Cerium dioxide nanoparticles increase immunogenicity of the influenza vaccine.

We have demonstrated the influence of cerium dioxide nanoparticles on the immunogenicity of the influenza vaccine on an example of liquid split inactivated Vaxigrip vaccine. Antibody titers were analyzed using the hemagglutination inhibition (HI) assay. Seroprotection, seroconversion, the geometric mean titers (GMTs) and the factor increase (FI) in the GMTs were calculated. The effect of nano-ceria surface stabilizer on the enhancement of immunogenicity was shown. The vaccine modified by citrate-stabilized nano-ceria, in contrast to a non-modified Vaxigrip vaccine, did not provide an adequate level of seroprotection, and seroconversion after vaccination was 66.7% on days 49-63 for virus strain А(H1N1) and 100% on day 49 for virus strain B/Yamagata. For the low immunogenic influenza B virus, the rise in antibody titers (GMT/IF) was 24.38/3.28 after the first injection and 50.40/6.79 on day 49. For the vaccine modified by non-stabilized nano-ceria, for all virus strains under study, on day 63, upon immunization notable levels of seroprotection, seroconversion and GMT/IF were registered (higher than for the non-modified Vaxigrip vaccine). The successful attempt to modify the influenza vaccine demonstrates the possible ways of increasing the specific activity of vaccines using nano-ceria.

Immunomodulation and T helper TH1/TH2 response polarization by CeO2 and TiO2 nanoparticles.

Immunomodulation by nanoparticles, especially as related to the biochemical properties of these unique materials, has scarcely been explored. In an in vitro model of human immunity, we demonstrate two catalytic nanoparticles, TiO2 (oxidant) and CeO2 (antioxidant), have nearly opposite effects on human dendritic cells and T helper (T(H)) cells. For example, whereas TiO2 nanoparticles potentiated DC maturation that led towards T(H)1-biased responses, treatment with antioxidant CeO2 nanoparticles induced APCs to secrete the anti-inflammatory cytokine, IL-10, and induce a T(H)2-dominated T cell profile. In subsequent studies, we demonstrate these results are likely explained by the disparate capacities of the nanoparticles to modulate ROS, since TiO2, but not CeO2 NPs, induced inflammatory responses through an ROS/inflammasome/IL-1ß pathway. This novel capacity of metallic NPs to regulate innate and adaptive immunity in profoundly different directions via their ability to modulate dendritic cell function has strong implications for human health since unintentional exposure to these materials is common in modern societies.

Cerium nitrate in the management of burns.

BACKGROUND: The introduction of early excision of the burn eschar has contributed to a reduction in burn-related mortality but is not appropriate in all circumstances. Cerium nitrate has been used since 1976, usually in combination with silver sulphadiazine, to improve outcome where early excision is not performed. However, has still not gained universal acceptance. The evidence for its use is reviewed. METHODS: A MEDLINE search was performed for the years 1966-2003 using keywords 'cerium', 'sulphadiazine', 'Flammacerium', 'lanthanides' and 'topical therapy for burns'. The reference lists of key articles were then sifted for other relevant articles. RESULTS: Cerium has been shown to reduce mortality and morbidity in the treatment of severe burns. This benefit is derived from its action on the burn eschar. It binds and denatures the lipid protein complex liberated from burnt skin that is responsible for the profound immunosuppression associated with major cutaneous burns. It has only limited antimicrobial properties. CONCLUSIONS: Cerium nitrate is an excellent topical treatment for most cutaneous burns not undergoing immediate excision and closure.