Vibrio cholerae-loaded poly(DL lactide co-glycolide) microparticles

Area of Science:

• Biomaterials Science
• Vaccine Delivery Systems
• Microbiology

Background:

• Developing effective oral vaccine delivery systems is crucial for combating infectious diseases like cholera.
• Microencapsulation offers a promising strategy to protect antigens and control their release.
• Poly(DL lactide-co-glycolide) (PLG) is a well-established biodegradable polymer for drug and vaccine delivery.

Purpose of the Study:

• To prepare and characterize Vibrio cholerae (VC)-loaded poly(DL lactide-co-glycolide) (PLG) microparticles.
• To investigate the effect of sodium chloride concentration on microparticle characteristics and VC loading.
• To evaluate the in-vitro release profile and in-vivo immunogenicity of the developed microparticles.

Main Methods:

• Water-in-oil-in-water emulsion/solvent extraction technique was employed for microparticle preparation.
• Poly(DL lactide-co-glycolide) (PLG) was dissolved in dichloromethane as the dispersed phase.
• Polyvinylpyrrolidone (PVP) and varying concentrations of sodium chloride (NaCl) were used in the continuous phase for stabilization and optimization.

Main Results:

• Microparticles with a size of 3.8 microm were obtained, achieving high VC loading efficiencies up to 97.8%.
• The inclusion of 5% w/v NaCl in the continuous phase significantly improved VC loading level (55.4 g/mg) and core region content compared to formulations without NaCl.
• A linear in-vitro release profile was observed, and preliminary studies in rats indicated effective immunogenicity for two months post-oral administration.

Conclusions:

• Optimized PLG microparticles demonstrate excellent potential for oral delivery of Vibrio cholerae (VC) vaccines.
• The formulation parameters, particularly NaCl concentration, significantly influence encapsulation efficiency and drug loading.
• These findings provide a foundation for developing advanced vaccine delivery carriers with enhanced immunogenicity.