Polysaccharide-covered nanoparticles with improved shell stability using click-chemistry strategies

Area of Science:

• Polymer Chemistry
• Nanotechnology
• Materials Science

Background:

• Biodegradable nanoparticles offer versatile applications in drug delivery and biomaterials.
• Developing stable nanoparticle formulations is crucial for their effective use.
• Dextran and polylactic acid (PLA) are biocompatible polymers with potential for nanoparticle development.

Purpose of the Study:

• To formulate dextran-covered polylactic acid (PLA) nanoparticles using two distinct strategies.
• To investigate the colloidal stability of these nanoparticles under various conditions.
• To compare the stability offered by physically adsorbed versus covalently linked dextran shells.

Main Methods:

• Synthesis of dextran-graft-PLA copolymers via click chemistry between azide-multifunctionalized dextran (DexN3) and alkyne end-functionalized PLA (α-alkyne PLA).
• Nanoprecipitation of copolymers without additional surfactants.
• Emulsification of DexN3 with PLA followed by in situ copolymer formation at the liquid/liquid interface using o/w emulsion/evaporation.
• Characterization of the resulting biodegradable core/shell nanoparticles.
• Assessment of colloidal stability in the presence of NaCl and sodium dodecyl sulfate (SDS).

Main Results:

• Biodegradable core/shell polymeric nanoparticles were successfully obtained through both formulation strategies.
• Physically adsorbed dextran shells were displaced by SDS, indicating limited stability.
• Covalently linked dextran shells demonstrated permanent colloidal stability, resisting displacement by SDS.

Conclusions:

• Two effective methods for creating dextran-covered PLA nanoparticles were developed.
• Covalently linking dextran to PLA provides superior and permanent colloidal stability compared to physical adsorption.
• These findings are significant for developing robust and stable nanocarriers for various applications.