Processing nanoparticles with A4F-SAXS for toxicological studies: Iron oxide in cell-based assays

Area of Science:

• Materials Science
• Nanotechnology
• Biotechnology

Background:

• Nanoparticles require pre-processing for reliable in vitro cell culture assays.
• Key steps include dispersion, de-agglomeration, size fractionation, and characterization.
• Engineered nanoparticles often present as polydisperse systems, complicating analysis.

Purpose of the Study:

• To develop an efficient method for preparing ready-to-use nanoparticle samples for biological assays.
• To characterize polyphosphate-stabilized iron oxide nanoparticles.
• To assess the suitability of processed nanoparticles for toxicological studies.

Main Methods:

• Combined asymmetrical flow field-flow fractionation (A4F) with small-angle X-ray scattering (SAXS) for online analysis.
• Developed a rapid 50-minute procedure for fractionation and size analysis.
• Utilized this method on polyphosphate-stabilized iron oxide nanoparticles in aqueous suspension.

Main Results:

• Achieved narrowly distributed nanoparticle fractions with radii of gyration (R(g)) ranging from 7 to 21 nm.
• Successfully processed highly polydisperse engineered nanoparticle samples.
• Demonstrated that A4F-SAXS processed particles are suitable for toxicological studies.

Conclusions:

• The A4F-SAXS combination offers a time-saving and effective approach for preparing well-characterized nanoparticle fractions.
• This method addresses the challenge of polydispersity in engineered nanoparticles.
• Preliminary tests indicate the potential for using fractionated iron oxide nanoparticles in cell-based toxicity assessments.