Multilayered Magnetic Nanobeads for the Delivery of Peptides Molecules Triggered by Intracellular Proteases

In this work, the versatility of layer-by-layer technology was combined with the magnetic response of iron oxide nanobeads to prepare magnetic mesostructures with a degradable multilayer shell into which a dye quenched ovalbumin conjugate (DQ-OVA) was loaded. The system was specifically designed to prove the protease sensitivity of the hybrid mesoscale system and the easy detection of the ovalbumin released. The uptake of the nanostructures in the breast cancer cells was followed by the effective release of DQ-OVA upon activation via the intracellular proteases degradation of the polymer shells. Monitoring the fluorescence rising due to DQ-OVA digestion and the cellular dye distribution, together with the electron microscopy studying, enabled us to track the shell degradation and the endosomal uptake pathway that resulted in the release of the digested fragments of DQ ovalbumin in the cytosol

Highly Sensitive Membrane-Based Pressure Sensors (MePS) for Real-Time Monitoring of Catalytic Reactions

Functional, flexible, and integrated lab-on-chips, based on elastic membranes, are capable of fine response to external stimuli, so to pave the way for many applications as multiplexed sensors for a wide range of chemical, physical and biomedical processes. Here, we report on the use of elastic thin membranes (TMs), integrated with a reaction chamber, to fabricate a membrane-based pressure sensor (MePS) for reaction monitoring. In particular, the TM becomes the key-element in the design of a highly sensitive MePS capable to monitor gaseous species production in dynamic and temporally fast processes with high resolution and reproducibility. Indeed, we demonstrate the use of a functional MePS integrating a 2 μm thick polydimethylsiloxane TM by monitoring the dioxygen evolution resulting from catalytic hydrogen peroxide dismutation. The operation of the membrane, explained using a diffusion-dominated model, is demonstrated on two similar catalytic systems with catalase-like activity, assembled into polyelectrolyte multilayers capsules. The MePS, tested in a range between 2 and 50 Pa, allows detecting a dioxygen variation of the μmol L^–1 s^–1 order. Due to their structural features, flexibility of integration, and biocompatibility, the MePSs are amenable of future development within advanced lab-on-chips