Regenerating the cell resistance of micromolded PEG hydrogels.

Polydimethylsiloxane stamp materials used during soft lithography undermine the non-fouling behaviour of bio-inert PEG-based hydrogels, resulting in increased protein adsorption and cell adhesion and migration on the gel. This previously unreported phenomenon undermines the function of lab-on-a-chip devices that require the device to be bio-inert, and slows the implementation of promising micromolding and imprinting methods for 3D culture and commercial cell culture systems. We illustrate that the degree of cell adhesion and protein adsorption to the gels correlates with the amount of residual stamp material remaining at the hydrogel interface after fabrication.

Photopatterning of hydrogel scaffolds coupled to filter materials using stereolithography for perfused 3D culture of hepatocytes.

In vitro models that recapitulate the liver's structural and functional complexity could prolong hepatocellular viability and function to improve platforms for drug toxicity studies and understanding liver pathophysiology. Here, stereolithography (SLA) was employed to fabricate hydrogel scaffolds with open channels designed for post-seeding and perfused culture of primary hepatocytes that form 3D structures in a bioreactor. Photopolymerizable polyethylene glycol-based hydrogels were fabricated coupled to chemically activated, commercially available filters (polycarbonate and polyvinylidene fluoride) using a chemistry that permitted cell viability, and was robust enough to withstand perfused culture of up to 1 µL/s for at least 7 days.

Expression of NF-kappaB and IkappaB proteins in skeletal muscle of gastric cancer patients.

The mechanisms eliciting cancer cachexia are not well understood. Wasting of skeletal muscle is problematic because it is responsible for the clinical deterioration in cancer patients and for the ability to tolerate cancer treatment. Studies done on animals suggest that nuclear factor of kappa B (NF-kappaB) signalling is important in the progression of muscle wasting due to several types of tumours.

Microtubule-mediated NF-kappaB activation in the TNF-alpha signaling pathway.

The microtubule cytoskeleton is known to play a role in cell structure and serve as a scaffold for a variety of active molecules in processes as diverse as motility and cell division. The literature on the role of microtubules in signal transduction, however, is marked by inconsistencies. We have investigated a well-studied signaling pathway, TNF-alpha-induced NF-kappaB activation, and found a connection between the stability of microtubules and the regulation of NF-kappaB signaling in C2C12 myotubes.