel microspheres of chitosan catalyzed the direct aldol reaction of para-nitrobenzaldehyde (1) or isatin (2) with ketones in water to afford the corresponding products 3 or 4 in 76-97% yield with up to 93% ee. When 2,4-dinitrophenol (DNP) or stearic acid was used as an additive, the enantiomeric excess of 3c was increased (DNP; anti/syn = 76:24, 92% ee for the anti product, stearic acid; anti/syn = 76:24, 93% ee for the anti product).
Biochar materials are compelling adsorbents for pollutants in aqueous solution. Most studies focus on experimenting on purpose-made biochar types to reveal removal mechanisms and their influence on adsorption performance. This work is an effort to bridge the gap between such studies and real-world upscaling by making use of widely available commercial biochar and evaluation of removal performance for Pb2+ and Cr3+. The objective is to compare performance achieved by employed biochar samples to constrain beneficial and detrimental characteristics to the removal process. This is done using both differences among biochar samples and sorbed contaminants. Nine commercial biochar samples from Italy, France and Germany have been characterized by means of CHNOS elemental analysis, surface analysis, thermogravimetric analysis and FT-IR spectroscopy, detecting a great degree of variability in terms of physical and chemical properties. Kinetic and isotherm adsorption experiments with contaminant concentrations up to 50 mg/L yield distinct removal performances for different biochar samples and contaminants. Changes in surface functionality - before and after water treatment - have been surveyed through FT-IR spectroscopy. Removal mechanisms are comparable for Pb2+ and Cr3+ and include complexation with oxygen containing functional groups, interaction with π-carbon bonds and ion exchange. Increasingly high contaminant concentrations pointed out further controls on the adsorption process tied to biochar’s pore structure in relation to the contaminant’s nature. Adsorption-desorption isotherms yielded by surface analysis suggest a subdivision in two groups of biochar samples depending on the occurrence of a H4 hysteresis loop. Such a loop is indicative of slit-shaped porosity, while an open one suggests an ink-bottle pore shape. Provided the presence of adequate surface functionality and area, ink bottle pores can hinder removal process efficiency by restricting access to metal complexes and being blocked by multilayer adsorption phenomena. Regardless of such effects, commercial biochar samples achieve performance levels greater or equal to literature counterparts in similar conditions. Upscaling readiness of commercial biochar materials is proven through deep insight into physical-chemical interactions occurring between sorbent and contaminant. A knowledgeable application of biochar technologies for water treatment requires proper standardized characterization and policy support and can additionally foster its sustainable proposition by limiting the need for costly and impactful post-production modifications.