Shape-anchored porous polymer monoliths for integrated online solid-phase extraction-microchip electrophoresis-electrospray ionization mass spectrometry.

We report a simple protocol for fabrication of shape-anchored porous polymer monoliths (PPMs) for on-chip SPE prior to online microchip electrophoresis (ME) separation and on-chip (ESI/MS). The chip design comprises a standard ME separation channel with simple cross injector and a fully integrated ESI emitter featuring coaxial sheath liquid channel. The monolith zone was prepared in situ at the injection cross by laser-initiated photopolymerization through the microchip cover layer.

A microfluidic chip for axonal isolation and electrophysiological measurements.

A microfluidic chip for culturing neurons and spatially isolating axons from somas is presented for use with visually guided whole-cell electrophysiological measurements. A modular design consisting of detachable and re-sealable layers is used to satisfy the requirements of both long-term neuron culturing as well as electrophysiological measurements. Whole cell patch clamp recordings indicate functional viability of neurons with isolated axons.

Cell adhesion and osteogenic differentiation on three-dimensional pillar surfaces.

We hypothesized that when compared with conventional two-dimensional (2D) cultures, substrates containing 3D micropillars would allow cells to grow at levels, activating their cytoskeleton to promote osteogenesis. Fibroblasts, osteoblast-like cells, and mesenchymal stem cells (MSCs) were studied. Planar substrates were compared with 200-nm-, 5-μm-, and 20-μm-high pillars of Ormocomp®, Si, diamond-like carbon, or TiO(2).

Oxygen and nitrogen plasma hydrophilization and hydrophobic recovery of polymers.

PLASMA HYDROPHILIZATION AND SUBSEQUENT HYDROPHOBIC RECOVERY ARE STUDIED FOR TEN DIFFERENT POLYMERS OF MICROFABRICATION INTEREST: polydimethylsiloxane (PDMS), polymethylmethacrylate, polycarbonate, polyethylene, polypropylene, polystyrene, epoxy polymer SU-8, hybrid polymer ORMOCOMP, polycaprolactone, and polycaprolactone/D,L-lactide (P(CL/DLLA)). All polymers are treated identically with oxygen and nitrogen plasmas, in order to make comparisons between polymers as easy as possible. The primary measured parameter is the contact angle, which was measured on all polymers for more than 100 days in order to determine the kinetics of the hydrophobic recovery for both dry stored and rewashed samples.