Effects of parylene‐C photooxidation on serum‐assisted glial and neuronal patterning

Abstract

The increasing use of patterned neural networks in multielectrode arrays and similar devices drives the constant development and evaluation of new biomaterials. Recently, we presented a promising technique to guide neurons and glia reliably and effectively. Parylene-C, a common hydrophobic polymer, was photolithographically patterned on silicon oxide (SiO(2)) and subsequently activated via immersion in serum. In this article, we explore the effects of ultraviolet (UV)-induced oxidation on parylene's ability to pattern neurons and glia. We exposed parylene-C stripe patterns to increasing levels of UV radiation and found a dose-dependent reduction in the total mass of patterned cells, as well as a gradual loss of glial and neuronal conformity to the patterns. In contrast, nonirradiated patterns had superior patterning results and increased presence of cells. The reduced cell adhesion and patterning after the formation of aldehyde and carboxyl groups on UV-radiated parylene-C supports our hypothesis that cell adhesion and growth on parylene is facilitated by hydrophobic adsorption of serum proteins. We conclude that unlike other cell patterning schemes, our technique does not rely on photooxidation of the polymer. Nonetheless, the precise control of oxygenated groups on parylene could pave the way for the differential binding of proteins and other molecules on the surface, aiding in the adhesion of alternative cell types. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

Selective hydrophilic modification of Parylene C films: a new approach to cell micro-patterning for synthetic biology applications

“…Selective patterning of hydrophilic and superhydrophobic areas on a Parylene C 3-D microstructure was achieved through employing two distinct plasma treatments, O 2 and SF 6 respectively, with applications in droplet-based microfluidics [15]. Other studies exploited Parylene C as a substrate for patterning neural cells and demonstrated that cell adhesion on Parylene is promoted by hydrophobic absorption of the serum proteins, which in fact is reduced when Parylene is oxidized through UV irradiation [16]. The need to model the complex interactions between cellular communities in living tissues and produce representative in vitro disease and pharmacological models remains one of the greatest challenges in synthetic biology.…”

The dual role of Parylene C in chemical sensing: Acting as an encapsulant and as a sensing membrane for pH monitoring applications

“…Oxygen plasma treatment has been previously employed to effectively modify the surface properties of such films [13,14], with special emphasis on utilizing the material as a cell culture substrate [15,16]. In other studies, Parylene has been employed for patterning cells and proteins either by enhancing attachment of proteins after UV exposure [17], or as a peel-off stencil [18].…”

Cell Patterning on Photolithographically Defined Parylene-C: SiO₂ Substrates

“…Once prepared, activation of chips in fetal bovine serum enables a wide range of cell types to be patterned in culture. Our group has successfully patterned primary murine hippocampal cells [14][15][16] , the HEK 293 cell line 17 , the human neuron-like teratocarcinoma (hNT) cell line 18 , primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells. Figure 4 illustrates the potential to augment the patterning platform by using alternative activation solutions.…”