Multimodal Dispersion of Nanoparticles: A Comprehensive Evaluation of Size Distribution with 9 Size Measurement Methods.

PURPOSE: Evaluation of particle size distribution (PSD) of multimodal dispersion of nanoparticles is a difficult task due to inherent limitations of size measurement methods. The present work reports the evaluation of PSD of a dispersion of poly(isobutylcyanoacrylate) nanoparticles decorated with dextran known as multimodal and developed as nanomedecine. METHODS: The nine methods used were classified as batch particle i.e. Static Light Scattering (SLS) and Dynamic Light Scattering (DLS), single particle i.e. Electron Microscopy (EM), Atomic Force Microscopy (AFM), Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle Tracking Analysis (NTA) and separative particle i.e. Asymmetrical Flow Field-Flow Fractionation coupled with DLS (AsFlFFF) size measurement methods. RESULTS: The multimodal dispersion was identified using AFM, TRPS and NTA and results were consistent with those provided with the method based on a separation step prior to on-line size measurements. None of the light scattering batch methods could reveal the complexity of the PSD of the dispersion. CONCLUSIONS: Difference between PSD obtained from all size measurement methods tested suggested that study of the PSD of multimodal dispersion required to analyze samples by at least one of the single size particle measurement method or a method that uses a separation step prior PSD measurement.

Asymmetrical flow field-flow fractionation with multi-angle light scattering and quasi-elastic light scattering for characterization of polymersomes: comparison with classical techniques.

Polymersomes formed from amphiphilic block copolymers, such as poly(ethyleneoxide-b-ε-caprolactone) (PEO-b-PCL) or poly(ethyleneoxide-b-methylmethacrylate), were characterized by asymmetrical flow field-flow fractionation coupled with quasi-elastic light scattering (QELS), multi-angle light scattering (MALS), and refractive index detection, leading to the determination of their size, shape, and molecular weight. The method was cross-examined with more classical ones, like batch dynamic and static light scattering, electron microscopy, and atomic force microscopy. The results show good complementarities between all the techniques; asymmetrical flow field-flow fractionation being the most pertinent one when the sample exhibits several different types of population.