Comparative study of DNA encapsulation into PLGA microparticles using modified double emulsion methods and spray...

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Molecular Biology

Background:

• Microencapsulation of DNA is explored for DNA immunization and tissue engineering.
• Key challenges include particle size, DNA stability, and controlled release.
• Existing methods like spray drying and double emulsion have limitations regarding DNA integrity.

Purpose of the Study:

• To investigate DNA microencapsulation methods that minimize shear forces and DNA degradation.
• To evaluate the use of polyethylenimine (PEI) for DNA stabilization and improved encapsulation.
• To compare spray drying and double emulsion techniques for encapsulating DNA and DNA/PEI complexes.

Main Methods:

• DNA microparticles were prepared using spray drying and modified WOW double emulsion techniques.
• Polyethylenimine (PEI) was used as a complexation agent to stabilize DNA.
• Particle size was analyzed using laser diffractometry and SEM; encapsulation efficiency was determined photometrically; DNA release kinetics were studied.

Main Results:

• Microparticles with sizes below 10 micrometers, suitable for phagocytic uptake, were successfully prepared.
• Encapsulation efficiencies ranged from 100% to 35% at low DNA loadings.
• DNA complexation with PEI significantly reduced initial burst release compared to non-complexed DNA.
• Double emulsion techniques demonstrated more continuous DNA release profiles than spray-dried particles without PEI.

Conclusions:

• Microencapsulation of DNA is feasible using spray drying and double emulsion techniques, with PEI complexation enhancing DNA stability and release profiles.
• These optimized microparticles hold promise for advanced DNA delivery applications in immunization and regenerative medicine.
• The choice of encapsulation technique and the use of PEI significantly impact DNA release characteristics and particle properties.