New approach for time-resolved and dynamic investigations on nanoparticles agglomeration

Abstract

Nanoparticle (NP) colloidal stability plays a crucial role in biomedical application not only for human and environmental safety but also for NP efficiency and functionality. NP agglomeration is considered as a possible process in monodispersed NP colloidal solutions, which drastically affects colloidal stability. This process is triggered by changes in the physicochemical properties of the surrounding media, such as ionic strength (IS), pH value, or presence of biomolecules. Despite different available characterization methods for nanoparticles (NPs), there is a lack of information about the underlying mechanisms at the early stage of dynamic behaviors, namely changing in NP size distribution and structure while placing them from a stable colloidal solution to a new media like biological fluids. In this study, an advanced in situ approach is presented that combines small angle X-ray scattering (SAXS) and microfluidics, allowing label-free, direct, time-resolved, and dynamic observations of the early stage of NP interaction/agglomeration initiated by environmental changes. It is shown for silica NPs that the presence of protein in the media enormously accelerates the NP agglomeration process compared to respective changes in IS and pH. High IS results in a staring agglomeration process after 40 min, though, in case of protein presence in media, this time decreased enormously to 48 s. These time scales show that this method is sensitive and precise in depicting the dynamics of fast and slow NP interactions in colloidal conditions and therefore supports understanding the colloidal stability of NPs in various media concluding in safe and efficient NP designing for various applications.

Development of Lactoferrin-Loaded Liposomes for the Management of Dry Eye Disease and Ocular Inflammation

“…Physicochemical parameters such as Z av and PI or ZP were acquired by dynamic light scattering (DLS) and electrophoresis laser doppler, respectively, using a ZetaSizer NanoZS (Malvern Instruments, Malvern, UK). Samples were diluted (1:20) and measurements were carried out by triplicate at 25 °C [ 36 ].…”

In‐situ Investigations on Gold Nanoparticles Stabilization Mechanisms in Biological Environments Containing HSA

“…Accordingly, the correlation signal decays slowly in time, and the reported NPs sizes are larger. [ 29,30,39 ]…”

“…Accordingly, the correlation signal decays slowly in time, and the reported NPs sizes are larger. [29,30,39] In Figure 3a, the experimental SAXS patterns and the corresponding model-based fits are shown. The SAXS patterns show a plateau in the low q-range.…”

“…This information helps to predetermine NPs behaviors and resultantly to steer their behavior in the biological environment. [ 5 ]…”

In situ Electron Microscopy of Complex Biological and Nanoscale Systems: Challenges and Opportunities

“…This is analogous to the well-developed single-particle image processing algorithms for cryo-EM (Punjani et al, 2017). To study the dynamics of proteins (Zheng et al, 2003;Chen and Lee, 2010;Lutz-Bueno et al, 2016;Knoška et al, 2020) and nanoparticles (Ghazal et al, 2016), microfluidic platforms have been coupled to optical (Zheng et al, 2003;Sakai et al, 2019), fluorescence microscopies (Chen and Lee, 2010;Ding et al, 2016;Hua et al, 2016;Tian et al, 2019), cryo-EM (Fuest et al, 2019;Mäeots et al, 2020), and small-angle Xray scattering (Lutz-Bueno et al, 2016;Anaraki et al, 2020). Some examples include capturing the transient conformations of DNA during self-assembly (Wang et al, 2020), imaging protein crystallization (Zheng et al, 2003) (Figure 6A) or adsorption (Yu et al, 2020), probing intracellular communication via gap junctions (Chen and Lee, 2010) (Figure 6B), mapping the dynamics of amyloid formation (Lutz-Bueno et al, 2016;Saar et al, 2016) (Figure 6C), chemical and molecular mapping of live biofilms (Ding et al, 2016) (Figure 6D), as well as imaging biomineralization and bio-sedimentation (He et al, 2019;Narayanan et al, 2020).…”