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  • 51.
    Selegard, Robert
    et al.
    Orebro Univ, Sweden.
    Musa, Amani
    Orebro Univ, Sweden.
    Nystroem, Pontus
    Orebro Univ, Sweden.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Bengtsson, Torbjörn
    Orebro Univ, Sweden.
    Khalaf, Hazem
    Orebro Univ, Sweden.
    Plantaricins markedly enhance the effects of traditional antibiotics against Staphylococcus epidermidis2019Inngår i: FUTURE COMPUTING ... the ... International Conference on Future Computational Technologies and Applications, ISSN 1746-0913, E-ISSN 1999-5903, Vol. 14, nr 3, s. 195-206Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Bacteriocins are considered as promising alternatives to antibiotics against infections. In this study, the plantaricins (Pln) A, E, F, J and K were investigated for their antimicrobial activity against Staphylococcus epidermidis. Materials amp; methods: The effects on membrane integrity were studied using liposomes and viable bacteria, respectively. Results: We show that PlnEF and PlnJK caused rapid and significant lysis of S. epidermidis, and induced lysis of liposomes. The PlnEF and PlnJK displayed similar mechanisms by targeting and disrupting the bacterial cell membrane. Interestingly, Pln enhanced the effects of different antibiotics by 30- to500-fold. Conclusion: This study shows that Pln in combination with low concentrations of antibiotics is efficient against S. epidermidis and may be developed as potential treatment of infections.

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  • 52.
    Selegård, Robert
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aronsson, Christopher
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Brommesson, Caroline
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär ytfysik och nanovetenskap. Linköpings universitet, Tekniska fakulteten.
    Dånmark, Staffan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Folding driven self-assembly of a stimuli-responsive peptide-hyaluronan hybrid hydrogel2017Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 7013Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Protein-metal ion interactions are ubiquitous in nature and can be utilized for controlling the self-assembly of complex supramolecular architectures and materials. Here, a tunable supramolecular hydrogel is described, obtained by self-assembly of a Zn2+-responsive peptide-hyaluronic acid hybrid synthesized using strain promoted click chemistry. Addition of Zn2+ triggers folding of the peptides into a helix-loop-helix motif and dimerization into four-helix bundles, resulting in hydrogelation. Removal of the Zn2+ by chelators results in rapid hydrogel disassembly. Degradation of the hydrogels can also be time-programed by encapsulation of a hydrolyzing enzyme within the gel, offering multiple possibilities for modulating materials properties and release of encapsulated species. The hydrogel further shows potential antioxidant properties when evaluated using an in vitro model for reactive oxygen species.

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  • 53.
    Selegård, Robert
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska högskolan.
    Enander, Karin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska högskolan.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska högskolan.
    Generic Phosphatase Activity Detection using Zinc Mediated Aggregation Modulation of Polypeptide-Modified Gold Nanoparticles2014Inngår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 6, nr 23, s. 14204-14212Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A challenge in the design of plasmonic nanoparticle-based colorimetric assays is that the change in colloidal stability, which generates the colorimetric response, is often directly linked to the biomolecular recognition event. New assay strategies are hence required for every type of substrate and enzyme of interest. Here, a generic strategy for monitoring of phosphatase activity is presented where substrate recognition is completely decoupled from the nanoparticle stability modulation mechanism, which enables detection of a wide range of enzymes using different natural substrates with a single simple detection scheme. Phosphatase activity generates inorganic phosphate that forms an insoluble complex with Zn2+. In a sample containing a preset concentration of Zn2+, phosphatase activity will markedly reduce the concentration of dissolved Zn2+ from the original value, which in turn affects the aggregation of gold nanoparticles functionalized with a designed Zn2+ responsive polypeptide. The change in nanoparticle stability thus provides a rapid and sensitive readout of the phosphatase activity. The assay is not limited to a particular enzyme or enzyme substrate, which is demonstrated using three completely different phosphatases and five different substrates, and thus constitutes a highly interesting system for drug screening and diagnostics.

