Recent Advances in Nanovaccines Using Biomimetic Immunomodulatory Materials

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

Biomimetic NPs have been investigated more as an alternative drug delivery carrier, due to their remarkable blood circulation time, biocompatibility, and targetability. Bacterial membranes stimulate innate and adaptive immunity inside the human body due to the presence of immunogenic adjuvants and antigens, which express numerous pathogens associated with molecular patterns (PAMPs) [61] . Therefore, bacterial-membrane-coated NPs are considered as potential vaccines for antibacterial therapy. Weiwei et al. reported an antibacterial vaccine that showed an effective immune response against pathogens for Neisseria meningitides treatments [60] . The functionalization of the Gold NP (size: 40 nm) with the outer vesicle of the bacterial membrane extracted from E. coli (BM-AuNPs) showed remarkable serum stability (shown in the Figure 5 ). Rapid DC maturation in the lymph node and strong antibody response were induced through the BM-AuNPs vaccination. BM-AuNPs produced bacterium specific T-cell response and higher production of interferon-gamma (IFN-γ) and interleukin 17 (IL-17), which is responsible for the Th1-and Th17-based T-cell response against bacterial infection [61] . against pathogens for Neisseria meningitides treatments [60] . The functionalization of the Gold NP (size: 40 nm) with the outer vesicle of the bacterial membrane extracted from E. coli (BM-AuNPs) showed remarkable serum stability (shown in the Figure 5 ). Rapid DC maturation in the lymph node and strong antibody response were induced through the BM-AuNPs vaccination. BM-AuNPs produced bacterium specific T-cell response and higher production of interferon-gamma (IFN-γ) and interleukin 17 (IL-17), which is responsible for the Th1-and Th17-based T-cell response against bacterial infection [61] . 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 sideeffects in patients. A large number of gelatinases are secreted from the ba