| 1. |
- Schael, S, et al.
(author)
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Precision electroweak measurements on the Z resonance
- 2006
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In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Aaron, F. D., et al.
(author)
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Multi-leptons with high transverse momentum at HERA
- 2009
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In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479. ; :10
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Journal article (peer-reviewed)abstract
- Events with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb(-1). The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e(+)p collision data with a scalar sum of the lepton transverse momenta above 100 GeV while 1.94 +/- 0.17 events are expected. Such events are not observed in e(-)p collisions for which 1.19 +/- 0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions.
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| 3. |
- Klein, T. E., et al.
(author)
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Estimation of the warfarin dose with clinical and pharmacogenetic data
- 2009
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In: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 360:8, s. 753-764
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Journal article (peer-reviewed)abstract
- BACKGROUND: Genetic variability among patients plays an important role in determining the dose of warfarin that should be used when oral anticoagulation is initiated, but practical methods of using genetic information have not been evaluated in a diverse and large population. We developed and used an algorithm for estimating the appropriate warfarin dose that is based on both clinical and genetic data from a broad population base.METHODS: Clinical and genetic data from 4043 patients were used to create a dose algorithm that was based on clinical variables only and an algorithm in which genetic information was added to the clinical variables. In a validation cohort of 1009 subjects, we evaluated the potential clinical value of each algorithm by calculating the percentage of patients whose predicted dose of warfarin was within 20% of the actual stable therapeutic dose; we also evaluated other clinically relevant indicators.RESULTS: In the validation cohort, the pharmacogenetic algorithm accurately identified larger proportions of patients who required 21 mg of warfarin or less per week and of those who required 49 mg or more per week to achieve the target international normalized ratio than did the clinical algorithm (49.4% vs. 33.3%, P<0.001, among patients requiring < or = 21 mg per week; and 24.8% vs. 7.2%, P<0.001, among those requiring > or = 49 mg per week).CONCLUSIONS: The use of a pharmacogenetic algorithm for estimating the appropriate initial dose of warfarin produces recommendations that are significantly closer to the required stable therapeutic dose than those derived from a clinical algorithm or a fixed-dose approach. The greatest benefits were observed in the 46.2% of the population that required 21 mg or less of warfarin per week or 49 mg or more per week for therapeutic anticoagulation.
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| 4. |
- Lewis, K., et al.
(author)
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Decreased epithelial barrier function evoked by exposure to metabolic stress and nonpathogenic E. coli is enhanced by TNF-a
- 2008
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In: American Journal of Physiology - Gastrointestinal and Liver Physiology. - : American Physiological Society. - 0193-1857 .- 1522-1547. ; 294:3
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Journal article (peer-reviewed)abstract
- A defect in mitochondrial activity contributes to many diseases. We have shown that monolayers of the human colonic T84 epithelial cell line exposed to dinitrophenol (DNP, uncouples oxidative phosphorylation) and nonpathogenic Escherichia coli (E. coli) (strain HB101) display decreased barrier function. Here the impact of DNP on macrophage activity and the effect of TNF-a, DNP, and E. coli on epithelial permeability were assessed. DNP treatment of the human THP-1 macrophage cell line resulted in reduced ATP synthesis, and, although hyporesponsive to LPS, the metabolically stressed macrophages produced IL-1ß, IL-6, and TNF-a. Given the role of TNF-a in inflammatory bowel disease (IBD) and the association between increased permeability and IBD, recombinant TNF-a (10 ng/ml) was added to the DNP (0.1 mM) + E. coli (106 colony-forming units), and this resulted in a significantly greater loss of T84 epithelial barrier function than that elicited by DNP + E. coli. This increased epithelial permeability was not due to epithelial death, and the enhanced E. coli translocation was reduced by pharmacological inhibitors of NF-?ß signaling (pyrrolidine dithiocarbamate, NF-?ß essential modifier-binding peptide, BAY 11-7082, and the proteosome inhibitor, MG132). In contrast, the drop in transepithelial electrical resistance was unaffected by the inhibitors of NF-?ß. Thus, as an integrative model system, our findings support the induction of a positive feedback loop that can severely impair epithelial barrier function and, as such, could contribute to existing inflammation or trigger relapses in IBD. Thus metabolically stressed epithelia display increased permeability in the presence of viable nonpathogenic E. coli that is exaggerated by TNF-a released by activated immune cells, such as macrophages, that retain this ability even if they themselves are experiencing a degree of metabolic stress. Copyright © 2008 the American Physiological Society.
