Polyethylenimine-Modified Fluorescent Carbon Dots As Vaccine Delivery System for Intranasal Immunization

Abstract

Fluorescent carbon dots (CDs) as a luminescent nanomaterial have obtained much attention in the biomedical field. To make good use of their luminescent property and nanoscaled size, we developed CDs as a vaccine delivery system for intranasal immunization in this work. To this aim, polyethylenimine-modified CDs were prepared via a simple microwave method. Intranasal immunization was performed by using the CDs as an antigen carrier to deliver model protein antigen ovalbumin. The results showed that the CDs as an intranasal vaccine delivery system enhanced the immunization efficacy by significantly increasing IgG titer, IgA induction in the local and distant mucous membrane sites, splenocyte proliferation, cytokine IFN-γ secretion by splenocytes, and memory T cells. From the results, the CDs could be used as vaccine delivery systems with the advantage of tracing the antigen transportation from administration site to the lymph organs.

Materials for Immunotherapy

“…Further, activated T cells contributed to significant tumor regression in a melanoma tumor model. Soon after, Liu and co‐workers prepared PEI‐conjugated fluorescent CDs to deliver antigenic OVA through electrostatic interactions for intranasal delivery . The PEI‐CDs/OVA were shown to induce the secretion of IFN‐γ as well as IgG and IgA antibodies, splenocyte proliferation, and memory T cell production.…”

Genipin cross-linked carbon dots for antimicrobial, bioimaging and bacterial discrimination

“…Li et al synthesized bright yellow fluorescent CDs for the label-free detection of fluoroquinolone and histidine [32]. Liu et al used a simple microwave method to prepare CDs as a vaccine delivery system for intranasal immunization wherein ovalbumin antigen was delivered using CDs as an antigen carrier [33]. Yang et al used the antibiotic metronidazole to prepare CDs via hydrothermal methods [34].…”

Aqueous Synthesis of Multi‐Carbon Dot Cross‐Linked Polyethyleneimine Particles with Enhanced Photoluminescent Properties

“…Branched polyethyleneimine (PEI) which consists of 25% primary, 50% secondary, and 25% tertiary amines has been used increasingly to transfect genes into living cells since its first report as a transfection agent in 1995 . Recently, PEI‐passivated carbon dots (PEI‐CD) have gained much interest in the biomedical field for molecular and pH sensing, cellular imaging, as well as gene and vaccine deliveries with bioimaging function . The PEI‐CDs are fabricated through two main approaches: 1) PEI molecule acting as both the passivating agent and the carbon source is oxidized with either nitric acid at 120 °C or with ammonium persulfate under hydrothermal treatment .…”

“…The PEI‐CDs are fabricated through two main approaches: 1) PEI molecule acting as both the passivating agent and the carbon source is oxidized with either nitric acid at 120 °C or with ammonium persulfate under hydrothermal treatment . 2) PEI molecule acts as a passivating agent while a precursor molecule such as citric acid, glycerol, sucrose folic acid, hyaluronate, or chitosan is used as a carbon source to generate carbon dots through either microwave radiation or hydrothermal treatment . The quantum yields of the PEI‐passivated carbon dots prepared by these methods are in the range of 2–54%.…”