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  • 54.
    Selegård, Robert
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Rouhbalchsh, Zeinab
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Shirani, Hamid
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Johansson, Leif
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Norman, Patrick
    KTH Royal Institute Technology, Sweden.
    Linares, Mathieu
    KTH Royal Institute Technology, Sweden.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Distinct Electrostatic Interactions Govern the Chiro-Optical Properties and Architectural Arrangement of Peptide-Oligothiophene Hybrid Materials2017Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 50, nr 18, s. 7102-7110Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of chiral optoelectronic materials is of great interest due to their potential of being utilized in electronic devices, biosensors, and artificial enzymes. Herein, we report the chiral optical properties and architectural arrangement of optoelectronic materials generated from noncovalent self-assembly of a cationic synthetic peptide and five chemically defined anionic pentameric oligothiophenes. The peptide-oligothiophene hybrid materials exhibit a three-dimensional ordered helical structure and optical activity in the pi-pi* transition region that are observed due to a single chain induced chirality of the conjugated thiophene backbone upon interaction with the peptide. The latter property is highly dependent on electrostatic interactions between the peptide and the oligothiophene, verifying that a distinct spacing of the carboxyl groups along the thiophene backbone is a major chemical determinant for having a hybrid material with distinct optoelectronic properties. The necessity of the electrostatic interaction between specific carboxyl functionalities along the thiophene backbone and the lysine residues of the peptide, as well as the induced circular dichroism of the thiophene backbone, was also confirmed by theoretical calculations. We foresee that our findings will aid in designing optoelectronic materials with dynamic architectonical precisions as well as offer the possibility to create the next generation of materials for organic electronics and organic bioelectronics.

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  • 55.
    Sivler, Tobias
    et al.
    S2Medical AB, Sunnorpsgatan, Linkoping, Sweden.
    Sivlér, Petter
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. S2Medical AB, Sunnorpsgatan, Linkoping, Sweden.
    Skog, Mårten
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten. S2Medical AB, Sunnorpsgatan, Linkoping, Sweden.
    Conti, Luca
    S2Medical AB, Sunnorpsgatan, Linkoping, Sweden.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Treatment of Nonhealing Ulcers with an Allograft/Xenograft Substitute: A Case Series2018Inngår i: Advances in Skin & Wound Care, ISSN 1527-7941, E-ISSN 1538-8654, Vol. 31, nr 7, s. 306-309Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    OBJECTIVE: Wound dressings that use biosynthetic cellulose may be a good alternative to dressings currently used to treat chronic and acute ulcers because their nanostructure is similar to collagen. The objective of this study was to evaluate a wound dressing created with a new material that is composed of a fibrillary network of biosynthetic cellulose. METHODS: A case series of 8 patients in primary healthcare centers in ostergotland county council, Sweden, with chronic and acute lower limb wounds were treated with a wound dressing based on eiratex (S2Medical AB, Linkoping, Sweden). The dressing was applied to traumatic (n = 5) and venous ulcers (n = 3). All ulcers were considered healed at the end of the treatment. MAIN OUTCOME MEASURE: The wounds were examined at regular intervals by a physician to determine healing time, number of dressing changes, and number of visits. MAIN RESULTS: Mean healing time was 43 6 days after the first application of the dressing. The mean number of visits was 5.7 +/- 0.6, and the mean number of dressings used per patient was 1.7 +/- 0.2. CONCLUSIONS: These results demonstrate the efficacy of a wound dressing made of eiratex to heal chronic and acute ulcers. The data show that the number of dressings used and dressing changes needed to heal the ulcers are lower than what have been reported in the literature for other dressing materials.

  • 56.
    Skog, Mårten
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Sivlér, Petter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Steinvall, Ingrid
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Hand- och plastikkirurgiska kliniken US.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Sjöberg, Folke
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Hand- och plastikkirurgiska kliniken US.
    Elmasry, Moustafa
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Hand- och plastikkirurgiska kliniken US.
    The Effect of Enzymatic Digestion on Cultured Epithelial Autografts2019Inngår i: Cell Transplantation, ISSN 0963-6897, E-ISSN 1555-3892, Vol. 28, nr 5, s. 638-644Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Severe burns are often treated by means of autologous skin grafts, preferably following early excision of the burnt tissue. In the case of, for example, a large surface trauma, autologous skin cells can be expanded in vitro prior to transplantation to facilitate the treatment when insufficient uninjured skin is a limitation. In this study we have analyzed the impact of the enzyme (trypsin or accutase) used for cell dissociation and the incubation time on cell viability and expansion potential, as well as expression of cell surface markers indicative of stemness. Skin was collected from five individuals undergoing abdominal reduction surgery and the epidermal compartment was digested in either trypsin or accutase. Trypsin generally generated more cells than accutase and with higher viability; however, after 7 days of subsequent culture, accutase-digested samples tended to have a higher cell count than trypsin, although the differences were not significant. No significant difference was found between the enzymes in median fluorescence intensity of the analyzed stem cell markers; however, accutase digestion generated significantly higher levels of CD117- and CD49f-positive cells, but only in the 5 h digestion group. In conclusion, digestion time appeared to affect the isolated cells more than the choice of enzyme.

