Preparation and characterization of nanoparticles from quaternized cyclodextrin-grafted chitosan associated with hyaluronic acid for cosmetics

Hyaluronic acid(HA, 20–50 kDa) is a hydrophilic macromolecule with anti-wrinkle effects and moisturizing properties. However, its high molecular weight prevents it from penetrating into the deeper layers of the skin and, thus, limits its benefits to topical effects. Thus, the objective of this study is to prepare nanoparticles of quaternized cyclodextrin-grafted chitosan(QCD-g-CS) associated with HA in different molar ratios of QCD-g-CS and HA. The conjugation of the carboxylic moieties of HA and the amides of QCD-g-CS was confirmed by Fourier-transform infrared spectroscopy. Thus, the system was optimized to create nanoparticles with a small size(235.63 ± 21.89 nm), narrow polydispersity index(0.13 ± 0.02), and zeta potential of 16.07 ± 0.65 m V. The association efficiency and loading efficiency were determined by ultra-performance liquid chromatography as 86.77 ± 0.69% and 10.85 ± 0.09%, respectively. The spherical morphology of the obtained nanoparticles was confirmed by transmission electron microscopy. Moreover, the in-vitro hydrating ability was significantly higher( P < 0.001) than that of bulk HA(3.29 ± 0.41 and 1.71 ± 0.05 g water/g sample, respectively). The safety of these nanoparticles at concentrations in the range of 0.01–0.10 mg/ml was confirmed via tests on human skin fibroblasts. Together, these results demonstrate that the developed nanoparticles are promising for future applications in cosmetics.

Review:Development of SARS-CoV-2 immuno-enhanced COVID-19 vaccines with nano-platform

Vaccination is the most effective way to prevent coronavirus disease 2019(COVID-19).Vaccine development approaches consist of viral vector vaccines,DNA vaccine,RNA vaccine,live attenuated virus,and recombinant proteins,which elicit a specific immune response.The use of nanoparticles displaying antigen is one of the alternative approaches to conventional vaccines.This is due to the fact that nano-based vaccines are stable,able to target,form images,and offer an opportunity to enhance the immune responses.The diameters of ultrafine nanoparticles are in the range of 1–100 nm.The application of nanotechnology on vaccine design provides precise fabrication of nanomaterials with desirable properties and ability to eliminate undesirable features.To be successful,nanomaterials must be uptaken into the cell,especially into the target and able to modulate cellular functions at the subcellular levels.The advantages of nano-based vaccines are the ability to protect a cargo such as RNA,DNA,protein,or synthesis substance and have enhanced stability in a broad range of pH,ambient temperatures,and humidity for long-term storage.Moreover,nano-based vaccines can be engineered to overcome biological barriers such as nonspecific distribution in order to elicit functions in antigen presenting cells.In this review,we will summarize on the developing COVID-19 vaccine strategies and how the nanotechnology can enhance antigen presentation and strong immunogenicity using advanced technology in nanocarrier to deliver antigens.The discussion about their safe,effective,and affordable vaccines to immunize against COVID-19 will be highlighted.