Conducting polymer hydrogels with electrically-tuneable mechanical properties as dynamic cell culture substrates.

Hydrogels are a popular substrate for cell culture due to their mechanical properties closely resembling natural tissue. Stimuli-responsive hydrogels are a good platform for studying cell response to dynamic stimuli. Poly(N-isopropylacrylamide) (pNIPAM) is a thermo-responsive polymer that undergoes a volume-phase transition when heated to 32 °C.

Stretchable microchannel-on-a-chip: A simple model for evaluating the effects of uniaxial strain on neuronal injury.

Background: Axonal injury is a major component of traumatic spinal cord injury (SCI), associated with rapid deformation of spinal tissue and axonal projections. In vitro models enable us to examine these effects and screen potential therapies in a controlled, reproducible manner.

New Method: A customized, stretchable microchannel system was developed using polydimethylsiloxane microchannels.

Evaluation of parylene derivatives for use as biomaterials for human astrocyte cell patterning.

Cell patterning is becoming increasingly popular in neuroscience because it allows for the control in the location and connectivity of cells. A recently developed cell patterning technology uses patterns of an organic polymer, parylene-C, on a background of SiO2. When cells are cultured on the parylene-C/SiO2 substrate they conform to the underlying parylene-C geometry.

Investigation of the Ca2+ response of human hNT astrocytes to laser removal of cellular processes.

We demonstrate, for the first time, UV laser ablative microsurgery as a method for pruning astrocytic processes from live hNT astrocytic networks in vitro. Calcium fluorescence imaging was used to evaluate the cellular response to process ablation. The results showed that ablation of astrocyte processes induced an immediate increase in intracellular calcium level which propagated through the cells cytoplasm as a wave originating from the ablation site.

Investigating parylene-HT as a substrate for human cell patterning.

We demonstrate, for the first time, how parylene-HT on SiO2 substrates can be used as a human cell patterning platform. We demonstrate this platform with hNT astrocytes, derived from the human NTera2.D1 cell line.

Low cost, patterning of human hNT brain cells on parylene-C with UV & IR laser machining.

This paper describes the use of 800nm femtosecond infrared (IR) and 248nm nanosecond ultraviolet (UV) laser radiation in performing ablative micromachining of parylene-C on SiO2 substrates for the patterning of human hNT astrocytes. Results are presented that support the validity of using IR laser ablative micromachining for patterning human hNT astrocytes cells while UV laser radiation produces photo-oxidation of the parylene-C and destroys cell patterning. The findings demonstrate how IR laser ablative micromachining of parylene-C on SiO2 substrates can offer a low cost, accessible alternative for rapid prototyping, high yield cell patterning.