Recent Advances in Nanovaccines Using Biomimetic Immunomodulatory Materials

Vijayan, Veena; Mohapatra, Adityanarayan; Uthaman, Saji; Park, In-Kyu

Highly active antiretroviral therapy (HAART) is a prominent strategy for the treatment of Wang et al. [4] had reported an anti-virulence biomimetic nanovaccine, assembled with cell membrane coating against methicillin-resistant staphylococcus aureus (MRSA) skin infection. The RBC-membrane coated PLGA NP acts as a natural substrate for pore-forming toxins that can entrap pore-forming staphylococcal α-hemolysin (Hla) onto the surface to reduce MRSA infections [20] . The VLPs vaccine was developed from the Hepatitis B virus core protein with a combination of Mycobacterium tuberculosis antigen culture filtrate protein 10 (CFP-10) against tuberculosis (TB). CFP 10 is a T-cell antigen that induces vigorous CTL activity and the secretion of IFN-γ, and it has been reported as a significant TB vaccine. This biomimetic vaccine has expressed antigen-specific Th1 immunity, and is considered as an effective TB vaccine [101] . Endolysins are bacteriophage-secreted enzymes that are responsible for the degradation of peptidoglycan presented in the bacterial cell wall. The liposomal delivery of endolysin is a significant way to treat against gram-positive bacteria. This can overcome the drawbacks of the native endolysin, which is unable to penetrate the outer membrane of the bacteria [102] . RBC membrane-coated biomimetic supramolecular gelatin nanoparticle loaded with vancomycin (Van-SGNPs@RBC) have been developed for the on-demand delivery of antibiotics [103] . The RBC membrane coating provides immune evasion and triggers the accumulation of nanovaccine at the infected site. Due to the RBC membrane coating on the surface, Van-SGNPs@RBC nanovaccine can adsorb bacterial endotoxins and reduce endotoxin-related side-effects in patients. A large number of gelatinases are secreted from the bacteria in an infectious microenvironment. The nanovaccine is responsible for hydrolyzing the gelatin, and triggers the loaded drug (vancomycin) to reduce bacterial infection [103] . The immune-evasion property of Van-SGNPs@RBC was examined by labelling the NPs with Cy5 and incubating them in RAW 264.7 macrophage cells. The results showed that Van-SGNPs@RBC has less macrophage uptake compared to Van-SGNPs, which indicates the circumvention of the Van-SGNPs@RBC NP by immune cells.