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| 5. |
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| 6. |
- Gullberg, Elisabet, et al.
(author)
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Identification of Cell Adhesion Molecules in the Human Follicle-Associated Epithelium That Improve Nanoparticle Uptake into the Peyer's Patches
- 2006
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In: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0022-3565 .- 1521-0103. ; 319:2, s. 632-639
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Journal article (peer-reviewed)abstract
- The aim of this study was to identify cell adhesion molecules that could serve as targets of the human follicle-associated epithelium (FAE) overlying Peyer's patches and to assess nanoparticle uptake levels across this epithelium. We first studied the expression of the mouse M-cell marker beta(1)-integrin and used a model of human FAE derived from intestinal epithelial Caco-2 cells and Raji B-cells to identify additional potential targets by cDNA array. The protein expression of potential targets in the model FAE and in human ileal FAE tissues was quantified by immunofluorescence. Integrin targeting was studied by investigating the transport of Arg-Gly-Asp (RGD)-coated (integrin- binding), Arg-Gly-Glu (RGE)-coated (nonintegrin-binding), and uncoated nanoparticles across ileal specimens mounted in Ussing chambers. Both beta(1)-integrin and the cell adhesion molecule CD9 were more abundantly expressed in the model and human FAE compared with the Caco-2 control cells or villus epithelium (VE). Uncoated nanoparticles were not taken up across either FAE or VE. General integrin targeting with RGD improved the nanoparticle transport dramatically across the FAE and to a lower extent across the VE. Compared with RGE, RGD improved transport 4-fold across the FAE. There was no difference in the transport of RGD- and RGE-coated nanoparticles across the VE. In conclusion, beta(1)-integrin and CD9 were identified as targets in human FAE. The difference in RGD- and RGE-mediated transport across the FAE, but not the VE, suggests that a specific integrin interaction was the dominating mechanism for improved nanoparticle uptake across the FAE., whereas charge interaction contributed substantially to the improved VE uptake.
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| 7. |
- Imboden, S., et al.
(author)
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A Haptic Enabled Multimodal Pre-Operative Planner for Hip Arthroplasty
- 2005
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In: World Haptics Conference: First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virutual Environment and Teleoperator Systems, Proceedings. - 0769523102 ; , s. 503-504
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Conference paper (peer-reviewed)abstract
- This paper introduces the multisense idea, with a special reference to the use of haptics in the medical field and, in particular, in the planning of total hip replacement surgery. We emphasise the integration of different modalities and the capability of the multimodal system to gather and register data coming from different sources.
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| 8. |
- Testi, D., et al.
(author)
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A multimodal and multisensorial pre-operative planning environment for total hip replacement
- 2005
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In: Proceedings - Third International Conference on Medical Information Visualisation - BioMedical Visualisation, MediVis 2005. - 0769523935 - 9780769523934 ; , s. 25-29
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Conference paper (peer-reviewed)abstract
- This paper describes a new environment for the pre-operative planning of total hip replacement. The system is based on a multimodal/multisensorial interface, which includes advanced software visualisation and evaluation modules for the planning and state-of-the-art technologies for immersive interface (stereoscopic display, different six degrees of freedom tracking technologies, speech recognition, and haptic feedbacks). This paper is focused on the final clinical application description. More specific visualisation-related modules are described in other related papers.
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| 9. |
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| 10. |
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| 11. |
- Andrady, Anthony, et al.