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  • 57.
    Skyttner, Camilla
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Enander, Karin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aronsson, Christopher
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Tuning Liposome Membrane Permeability by Competitive Coiled Coil Heterodimerization and Heterodimer Exchange2018Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, nr 22, s. 6529-6537Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Membrane-active peptides that enable the triggered release of liposomal cargo are of great interest for the development of liposome-based drug delivery systems but require peptide-lipid membrane interactions that are highly defined and tunable. To this end, we have explored the possibility to use the competing interactions between membrane partitioning and heterodimenzation and the folding of a set of four different de novo designed coiled coil peptides Covalent conjugation of the cationic peptides triggered rapid destabilization of membrane mtegrity and the release of encapsulated species. The release was inhibited when introducing complementary peptides as a result of heterodimenzation and folding into coiled mils The degree of inhibition was shown to be dictated by the coiled coil peptide heterodimer dissociation constants, and liposomal release could be reactivated by a heterodimer exchange to render the membrane bound peptide free and thus membrane-active. The possibility to tune the permeability of lipid membranes using highly specific peptide-folding-dependent interactions delineates a new possible approach for the further development of responsive liposome-based drug delivery systems.

    Fulltekst (pdf)
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  • 58.
    Skyttner, Camilla
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Selegård, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Larsson, Jakob
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aronsson, Christopher
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Enander, Karin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Sequence and length optimization of membrane active coiled coils for triggered liposome release2019Inngår i: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1862, nr 2, s. 449-456Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Defined and tunable peptide-lipid membrane interactions that trigger the release of liposome encapsulated drugs may offer a route to improving the efficiency and specificity of liposome-based drug delivery systems, but this require means to tailor the performance of the membrane active peptides. In this paper, the membrane activity of a de novo designed coiled coil peptide has been optimized with respect to sequence and size to improve release efficiency of liposome encapsulated cargo. The peptides were only membrane active when covalently conjugated to the liposomes. Two amino acid substitutions were made to enhance the amphipathic characteristics of the peptide, which increased the release by a factor of five at 1 mu M. Moreover, the effect of peptide length was investigated by varying the number of heptad repeats from 2 to 5, yielding the peptides KVC2-KVC5. The shortest peptide (KVC2) showed the least interaction with the membrane and proved less efficient than the longer peptides in releasing the liposomal cargo. The peptide with three heptads (KVC3) caused liposome aggregation whereas KVC4 proved to effectively release the liposomal cargo without causing aggregation. The longest peptide (KVC5) demonstrated the most defined a-helical secondary structure and the highest liposome surface concentration but showed slower release kinetics than KVC4. The four heptad peptide KVC4 consequently displayed optimal properties for triggering the release and is an interesting candidate for further development of bioresponsive and tunable liposomal drug delivery systems.

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  • 59.
    Wang, Yi
    et al.
    Nanyang Technological University, Singapore.
    Liu, Xiaohu
    Nanyang Technological University, Singapore.
    Zhang, Jinling
    Nanyang Technological University, Singapore.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska högskolan. Nanyang Technological University, Singapore.
    Liedberg, Bo
    Nanyang Technological University, Singapore.
    Time-resolved botulinum neurotoxin A activity monitored using peptide-functionalized Au nanoparticle energy transfer sensors2014Inngår i: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 5, nr 7, s. 2651-2656Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report herein on the employment of synthetic peptide-functionalized gold nanoparticles (AuNPs) with various diameters as radiative quenchers for the time-resolved monitoring of botulinum A light chain (BoLcA) activity. The results demonstrate that larger AuNPs provide higher energy transfer efficiencies between the dye and the AuNPs, but poorer BoLcA activities for the proteolysis of peptides because of steric constraints. The initial turnover number for the BoLcA proteolysis of peptides on 18 nm AuNPs was retarded by a factor of 80 as compared with 1.4 nm AuNPs. A similar phenomenon has been observed for trypsin, however, with less hindrance on large AuNPs. Thus, the use of smaller 1.4 nm AuNPs in conjunction with robust synthetic peptides provides an attractive format for the time-resolved monitoring of protease activity and for BoLcA sensing at a highly competitive limit of detection (1 pM).

