Carbon Dot‐Based Hydrogels: Preparations, Properties, and Applications (Small 17/2023)

Plant Extract-Derived Carbon Dots as Cosmetic Ingredients

“…Multiple delivery systems can be used to ensure their stability, effectiveness, and safety when incorporating C-dots into cosmetic products. The typical delivery systems containing carbon dots for cosmetic applications include nanoemulsions, liposomes, solid lipid nanoparticles (SLNs), and hydrogels (Figure 7 and Table 2) [73][74][75]. First, C-dots can be dispersed in oil-in-water (O/W) or water-in-oil (W/O) nanoemulsions, which are highly stable and have a small droplet size due to their small size, which leads to valuable properties such as high surface area per unit volume, robust stability, optically transparent appearance, and tunable rheology [74,76].…”

“…The SLN system promotes skin hydration via stratum corneum occlusion, which prevents water loss by evaporation, and via the reinforcement of the skin's lipid-film barrier, which occurs through the adhesion of the NPs to the stratum corneum [77,78]. Fourth, C-dot-based hydrogel systems are prepared from biopolymer molecules with three-dimensional network structures that contain a relatively large amount of water [75]. The core of a hydrogel is a polymeric channel system, which may be formed through the physical or chemical cross-linking of homopolymers or copolymers, resulting in swelling when subjected to an aqueous surrounding [75,79].…”

“…Fourth, C-dot-based hydrogel systems are prepared from biopolymer molecules with three-dimensional network structures that contain a relatively large amount of water [75]. The core of a hydrogel is a polymeric channel system, which may be formed through the physical or chemical cross-linking of homopolymers or copolymers, resulting in swelling when subjected to an aqueous surrounding [75,79]. Hydrogels have been used for a long time in dermatology and cosmetic fields due to their biocompatibility, their good spreading and adherence to the site of application, and their long resident time on the site of action facilitating diffusion in the skin [75,79].…”

“…In addition, these delivery systems are composed of physiological lipid membranes that can reduce the danger of acute and chronic toxicity [73,76,77]. Furthermore, these delivery systems can remain stable against various chemical and environmental changes, thereby increasing the stability of the C-dots in cosmetic formulations, consequently enhancing the performance of cosmetic products [74,75]. Using delivery systems as effective vehicles protects reactive or sensitive compounds against environmental conditions, including light, temperature, pH, humidity, and oxygen.…”

“…The lipid bilayers are likely to enhance the water solubility of C-dots and be homogenously dispersed in cosmetic formulations for the significantly increased bioavailability of C-dots. Moreover, these delivery systems, with their small sizes and spherical bilayer structures, can mimic the cell membrane constituents and improve dermal and transdermal active-C-dot delivery [74,75]. likely to enhance the water solubility of C-dots and be homogenously dispersed in cosmetic formulations for the significantly increased bioavailability of C-dots.…”