Laurent Guyon

Dr. Laurent Guyon

Interdisciplinary Research Institute of Grenoble (IRIG), Universite Grenoble Alpes, 38000 Grenoble, France
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Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 May 2021 in Cancers
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SSSoha Reda El Sayed
Soha Reda El Sayed
JCJustine Cristante
Justine Cristante
Laurent GuyonLaurent Guyon
Laurent Guyon
JDJosiane Denis
Josiane Denis
OCOlivier Chabre
Olivier Chabre
NCNadia Cherradi
Nadia Cherradi
The discovery of microRNAs (miRNAs) in 1993 has challenged the dogma of gene expression regulation. MiRNAs affect most of cellular processes from metabolism, through cell proliferation and differentiation, to cell death. In cancer, deregulated miRNA expression leads to tumor development and progression by promoting acquisition of cancer hallmark traits. The multi-target action of miRNAs, which enable regulation of entire signaling networks, makes them attractive tools for the development of anti-cancer therapies. Hence, supplementing downregulated miRNA by synthetic oligonucleotides or silencing overexpressed miRNAs through artificial antagonists became a common strategy in cancer research. However, the ultimate success of miRNA therapeutics will depend on solving pharmacokinetic and targeted delivery issues. The development of a number of nanocarrier-based platforms holds significant promises to enhance the cell specific controlled delivery and safety profile of miRNA-based therapies. In this review, we provide among the most comprehensive assessments to date of promising nanomedicine platforms that have been tested preclinically, pertaining to the treatment of selected solid tumors including lung, liver, breast, and glioblastoma tumors as well as endocrine malignancies. The future challenges and potential applications in clinical oncology are discussed.

15 April 2006 in Journal of Applied Physics
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Journal Article
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MBMatthieu Baudelet
Matthieu Baudelet
Laurent GuyonLaurent Guyon
Laurent Guyon
JYJin Yu
Jin Yu
JWJean-Pierre Wolf
Jean-Pierre Wolf
TATanguy Amodeo
Tanguy Amodeo
PLPatrick Laloi
Patrick Laloi
Bacterial samples (Escherichia coli and Bacillus subtilis) have been analyzed by laser-induced breakdown spectroscopy (LIBS) using femtosecond pulses. We compare the obtained spectra with those resulting from the classical nanosecond LIBS. Specific features of femtosecond LIBS have been demonstrated, very attractive for analyzing biological sample: (i) a lower plasma temperature leading to negligible nitrogen and oxygen emissions from excited ambient air and a better contrast in detection of trace mineral species; and (ii) a specific ablation regime that favors intramolecular bonds emission with respect to atomic emission. A precise kinetic study of molecular band head intensities allows distinguishing the contribution of native CN bonds released by the sample from that due to carbon recombination with atmospheric nitrogen. Furthermore a sensitive detection of trace mineral elements provide specific spectral signature of different bacteria. An example is given for the Gram test provided by different magnesium emissions from Escherichia coli and Bacillus subtilis. An entire spectrum consists of hundred resolved lines belonging to 13 atomic or molecular species, which provides an ensemble of valuable data to identify different bacteria.

1 January 2009 in Journal of Biomedical Optics
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ITIsabelle Texier
Isabelle Texier
MGMathieu Goutayer
Mathieu Goutayer
ASAnabela Da Silva
Anabela Da Silva
Laurent GuyonLaurent Guyon
Laurent Guyon
NDNadia Djaker
Nadia Djaker
FVFrançoIse Vinet
FrançoIse Vinet
Fluorescence is a very promising radioactive-free technique for functional imaging in small animals and, in the future, in humans. However, most commercial near-infrared dyes display poor optical properties, such as low fluorescence quantum yields and short fluorescence lifetimes. In this paper, we explore whether the encapsulation of infrared cyanine dyes within the core of lipid nanoparticles (LNPs) could improve their optical properties. Lipophilic dialkylcarbocyanines DiD and DiR are loaded very efficiently in 30–35-nm-diam lipid droplets stabilized in water by surfactants. No significant fluorescence autoquenching is observed up to 53 dyes per particle. Encapsulated in LNP, which are stable for more than one year at room temperature in HBS buffer (HEPES 0.02 M, EDTA 0.01 M, pH 5.5), DiD and DiR display far improved fluorescence quantum yields Φ (respectively, 0.38 and 0.25) and longer fluorescence lifetimes τ (respectively, 1.8 and 1.1ns) in comparison to their hydrophilic counterparts Cy5 (Φ=0.28, τ=1.0ns) and Cy7 (Φ=0.13, τ=0.57ns). Moreover, dye-loaded LNPs are able to accumulate passively in various subcutaneous tumors in mice, thanks to the enhanced permeability and retention effect. These new fluorescent nanoparticles therefore appear as very promising labels for in vivo fluorescence imaging.

