Comparison and process optimization of PLGA, chitosan and silica nanoparticles for potential oral vaccine delivery.

Aim: The study compared performance of nanoparticles prepared from synthetic organic, natural organic and inorganic materials as vaccine delivery platforms. Materials & methods: Various formulation (concentration, polymer/silica:surfactant ratio, solvent) and process parameters (homogenization speed and time, ultrasonication) affecting functional performance characteristics of poly(lactic-co-glycolic acid) (PLGA), chitosan and silica-based nanoparticles containing bovine serum albumin were investigated. Nanoparticles were characterized using dynamic light scattering, x-ray diffraction, scanning/transmission electron microscopy, Fourier transform infrared spectroscopy and in vitro protein release. Results: Critical formulation parameters were surfactant concentration (PLGA, silica) and polymer concentration (chitosan). Optimized nanoparticles were spherical in shape with narrow size distribution and size ranges of 100-300 nm (blank) and 150-400 nm (protein loaded). Protein encapsulation efficiency was 26-75% and released within 48 h in a sustained manner. Conclusion: Critical formulation and process parameters affected size of PLGA, chitosan and silica nanoparticles and protein encapsulation, while silica produced the smallest and most stable nanoparticles.