  • 60.
    Wang, Yusong
    et al.
    Nanyang Technology University, Singapore Nanyang Technology University, Singapore .
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Selegård, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Tay, Yeeyan
    Nanyang Technology University, Singapore .
    Baltzer, Lars
    Uppsala University, Sweden .
    Zhang, Hua
    Nanyang Technology University, Singapore Nanyang Technology University, Singapore .
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Specific functionalization of CTAB stabilized anisotropic gold nanoparticles with polypeptides for folding-mediated self-assembly2012Inngår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, nr 38, s. 20368-20373Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anisotropic nanoparticles stabilized by cetyltrimethylammonium bromide (CTAB) are notoriously difficult to homogenously functionalize using conventional gold-thiol chemistry. Using surface assisted laser desorption time of flight mass spectroscopy and scanning transmission electron microscopy-energy dispersive X-ray spectroscopy, we demonstrate that silver species adsorbed on the particle surface prevent effective surface functionalization. When covered by a thin gold film, particle functionalization was drastically improved. A thiol-containing polypeptide was immobilized on arrowhead gold nanorods (NRs) and was subsequently able to selectively heteroassociate with a complementary polypeptide resulting in a folding-mediated bridging aggregation of the NRs. Despite using arrowhead NRs with a pronounced difference in surface arrangement on the {111} facets on the arrowheads compared to the {100} facets at the particle sides, the polypeptides were efficiently and homogeneously immobilized on the particles after gold film overgrowth.

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  • 61.
    Wetterö, Jonas
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi.
    Hellerstedt, T.
    Nygren, Patrik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik.
    Broo, K.
    Occupational and Environmental Medicine, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden.
    Aili, Daniel
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik.
    Liedberg, Bo
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik.
    Magnusson, Karl-Eric
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Immobilized chemoattractant peptides mediate adhesion and distinct calcium-dependent cell signaling in human neutrophils2008Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, nr 13, s. 6803-6811Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chemotaxis is the stimulated directional migration of cells in response to chemotactic factors, manifested for instance during leukocyte interaction with chemoattractants in inflammation. The N-formyl-Met-Leu-Phe (fMLF) bacterial peptide family is particularly potent in attracting and activating neutrophilic granulocytes. To accomplish defined circumstances for recruitment and activation of cells, we fabricated semitransparent gold-coated glass coverslips functionalized with chemoattractant fMLF receptor peptide agonist analogues. Peptides based on a common leading four-amino-acid sequence Gly-Gly-Gly-Cys were thus coupled to two potent fMLF receptor agonists, N-formyl-Tyr-Nle-Phe-Leu- Nle-Gly-Gly-Gly-Cys and N-formyl-Met-Leu-Phe-Gly-Gly-Gly-Cys, and a formylated control peptide, N-formyl-Gly-Gly-Gly-Cys. They were anchored via the SH group of Cys either directly to the gold surface or a mixed self-assembled monolayer composed of maleimide- and hydroxyl-terminated oligo(ethylene glycol) alkyldisulfides. The overall peptide immobilization procedure was characterized with ellipsometry, contact angle measurement, and infrared spectroscopy. When exposed to granulocytes, the agonist surface rapidly recruited neutrophils and the cells responded with extensive spreading and intracellular calcium transients within minutes. The reference peptide generated no such activation, and the cells maintained a more spherical morphology, suggesting that we have been able to immobilize chemoattractant receptor agonist peptides with retained bioactivity. This is a crucial step in designing surfaces with specific effects on cellular behavior. © 2008 American Chemical Society.

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  • 62.
    Wickham, Abeni
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Koppal, Sandeep
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten.
    Dånmark, Staffan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    de Muinck, Ebo
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Influence of Polycaprolactone Scaffold Topography on Progenitor and Mesenchymal Cell ProliferationManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Polycaprolactone (PCL) is a frequently used polymer for tissue engineering applications and has been suggested as a suitable scaffold for cardiac regeneration. PCL can be effectively procesed using electrospinning to form fibrous scaffolds with defined topographies. The topography, as well as the materials and suraface properties, signficanltly effect the performance and host response of the scaffold. We have investigated the effect of PCL scaffold topology on protein adsorption and how this translate to cell adhesion and proliferation. PCL sheets are relatively hydrophobic with a water contact angle of 72o. The surface energy of PCL (20 mJ m‐2) was obatined using the Good van OSS and Chaudhury (GvOC) method, and is in the range of many antifouling materials. Non-specific protein adsorption on PCL sheets was yet substantial (0.45 mg cm‐2) when exposed to serum. A lower protein surface concentration was seen on fibrous PCL scaffolds prepared by electrospinning, presumably as a consequence of the lower diffusion in the scaffold. Proliferation of mesenchymal stem cells and cardiac progenitor cells was significantly improved when cultured on PCL sheets pre-treated with serum, but significantly lower than for fibrous PCL scaffolds. For the latter, no significant effect of serum pretreatment was observed, indicating that for PCL, fibre dimensions and scaffold topography has a larger influence on cell adhesion and proliferation than a high surface concentration of adsorbed proteins.

