Csilla Gergely - Academia.edu (original) (raw)

Papers by Csilla Gergely

Scientific Reports, 2020

In recent years, fluorescent nanodiamond (fND) particles containing nitrogen-vacancy (NV) centers... more In recent years, fluorescent nanodiamond (fND) particles containing nitrogen-vacancy (NV) centers gained recognition as an attractive probe for nanoscale cellular imaging and quantum sensing. For these applications, precise localization of fNDs inside of a living cell is essential. Here we propose such a method by simultaneous detection of the signal from the NV centers and the spectroscopic Raman signal from the cells to visualize the nucleus of living cells. However, we show that the commonly used Raman cell signal from the fingerprint region is not suitable for organelle imaging in this case. Therefore, we develop a method for nucleus visualization exploiting the region-specific shape of C-H stretching mode and further use k-means cluster analysis to chemically distinguish the vicinity of fNDs. Our technique enables, within a single scan, to detect fNDs, distinguish by chemical localization whether they have been internalized into cell and simultaneously visualize cell nucleus wi...

Neurochemistry International, 2021

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License

ACS Applied Materials & Interfaces, 2019

International Journal of Experimental Dental Science, 2016

Proper treatment of dental caries demands detection of carious lesions at an early stage and a mi... more Proper treatment of dental caries demands detection of carious lesions at an early stage and a minimal invasive cavity preparation to preserve the maximum tooth structure. Various devices use fluorescence for caries detection via recording the red fluorescence generated by dentin caries under illumination. The aim of this study was to evaluate the porphyrin and pentosidine involvement in the red fluorescence observed in enamel and dentin caries when illuminated with the Soprolife® camera (Sopro, Acteon Group, La Ciotat, France) and Vistacam® camera (Dürr Dental AG, Bietigheim-Bissingen, Germany). Three techniques were used: single photon fluorescence spectroscopy, micro-Raman spectroscopy, and color analysis with ImajeJ software. Cross-sections of human teeth, scored from 0–6 with the International Caries Detection and Assessment System (ICDAS), were examined by fluorescence microscopy. Teeth spectra of each ICDAS score were compared with those of protoporphyrin IX (PpIX), porphyrin...

Stem Cell Research & Therapy, 2018

Langmuir : the ACS journal of surfaces and colloids, Jul 19, 2016

Selective deposition of peptides from liquid solutions to n- and p-doped silicon has been demonst... more Selective deposition of peptides from liquid solutions to n- and p-doped silicon has been demonstrated. The selectivity is governed by peptide/silicon adhesion differences. A noninvasive, fast characterization of the obtained peptide layers is required to promote their application for interfacing silicon-based devices with biological material. In this study we show that spectroscopic ellipsometry-a method increasingly used for the investigation of biointerfaces-can provide essential information about the amount of adsorbed peptide material and the degree of coverage on silicon surfaces. We observed the formation of peptide multilayers for a strongly binding adhesion peptide on p-doped silicon. Application of the patterned layer ellipsometric evaluation method combined with Sellmeier dispersion led to physically consistent results, which describe well the optical properties of peptide layers in the visible spectral range. This evaluation allowed the estimation of surface coverage, wh...

Journal of Biomedical Optics, 2015

Nanoscale research letters, 2014

The way cells explore their surrounding extracellular matrix (ECM) during development and migrati... more The way cells explore their surrounding extracellular matrix (ECM) during development and migration is mediated by lamellipodia at their leading edge, acting as an actual motor pulling the cell forward. Lamellipodia are the primary area within the cell of actin microfilaments (filopodia) formation. In this work, we report on the use of porous silicon (pSi) scaffolds to mimic the ECM of mesenchymal stem cells from the dental pulp (DPSC) and breast cancer (MCF-7) cells. Our atomic force microscopy (AFM), fluorescence microscopy, and scanning electron microscopy (SEM) results show that pSi promoted the appearance of lateral filopodia protruding from the DPSC cell body and not only in the lamellipodia area. The formation of elongated lateral actin filaments suggests that pores provided the necessary anchorage points for protrusion growth. Although MCF-7 cells displayed a lower presence of organized actin network on both pSi and nonporous silicon, pSi stimulated the formation of extended...

