Protective efficacy of Hla-MntC-SACOL0723 fusion protein adjuvanted in alum and MPL against Staphylococcus aureus sepsis infection in mice

Monophosphoryl lipid A as a co-adjuvant in methicillin-resistant Staphylococcus aureus vaccine development: improvement of immune responses in a mouse model of infection

To increase the effectiveness of methicillin-resistant Staphylococcus aureus vaccines (MRSA), a new generation of immune system stimulating adjuvants is necessary, along with other adjuvants. In some vaccines, monophosphoryl lipid A (MPLA) as a toll-like receptor 4 agonist is currently used as an adjuvant or co-adjuvant. MPLA could increase the immune response and vaccine immunogenicity. The current investigation assessed the immunogenicity and anti-MRSA efficacy of recombinant autolysin formulated in MPLA and Alum as co-adjuvant/adjuvant. r-Autolysin was expressed and purified by Ni-NTA affinity chromatography and characterized by SDS-PAGE. Then, the vaccine candidate formulation in MPLAs and Alum was prepared. To investigate the immunogenic responses, total IgG, isotype (IgG1 and IgG2a) levels, and cytokines (IL-4, IL-12, TNF-α, and IFN-γ) profiles were evaluated by ELISA. Also, the bacterial burden in internal organs, opsonophagocytosis, survival rate, and pathobiology changes was compared among the groups. Results demonstrated that mice immunized with the r-Autolysin + Alum + MPLA Synthetic and r-Autolysin + Alum + MPLA Biologic led to increased levels of opsonic antibodies, IgG1, IgG2a isotype as well as increased levels of cytokines profiles, as compared with other experimental groups. More importantly, mice immunized with MPLA and r-Autolysin exhibited a decrease in mortality and bacterial burden, as compared with the control group. The highest level of survival was seen in the r-Autolysin + Alum + MPLA Synthetic group. We concluded that both MPLA forms, synthetic and biological, are reliable candidates for immune response improvement against MRSA infection.

Core-shell alum-borneol fiber for high bioavailability

Currently, the treatment of burns poses a significant challenge to clinical surgical. The use of nanofibers combined with drugs provides an entirely new option for treating burns. Alum-borneol combination has been shown as a promising alternative in clinical burn treatment. However, the utilization of the alum-borneol combination is not optimistic due to the low solubility of borneol. In this study, alum-borneol incorporated polyvinyl pyrrolidone fibers with a core-shell structure were fabricated through coaxial electrospinning. In vitro Borneol release behavior of fibers with different ratios of alum to borneol was explored. Scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimeter, in vitro drug release, and in vitro release mechanism were evaluated. The results showed that the fiber membranes maintained an integrated morphology. In vitro dissolution data showed an improved solubility of borneol, which reached more than 82% at 240 min in alum-borneol fibers. It was 4.8 times higher than borneol powder, and the ratio of alum to borneol was 2:1 for the best results. Therefore, alum-borneol incorporated polyvinyl pyrrolidone fibers can significantly improve the dissolution rate of borneol, which opens up a new way for the combined application of the alum and borneol.