11 March 2010 in Bioconjugate Chemistry
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Journal Article
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ABAude Bernardin
Aude Bernardin
ACAurélie Cazet
Aurélie Cazet
Laurent GuyonLaurent Guyon
Laurent Guyon
Philippe DelannoyPhilippe Delannoy
Philippe Delannoy
FVFrançoise Vinet
Françoise Vinet
ITIsabelle Texier
Isabelle Texier

6 February 2006 in Applied Physics Letters
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Journal Article
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MBMatthieu Baudelet
Matthieu Baudelet
Laurent GuyonLaurent Guyon
Laurent Guyon
JYJin Yu
Jin Yu
JWJean-Pierre Wolf
Jean-Pierre Wolf
TATanguy Amodeo
Tanguy Amodeo
PLPatrick Laloi
Patrick Laloi
A sample of Escherichia coli has been analyzed by laser-induced breakdown spectroscopy (LIBS) using femtosecond pulses. The spectrum shows strong CN molecular bands due to the direct ablation of native CN molecular bonds from the bacteria in contrast with weak atomic lines from carbon. The native nature of the observed CN bonds is supported by the kinetic behavior of the CN band head which rapidly decays with a time constant of 94 ns, while for a pure graphite sample the CN band head increases with a delay of 450 ns due to recombination with the ambient air. Moreover, about hundred resolved lines belonging to 12 atomic or molecular species are recorded, providing a valuable spectral signature to identify the bacterium.

15 March 2019 in Circulation Research
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LTLy TU
Ly TU
ADAgnes Desroches-Castan
Agnes Desroches-Castan
CMChristine Mallet
Christine Mallet
Laurent GuyonLaurent Guyon
Laurent Guyon
ACAmélie Cumont
Amélie Cumont
Christophe GuignabertChristophe Guignabert
Christophe Guignabert
Rationale:: Although many familial cases of pulmonary arterial hypertension exhibit an autosomal dominant mode of inheritance with the majority having mutations in essential constituents of the BMP (bone morphogenetic protein) signaling, the specific contribution of the long-term loss of signal transduction triggered by the BMPR2 (type 2 BMP receptor) remains poorly characterized. Objective:: To investigate the role of BMP9, the main ligand of ALK1 (Activin receptor-like kinase 1)/BMPR2 heterocomplexes, in pulmonary hypertension. Method and Results:: The absence of BMP9 in Bmp9 −/− mice and its inhibition in C57BL/6 mice using neutralizing anti-BMP9 antibodies substantially prevent against chronic hypoxia-induced pulmonary hypertension judged by right ventricular systolic pressure measurement, right ventricular hypertrophy, and pulmonary distal arterial muscularization. In agreement with these observations, we found that the BMP9/BMP10 ligand trap ALK1 ECD administered in monocrotaline or Sugen/hypoxia (SuHx) rats substantially attenuate proliferation of pulmonary vascular cells, inflammatory cell infiltration, and regresses established pulmonary hypertension in rats. Our data obtained in human pulmonary endothelial cells derived from controls and pulmonary arterial hypertension patients indicate that BMP9 can affect the balance between endothelin-1, apelin, and adrenomedullin. We reproduced these in vitro observations in mice chronically exposed to hypoxia, with Bmp9 −/− mice exhibiting lower mRNA levels of the vasoconstrictor peptide ET-1 (endothelin-1) and higher levels of the 2 potent vasodilator factors apelin and ADM (adrenomedullin) compared with Bmp9 +/+ littermates. Conclusions:: Taken together, our data indicate that the loss of BMP9, by deletion or inhibition, has beneficial effects against pulmonary hypertension onset and progression.