Ref HAL: hal-01920172_v1
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Quantum sensing with diamond

PMID 28442236
DOI: 10.1016/j.clnu.2017.04.005
WoS: 000436204200006
9 Citations

Ref HAL: hal-01899157_v1
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Microgels display specific features attracting a high research interest in several applications such as bioactives, drug delivery or protein purification. Whey protein microgels (WPM) are obtained by promoting whey protein intramolecular cross-linking through heat treatment. Temperature-induced protein denaturation and aggregation involves several kinds of interactions such as electrostatic repulsions and disulfide bonds. In the present work, the WPM particles topography and nanomechanical properties were investigated at native pH (6.5) and acid pH (5.5 and 3.0) by atomic force microscopy (AFM) in contact mode in a liquid environment. Prior to AFM analysis, WPM particles were captured on a gold substrate via low energy interactions by means of specific monoclonal antibodies. The 2D AFM images clearly showed a swelling of WPM particles induced by pH decrease. At native pH, they displayed an average width and height of 192 ± 27 nm and 44 ± 9 nm, respectively. A decrease in pH to 5.5 led to a significant (p<0.05) increase in WPM particles width (282 ± 9 nm) and height (101 ± 1 nm). At pH 3.0, a further increase in WPM size (a width of 420 ± 25 nm and a height of 78 ± 1 nm). The AFM elasticity (E) data showed a significant (p<0.05) increase in stiffness at pH 5.5 (E: 199 ± 9 kPa) and pH 3.0 (E: 187 ± 12 kPa) compared to native pH (E: 12 ± 1 kPa). These findings indicate that the mechanical profiles of WPM network directly varied with pH decrease. The WPM topographic and nanomechanical changes induced by acidification were most likely due to substantial changes in the shape and the structure of WPM particles. These strengthened internally crosslinked structures, modified by acidification, could display interesting encapsulation properties, providing an additional proof for their use as nanovectors monitoring bioactives release to the desired target after ingestion.

Ref HAL: hal-01899130_v1
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Atomic force microscopy-based nanomechanical methods were directly applied in order to elucidate important questions related to brain metastasis formation and amyotrophic lateral sclerosis (ALS). Force mapping with single cell force spectroscopy was combined in order to gain direct insight into the surface “screening” process of tumor cells during their extravasation into the brain parenchyma. Furthermore, comparative SCFS measurements were performed between three melanoma cell types (WM35, A2058 and A375), showing altered invasive characteristics, and blood vessel lining endothelials in order to examine how the metastatic potential relates to tumor cell’s autonomous and inter-cellular nanomechanical properties. In case of ALS by comparing the adhesion of CD8+ cytotoxic T cells isolated from wild-type as well as SOD1G93A mutant mice against wild-type motor neurons we found that cytotoxic T cells are active contributors of neurodegeneration in the development of ALS. In addition, nanomechanical mapping of wild-type and SOD1G93A mutant mice derived single elongated myoblasts and multinuclear myotubes revealed differences in elasticity during early differentiation stage into myotubes. These findings provide valuable knowledge to the understanding of brain metastasis formation and ALS pathogenesis.

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Ref HAL: hal-01826241_v1
DOI: 10.1016/j.pdpdt.2018.02.015
WoS: 000435053900012
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7 Citations
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Here we demonstrate for the first time that Mn2+-doped Prussian blue nanoparticles of c.a. 70 nm act as effective agents for photothermal therapy under two-photon excitation with an almost total eradication of malignant cells (97 and 98%) at a concentration of 100 μg mL−1 24 h after NIR excitation. This effect combined with interesting longitudinal NMR relaxivity values offer new perspectives for effective imaging and cancer treatment.

Commentaires: Highlights• Design of multifunctional nanoparticles able to provide efficient photothermal effect associated with imaging is highly challenging.• New Prussian blue nanoparticles compete with conventional PTT agents in terms of their efficiency and multifunctionality.• We demonstrate that Mn2+-doped Prussian blue nanoparticles act as efficient agents for PTT under two-photon excitation.• These nanoparticles induce an almost total eradication of malignant cells (97 and 98 %) 24 h after NIR excitation.• The combination of PTT with MRI offers new perspectives for efficient cancer treatment with imaging.

Ref HAL: hal-01813230_v1
DOI: 10.1016/j.snb.2018.05.154
WoS: 000439715000027
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10 Citations
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Cost-effective health care technologies for detection of disease biomarkers at ultralow concentrations can significantly improve the quality of life in resource-constrained countries. However, current techniques require expensive instruments, complex conjugation protocols and tedious laboratory procedures that may not be affordable for the major part of the world population. Here, we propose to sidestep the problem by establishing a simple, relatively inexpensive sensing method employing a photonic substrate, a material affinity peptide, and a smart phone CCD detector to achieve detection of clinically relevant proteins in serum at concentrations much lower than standard enzyme-linked immunosorbent assay (ELISA). Easy to process porous silicon (PSi) micro-cavities were employed as substrates that provide a three-dimensionality, large surface area, and convenient light enhancement properties for molecular detection. Anti-histone H2B antibodies and biomarkers of severe illnesses are detected in whole serum at concentrations as low as 10 fg mL−1 by using the proposed PSi-ELISA protocol. Due to its easy use, cost effectiveness and high sensitivity, the proposed method has potential large- scale applications in ultrasensitive sensing of different other clinically relevant molecules for early stage diagnostics.