Functional nanothin films plasma-deposited from 2-isopropenyl-2-oxazoline for biosensor applications.

Plasma polymers derived from oxazoline precursors present a range of versatile properties that is fueling their use as biomaterials. However, coatings deposited from commonly used methyl and ethyl oxazoline precursors can be sensitive to the plasma deposition conditions. In this work, we used various spectroscopic methods (ellipsometry, x-ray photoelectron spectroscopy, and time of flight secondary ion mass spectrometry) and cell viability assays to evaluate the transferability of deposition conditions from the original plasma reactor developed by Griesser to a new wider, reactor designed for upscaled biosensors applications. The physicochemical properties, reactivity, and biocompatibility of films deposited from 2-isopropenyl-2-oxazoline were investigated. Thanks to the availability of an unsaturated pendant group, the coatings obtained from this oxazoline precursor are more stable and reproducible over a range of deposition conditions while retaining reactivity toward ligands and biomolecules. This study identified films deposited at 20 W and 0.012 mbar working pressure as being the best suited for biosensor applications.

Plasma enabled devices for the selective capture and photodynamic identification of prostate cancer cells.

Prostate cancer is the second most common cancer in men and the second leading cause of male cancer deaths. The current blood test for detecting prostate cancers measures prostate-specific antigen. It has many limitations including a very high rate of false positives. Herein, prostate-specific membrane antigen (PSMA) based immunocapture and hexaminolevulinate (HAL) based photodetection are integrated into a new diagnostic device designed to selectively identify whole prostate cancer cells from voided urine with the aim of providing an accurate noninvasive alternative to current diagnosis methods. Prestained, prostate cancer cells spiked in urine samples at concentrations ranging from 1500 to 2000 cells/ml were captured with 89% sensitivity and 95% specificity. HAL, a cancer specific photosensitizer, was then used to circumvent the need for prestaining. Optimum HAL incubation conditions were identified (50 µM at 37 °C for 2 h) where the mean HAL-induced fluorescence intensity of LNCaP cells was three times that of healthy PNT2 cells, thus providing an independent way to discriminate captured cancer cells from background metabolites. Combining anti-PSMA immunocapture with HAL-induced fluorescent detection, 86% sensitivity and 88% selectivity were achieved, thereby proving the validity of the dual-method for the selective photospecific detection of prostate cancer cells.