Molecularly imprinted polymers (MIPs) are promising artificial receptors for biomolecular recognition, yet protein imprinting remains challenging due to denaturation and mass-transfer limitations during polymerization. Here, we report a soft and straightforward strategy to create biomimetic imprints directly inside silica capillaries via sol-gel polymerization of silylated amino acids under biocompatible conditions. The approach relies on the polymerization of silylated amino acids around adsorbed protein templates, generating hybrid organic-inorganic cavities that combine shape complementarity with tailored chemical functionalities. The resulting open-tubular imprinted capillaries were evaluated by capillary electrochromatography using proteins of different size and isoelectric point. All imprinted materials exhibited strong and selective recognition of their target proteins, with selective retention ratios exceeding 5, whereas non-target proteins displayed values below 2. The coatings showed excellent repeatability and long-term stability, with variations below 5% in electrochromatographic performance. Selective separations were achieved for several protein templates, including lysozyme, ribonuclease A, cytochrome C, α-lactalbumin and bovine serum albumin. Importantly, the imprinted capillaries maintained their selectivity in human plasma samples. The strategy was further extended to a nanobody template, yielding selective antibody-like molecular recognition in a complex biological matrix. This work demonstrates a versatile and protein-compatible route to create biomimetic recognition sites directly within capillary stationary phases. The proposed platform offers new opportunities for selective bioseparation, biomolecular analysis, and affinity-based analytical technologies.

This paper presents the design of a positive chemically amplified hybrid photoresist for thick-layer microfabrication. The formulation combines TBMA and MAPTMS to achieve acid-catalyzed deprotection for aqueous base solubility while providing mechanical robustness through sol-gel chemistry. Structural analyses (FTIR spectroscopy, 1H, 13C, and 29Si NMR) confirm controlled copolymerization and a limited degree of condensation, preserving Si-OH groups that enhance adhesion to glass substrates. Photolithographic tests demonstrate good uniformity and pattern resolution, despite a narrow process window caused by the competition between deprotection and condensation catalyzed by photoacids. These findings provide promising perspectives for applications in microfluidics and optoelectronics, with future work focusing on broadening process latitude and integrating advanced functionalities.

Hydrogen is considered a promising alternative to conventional fossil fuels, as it can be easily produced from renewable energy sources. While electrocatalytic water splitting can achieve near-unity faradaic efficiency in producing hydrogen from water, the widespread implementation of large-scale water electrolysis is hindered by reliance on costly platinum group metal-based electrocatalysts. Here, we report on the rational design of Molybdenum-containing SiCN composites (Mo-SiCN) through an active-filler controlled pyrolysis (AFCOP) strategy. Our investigation into the composite's microstructural evolution revealed the formation of a Mo4.8Si3C0.6 Nowotny phase at a relatively low temperature of 1000 degrees C. After optimization, the resulting catalyst demonstrated a Tafel slope below 95 mV dec-1 and an overpotential near 575 mV at a normalized current density of 1 mA mu F-1. As a proof of concept, the AFCOP strategy was employed to engineer a crack-free Mo-SiCN micropattern, enabling the miniaturization of a Pt-free electrochemical water splitting (EWS) reactor. Produced via soft lithography, the Mo-SiCN pattern exhibits feature sizes ranging from 10 to 200 mu m, with near-net-shape replication and a Young's modulus of approximate to 60 GPa.