(author)
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Environmental effects of ozone depletion and its interaction with climate change: Progress report 2007
- 2008
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In: Photochemical and Photobiological Sciences. - : Springer Science and Business Media LLC. - 1474-9092 .- 1474-905X. ; 7:1, s. 15-27
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Research review (peer-reviewed)abstract
- This year theMontreal Protocol celebrates its 20th Anniversary. In September 1987, 24 countries signed the ‘Montreal Protocol on Substances that Deplete the Ozone Layer’. Today 191 countries have signed and have met strict commitments on phasing out of ozone depleting substances with the result that a 95% reduction of these substances has been achieved. The Montreal Protocol has also contributed to slowing the rate of global climate change, since most of the ozone depleting substances are also effective greenhouse gases. Even though much has been achieved, the future of the stratospheric ozone layer relies on full compliance of the Montreal Protocol by all countries for the remaining substances, including methyl bromide, as well as strict monitoring of potential risks from the production of substitute chemicals. Also the ozone depleting substances existing in banks and equipment need special attention to prevent their release to the stratosphere. Since many of the ozone depleting substances already in the atmosphere are long-lived, recovery cannot be immediate and present projections estimate a return to pre-1980 levels by 2050 to 2075. It has also been predicted that the interactions of the effects of the ozone layer and that of other climate change factors will become increasingly important.
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| 12. |
- Andrady, Anthony, et al.
(author)
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Environmental effects of ozone depletion and its interactions with climate
- 2009
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In: Photochemical and Photobiological Sciences. - 1474-9092. ; 8:1, s. 13-22
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Research review (peer-reviewed)abstract
- After the enthusiastic celebration of the 20th Anniversary of the Montreal Protocol on Substances that Deplete the Ozone Layer in 2007, the work for the protection of the ozone layer continues. The Environmental Effects Assessment Panel is one of the three expert panels within theMontreal Protocol. This “EEAP” deals with the increase of the UV irradiance on the Earth’s surface and its effects on human health, animals, plants, biogeochemistry, air quality and materials. For the past few years, interactions of ozone depletion with climate change have also been considered. It has become clear that the environmental problems will be long-lasting. In spite of the fact that the worldwide production of ozone depleting chemicals has already been reduced by 95%, the environmental disturbances are expected to persist for about the next half a century, even if the protective work is actively continued, and completed. The latest full report was published in Photochem. Photobiol. Sci., 2007, 6, 201–332, and the last progress report in Photochem. Photobiol. Sci., 2008, 7, 15–27. The next full report on environmental effects is scheduled for the year 2010. The present progress report 2008 is one of the short interim reports, appearing annually.
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| 13. |
- Caldwell, Karin D., et al.
(author)
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The Origin of Sepahdex
- 2006
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In: GIT Laboratory Journal: Europe. ; 10:5, s. 18-20
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Journal article (other academic/artistic)
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| 14. |
- Caldwell, K, et al.
(author)
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Field-Flow Fractionation
- 2005
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In: Methods for Structural Analysis of Protein Pharmaceuticals.
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Book chapter (other academic/artistic)abstract
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| 15. |
- Feiler, Adam A., et al.
(author)
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Adsorption and viscoelastic properties of fractionated mucin (BSM) and bovine serum albumin (BSA) studied with quartz crystal microbalance (QCM-D)
- 2007
-
In: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 315:2, s. 475-481
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Journal article (peer-reviewed)abstract
- The adsorption profile and viscoelastic properties of bovine submaxillary gland mucin (BSM) and bovine serum albumin (BSA), extracted from a commercial mucin preparation, adsorbing to polystyrene surfaces has been studied using quartz crystal microbalance with dissipation monitoring (QCM-D). A significant difference in the adsorption properties of the different proteins was detected; with the BSA adsorbing in a flat rigid layer whilst the mucin adsorbed in a diffuse, highly viscoelastic layer. Subsequent addition of BSA to the preadsorbed mucin layer resulted in stiffening of the protein layer which was attributed to complexation of the mucin by BSA. In contrast, a preadsorbed layer of BSA prevented mucin adsorption altogether. Combined mixtures of mucin and BSA in well defined ratios revealed intermediate properties between the two separate protein species which varied systematically with the protein ratios. The results shed light on the synergistic effects of complexation of lower molecular weight biomolecular species with mucin. The possibility to selectively control protein uptake and tailor the physical properties of the adsorbed layer makes mucin an attractive option for application in biomaterial coatings.
