Ionically crosslinked chitosan/tripolyphosphate nanoparticles for oligonucleotide and plasmid DNA delivery

Area of Science:

• Biomaterials Science
• Gene Therapy
• Nanotechnology

Background:

• Chitosan (CS) nanoparticles are explored for gene delivery.
• Ionic gelation with pentasodium tripolyphosphate (TPP) is a common formulation method.
• Investigating CS/TPP nanoparticles for DNA delivery is crucial for non-viral gene therapy.

Purpose of the Study:

• To formulate and characterize ionically crosslinked chitosan (CS)/pentasodium tripolyphosphate (TPP) nanoparticles for gene delivery.
• To evaluate their physical-chemical properties, in vitro transfection efficiency, cellular uptake, and in vivo gene expression.
• To assess the impact of co-formulating with bovine serum albumin (BSA).

Main Methods:

• Formulation of CS/TPP nanoparticles using ionic gelation with plasmid DNA or dsDNA oligomers.
• Characterization using TEM, assessment of encapsulation efficiency, physical stability, and DNA release.
• In vitro studies in HEK 293 cells for transfection efficiency and cellular uptake (confocal microscopy).
• In vivo gene expression analysis in mice after intratracheal administration.

Main Results:

• CS/TPP nanoparticles exhibited high encapsulation efficiencies for DNA, independent of CS molecular weight.
• TEM revealed spherical nanoparticles, unlike conventional chitosan polyplexes.
• Low molecular weight (LMW) CS/TPP nanoparticles demonstrated sustained high gene expression in vitro (4-10 days).
• LMW CS/TPP nanoparticles showed strong in vivo beta-galactosidase expression after intratracheal administration.

Conclusions:

• Ionically crosslinked CS/TPP nanoparticles are a stable and effective non-viral gene delivery system.
• LMW CS/TPP nanoparticles offer promising sustained gene expression and in vivo efficacy.
• These nanoparticles provide a foundation for further optimization in gene therapy applications.