Inter-individual variability in muscle responses to mechanical stress during exercise is poorly understood. Therefore, new cell culture scaffolds are needed to gain deeper insights into the cellular mechanisms underlying the influence of mechanical stress on human myogenic progenitor cells behavior. To this end, we propose the first in vitro model involving uniaxial mechanical stress applied to aligned human primary muscle-derived cells, employing a biocompatible organic-inorganic photostructurable hybrid material (OIPHM) covalently attached to a stretchable PDMS support. Using a laser printing technique with an additive photolithographic process, we optimally micropatterned the PDMS support to create longitudinal microgrooves, achieving well-aligned muscle fibers without significantly affecting their diameter. This support was biofunctionalized with peptide sequences from the ECM, which interact with cellular adhesion receptors and prevent myotube detachment induced by stretching. X-ray photoelectron spectroscopy (XPS) of biofunctionalized PDMS with RGD-derived peptide deposition revealed a significant increase in nitrogen compared to silicon, associated with the presence of a 380 nm thick layer measured by atomic force microscopy (AFM). Upon cell culture, we observed that functionalization with an RGD peptide had a beneficial impact on cell fusion rate and myotube area compared to bare PDMS. At the initiation of the stretching protocol, we observed a three-fold rapid and transient increase in RNA expression for the mechanosensitive ion channel protein piezo and a decrease in the ratio of nuclei expressing myogenin relative to the total nuclei count (43 ± 16% vs. 6 ± 6%, p < 0.01). Compared to day 0 of differentiation, stretching the myotubes induced MHC and Titin colocalization (0.66 ± 0.13 vs. 0.93 ± 0.05, p < 0.01), favoring sarcomere organization and maturation. In this study, we propose and validate an optimized protocol for culturing human primary muscle-derived cells, allowing standardized uniaxial mechanical stress with a biocompatible OIPHM covalently linked to PDMS biofunctionalized with an ECM-derived peptide, to better characterize the behavior of myogenic progenitor cells under mechanical stress in future studies.

We explore a bioinspired approach to design tailored functionalized capillary electrophoresis (CE) surfaces based on covalent grafting for biomolecules analysis. First, the approach aims to overcome well-known common obstacles in CE protein analysis affecting considerably the CE performance (asymmetry, resolution, and repeatability) such as the unspecific adsorption on fused silica surface and the lack of control of electroosmotic flow (EOF). Then, our approach, which relies on new amino-amide mimic hybrid precursors synthesized by silylation of amino-amides (Si-AA) derivatives with 3-isocyanatopropyltriethoxysilane, aims to recapitulate the diversity of protein-protein interactions (π-π stacking, ionic, Van der Waals…) found in physiological condition (bioinspired approach) to improve the performance of CE protein analysis (electrochromatography). As a proof of concept, these silylated Si-AA (tyrosinamide silylation, serinamide silylation, argininamide silylation, leucinamide silylation, and isoglutamine silylation acid) have been covalently grafted in physiological conditions in different amount on bare fused silica capillary giving rise to a biomimetic coating and allowing both the modulation of EOF and protein-surface interactions. The analytical performances of amino-amide functionalized capillaries were assessed using lysozyme, cytochrome C and ribonuclease A and compared to traditional capillary coatings poly(ethylene oxide), poly(diallyldimethylammonium chloride), and sodium poly(styrenesulfonate). EOF, protein adsorption rate, protein retention factor k, and selectivity were determined for each coating. All results obtained showed this approach allowed to modulate the EOF, reduce unspecific adsorption, and generate specific interactions with proteins by varying the nature and the amount of Si-AA in the functionalization mixture.

Silica aerogels have many potential applications, including as host matrices for chemical species or nuclear waste storage. For these applications, the permeability is a key parameter and data show that the silica aerogels have poor permeability (~10–60 nm2). In this chapter we review the method to measure the liquid and gas permeability in gels, aerogels, and composite aerogels. Ideally, permeability does not depend on the type of pore fluid, therefore permeability measured using gas should be the same as that measured using water. We measured gas and water permeability in sets of nanocomposite silica aerogels. Experimental results show that gas permeability in aerogels was larger than water permeability by almost two orders of magnitude. The observed difference in gas and water permeability was analyzed from the point of view of the slip regime (Klinkenberg correction) and transition regime (Knudsen correction); the slip flow of gas at pore walls enhances the gas flow when pore sizes are small. This work addresses the problem of estimating permeability with high porosity materials such as aerogels. The effects of structural parameters of porous media (pore volume, tortuosity, fractal features) on the Klinkenberg and Knudsen corrections are discussed and the different models proposed in the literature are tested.

