Dmitry Klinov

Various graphite materials are either already in use or are considered to be preferred in biomedical applications, such as biomaterials or sensor substrates. Most of these applications are related to important issues such as biocompatibility, adsorption of protein molecules and, in particular, the conformational state of adsorbed protein molecules on graphite. Using high-resolution AFM, we have shown that the surface of highly oriented pyrolytic graphite (HOPG) induces the denaturation of four human plasma proteins, such as ferritin, fibrinogen, human serum albumin (HSA), and immunoglobulin (IgG). Protein denaturation is accompanied by a decrease in the height of protein globules and spreading of the denatured part of the protein molecule over the surface. In contrast, the modification of graphite with amphiphilic oligoglycines with hydrocarbon tails, leading to the formation of a monolayer, preserves the native conformation of protein molecules and provides milder conditions for protein adsorption compared to commonly used mica. Protein denaturation on graphite can be universal for "soft" globular proteins.
We have shown that proteins adsorbed on a surface can influence the interaction of this surface with cells. In this study, we studied the binding of human serum albumin (HSA), fibrinogen (FBR), and immunoglobulin G (IgG) to pegylated single-walled carbon nanotubes (PEG-SWNTs) and evaluated the effect of PEG-SWCNTs treated with these proteins on neutrophils in whole blood samples. Measurements of adsorption parameters showed the tight binding of proteins to PEG-SWCNTs. AFM was used to directly observe protein binding to the side walls of PEG-SWCNTs. We used fluorescein-labeled IgG to establish the stability of PEG-SWNT-IgG complexes in plasma. When SWCNTs with proteins were added to blood samples, all of the listed plasma proteins mitigated damage to neutrophils and damage was observed only after blood irradiation. Our data demonstrate the ability of adsorbed plasma proteins to influence the neutrophil response induced by the presence of PEG-SWNTs in whole blood.

1. Morozova OV, Sokolova AI, Pavlova ER, Isaeva EI, Obraztsova EA, Ivleva EA, Klinov DV. Protein nanoparticles: cellular uptake, intracellular distribution, biodegradation and induction of cytokine gene expression. Nanomedicine. 2020 Nov;30:102293. doi: 10.1016/j.nano.2020.102293. Epub 2020 Aug 25. PMID: 32853784.
2. Klinov DV, Protopopova AD, Andrianov DS, Litvinov RI, Weisel JW. An Improved Substrate for Superior Imaging of Individual Biomacromolecules with Atomic Force Microscopy. Colloids Surf B Biointerfaces. 2020 Dec;196:111321. doi: 10.1016/j.colsurfb.2020.111321. Epub 2020 Aug 16. PMID: 32841787.
3. Konopsky V, Mitko T, Aldarov K, Alieva E, Basmanov D, Moskalets A, Matveeva A, Morozova O, Klinov D. Photonic crystal surface mode imaging for multiplexed and high-throughput label-free biosensing. Biosens Bioelectron. 2020 Nov 15;168:112575. doi: 10.1016/j.bios.2020.112575. Epub 2020 Sep 1. PMID: 32892115.
4. Reshetnikov RV, Stolyarova AV, Zalevsky AO, Panteleev DY, Pavlova GV, Klinov DV, Golovin AV, Protopopova AD. A coarse-grained model for DNA origami. Nucleic Acids Res. 2018 Feb 16;46(3):1102-1112. doi: 10.1093/nar/gkx1262. PMID: 29267876; PMCID: PMC5814798.
5. Dubrovin EV, Barinov NA, Schäffer TE, Klinov DV. In Situ Single-Molecule AFM Investigation of Surface-Induced Fibrinogen Unfolding on Graphite. Langmuir. 2019 Jul 30;35(30):9732-9739. doi: 10.1021/acs.langmuir.9b01178. Epub 2019 Jul 18. PMID: 31282164.
6. Morozova OV, Pavlova ER, Bagrov DV, Barinov NA, Prusakov KA, Isaeva EI, Podgorsky VV, Basmanov DV, Klinov DV. Protein nanoparticles with ligand-binding and enzymatic activities. Int J Nanomedicine. 2018 Oct 18;13:6637-6646. doi: 10.2147/IJN.S177627. PMID: 30425479; PMCID: PMC6202000.
7.Kasumov AY, Kociak M, Guéron S, Reulet B, Volkov VT, Klinov DV, Bouchiat H. Proximity-induced superconductivity in DNA. Science. 2001 Jan 12;291(5502):280-2. doi: 10.1126/science.291.5502.280. PMID: 11209072.