Direct real-time measurements of superoxide release from skeletal muscles in rat limbs and human blood platelets using an implantable Cytochrome C microbiosensor.

Oxidative stress and excessive accumulation of the superoxide (O) anion are at the genesis of many pathological conditions and the onset of several diseases. The real time monitoring of (O) release is important to assess the extent of oxidative stress in these conditions. Herein, we present the design, fabrication and characterization of a robust (O) biosensor using a simple and straightforward procedure involving deposition of a uniform layer of L-Cysteine on a gold wire electrode to which Cytochrome C (Cyt c) was conjugated.

Molecular stiffness cues of an interpenetrating network hydrogel for cell adhesion.

Understanding cells' response to the macroscopic and nanoscale properties of biomaterials requires studies in model systems with the possibility to tailor their mechanical properties and different length scales. Here, we describe an interpenetrating network (IPN) design based on a stiff PEGDA host network interlaced within a soft 4-arm PEG-Maleimide/thiol (guest) network. We quantify the nano- and bulk mechanical behavior of the IPN and the single network hydrogels by single-molecule force spectroscopy and rheological measurements.

Optoregulated force application to cellular receptors using molecular motors.

Progress in our understanding of mechanotransduction events requires noninvasive methods for the manipulation of forces at molecular scale in physiological environments. Inspired by cellular mechanisms for force application (i.e.

Imaging of Candida albicans Hyphal Growth via Atomic Force Microscopy.

is an opportunistic fungal pathogen of humans known for its ability to cause a wide range of infections. One major virulence factor of is its ability to form hyphae that can invade host tissues and cause disseminated infections. Here, we introduce a method based on atomic force microscopy to investigate hyphae on silicone elastomer substrates, focusing on the effects of temperature and antifungal drugs.

The mechanics of single cross-links which mediate cell attachment at a hydrogel surface.

The response of cultured cells to the mechanical properties of hydrogel substrates depends ultimately on the response of single crosslinks to external forces exerted at cell attachment points. We prepared hydrogels by co-polymerization of poly(ethylene glycol diacrylate) (PEGDA) and carboxy poly(ethylene glycol) acrylate (ACPEG-COOH) and confirmed fibroblast spreading on the hydrogel after the ACPEG linker was functionalized with the RGD cell adhesive motif. We performed specific force spectroscopy experiments on the same ACPEG linkers in order to probe the mechanics of single cross-links which mediate the cell attachment and spreading.

Coating agent-induced mechanical behavior of 3D self-assembled nanocrystals.

The Young's modulus of three-dimensional self-assembled Ag nanocrystals, as so-called supracrystals, is correlated with the type of coating agent as well as the nanocrystal morphology. The Young's moduli of supracrystals of icosahedral Ag nanocrystals are measured in the range of tens to hundreds of megapascals revealing an extremely soft mechanical behavior. The alkylamine molecules used as coating agents weakly interact with the Ag nanocrystal surface favoring translational and orientational ordering of atomic lattice planes of nanocrystals.