  • 63.
    Wickham, Abeni
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Sjölander, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Bergström, Gunnar
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teknisk biologi. Linköpings universitet, Tekniska fakulteten.
    Wang, Ergang
    Chalmers, Sweden.
    Rajendran, Vijayalakshmi
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Hildesjö, Camilla
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten.
    Skoglund, Karin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Near-Infrared Emitting and Pro-Angiogenic Electrospun Conjugated Polymer Scaffold for Optical Biomaterial Tracking2015Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, nr 27, s. 4274-4281Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Noninvasive tracking of biomaterials is vital for determining the fate and degradation of an implant in vivo, and to show its role in tissue regeneration. Current biomaterials have no inherent capacity to enable tracing but require labeling with, for example, fluorescent dyes, or nanoparticles. Here a novel biocompatible fully conjugated electrospun scaffold is described, based on a semiconducting luminescent polymer that can be visualized in situ after implantation using fluorescence imaging. The polymer, poly [2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt -thiophene-2,5-diyl] (TQ1), is electrospun to form a fibrous mat. The fibers display fluorescence emission in the near-infrared region with lifetimes in the sub-nanosecond range, optimal for in situ imaging. The material shows no cytotoxic behaviors for embryonic chicken cardiomyocytes and mouse myoblasts, and cells migrate onto the TQ1 fibers even in the presence of a collagen substrate. Subcutaneous implantations of the material in rats show incorporation of the TQ1 fibers within the tissue, with limited inflammation and a preponderance of small capillaries around the fibers. The fluorescent properties of the TQ1 fibers are fully retained for up to 90 d following implantation and they can be clearly visualized in tissue using fluorescence and lifetime imaging, thus making it both a pro-angiogenic and traceable biomaterial.

    Fulltekst (pdf)
    fulltext
  • 64.
    Wickham, Abeni
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Vagin, Mikhail
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Khalaf, Hazem
    University of Örebro, Sweden.
    Bertazzo, Sergio
    UCL, England.
    Hodder, Peter
    TA Instruments Ltd, England.
    Dånmark, Staffan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Bengtsson, Torbjorn
    University of Örebro, Sweden.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Electroactive biomimetic collagen-silver nanowire composite scaffolds2016Inngår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 8, nr 29, s. 14146-14155Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm(-2) and a charge injection capacity of 0.3 mC cm(-2), which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications.

    Fulltekst (pdf)
    fulltext
  • 65.
    Zeng, Shuangshuang
    et al.
    Uppsala Univ, Sweden.
    Li, Shiyu
    Uppsala Univ, Sweden.
    Utterström, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biofysik och bioteknik. Linköpings universitet, Tekniska fakulteten.
    Wen, Chenyu
    Uppsala Univ, Sweden.
    Selegård, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biofysik och bioteknik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Shi-Li
    Uppsala Univ, Sweden.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biofysik och bioteknik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Zhen
    Uppsala Univ, Sweden.
    Mechanism and Kinetics of Lipid Bilayer Formation in Solid-State Nanopores2020Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 36, nr 6, s. 1446-1453Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solid-state nanopores provide a highly versatile platform for rapid electrical detection and analysis of single molecules. Lipid bilayer coating of the nanopores can reduce nonspecific analyte adsorption to the nanopore sidewalls and increase the sensing selectivity by providing possibilities for tethering specific ligands in a cell-membrane mimicking environment. However, the mechanism and kinetics of lipid bilayer formation from vesicles remain unclear in the presence of nanopores. In this work, we used a silicon-based, truncated pyramidal nanopore array as the support for lipid bilayer formation. Lipid bilayer formation in the nanopores was monitored in real time by the change in ionic current through the nanopores. Statistical analysis revealed that a lipid bilayer is formed from the instantaneous rupture of individual vesicle upon adsorption in the nanopores, differing from the generally agreed mechanism that lipid bilayer forms at a high vesicle surface coverage on a planar support. The dependence of the lipid bilayer formation process on the applied bias, vesicle size, and concentration was systematically studied. In addition, the nonfouling properties of the lipid bilayer coated nanopores were demonstrated during long single-stranded DNA translocation through the nanopore array. The findings indicate that the lipid bilayer formation process can be modulated by introducing nanocavities intentionally on the planar surface to create active sites or changing the vesicle size and concentration.

12 51 - 65 of 65
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