Carbohydrate modified ultrafine ceramic nanoparticles for allergen immunotherapy.

The uses of drug-delivery systems in allergen specific immunotherapy appear to be a promising approach due to their ability to act as adjuvants, transport the allergens to immune-competent cells and tissues and reduce the number of administrations. The aim of this work was to evaluate the carbohydrate modified ultrafine ceramic core based nanoparticles (aquasomes) as adjuvant/delivery vehicle in specific immunotherapy using ovalbumin (OVA) as an allergen model. Prepared nanoparticles were characterized for size, shape, zeta potential, antigen integrity, surface adsorption efficiency and in vitro release. The humoral and cellular-induced immune responses generated by OVA adsorbed aquasomes were studied by two intradermal immunizations in BALB/c mice. OVA sensitized mice were treated with OVA adsorbed aquasomes and OVA adsorbed aluminum hydroxide following established protocol. Fifteen days after therapy, animals were challenged with OVA and different signs of anaphylactic shock were evaluated. Developed aquasomes possessed a negative zeta potential (-11.3 mV) and an average size of 47 nm with OVA adsorption efficiency of ~60.2 μg mg(-1) of hydroxyapatite core. In vivo immune response after two intradermal injections with OVA adsorbed aquasomes resulted in a mixed Th1/Th2-type immune response. OVA-sensitized mice model, treatment with OVA adsorbed aquasomes elicited lower levels of IgE (p<0.05), serum histamine and higher survival rate in comparison with alum adsorbed OVA. Symptoms of anaphylactic shock in OVA aquasome-treated mice were weaker than the one induced in the alum adsorbed OVA group. Results from this study demonstrate the valuable use of aquasomes in allergen immunotherapy.