A Fortran program for analysis of ellipsometer measurements

McCrackin, Frank L.

doi:10.6028/nbs.tn.479

Cited by 119 publications

(72 citation statements)

References 5 publications

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“…The Auto-Ell III ellipsometer (Rudolph Research, Fairfield, NJ, USA) was programmed for measurements on silicon, and this option was used. The protein film thickness was calculated according to the McCrackin evaluation algorithm [32] and the adsorbed amount per unit area calculated by De Feijter's formula [33]. The refractive indices used were 1.335 and 1.465 for the buffer and the adsorbed APTES and proteins, respectively [34,35].…”

Section: Ellipsometrymentioning

confidence: 99%

Solid-phase classical complement activation by C-reactive protein (CRP) is inhibited by fluid-phase CRP–C1q interaction

Sjöwall

Wetterö

Bengtsson

et al. 2007

Biochemical and Biophysical Research Communications

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C-reactive protein (CRP) interacts with phosphorylcholine (PC), Fc receptors, complement factor C1q and cell nuclear constituents, yet its biological roles are insufficiently understood.The aim was to characterize CRP-induced complement activation by ellipsometry. PC conjugated with keyhole limpet hemocyanin (PC-KLH) was immobilized to cross-linked fibrinogen. A low-CRP serum with different amounts of added CRP was exposed to the PCsurfaces. The total serum protein deposition was quantified and deposition of IgG, C1q, C3c, C4, factor H and CRP detected with polyclonal antibodies. The binding of serum CRP to PC-KLH dose-dependently triggered activation of the classical pathway. Unexpectedly, the activation was efficiently down-regulated at CRP levels >150 mg/L. Using radial immunodiffusion, CRP-C1q interaction was observed in serum samples with high CRP concentrations. We propose that the underlying mechanism depends on fluid-phase interaction between C1q and CRP. This might constitute another level of complement regulation, which has implications for systemic lupus erythematosus where CRP is often low despite flare-ups.

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Section: Ellipsometrymentioning

confidence: 99%

Solid-phase classical complement activation by C-reactive protein (CRP) is inhibited by fluid-phase CRP–C1q interaction

Sjöwall

Wetterö

Bengtsson

et al. 2007

Biochemical and Biophysical Research Communications

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“…The average thicknesses of the adsorbed layers were calculated according to the McCrackin algorithm [24]. The average adsorbed mass per unit area was calculated according to deFeijter [25] using dn/dc = 0.169 cm 3 /g, and a layer of 1 nm thickness then corresponded to approximately 70 ng/cm 2 .…”

Section: In Situ Null Ellipsometrymentioning

confidence: 99%

Whole blood coagulation on protein adsorption-resistant PEG and peptide functionalised PEG-coated titanium surfaces

HANSSON¹

2004

Biomaterials

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The aim of this study was to investigate whole blood coagulation on low blood plasma protein adsorbing surfaces. For this purpose, the polycationic graft copolymer poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG), PLL-g-PEG grafted with a cell adhesive peptide containing the amino acid sequence -Arg-Gly-Asp-(RGD), and PLL-g-PEG with a control peptide -Arg-Asp-Gly-(RDG) were adsorbed onto titanium (oxide), forming stable monomolecular adlayers through electrostatic attraction. Free oscillation rheometry and complementary techniques were used to measure the coagulation time and other interactions of the surfaces with native whole blood, recalcified platelet rich plasma (PRP), and recalcified citrated platelet free plasma (PFP). The results show that the uncoated titanium surfaces (reference) activated platelets and quickly triggered the coagulation cascade via the intrinsic pathway, whereas the PLL-g-PEG surfaces displayed a prolonged coagulation time, approximately 2-3 times longer compared to uncoated titanium. We hypothesize that blood coagulates outside the vascular system independent of low protein adsorption to or activation by surfaces, due to the absence of an active down-regulation of procoagulative processes by the vascular endothelium.1

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“…Protein adsorption on Si was measured with NE in air and thickness values were calculated with the McCrackin algorithm [26]. Here n p =1.457, which equals the refractive index of SiO 2 at 633 nm, was used to facilitate determination of using a method developed by Stenberg et al [27].…”

Section: Fig 2 Schematic Model (Left) and Optical Model (Right) Usementioning

confidence: 99%

“…The measurements were performed with NE in situ in veronal buffered saline supplemented with 0.15 mM CaCl 2 and 0.5 mM MgCl 2 (VB ++ ). The adsorbed protein layer thicknesses were calculated with the McCrackin algorithm [26] using n a = 1.335 and n p = 1.465 [28]. The surface mass density, Γ, was calculated using de Feijter's formula with n p =1.465 and dn/dc=0.18 cm 3 /g.…”

Section: Procedures For Blood Plasma Incubation Using Nementioning

confidence: 99%

Protein adsorption on thin films of carbon and carbon nitride monitored with in situ ellipsometry

et al. 2011

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Amorphous carbon and amorphous, graphitic and fullerene-like carbon nitride thin filmswere deposited by reactive magnetron sputtering and optically characterized withspectroscopic ellipsometry. The films were exposed to human serum albumin and theadsorption was monitored in situ using dynamic ellipsometry. From the ellipsometric data theadsorbed amount of proteins was quantified in terms of surface mass density using de Feijter'smodel. The results indicated larger adsorption of proteins onto the amorphous films comparedto the films with a more ordered microstructure. Complementary studies with labeled HSAusing radioimmunoassay showed up to 6 times higher protein adsorption compared to theellipsometry measurement which partly might be explained by differences in surfaceroughness (from 0.3 to 13 nm) among the films. The elutability of adsorbed labeled HSAusing unlabeled HSA and sodium dodecyl sulphate was low compared to a silicon reference.In addition, the four types of films were incubated in blood plasma followed by antifibrinogen,anti-HMWK or anti-C3c revealing the materials response to complement andcontact activation. Three of the films indicated immunoactivity, whereas the amorphouscarbon showed less immunoactivity compared to a titanium reference. All films showedindications of a stronger ability to initiate the intrinsic pathway of coagulation, compared tothe reference. Finally, the surfaces bone bonding ability was investigated by examination oftheir ability to form calcium phosphate (CaP) crystals in a simulated body fluid, with a-CNxdepositing most CaP after 21 days of incubation.Original Publication:Torun Berlind, Pentti Tengvall, Lars Hultman and Hans Arwin, Protein adsorption on thin films of carbon and carbon nitride monitored with in situ ellipsometry, 2011, ACTA BIOMATERIALIA, (7), 3, 1369-1378.http://dx.doi.org/10.1016/j.actbio.2010.10.024Copyright: Elsevier Science B.V. Amsterdamhttp://www.elsevier.com

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A Fortran program for analysis of ellipsometer measurements

Cited by 119 publications

References 5 publications

Solid-phase classical complement activation by C-reactive protein (CRP) is inhibited by fluid-phase CRP–C1q interaction

Solid-phase classical complement activation by C-reactive protein (CRP) is inhibited by fluid-phase CRP–C1q interaction

Whole blood coagulation on protein adsorption-resistant PEG and peptide functionalised PEG-coated titanium surfaces

Protein adsorption on thin films of carbon and carbon nitride monitored with in situ ellipsometry

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