Preparation of Chitosan Nanoparticles as a Capable Carrier for Antigen Delivery and Antibody Production

BACKGROUND: Chitosan (CS) nanoparticles have attracted considerable attention as a non-viral and cationic carrier for delivery of therapeutic proteins and antigens and offer non-invasive routes of administration such as oral, nasal and ocular routes, and also show adjuvant characteristics for vaccines. OBJECTIVES: Preparation and formulation of CS nanoparticles as a capable carrier with immunoadjuvant properties to enhance the bioavailability of antigen and produce antibody with high affinity. MATERIALS AND METHODS: CS nanoparticles were produced by ionic gelation process of sodium tripolyphosphate (TPP) with CS. Particle size and morphology of nanoparticles were determined using Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM) and also direct observation under light microscope. The influence of the initial BSA concentration and CS concentration on loading efficiency and release behavior was evaluated. The ε-toxin (derived from Clostridium perfringens type D) was loaded on CS nanoparticles and the complex was injected hypodermically into the rabbits for once. The anti ε-toxin antibody level in blood serum was evaluated using Dot Blot and ELISA methods. RESULTS: The CS nanoparticles in different groups have a particle diameter (Z-average) in approximate ranges of 200-400, 300-600, 450-800 nm and a positive Zeta potential (32.4 - 48.6 mv). Optimum loading efficiency was achieved for CS at a concentration of 0.5 mg.mL(-1) and TPP of 1.0 mg.mL(-1). The results showed that the toxin-CS complex produces antitoxin at levels more than twice as high the control. CONCLUSION: The CS nanoparticles can be used as a good biodegradable carrier for protein and antigen delivery.