Synthesis and development of nanocomposites of magnetic nanoparticles-silica-mannan as vaccine adjuvants

Abstract

Over the past years, vaccination has been considered as an effective treatment against a wide range of pathogens and diseases. Despite a promising outcome, the lack of strong immune response of some types of vaccines is still challenging. Therefore, targeting and activating dendritic cells (DCs) using nanomaterial-based vaccine adjuvant is of our interest. Herein, superparamagnetic iron oxide nanoparticles (SPIONs) have been exploited as directing agents to the targeted dendritic cells (DCs). In addition, mannan extracted from Saccharomyces cerevisiae was used as targeting molecules for targeting DCs. Nanocomposites of silica-magnetic nanoparticles-mannan (S-SPION-MN) were successfully fabricated. The synthesized particles were morphologically and physically characterized using FESEM, TEM, XRD, VSM and ICP-OES techniques. For biological studies, the synthesized materials were determined for cytotoxicity, DC maturation, cytokine production, and cellular uptake. As a result, alteration in surface charge from highly negative charge to slightly negative charge suggested the successful coating of mannan on nanocomposite surfaces. Under a magnetic induction, S-SPION-MN showed great enhancement of DCs targeting within 15 min due to the synergistic effect of mannan and magnetic nanoparticles. The co-existence of SPIONs and mannan significantly facilitated the DCs targeting ability and maturation of DCs. As a result, the nanocomposites from this work can be beneficial for further development in vivo study as a potential candidate in antigen delivery to targeted immune cells.