2 research outputs found
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<sup>–1</sup> s<sup>–1</sup> order. Due to their structural
features, flexibility of integration, and biocompatibility, the MePSs
are amenable of future development within advanced lab-on-chips