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| 16. |
- Fromell, Karin, et al.
(author)
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A particulate platform for bioluminescent immunosensing
- 2007
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 79:22, s. 8601-8607
-
Journal article (peer-reviewed)abstract
- The present study examines pyruvate kinase-conjugated antibodies for potential use in EUSA applications. The conjugates had an acceptable stability, and the coupling inflicted only minor impairment on the kinase activity. To mimic the setup of an immunoassay under development, a test antigen (BSA) was attached to polystyrene nanoparticles. This arrangement was found to be suitable as solid support for presentation of antigens in sensitive bioluminescence assays. The nanoparticles were well characterized in terms of protein surface load and were used to establish the number of conjugate complexes needed to generate a detectable signal. Under the biochemical conditions employed here, the detection limit of the pyruvate kinase conjugate lies in the femtomole range.
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| 17. |
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| 18. |
- Lundin, Maria, et al.
(author)
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Comparison of the adsorption kinetics and surface arrangement of "as received" and purified bovine submaxillary gland mucin (BSM) on hydrophilic surfaces
- 2009
-
In: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 336:1, s. 30-39
-
Journal article (peer-reviewed)abstract
- The effect of bovine serum albumin (BSA) as impurity in a commercial bovine submaxillary gland mucin preparation (BSM; Sigma M3895) on the adsorption of BSM to hydrophilic surfaces (mica and silica) has been Studied in terms of adsorption kinetics, amount and structure of the formed adlayer. The Surface Force Apparatus (SFA) was used to gain information about the extended and compressed structure of adsorbed "as received" BSM, purified BSM, BSA extracted from the "as received" BSM and mixtures of the latter Purified proteins. The adsorbed amount was estimated using a combination of X-ray Photoelectron Spectroscopy (XPS), Enzyme-Linked Immuno Sorbent Assay (ELISA), Enzyme-Linked Lectin Assay (ELLA), Dual Polarization Interferometry (DPI) and Quartz Crystal Microbalance (QCM-D) measurements. Under the used conditions, purified BSM showed very low affinity for silica and only small amounts were found to adsorb on mica. Initially, the BSM molecules adopted an extended conformation on the mica surface with tails extending into the bulk phase. These tails were irreversibly compressed into a very thin (10 A) layer upon applying a high load. "As received" BSM formed considerably thicker Compressed layers (35 A); however, the extended layer structure was qualitatively the same. When Mixtures of purified BSM and BSA were coadsorbed on mica, a 9 wt-% albumin content gave a comparable layer thickness as the "as received" BSM and from XPS data we draw the conclusion that the albumin content in the layer adsorbed from "as received" BSM was approximately 5 wt-%. Adsorption from an equal amount of BSM and BSA revealed that even though the amount of BSM is scarce in the mixed layer, the few BSM molecules have a drastic effect on the adsorbed thickness and Structure. Clearly, this study shows the importance of characterizing the mucin used since differences in purity give rise to different adsorption behaviours in terms of both adsorbed amount and layer Structure. (C) 2009 Elsevier Inc. All rights reserved.
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| 19. |
- Margreiter, Gerd, et al.
(author)
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Size characterization of inclusion bodies by sedimentation field-flow fractionation
- 2008
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In: Journal of Biotechnology. - : Elsevier BV. - 0168-1656 .- 1873-4863. ; 138:3-4, s. 67-73
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Journal article (peer-reviewed)abstract
- Sedimentation field-flow fractionation (sedFFF) was evaluated to characterize the size of Delta(4-23)TEM-beta-lactamase inclusion bodies (IBs) overexpressed in fed-batch cultivations of Escherichia coli. Heterologous Delta(4-23)TEM-beta-lactamase protein formed different sizes of IBs, depending upon the induction conditions. In the early phases of recombinant protein expression, induced with low concentrations of IPTG (isopropyl-beta-d-thiogalactoside), IB masses were larger than expected and showed heterogeneous size distributions. During cultivation, IB sizes showed a Gaussian distribution and reached a broad range by the end of the fed-batch cultivations. The obtained result proved the aptitude of sedFFF to rapidly assess the size distribution of IBs in a culture.
