Casein micelle (CM), porous colloidal phosphoprotein-mineral complex, naturally present in milk to deliver minerals, also has several features, which could ensure its use as nanocarrier for bioactives. CM structure being not steady according to the physico-chemical conditions, its stability can be improved by intra-micellar cross-linking using transglutaminase (TGase) inducing a strengthened structure called casein nanogel. The aim of this research was to investigate the morphology and nanomechanics of casein nanogel particles cross-linked by TGase (TG-CM) using atomic force microscopy (AFM) in native-like liquid environment (lactose-free simulated milk ultrafiltrate, SMUF). Prior to AFM, TG-CM were captured by anti-phospho-Ser/Thr/Tyr monoclonal antibodies covalently bound to a gold-coated slide via carbodiimide chemistry. Surface topography and size properties evaluation revealed an increase in size of TG-CM compared to native CM, TG-CM being characterized by a mean width of 264 ± 7 nm and a mean height of 111 ± 5 nm. TG-CM displayed a relatively high contact angle (62°) indicating a limited flattening of these particles after adsorption on the substrate. The TG-CM elasticity was then evaluated applying low indentation forces on single TG-CM. The TGase treatment led to a significant modification of CM nanomechanics attributed to intramolecular rearrangements within the micellar structure. The elasticity distribution of TG-CM revealed three elasticity peaks centered at 219±14kPa, 536±14kPa and 711 ± 11 kPa. The lower elasticity peak is related to the native CM nanomechanical signature and the two stiffer peaks were attributed to the substantial changes in the TG-CM structure.

Dentin carious lesion is a dynamic process that involves de- mineralization and collagen denaturation. Collagen type I is the major protein in dentin and it has been investigated based on its optical properties. Multiphoton microscopy (MPM) is a nonlinear imaging technique that reveals the car- ies process using the collagen two-photon excitation fluo- rescence (2PEF) and its second-harmonic generation (SHG). Combining the histological and the International Caries De- tection and Assessment System (ICDAS) classifications with nonlinear optical spectroscopy (NLOS), 2PEF and SHG inten- sities of enamel and dentin were highly altered during the caries process. It has been proven that the ratio SHG/2PEF is a relevant indicator of the organic matrix denaturation [Ter- rer et al.: J Dent Res 2016;96:574–579]. In the present study, a series of measurable signals is made to detect early stages of carious lesion according to the ICDAS classification and to explore the relationship between these measures and theICDAS scale. Comparison of the efficiency of nonlinear opti- cal signals for caries detection with the ICDAS classification is essential to evaluate their potential for clinical applica- tion. In our study, the use of the NLOS measured by MPM allowed us to monitor a quantitative parameter (SHG/2PEF ratio) according to the dentin carious lesion state (ICDAS and histological examination). Three coherent new groups were defined (ICDAS 0/1; ICDAS 2/3; ICDAS 4/5/6), where the carious process can be clearly described with a statistically significant decrease of the SHG/2PEF ratio.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that a ects the motorsystem leading to generalized paralysis and death of patients. The understanding of early pathogenic mechanisms will help to de ne early diagnostics criteria that will eventually provide basis for e cient therapeutics. Early symptoms of ALS usually include muscle weakness or sti ness. Therefore, mechanical response of di erentiated myotubes from primary cultures of mice, expressing the ALS- causing SOD1G93A mutation, was examined by atomic force microscopy. Simultaneous acquisition of topography and cell elasticity of ALS myotubes was performed by force mapping method, compared with healthy myotubes and supplemented with immuno uorescence and qRT-PCR studies. Wildtype myotubes reveal a signi cant di erence in elasticity between a narrow and a wide population, consistent with maturation occurring with higher actin expression relative to myosin together with larger myotube width. However, this is not true for SOD1G93A expressing myotubes, where a signi cant shift of thin population towards higher elastic modulus values was observed. We provide evidence that SOD1 mutant induces structural changes that occurs very early in muscle development and well before symptomatic stage of the disease. These ndings could signi cantly contribute to the understanding of the role of skeletal muscle in ALS pathogenesis.

Background: Understanding stem cell behavior as a delivery tool in cancer therapy is essential for evaluating their future clinical potential. Previous in-vivo studies proved the use of mesenchymal stem cells (MSCs) for local delivery of the commonest anticancer drug, paclitaxel (PTX). Dental pulp is a relatively abundant noninvasive source of MSCs. We assess dental pulp stem cells (DPSCs), for the first time, as anticancer drug carriers. Confocal Raman microscopy is a unique tool to trace drug and cell viability without labeling.Methods: Drug uptake and cell apoptosis are identified through confocal Raman microscope. We traced translocation of cytochrome c enzyme from the mitochondria, as a biomarker for apoptosis, after testing both cancer and stem cells. The viability of stem cells was checked by means of confocal Raman microscope and by cytotoxicity assays.Results: In this study, we prove that DPSCs can be loaded in vitro with the anticancerous drug without affecting their viability, which is later released in the culture medium of breast cancer cells (MCF-7 cells) in a time-dependent fashion. The induced cytotoxic damage in MCF-7 cells was observed consequently after PTX release by DPSCs. Additionally, quantitative Raman images of intracellular drug uptake in DPSCs and MCF-7 cells were obtained. Cytotoxic assays prove the DPSCs to be more resistant to PTX as compared to bone marrow-derived MSCs, provided similar conditions.Conclusions: Applications of dental stem cells for targeted treatment of cancer could be a revolution to reduce morbidity due to chemotherapy, and to increase the efficacy of systemic cancer treatment.

Nuclear magnetic resonance (NMR) experiments are usually carried out at very high and homogenous magnetic fields. However, portable systems have emerged in recent years at low fields, offering many advantages like easier maintenance and open design that permit us to imagine a variety of coil configurations in order to maximize the homogeneity of the static field B-0 and the radio-frequency field B-1. The wire winding distribution based on space harmonics suppression (SHS) of the cosine current density distribution offers new possibilities of producing homogenous static fields B-0. In this work, an extension of the SHS method, allowing homogeneity enhancement and flexibility of the coil design, is presented. The efficiency of the method is demonstrated through the construction of homogenous magnetic field coils dedicated to a very low magnetic field (8 mT) H-1 NMR spectrometer. The performance of these coils in terms of magnetic field intensity and homogeneity as well as self-heating behavior is compliant with in planta experiments for agronomic studies.

The climate warming implies an increase of stress of plants (drought and torrential rainfall). The understanding of plant behavior, in this context, takes a major importance and sap flow measurement in plants remains a key issue for plant understanding. Magnetic Resonance Imaging (MRI) which is well known to be a powerful tool to access water quantity can be used to measure moving water. We describe a novel flow-MRI method which takes advantage of inflow slice sensitivity. The method involves the slice selectivity in the context of multi slice spin echo sequence. Two sequences such as a given slice is consecutively inflow and outflow sensitive are performed, offering the possiblility to perform slow flow sensitive imaging in a quite straigthforward way. The method potential is demonstrated by imaging both a slow flow measurement on a test bench (as low as 10 μm.s−1) and the Poiseuille’s profile of xylemian sap flow velocity in the xylematic tissues of a tomato plant stem.