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Tengvall, Pentti
Publications (10 of 87) Show all publications
Linderbäck, P., Agholme, F., Wermelin, K., Närhi, T., Tengvall, P. & Aspenberg, P. (2012). Weak effect of strontium on early implant fixation in rat tibia. Bone, 50(1), 350-356
Open this publication in new window or tab >>Weak effect of strontium on early implant fixation in rat tibia
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2012 (English)In: Bone, ISSN 8756-3282, E-ISSN 1873-2763, Vol. 50, no 1, p. 350-356Article in journal (Refereed) Published
Abstract [en]

Strontium ranelate increases bone mass and is used in the treatment of osteoporosis. Its effects in metaphyseal bone repair are largely unknown. We inserted a stainless steel and a PMMA screw into each tibia of male Sprague-Dawley rats. The animals were fed with ordinary feed (n =40) or with addition of strontium ranelate (800mg/kg/day; n = 20). As a positive control, half of the animals on control feed received alendronate subcutaneously. The pullout force of the stainless steel screws was measured after 4 and 8 weeks, and μCT was used to assess bone formation around the PMMA screws. No significant effects of strontium treatment on pullout force were observed, but animals treated with bisphosphonate showed a doubled pullout force. Strontium improved the microarchitecture of the cancellous bone below the primary spongiosa at the growth plate, but no significant effects were found around the implants. Strontium is known to improve bone density, but it appears that this effect is weak in conjunction with metaphyseal bone repair and early implant fixation.

Place, publisher, year, edition, pages
Elsevier, 2012
Keywords
Bisphosphonate; bone; implant; rat; screw; Strontium ranelate
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-71288 (URN)10.1016/j.bone.2011.10.034 (DOI)000299064200045 ()
Note
funding agencies|Swedish Research Council| VR-2009-6725 |local strategic research project Materials in Medicine||County Council of Ostergotland||Linkopings Universitet, Sweden||Available from: 2011-10-10 Created: 2011-10-10 Last updated: 2017-12-08Bibliographically approved
Hammarström, P., Ali, M. M., Mishra, R., Salagic, B., Svensson, S., Tengvall, P. & Lundström, I. (2011). An Auto-Catalytic Surface for Conformational Replication of Amyloid Fibrils-Genesis of an Amyloid World?. Origins of life and evolution of the biosphere, 41(4), 373-383
Open this publication in new window or tab >>An Auto-Catalytic Surface for Conformational Replication of Amyloid Fibrils-Genesis of an Amyloid World?
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2011 (English)In: Origins of life and evolution of the biosphere, ISSN 0169-6149, E-ISSN 1573-0875, Vol. 41, no 4, p. 373-383Article in journal (Refereed) Published
Abstract [en]

Amyloid fibrils are composed of self assembled stacked peptide or protein molecules folded and trapped in a stable cross-beta-sheet conformation. The amyloid fibrillation mechanism represents an intriguing self-catalyzed process rendering replication of a molecular conformational memory of interest for prebiotic chemistry. Herein we describe how a solid surface can be rendered auto-catalytic for fibrillation of a protein solution. We have discovered that a hydrophobic silicon or glass surface can be made to continuously fibrillate solutions of insulin monomers under stressed conditions (pH 1.6, 65 degrees C). It was found that the surface acts as a platform for the formation of nascent seeds that induce fibril replication on and at the surface. This autocatalytic effect stems from a layer a few insulin molecules thick representing an oligomeric layer of misfolded, conformationally trapped, insulin molecules that rapidly through epitaxial growth catalyze the rate determining step (nucleation) during fibril replication. This autocatalytic layer is generated by the protein-solid surface interaction and conformational changes of the adsorbed protein during exposure at the air-water interface. The resulting autocatalytic surface thus both initiates local conformational molecular self-replication and acts as a reservoir for fibril seeds budding off into solution spreading fibril replication entities to the surrounding medium. The possibility of catalysis of the conformational replication process by minute amounts of nucleation sites located on a recruiting surface can evade the issue of dramatic concentration dependence of amyloidogenesis.