Objective: Dentin, enamel and the transition zone, called the dentin-enamel junction (DEJ), have an organization and properties that play a critical role in tooth resilience and in stopping the propagation of cracks. Understanding their chemical and micro-biomechanical properties is then of foremost importance. The aim of this study is to apply Brillouin microscopy on a complex biological structure, that is, the DEJ, and to compare these results with those obtained with Raman microscopy. Design: Both techniques allow noncontact measurements at the microscopic scale. Brillouin microscopy is based on the interaction between acoustic phonons and laser photons and gives a relation between the frequency shift of the scattered light and the stiffness of the sample. Raman spectra contain peaks related to specific chemical bonds. Results: Comparison of the Brillouin and Raman cartographies reveals correlations between mechanical and chemical properties. Indeed, the shapes of the phosphate content and stiffness curves are similar. The two spectroscopies give compatible values for the mean distance between two tubules, i.e., 4-6 & mu;m. Moreover, for the first time, the daily cross striations of enamel could be studied, indicating a relationship between the variation in the phosphate concentration and the variation in the rigidity within the enamel prisms. Conclusions: We demonstrate here the possibility of using Brillouin scattering microscopy to both study complex biological materials such as the enamel-dentin junction and visualize secondary structures. Correlations between the chemical composition and mechanical properties could help in better understanding the tissue histology.

The development of artificial receptors able to selectively recognize a target protein is of particular in -terest in separation, diagnostics, and therapeutics fields. Herein, we disclose a method to prepare bio-mimetic and functionalized protein imprints in biocompatible conditions avoiding any protein denaturation. For that purpose, a set of different hybrid silylated amino acid derivatives were synthesized and used without tetraethyl orthosilicate to prepare our molecularly imprinted polymers, allowing to reduce to a minimum of the silicon amount, in order to obtain imprints made almost entirely of amino acids to mimic paratope surfaces of antibodies. Such functional building blocks were polymerized on the surface of magnetic silica nanoparticles at pH 8.5 in ultrapure water in the presence of two globular proteins: cytochrome C or lysozyme. The resulting imprinted hybrid materials were evaluated for their adsorption capacity, specificity, and selectivity by quartz-crystal microbalance with dissipation and magnetic enzyme-linked immunosorbent assay (ELISA) assays. High imprinting factors of 8.7 were measured for these biomimetic hybrid materials (corresponding to approximately 4000 and 450 ng of protein per cm2 immobilized on molecularly imprinted polymers and non-imprinted polymer nano-particles, respectively), representing a significant breakthrough in sol-gel-based molecular imprinting materials. Moreover, competition experiments performed by magnetic ELISA (mELISA) show very good specificity of our imprints at the usual concentrations of ELISA measurements.(c) 2022 Elsevier Ltd. All rights reserved.

Non-oxide ceramic MEMS based on Si, C, N and B elements are of great importance for high-temperature applications in harsh and oxidizing conditions including electronics, photonics and actuators. Yet, structuring and patterning ceramics is challenging and often relies on conventional soft-lithography or molding processes that can introduce defects and cracks leading to a decrease in the device’s performance. Herein, we report on the design for the first time of SiBCN ceramic micro-components (in the 20–200 µm range) from direct patterning of “tailor-made” UV-curable boron-modified polyvinylsilazane preceramic (polyborovinylsilazane) resins. This approach first involves a two-step chemical synthesis of patternable preceramic polymers through acrylate or methacrylate grafting onto polyborovinylsilazane followed by subsequent crosslinking under UV light. FTIR and NMR spectroscopies confirmed the successful grafting of boron and photocurable units on the preceramic polymers while thermogravimetric analysis was used to monitor the polymer-to-ceramic conversion. SiBCN micro-objects obtained after pyrolysis were thoroughly characterized by SEM, AFM, nanoindentation and profilometry techniques. The Young’s modulus results for such microstructures (∼60 GPa) are characteristic of good mechanical properties making these ceramic microstructures promising materials for MEMS applications.

