How Nanoparticles Promote The Development And Utilization Of Vaccines

Despite advances in conventional vaccines, improvements are still needed due to concerns about low toxicity, instability, and the need for multiple vaccination. To overcome these problems, nanotechnology has recently been incorporated into vaccine development. With the development of nanotechnology, nanotechnology is playing an increasingly important role in vaccine development, and nanocarriers provide opportunities to enhance cellular and humoral immune responses. The application of nanoparticles in vaccine formulations can not only enhance the immunogenicity and stability of the antigen, but also can target delivery and sustained release.

In the past decade, nanoscale materials such as virus-like particles, liposomes, ISCOMs, polymers, inorganic nanoparticles, and emulsions have attracted attention as potential carriers of vaccine antigens because they can stabilize vaccine antigens, and can also be used as adjuvants. This advantage is due to the nano-sized particle size, which facilitates the uptake of antigen-presenting cells (APCs), and in turn leads to efficient antigen recognition and presentation. Using different targeting sites to modify the surface of nanoparticles, antigens can be delivered to specific receptors on the cell surface, thereby stimulating selective and specific immune responses.

Figure 1. Schematic of a nanocarrier. The antigen can be conjugated to the surface of the nanoparticle or encapsulated in the core of the particle.

Existing research found some nanoparticles themselves can stimulate different immune cells to enhance host immunity. Nanoparticle size, shape, and surface chemistry are important factors that determine its potential to activate an immune response. In general, nanoparticles are able to stimulate immune responses by increasing the synthesis of defense genes and inflammatory responses. Various types of nanoparticles, such as gold, carbon, dendrimers, polymers, and liposomes, have the ability to induce cytokines and antibody responses. In addition to their potential to deliver various immune stimulants to specific sites and deep tissues that may not be accessible only by vaccine molecules, these nanoparticles have also been used as adjuvants to enhance the immunogenicity of candidate vaccines.

Emerging research has demonstrated that nanocarriers are useful mediators in the development of vaccines for various diseases. In this case, using nanoparticles as vaccine carriers can deliver the immunogen to antigen-presenting cells, especially dendritic cells, to induce an effective antigen-specific t-cell response. Some nanocarriers have been shown to specifically activate dendritic cells, thereby generating an immune response against tumors or viruses. In a recent report, Zhu et al. proposed that nano-tio2 and Fe3O4-TiO2 particles can be used as an effective carrier to promote the delivery of vaccines in immune cells. In this study, after co-incubating titanium dioxide and Fe3O4-TiO2 nanoparticles with dendritic cells, it was found that TNF-α expression was increased, and CD80 expression was regulated by NF-κB CD86 and MHC class II molecular signaling pathways. Therefore, various NP preparations such as erythrocyte membrane-encapsulated poly (D, 1-propanediol ester) (PLGA) NPs against antigen peptides (hgp10025-33) and TLR-4 agonists, VLPs expressing RSV glycoproteins, and chitosan coating the immune efficacy of EphrinA1-PE38 / GM-CSF have been improved. Thus the use of nanoparticles as a carrier for vaccine development can effectively improve the stability of the antigen, confer targeted delivery of the antigen, and also enhance its immunogenic properties.