Adsorption of proteins to thin-films of PDMS and its effect on the adhesion of human endothelial cells

Abstract

This paper describes a simple and inexpensive procedure to produce thin-films of poly(dimethylsiloxane). Such films were characterized by a variety of techniques (ellipsometry, nuclear magnetic resonance, atomic force microscopy, and goniometry) and used to investigate the adsorption kinetics of three model proteins (fibrinogen, collagen type-I, and bovine serum albumin) under different conditions. The information collected from the protein adsorption studies was then used to investigate the adhesion of human dermal microvascular endothelial cells. The results of these studies suggest that these films can be used to model the surface properties of microdevices fabricated with commercial PDMS. Moreover, the paper provides guidelines to efficiently attach cells in BioMEMS devices.

Interference-blind microfluidic sensor for ascorbic acid determination by UV/vis spectroscopy

“…A relatively high concentration of enzyme (i.e., 1 µg/mL) was chosen for immobilization to maintain their native conformation (maximum enzymatic activity). [21][22][23] The freshly prepared enzyme-loaded microchip was used for AA oxidation. Fig.…”

Immobilization of glucose oxidase to nanostructured films of polystyrene-block-poly(2-vinylpyridine)

“…However, when multiple experiments were analyzed, significant increases in the MSE value were obtained, indicating that the proposed model was not able to accurately describe the optical properties of the sample and therefore may not represent the physical meaning of the measurement. Therefore, and in order to consider the possibility of GOx penetrating into the structure of the polymer, the EMA layer was modified to include the protein (also described with a Cauchy function, n (λ) = 1.45 + 0.01·λ −2 ) [33, 40, 41] as an additional component. The resulting model, schematically shown in Figure 4B, allowed calculating changes in the total thickness of the substrates as well as the relative contribution of the protein to the film.…”

Protein adsorption onto nanomaterials for the development of biosensors and analytical devices: A review

“…Since it measures the ratio of two values originated by the same signal, the measurements are highly accurate and reproducible. The measurements are complementary to the information obtained by QCM and can be used to determine the optical properties of asubstrate and the thickness of multiple layers on the surface.The technique is simple, nondestructive, has angstrom resolution, and has the capability of allowing the observation of the adsorption process inreal time[94, 134, 135]. The use of imaging ellipsometry can also provide spatial resolution of protein binding [136].…”

“…Albumin (and most commonly BSA) is a heart-shaped soft protein with a molecular weight of 66.5 kDa and an IEP of 4.8 [108]. Because BSA typically exhibits significant surface-induced spreading upon adsorption, a stable layer of the protein can be formed under a wide number of conditions in less than 1 h [135, 205, 303]. For these reasons (and its low cost), it has been extensively used as a model protein to study adsorption [68, 80, 110, 134, 137, 139, 304, 305], to aid in the suspension of CNT [306], and to block the remaining sites of surfaces after the immobilization of a biorecognition element [250, 260, 294, 307].…”