The Role of Integrated Approach in the Determination of Nanoparticle Sizes in Dispersions

Abstract

Aqueous dispersions of gold and silver nanoparticles (NPs) stabilized with sodium citrate, as well as polymeric NPs based on poly(lactide-co-glycolide) (70 : 30 mol %) stabilized with poly(vinyl alcohol) have been obtained. The sizes of NPs have been determined by transmission electron microscopy (TEM), dynamic light scattering (DLS), and analytical ultracentrifugation (AUC). It has been shown that the diameter of both metallic and polymeric particles measured by TEM is significantly lower than their hydrodynamic diameter Dh determined by DLS. Moreover, it has been found that the Dh value obtained for the studied particles from DLS distributions is overestimated compared to that determined by AUC, because the AUC method is less sensitive to the particle size polydispersity and the presence of large objects in a dispersion.

Preparation and Characterization of Polymeric Microparticles Based on Poly(ethylene brassylate-co-squaric Acid) Loaded with Norfloxacin

“…The dimensional differences that appear between STEM and DLS analysis can be attributed to the fact that microparticles are in a dry, compact state in the first case and a hydrated state in the second one. In the DLS investigation, solvent molecules are attached to the surface of the microparticles through various interactions, which increases the recorded D h [ 50 , 51 ].…”

Synergistic bactericidal combinations between gentamicin and chitosan capped ZnO nanoparticles: A promising strategy for repositioning this first-line antibiotic

“…The tendency to increase particle size when incorporating CS was in agreement with the analysis previously carried out by DLS. However, some differences are observed in the values obtained by SEM since this technique does not allow determining the average diameter in the solvated state, therefore the observed sizes are smaller than those obtained by DLS [ 33 ].

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Highly Stable Docetaxel-Loaded Nanoparticles Based on Poly(D,L-lactide)-b-Poly(ethylene glycol) for Cancer Treatment: Preparation, Characterization, and In Vitro Cytotoxicity Studies

“…As one can see from Figure 2 , TEM images of the particles based on P(D,L)LA n - b -PEG 113 copolymers with relatively short P(D,L)LA block lengths ( n = 50, 180) revealed two populations: individual particles with D < 100 nm and their submicron aggregates ( Figure 2 a,b), which is in accordance with DLS data ( Figure 1 a,b). It should be noted that the presence in suspension of solvated PEG chains surrounding the P(D,L)LA core led to higher values of NP size evaluated by DLS, compared with those estimated by TEM ( Table 3 ), where the corona chains collapsed during drying [ 48 ].…”