Biology subjects

Katti, D. S.

Publications and source records attributed to Katti, D. S..

2 recordsLinked to original sources

bioRxiv2019

Physicochemical changes in plasma membrane mirror nanoparticle-mediated cytotoxicity

The aim of this chapter was to understand the influence of nanoparticle challenge on physicochemical characteristics of the cells and to correlate these changes with cytotoxic response of nanoparticles. A nanoparticle surface charge and a concentration-dependent cytotoxic response were observed in the breast cancer cell lines MDA MB 231 and SKBR3. The cationic gold nanoparticles were more cytotoxic to cells as compared to anionic gold nanoparticles. It was also observed that cationic nanoparticles compromised the integrity of the plasma membrane at higher concentrations. Cationic nanoparticle challenge also caused changes in physicochemical characteristics of plasma membrane. Higher concentration of cationic nanoparticles caused an irreversible change in the surface charge density of cells. However, anionic gold nanoparticles did not show any such effect. It was observed that the ROS-mediated oxidative stress was the mechanism of cationic gold nanoparticle-mediated cytotoxic effect. Mitochondrial depolarization was observed in both anionic and cationic nanoparticle challenge. Therefore, the role of mitochondrial ROS in nanoparticle-mediated cytotoxicity is questionable. Finally, a generalized model involving modulation of intracellular Ca2+ can potentially provide an explanation for the observed pluralistic response of the cells towards nanoparticle challenge.

bioengineering↗

bioRxiv2018

Quantitative Estimation of Long-Range Interactions at the Nanoscale

Nano-bio interfaces attune nanoparticle-mediated biological responses. The nano-bio interface, like all interfacial interactions, is governed by non-covalent long-range interactions (LRIs). These LRIs include electrostatic, electrodynamic and acid-base interactions. There is a lack of understanding about the contribution of LRIs at the nano-bio interface for want of suitable methods for the estimation of dispersive, acidic, and basic components of the surface tension of nanoparticles. To address this, we developed an experimental and theoretical framework for the estimation of surface tension components of nanoparticles and biomacromolecules by partitioning them in a biphasic system. The work presented here is the first instance in the literature for estimating the surface tension components of nanoparticles and biomacromolecules suspended in aqueous suspensions. We also observed that LRIs have a deterministic role in biologically relevant phenomena such as salt-induced nanoparticle agglomeration and protein-nanoparticle interaction. Collectively, the results presented in this work provide a rapid and inexpensive framework for predicting the energetics of nanoparticle-nanoparticle and nanoparticle-protein interactions by estimating average ensemble surface characteristics like surface tension and surface charge density.

bioengineering↗