Adsorption Phenomena of Anionic and Cationic Nanoliposomes on the Surface of Poly(dimethylsiloxane) Microchannel

Abstract

The poly(dimethylsiloxane) (PDMS)-based microchannel of a microcapillary chip is attractive for characterization of nanoparticles (NPs). The surface potential of PDMS is negative in nature, and in the presence of charged NPs, an interaction exists between the NPs and microchannel surface. In this study, the adsorption phenomena of nanoliposomes in the microchannel was investigated using a microfluidic chip designed for the autonomous compensation of hydrostatic pressure flow in the presence of neutral or cationic polymer coating. The Brownian motion of the nanoliposomes in the region of interest was stably observed without any fluid flow. The adsorption phenomena of the nanoliposomes on the microchannel surface arose from hydrophobic and electrostatic interaction, and can be attenuated based on electrostatic repulsion and the excluded volume effect.

Experimental Evaluation and Modeling of Adsorption Phenomena of Nanoliposomes on Poly(dimethylsiloxane) Surfaces

“…The nanoliposomes were prepared using the thinfilm hydration method [10,13]. An appropriate molar ratio of lipids and cholesterol was dissolved in chloroform and the lipid film was deposited on a vial by evaporating the solvent.…”

“…The measured average size of DLPC, DOTMA, and PS nanoliposomes were 117.0 nm, 117.3 nm, and 111.7 nm, whereas the polydispersity indexes were 0.10, 0.08, and 0.08, respectively. The adsorption data of three different nanoliposomes in microchannels (200 μm width, 200 μm height, and 10 mm length,) were obtained from light-sheet illumination [13]. All three nanoliposomes were found to have particle numbers in the region of interest (ROI).…”

“…Adsorption phenomena are crucial in many applications and studies involving NPs [12]. Moreover, adsorption depends on the properties of both NPs and solid surfaces; accordingly, there are different types of interactions, such as hydrophobic or electrostatic interactions [13,14].…”

“…In this study, we attempted to establish a platform for analyzing the adsorption of NPs on solid surfaces using a microchannel setup. The adsorption of nanoliposomes observed under light-sheet illumination was quantitatively analyzed using the experimental data reported in our previous study [13]. An adsorption model was developed to analyze the transient adsorption phase of the nanoliposomes on the PDMS surface under a shorter observation time.…”

Chemical Etching Treatment of Polydimethylsiloxane for Smoothing Microchannel Surface

“…Recently, light-sheet technology, where only the molecules or particles within the focused plane can be illuminated [13], has been combined with microfluidic devices for planar illumination inside the microchannels [14][15][16][17]. Dark field light scattering imaging method using the light sheet illumination inside microchannels enables the observation of individual polymer nanoparticles, nanoliposomes and exosomes [18][19][20][21]. When considering the surface roughness of the microchannel side wall, the uneven (non-smooth) surface at the interface between PDMS and the sample solution causes refraction and scattering of light sheet and thus, results in the degradation of the image quality due to increase in background noise.…”