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| 20. |
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| 21. |
- Sandberg, Tomas, et al.
(author)
-
Potential use of mucins as biomaterial coatings. I. Fractionation, characterization, and model adsorption of bovine, porcine, and human mucins
- 2009
-
In: Journal of Biomedical Materials Research Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 91A:3, s. 762-772
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Journal article (peer-reviewed)abstract
- Previously, we presented evidence that mucins have potential as biomaterial coatings. Here, we reveal substantial batch-to-batch variations for a frequently used commercial bovine salivary mucin preparation (BSM) and stress the importance of standardizing mucins intended for comparative purposes. "Mild" fractionation strategies, aiming at preserving natural mucin functions, were used to prepare two more defined BSM fractions as well as three mucin fractions from porcine gastric (PGM) and human salivary (MG1) sources. While the BSM and PGM were highly purified and mainly adopted random coil conformations in solution, the MG1 contained mucin-bound components (1.6 wt% albumin) and appeared compact. Average molar masses and root-mean-square radii for the predominant BSM, PGM, and MG1 species spanned 0.8-4.2 MDa and 46-86 nm, respectively. An ellipsometric evaluation, using hydrophilic and hydrophobic silica, showed the mucin adsorption to be slow and related to mucin charge, size, conformation, and compositional complexity. The mass uptakes on hydrophobic silica averaged 2.6, 2.6, and 5.0 mg/m(2), for BSM, PGM, and MG1, respectively. Finally, we find that stable mucin coatings can be formed on polymers of different wettability. The reported mucin preparations serve as platforms for a series of studies on the biocompatibility of mucin coatings.
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| 22. |
- Sandberg, Tomas, et al.
(author)
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Potential use of mucins as biomaterial coatings. II. Mucin coatings affect the conformation and neutrophil-activating properties of adsorbed host proteins – Towards a mucosal mimic
- 2009
-
In: Journal of Biomedical Materials Research: Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 91A:3, s. 773-785
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Journal article (peer-reviewed)abstract
- In continuation of our recent fractionation and characterization study on mucins of bovine salivary (BSM), porcine gastric (PGM), and human salivary (MG1) origin, this study evaluates the effect of mucin precoating on the conformation and neutrophil-activating properties of host proteins adsorbed to a polyethylene terephthalate-based model biomaterial. Microscopy combined with assays for the neutrophil releases of reactive oxygen species and human neutrophil lipocalin showed that mucin precoating greatly reduced the strong immune-response normally induced by adsorbed immunoglobulin G (IgG) and secretory immunoglobulin A (sIgA), respectively. A similar finding was made for the proinflammatory fibrinogen. Although the total uptakes of these proteins depended on the mucin surface concentration, a detailed composite analysis suggested the fraction Of surface-exposed protein to be a stronger determinant of coating performance. The unexpectedly low neutrophil activation showed by composites containing near-monolayer concentrations of exposed IgG and sIgA, respectively, suggested that these act synergistically with mucin on the surface. In support of this hypothesis, quartz crystal microbalance with dissipation monitoring measurements revealed that a preadsorbed BSM layer stabilizes IgG through complexation on a polymeric model surface. Our findings link well to the complex in vivo situation and suggest that functional mucosal mimics can be created in situ for improved biomaterials performance.
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| 23. |
- Sandberg, Tomas, et al.
