Differential Immunomodulatory Effect of Carbon Dots Influenced by the Type of Surface Passivation Agent.

Carbon nanodots (CDs) are often synthesized from natural sources including honey, molasses, fruits, and foods, and plant extracts simply through caramelization. They have wide biological applications especially as drug delivery vehicles and bioimaging agent due to their small size and biocompatibility. This article details the synthesis of carbon dots from carob and its derivatives by surface passivation with polyethylene glycol (PEG), polyvinyl alcohol (PVA), and alginate (ALG). We investigated the immune response against CDs and evaluated the effect of surface passivation agents on their immunomodulatory functions. CDPVA had strong anti-inflammatory activities, whereas CDALG were pro-inflammatory. CDPEG had mild anti-inflammatory activities suggesting that these CDs can be used in the drug delivery studies as inert carriers. These results showed that depending on the type of activated groups dominated on the surface, CDs exerted differential effects on the inflammatory potential of the macrophages by changing the pro-inflammatory TNFα and IL6 production levels.

Development of adjuvant nanocarrier systems for seasonal influenza A (H3N2) vaccine based on Astragaloside VII and gum tragacanth (APS).

Adjuvants are chemical/biological substances that are used in vaccines to increase the immunogenicity of antigens. A few adjuvants have been developed for use in human vaccines because of their limitations including lack of efficacy, unacceptable local or systemic toxicity, the difficulty of manufacturing, poor stability, and high cost. For that reasons, novel adjuvants/adjuvant systems are under search. Astragaloside VII (AST-VII), isolated from Astragalus trojanus, exhibited significant cellular and humoral immune responses. The polysaccharides (APS) obtained from the roots of Astragalus species have been used in traditional Chinese medicine and possess strong immunomodulatory properties. In the present study, the immunomodulatory effects of a newly developed nanocarrier system (APNS: APS containing carrier) and its AST-VII containing formulation (ANS: AST-VII + APNS), on seasonal influenza A (H3N2) vaccine were investigated. Inactivated H3N2 alone or its combinations with test compounds/formulations were intramuscularly injected into Swiss albino mice. Four weeks after immunization, the immune responses were evaluated in terms of antibody and cytokine responses as well as splenocyte proliferation. APNS demonstrated Th2 mediated response by increasing IgG1 antibody titers, whereas ANS showed response towards Th1/Th2 balance and Th17 by producing of IFN-γ, IL-17A and IgG2a. Based on these results, we propose that APNS and ANS are good candidates to be utilized in seasonal influenza A vaccines as adjuvants/carrier systems.

In vitro growth stimulatory and in vivo wound healing studies on cycloartane-type saponins of Astragalus genus.

AIM OF THE STUDY: The present study was undertaken to evaluate the wound healing effects of the four chief saponins of Astragalus species [cycloastragenol (CA), astragaloside IV (AG), cyclocephaloside I (CCI) and cyclocanthoside E (CCE)]. MATERIAL AND METHODS: Effects of cell viability and proliferation of the isolated compounds were evaluated by the MTT assay on human keratinocyte. The wound healing activity was studied by using in vitro wound healing, proliferation and migration scratch assay. In order to see in vivo effectiveness of the compounds, an animal study with Sprague-Dawley male rats at the age of 12 weeks was carried out, and then the main histological outcomes were investigated to observe reepithelization, neovascularization, and presence of inflammatory cells, granulation tissue amount and maturation. RESULTS: All the compounds increased both fibroblast proliferation and migration, but the effects were much superior for CA at 1 ng/ml concentration. Among the compounds, based on the histological findings, 5% CA preparation was found to be the most remarkable in vivo wound healing agent showing greater cell density, more regularly organized dermis and more newly formed blood vessels. CONCLUSION: Results of this study indicate that the cycloartane-type saponins are the principal constituents responsible for wound healing activities of the roots of Astragalus species substantiating its use in traditional medicine.