N-Acetylcysteine-Loaded Magnetic Nanoparticles for Magnetic Resonance Imaging

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Acute respiratory distress syndrome (ARDS) involves rapid lung inflammation, necessitating precise drug distribution monitoring.
• Targeted drug delivery to heterogeneously damaged lungs requires methods to track spatial distribution.

Purpose of the Study:

• To optimize N-acetylcysteine (NAC) adsorption on poly-l-lysine-modified magnetic nanoparticles (PLLMNPs).
• To evaluate the potential of NAC-loaded PLLMNPs for monitoring drug distribution in the lungs using MRI.

Main Methods:

• Physicochemical characterization of PLLMNPs with varying NAC loading (morphology, size, charge, magnetic properties).
• Thermogravimetric analysis for NAC quantification and cytotoxicity assays.
• MRI relaxometry to assess the magnetic properties and suitability for in vivo imaging.

Main Results:

• An optimal NAC loading concentration of 0.25 mg/mL was identified, yielding nanoparticles of 154 nm size and +32 mV surface charge with good stability and no cytotoxicity.
• MRI relaxometry demonstrated prevailing transverse relaxation with high transverse relaxivity and an r2*/r1 ratio, causing visible hypointensity.
• NAC adsorption significantly altered PLLMNP relaxation properties, indicating potential for drug release monitoring.

Conclusions:

• NAC-loaded PLLMNPs are suitable for in vivo drug distribution studies using MRI.
• The observed MRI signal changes can facilitate in vitro and in vivo monitoring of drug release.