Nanoscale Research Letters, 2012

PloS one, 2013

A prior peripheral nerve injury in vivo, promotes a rapid elongated mode of sensory neurons neuri... more A prior peripheral nerve injury in vivo, promotes a rapid elongated mode of sensory neurons neurite regrowth in vitro. This in vitro model of conditioned axotomy allows analysis of the cellular and molecular mechanisms leading to an improved neurite re-growth. Our differential interference contrast microscopy and immunocytochemistry results show that conditioned axotomy, induced by sciatic nerve injury, did not increase somatic size of adult lumbar sensory neurons from mice dorsal root ganglia sensory neurons but promoted the appearance of larger neurites and growth cones. Using atomic force microscopy on live neurons, we investigated whether membrane mechanical properties of growth cones of axotomized neurons were modified following sciatic nerve injury. Our data revealed that neurons having a regenerative growth were characterized by softer growth cones, compared to control neurons. The increase of the growth cone membrane elasticity suggests a modification in the ratio and the in...

Journal of chemical information and modeling, Jan 28, 2014

Despite extensive recent research efforts on material-specific peptides, the fundamental problem ... more Despite extensive recent research efforts on material-specific peptides, the fundamental problem to be explored yet is the molecular interactions between peptides and inorganic surfaces. Here we used computer simulations (density functional theory and classical molecular dynamics) to investigate the adsorption mechanism of silicon-binding peptides and the role of individual amino acids in the affinity of peptides for an n-type silicon (n(+)-Si) semiconductor. Three silicon binding 12-mer peptides previously elaborated using phage display technology have been studied. The peptides' conformations close to the surface have been determined and the best-binding amino acids have been identified. Adsorption energy calculations explain the experimentally observed different degrees of affinity of the peptides for n(+)-Si. Our residual scanning analysis demonstrates that the binding affinity relies on both the identity of the amino acid and its location in the peptide sequence.

We report on a strong and tunable magnetic optical nonlinear response of Bacteriorhodopsin (BR) u... more We report on a strong and tunable magnetic optical nonlinear response of Bacteriorhodopsin (BR) under "off resonance" femtosecond (fs) pulse excitation, by detecting the polarization map of the noncollinear second harmonic signal of an oriented BR film, as a function of the input beam power. BR is a light-driven proton pump with a unique photochemistry initiated by the all trans retinal chromophore embedded in the protein. An elegant application of this photonic molecular machine has been recently found in the new area of optogenetics, where genetic expression of BR in brain cells conferred a light responsivity to the cells enabling thus specific stimulation of neurons. The observed strong tunable magnetic nonlinear response of BR might trigger promising applications in the emerging area of pairing optogenetics and functional magnetic resonance imaging susceptible to provide an unprecedented complete functional mapping of neural circuits.

Journal of the Optical Society of America B, 2013

The Journal of Chemical Physics, 2001

We present a comparative study of the structural parameters characterizing thin macromolecular ad... more We present a comparative study of the structural parameters characterizing thin macromolecular adsorbed films that are obtained from two optical techniques: optical waveguide lightmode spectroscopy (OWLS) and scanning angle reflectometry (SAR). We use polyelectrolyte multilayers and polyelectrolyte multilayers/protein films to perform this study. The comparison between the information obtained with the two methods is possible because the buildup of the polyelectrolyte multilayers is known to become substrate independent after the deposition of the first few polyelectrolyte layers. The analysis of the optical data requires usually to postulate a refractive index profile for the interface. Two profiles have been used: the homogeneous and isotropic monolayer and the bilayer profiles. When the refractive index profile of an adsorbed film is well approximated by a homogeneous and isotropic monolayer, as shown by using an analysis of the deposited films in terms of optical invariants, the...

Journal of Chemical Information and Modeling, 2013

Journal of Biomedical Optics, 2013

Biophysical Journal, 1997