An integrated device for patterning cells and selectively detaching

Abstract

Cell detachment is an ordinary cell behavior, and acts a significant role in numerous physiological processes. In addition, as massive cell groups have specific shapes in vivo, selectively controlling detachment of patterned cells is crucial for both clinical and fundamental research, because it may act as a platform for studying many processes in vitro, and also may be used for tissue engineering. However, it is difficult to first pattern cell groups into isolated islands and then to control their detachment dynamically. Herein, we developed an integrated device that could confine cell groups into various designed shapes, and selectively detach them by applying a low potential. This device contains electrode arrays (EAs) for cell pattern and detachment; and an automatic control system (ACS) connected to a computer for electrically controlling cell detachment. By microfabrication technology, EAs are fabricated on a glass substrate and isolated by surrounding insulating layer (Parylene-C). A new surface modification method is developed: within one step, oligopeptide (CCRRGDWLC) can bond to the gold surface of EAs for cell adhesion or detachment, and PLL-PEG grafts to other parts around the gold surface to resist cell adhesion simultaneously. When a low potential is applied by the ACS to the selected electrodes, cell groups on these electrodes would round up and detach from the surface. Comparing with previous methods, our method can first pattern cells and then selectively detach them. Besides, this device is easy to operate, fast response, and the detaching units are high through-put, and we believe it will be widely used in biological and medical labs.

Redox-Triggered Control of Cell Adhesion and Deadhesion on Poly(lysine)-g-poly(ethylene oxide) Adlayers

“…An adlayer of PLL- g -PEG can achieve antifouling on plastics, ceramics, metal oxides, etc. Surface protection by PLL- g -PEG is now applied in micropatterning methods for mammal cell cultures − and is used in commercial biosensors and biomedical microdevices. − We added two functions into PLL- g -PEG derivatives: first, a disulfide linker between the PLL backbone and PEG side chains (PLL- g -SSPEG) made it redox cleavable. Second, the introduction of azide-ended PEG strands (PLL- g -SSPEGN 3 ) enabled copper-free click conjugation with adhesion peptides .…”

The effect of Ti adhesion layer on the thermoelectric noise of a high resolution thermopile for nanowatt heat flux sensor

“…Due to a lack of adhesive force on the substrate, most metals are deposited with an adhesion layer of 10 to 50 nm thick Ti or Cr. [15][16][17][18][19][20] Although the adhesion layer bonds the thermopile junctions, it does not affect the thermoelectric voltage due to the intermediate law of thermocouple theory. However, the changed interfaces at thermocouple junctions are closely related to the surface contact resistance as well as the thermoelectric noise at the point of total resistance.…”