The integration of optical circuits with microfluidic lab-on-chip (LoC) devices has resulted in a new era of potential in terms of both sample manipulation and detection at the micro-scale. On-chip optical components increase both control and analytical capabilities while reducing reliance on expensive laboratory photonic equipment that has limited microfluidic development. Notably, in-situ LoC devices for bio-chemical applications such as diagnostics and environmental monitoring could provide great value as low-cost, portable and highly sensitive systems. Multiple challenges remain however due to the complexity involved with combining photonics with micro-fabricated systems. Here, we aim to highlight the progress that optical on-chip systems have made in recent years regarding the main LoC applications: (1) sample manipulation and (2) detection. At the same time, we aim to address the constraints that limit industrial scaling of this technology. Through evaluating various fabrication methods, material choices and novel approaches of optic and fluidic integration, we aim to illustrate how optic-enabled LoC approaches are providing new possibilities for both sample analysis and manipulation.

Silica aerogels are known to be materials with exceptional characteristics, such as ultra-low density, high surface area, high porosity, high adsorption, and low-thermal conductivity. In addition, these unique properties are mainly related to their specific processing. Depending on the aerogel synthesis procedure, the aerogels texture can be tailored with meso and/or macroporosity. Fractal geometry has been observed and used to describe silica aerogels at nanoscales in certain conditions. In this review paper, we describe the fractal structure of silica aerogels that can develop depending on the synthesis conditions. X-ray and neutron scattering measurements allow to show that silica aerogels can exhibit a fractal structure over one or even more than two orders of magnitude in length. The fractal dimension does not depend directly on the material density but can vary with the synthesis conditions. It ranges typically between 1.6 and 2.4. The effect of the introduction of silica particles or of further thermal treatment or compression of the silica aerogels on their microstructure and their fractal characteristics is also resumed.

We studied a colloidal suspension of polystyrene beads deposited on a glass substrate. The glass substrate contained either straight rough areas on the borders of an open channel or only straight rough areas. The drying of the suspension was observed with an optical microscope, the light bulb of which acted as an energy source to evaporate the suspension. Moreover, the light bulb of the microscope provided optical pressure due to light. We observed that the colloidal particles were trapped on the rough areas of the substrate and not in the open channel at the end of the drying process. In order to understand the experimental results, we modeled numerically the drying of the suspension using a Molecular Dynamics program. The forces imposed on the substrate by the particles are their weight, the optical pressure due to the light bulb of the optical microscope, the attractive Van der Waals force and the repulsive diffuse layer force. The forces acting between two particles are the attractive Van der Waals forces, the repulsive diffuse layer force and the capillary force. The Gaussian random force (linked to Brownian motion) and the particle liquid viscous drag force (also linked to Brownian motion) are horizontal and applied on one particle. The relation between the normal forces N (forces acting by the particles on the substrate) and the horizontal forces F is Amontons’ third law of friction F≤μkN; in rough areas of the substrate, μk is larger than in smooth areas. This explains that particles are trapped in the areas with high roughness.

Rationale: Prolonged mechanical ventilation is often associated with either a decrease (known atrophy) or an increase (supposed injury) in diaphragmatic thickness. Shear wave elastography is a noninvasive technique that measures shear modulus, a surrogate of tissue stiffness and mechanical properties. Objectives: To describe changes in shear modulus (SM) during the ICU stay and the relationship with alterations in muscle thickness. To perform a comprehensive ultrasound-based characterization of histological and force production changes occurring in the diaphragm. Methods: Translational study using critically ill patients and mechanically ventilated piglets. Serial ultrasound examination of the diaphragm collecting thickness and SM was performed in both patients and piglets. Transdiaphragmatic pressure and diaphragmatic biopsies were collected in piglets. Measurements and Main Results: We enrolled 102 patients, 88 of whom were invasively mechanically ventilated. At baseline, SM was 14.3 ± 4.3 kPa and diaphragm end-expiratory thickness was 2.0 ± 0.5 mm. Decrease or increase by more than 10% from baseline was reported in 86% of the patients for thickness and in 92% of the patients for SM. An increase in diaphragmatic thickness during the stay was associated with a decrease in SM (β = -9.34 ± 4.41; P = 0.03) after multivariable analysis. In the piglet sample, a decrease in SM over 3 days of mechanical ventilation was associated with loss of force production, slow and fast fiber atrophy, and increased lipid droplets accumulation. Conclusions: Increases in diaphragm thickness during critical illness is associated with decreased tissue stiffness as demonstrated by shear wave ultrasound elastography, consistent with the development of muscle injury and weakness. Clinical trial registered with www.clinicaltrials.gov (NCT03550222).

