pH-sensitive nanoparticles of poly(amino acid) dodecanoate complexes

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Development of novel nanoparticle systems for drug delivery is crucial.
• Poly(amino acids) offer versatile building blocks for functional materials.
• Complexation with fatty acids can yield stable nanoparticle structures.

Purpose of the Study:

• To synthesize and characterize nanoparticles formed by poly(L-arginine) (PLA), poly(L-histidine) (PLH), and poly(L-lysine) (PLL) complexed with dodecanoic acid (C12).
• To investigate the pH-sensitive properties, stability, and morphology of these complex nanoparticles.
• To evaluate their potential as carriers for hydrophobic molecules.

Main Methods:

• Nanoparticle synthesis via complexation of poly(amino acids) with dodecanoic acid.
• Characterization using dynamic light scattering, zeta potential, atomic force microscopy, fluorescence, and circular dichroism spectroscopy.
• Encapsulation efficiency and drug loading studies using Q(10) as a model drug.

Main Results:

• Synthesized nanoparticles (PLA-C12, PLH-C12, PLL-C12) with diameters ranging from 120-200 nm.
• Demonstrated pH-sensitive dissolution and tunable surface charges based on the poly(amino acid) used.
• Observed core-shell morphology with a stoichiometric complex core and a shell of uncomplexed poly(amino acid).
• Achieved a maximum Q(10) drug loading of approximately 13% (w/w).
• Circular dichroism revealed predominantly alpha-helix structures for PLA-C12 and PLL-C12, and beta-sheet for PLH-C12.

Conclusions:

• Poly(amino acid)-dodecanoic acid complexes form stable, pH-sensitive nanoparticles with tunable properties.
• The core-shell structure and adjustable surface charge make them promising for drug delivery applications.
• These nanoparticles represent a simple and attractive system for controlled release of hydrophobic drugs.