Versatile multicharacterization platform involving tailored superhydrophobic SU-8 micropillars for the investigation of breast cancer estrogen receptor isoforms

Here, the authors report the fabrication of lotus-leaf-like tailored SU8 micropillars and their application in the context of a multitechnique characterization protocol for the investigation of the structural properties of the two estrogen receptors (ER alpha 66/ER alpha 46). ER (alpha) expression is undoubtedly the most important biomarker in breast cancer, as it provides the index for sensitivity to endocrine treatment. Beside the well-characterized ER alpha 66 isoform, a shorter one (ER alpha 46) is also expressed in ER alpha positive breast cancers and breast cancer cell lines. The superhydrophobic supports were developed by using a two-step approach including an optical lithography process and a plasma reactive ion roughening one. Upon drying on the micropillars, the biological samples resulted in stretched fibers of different diameters which were then characterized by synchrotron xray diffraction (XRD), Raman and Fourier-transform infrared spectroscopy. The evidence of both different spectroscopic vibrational responses and XRD signatures in the two estrogen receptors suggests the presence of conformational changes between the two biomarkers. The SU8 micropillar platform therefore represents a valid tool to enhance the discrimination sensitivity of structural features of this class of biomarkers by exploiting a multitechnique in situ characterization approach. (C) 2016 American Vacuum Society.