Ordered mesoporous materials and their modification with multiple functional groups are of wide scientific interest for many applications involving interaction with biological systems and biomolecules (e.g., catalysis, separation, sensor design, nano-science or drug delivery). In particular, the immobilization of enzymes onto solid supports is highly attractive for industry and synthetic chemistry, as it allows the development of stable and cheap biocatalysts. In this context, we developed novel silylated amino acid derivatives (Si-AA-NH2) that have been immobilized onto SBA-15 materials in biocompatible conditions avoiding the use of toxic catalyst, solvents or reagents. The resulting amino acid-functionalized materials (SBA-15@AA) were characterized by XRD, TGA, EA, Zeta potential, nitrogen sorption and FT-IR. Differences of the physical properties (e.g., charges) were observed while the structural ones remained unchanged. The adsorption of the enzyme lysozyme (Lyz) onto the resulting functionalized SBA-15@AA materials was evaluated at different pHs. The presence of different functional groups compared with bare SBA-15 showed better adsorption results, for example, 79.6 nmol of Lyz adsorbed per m2 of SBA-15@Tyr compared with the 44.9 nmol/m2 of the bare SBA-15.

Lipidic polyols based on alpha-hydroxyketone reactive groups were investigated for polyurethane thermosets. The reactivity of this peculiar secondary alcohol group in triacylglycerol structure was compared, without use of catalyst, to that of poly(1,2-diol) triacylglycerol and castor oil to demonstrate the influence of ketone in the alpha position of the alcohol group in the presence of HDI for the urethanization rate. The kinetic effect of the ketone group was also studied on various lipidic architectures: mono(alpha-hydroxyketone) ester, di(alpha-hydroxyketone) diester and tri(alpha-hydroxyketone) triacylglycerol. The presence of hydrogen bonds in the network coming from urethane, residual alcohol, and ketone in hard segments of PU was discussed and correlated with the thermal stability and the soft mechanical properties of the resulting polyurethane thermosets.

In the publication of this article [1], there was an error in the Family Name of one of the authors. This has now been updated in the original article.

A comprehensive characterization of physical-chemical properties and biological interactions of ca. 200-nmthick hybrid films based on silylated (inorganic part) castor oil (organic part) is proposed. A series of such nanofilms was fabricated and cross-linked by a sol-gel procedure, and their properties such as hydrophilicity, hardness and water vapour transmission rate were systematically studied as a function of the ratio of silylated agent to castor oil. It was found that the nanofilms have contact angles always below 90 degrees, tunable Young modulus and hardness in the MPa range. Moreover, their water vapour transmission rates are increased by decreasing the silica ratio. The protein adsorption and cytocompatibility were evaluated using model proteins and cells. The adsorption of the proteins bovine serum albumin (BSA) and lysozyme was characterized using a quartz crystal microbalance in energy dissipation mode (QCM-D), and atomic force microscopy (AFM). The combination of the latter provided evidence for the different affinities of the proteins with the films. It was found that BSA and lysozyme form rigid layers on the surface with surface coverage close to 30%, and that both protein layers decrease their thickness after their dehydration. Finally, cell culture experiments exhibited a good viability of the fibroblasts compared to ultra-low adhesion surfaces, which makes them potential candidates for biomedical applications.