(author)
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Surface analysis of pure and complex mucin coatings
- 2009
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In: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 333:1, s. 180-187
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Journal article (peer-reviewed)abstract
- In the past, we introduced the idea of using mucin coatings to improve biomaterials performance. Here, we evaluate non-radioactive methods for the analysis of pure and human host protein-containing (complex) mucin coatings on a real-type substrate (Thermanox). A common protein quantification assay (mBCA) was combined with mass-calibrated, enzyme-amplified assays based on lectin (ELLA) and antibody (ELISA) recognition, to determine the total and specific amounts of surface-associated proteins. Model studies showed the mBCA assay to be of limited use at low mass loads, and steric effects to influence the ELLA at high surface layer densities. Non-specific responses due to substrate interaction were low for the ELLA and ELISAs. Cross-reactions were observed during ELLA analysis of analytes sharing high degree of O-glycosylation. Combined mBCA-ELLA-ELISA analysis suggested that mucin desorption was low upon protein addition and that low concentrations of ELISA-determined Protein for the complex coatings Could be explained in terms of low accessibility of proteins to the bulk environment. Specifically, a methodology is presented for the determination of the fraction of surface-exposed, presumed bioactive proteins in a complex mucin coating. Finally, X-ray photoelectron spectroscopy and infrared reflectance spectroscopy combined with multivariate data analysis were proven useful in the evaluation of mucin-based coatings.
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| 24. |
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| 25. |
- Åsberg, Peter, 1973-
(author)
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Hydrogels of conjugated polyelectrolytes for biosensor and biochip applications
- 2005
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Doctoral thesis (other academic/artistic)abstract
- This thesis describes the use of conjugated polyelectrolytes (CPEs) in biosensor devices. The method is based on non-covalent assembly of the biomolecule of interest and the CPE functioning as the reporter, in one case as a transducer, of biomolecular events. Devices of these assemblies on solid supports that can operate in liquid solutions have been the focus. Polythiophenes, both semiconducting and conducting, is the class of materials that has been used in this work. The semiconducting polythiophenes have ionic side chains which makes them water soluble. This ionic side chain is capable of both forming electrostatic and hydrogen bonds, and when paired with the hydrophobic backbone of the polymer a great number of interactions with biomolecules are possible. The highly conducting polythiophene derivative PEDOT -PSS, (PEDOT) doped with ionic and water soluble PSS polyelectrolyte, was used as the conducting material in 3D-electrode. Both the semiconducting and conducting polymers described above forms hydrogels on solid supports if crosslinked with the appropriate ion, biomolecule or polymer. Evaluation of the CPEs, both with and without biomolecules, was performed in liquid, solid and hydrogel state using a number of techniques. This was done to understand how the CPEs behave when exposed to different buffer systems and various biomolecules.Hydrogels of conjugated polyelectrolytes combined with biomolecules are attractive as biosensors. The advantage with the hydrogel format is the high water content, the porous structure and the large capacity of binding molecules. High water content is important to preserve the biomolecules by providing the correct buffered environment. In this thesis we demonstrated a hydrogel of the highly conducting PEDOT -PSS polymer that was crosslinked on a solid support together with horseradish peroxidase (HRP) enzyme, forming an enzyme-enhanced electrode. Further studies of hydrogels were done using in situ quartz crystal microbalance with dissipation (QCM-D). POWT is a CPE withproperties well suited for biochip applications and readily forms hydrogels when exposed to water-based buffer solutions or biomolecule solutions. Detection ofcomplementary DNA and rejection of non-complementary DNA in a POWT hydrogel was demonstrated. The interaction between POWT and DNAoligonucleotides was also evaluated using fluorescence resonance energy transfer (FRET) in solution. Labeled DNA oligonucleotides with energy accepting or donating fluorophores allowed us to determine distance and binding stoichiometry in the non-covalent POWT-DNA complex.Patterning and anchoring of biomolecules and non-covalent assembled CPE-biomolecule complexes to a chip surface was studied; in the adsorbed state these complexes are hydrogels. Our novel method is based on the modification of the surface energy of a hydrophilic substrate surface using hydrophobic poly(dimethylsiloxane) (PDMS) elastomer stamp containing a relief pattern. Different conformations in biomolecules could be detected using fluorescence microscopy, where the CPEs acts as reporters and the PDMS modified substrates as discriminator. Also, excellent enzyme activity in patterned CPE/Horseradish peroxidase (HRP) enzyme was shown.Distances between the individual molecules in solid state devices of conjugated polymers can be small. In luminescence devices, such as light emitting diodes or fluorescence biosensors, there is a chance of interaction between conjugated molecules especially if more than one type of molecule is present. Quenching of the light and fluorescence energy transfer can occur and a simple approach to study this was developed.
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