Place, publisher, year, edition, pages
Springer Verlag (Germany), 2011
Keywords
Amyloid, Molecular replication, Self-assembly, Origin of life
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-75743 (URN)10.1007/s11084-010-9230-1 (DOI)000300367300007 ()
Note
Funding Agencies|Swedish Research Council||Knut and Alice Wallenberg Foundation||Swedish Foundation for Strategic Research||Available from: 2012-03-09 Created: 2012-03-09 Last updated: 2018-04-25
Pettersson, S., Wetterö, J., Tengvall, P. & Kratz, G. (2011). Cell expansion of human articular chondrocytes on macroporous gelatine scaffolds: — impact of micro carrier selection on cell proliferation. Biomedical Materials, 6(6), 065001
Open this publication in new window or tab >>Cell expansion of human articular chondrocytes on macroporous gelatine scaffolds: — impact of micro carrier selection on cell proliferation
2011 (English)In: Biomedical Materials, ISSN 1748-6041, E-ISSN 1748-605X, Vol. 6, no 6, p. 065001-Article in journal (Refereed) Published
Abstract [en]

This study investigates human chondrocyte expansion on four macroporous gelatine microcarriers (CultiSpher) differing with respect to two manufacturing processes—the amount of emulsifier used during initial preparation and the gelatine cross-linking medium. Monolayer-expanded articular chondrocytes from three donors were seeded onto the microcarriers and cultured in spinner flask systems for a total of 15 days. Samples were extracted every other day to monitor cell viability and establish cell counts, which were analysed using analysis of variance and piecewise linear regression. Chondrocyte densities increased according to a linear pattern for all microcarriers, indicating an ongoing, though limited, cell proliferation. A strong chondrocyte donor effect was seen during the initial expansion phase. The final cell yield differed significantly between the microcarriers and our results indicate that manufacturing differences affected chondrocyte densities at this point. Remaining cells stained positive for chondrogenic markers SOX-9 and S-100 but extracellular matrix formation was modest to undetectable. In conclusion, the four gelatine microcarriers supported chondrocyte adhesion and proliferation over a two week period. The best yield was observed for microcarriers produced with low emulsifier content and cross-linked in water and acetone. These results add to the identification of optimal biomaterial parameters for specific cellular processes and populations.

Place, publisher, year, edition, pages
Bristol, UK: Institute of Physics Publishing Ltd., 2011
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-54114 (URN)10.1088/1748-6041/6/6/065001 (DOI)000298241800001 ()
Note
Funding agencies|Swedish foundation for strategic research| A302:319 |Linkoping University and Landstinget i Ostergotland||Available from: 2010-02-23 Created: 2010-02-23 Last updated: 2017-12-12
Berlind, T., Tengvall, P., Hultman, L. & Arwin, H. (2011). Protein adsorption on thin films of carbon and carbon nitride monitored with in situ ellipsometry. ACTA BIOMATERIALIA, 7(3), 1369-1378
Open this publication in new window or tab >>Protein adsorption on thin films of carbon and carbon nitride monitored with in situ ellipsometry
2011 (English)In: ACTA BIOMATERIALIA, ISSN 1742-7061, Vol. 7, no 3, p. 1369-1378Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
Elsevier Science B.V. Amsterdam, 2011
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-19706 (URN)10.1016/j.actbio.2010.10.024 (DOI)000287643900049 ()
Note
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.2010.10.024 Copyright: Elsevier Science B.V. Amsterdam http://www.elsevier.com/ Available from: 2009-07-16 Created: 2009-07-16 Last updated: 2016-08-31Bibliographically approved
Abtahi, J., Tengvall, P. & Aspenberg, P. (2010). Bisphosphonate coating might improve fixation of dental implants in the maxilla: A pilot study. International Journal of Oral and Maxillofacial Surgery, 39(7), 673-677
Open this publication in new window or tab >>Bisphosphonate coating might improve fixation of dental implants in the maxilla: A pilot study
2010 (English)In: International Journal of Oral and Maxillofacial Surgery, ISSN 0901-5027, E-ISSN 1399-0020, Vol. 39, no 7, p. 673-677Article in journal (Refereed) Published
Abstract [en]

This pilot study evaluates the clinical stability of bisphosphonate-coated dental implants placed using a two-stage surgical procedure in five patients. Each patient received seven regular Branemark implants, one of which was coated with bisphosphonate in a fibrinogen matrix. The coated implant was inserted where the bone was expected to have the least favourable quality. The level of the marginal bone around each implant was measured by intraoral periapical radiographs and implant stability was recorded using resonance frequency measurements. Frequency values (ISQ) were obtained peroperatively before flap closure and after 6 months at abutment connection. At abutment connection the bisphosphonate-coated implants were removed en bloc in two patients for histological examination. An animal experiment had previously confirmed that gamma-sterilization did not reduce bioactivity of the bisphosphonate coating. In each patient, the bisphosphonate-coated implant showed the largest improvement in ISQ level of all implants. Their values at the start tended to be lower, and the absolute value at 6 months did not differ. No complications occurred with the coated implants. Histology showed no abnormalities. Improvement in ISQ values was an expected effect of the bisphosphonate coating, but could be due to the choice of insertion site. This finding warrants a randomized blinded study.

Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam, 2010
Keywords
bisphosphonate coating; dental implants; fixation
National Category
Orthopaedics Other Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-58193 (URN)10.1016/j.ijom.2010.04.002 (DOI)000279972500007 ()
Available from: 2010-08-11 Created: 2010-08-09 Last updated: 2018-01-12
Skoglund, C., Wetterö, J., Tengvall, P. & Bengtsson, T. (2010). C1q induces a rapid up-regulation of P-selectin and modulates collagen- and collagen-related peptide-triggered activation in human platelets. Immunobiology, 215(12), 987-995
Open this publication in new window or tab >>C1q induces a rapid up-regulation of P-selectin and modulates collagen- and collagen-related peptide-triggered activation in human platelets
2010 (English)In: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 215, no 12, p. 987-995Article in journal (Refereed) Published
Abstract [en]

Blood platelets are emerging as important immunomodulatory cells, but complement interaction with platelets is not well understood. Several platelet structures have been described as complement protein 1q (C1q) binding receptors, such as C1qRp/CD93 and gC1qR. However, there are conflicting results whether these receptors are C1q binding structures, or even at all expressed on the cell surface. Recently, the collagen-binding integrin alphaIIbetaI was reported to bind C1q on mast cells, and this receptor is also present on platelets. The aim of this study was to further characterize the effects of C1q on platelets, by quantifying the platelet surface expression of P-selectin (CD62P) and monitoring the formation of platelet-neutrophil aggregates. Using flow cytometry, we found that C1q dose-dependently triggered a rapid but moderate and transient up-regulation of P-selectin already within 5s of C1q exposure. Pre-incubation with an antibody directed against gC1qR significantly inhibited (with 57% compared to control) the up-regulation, whereas an antibody towards the alphaIIbetaI-integrin showed no effect. Stimulation with C1q did not change the cytosolic calcium-levels, as measured with the fluorescent ratiometric probe Fura-2, however, a protein kinase C inhibitor (GF109203x) blocked the C1q-induced P-selectin expression. Furthermore, pre-incubation of platelets with C1q diminished both the collagen as well as the collagen-related peptide-induced up-regulation of P-selectin, most evident after 90s of stimulation. This indicates that C1q may regulate platelet activation via the GPVI receptor, which is a novel finding. Moreover, C1q antagonized the collagen-induced formation of platelet-neutrophil aggregates, indicating a reduced interaction between platelet P-selectin and neutrophil P-selectin glycoprotein ligand-1(PSGL-1/CD162). In summary, C1q induces a moderate rapid platelet P-selectin expression, modulates subsequent collagen and collagen-related peptide stimulation of platelets, and inhibits the formation of platelet-neutrophil aggregates. These immuno-regulatory effects of C1q may have a crucial role in innate immunity and inflammation.

Keywords
AlfaIIbetaI integrin (αIIβI, GpIa/IIa), Blood platelet, C1q, C1qR, Complement, Platelet–neutrophil aggregates, P-selectin (CD62 P)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-54665 (URN)10.1016/j.imbio.2009.11.004 (DOI)000285532100007 ()20163886 (PubMedID)
Note
Original Publication: Caroline Skoglund, Jonas Wetterö, Pentti Tengvall and Torbjörn Bengtsson, C1q induces a rapid up-regulation of P-selectin and modulates collagen- and collagen-related peptide-triggered activation in human platelets, 2010, Immunobiology, (215), 12, 987-995. http://dx.doi.org/10.1016/j.imbio.2009.11.004 Copyright: Elsevier Science B. V., Amsterdam http://www.elsevier.com/ Available from: 2010-03-30 Created: 2010-03-30 Last updated: 2017-12-12
Berlind, T., Poksinski, M., Tengvall, P. & Arwin, H. (2010). Formation and cross-linking of fibrinogen layers monitored with in situ spectroscopic ellipsometry. Colloids and Surfaces B: Biointerfaces, 75(2), 410-417
Open this publication in new window or tab >>Formation and cross-linking of fibrinogen layers monitored with in situ spectroscopic ellipsometry
2010 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 75, no 2, p. 410-417Article in journal (Other academic) Published
Abstract [en]

Thick matrices of fibrinogen with incorporation of a matrix metalloproteinaseinhibitor were covalently bonded on functionalized silicon surfaces using an ethyl-3-dimethyl-aminopropyl-carbodiimide and N-hydroxy-succinimide affinity ligand couplingchemistry. The growth of the structure was followed in situ using dynamic ellipsometryand characterized at steady-state with spectroscopic ellipsometry. The growth wascompared with earlier work on ex situ growth of fibrinogen layers studied by singlewavelength ellipsometry. It is found that in situ growth and ex situ growth yield differentstructural properties of the formed protein matrix. Fibrinogen matrices with thicknessesup to 58 nm and surface mass densities of 1.6 μg/cm2 have been produced.

Keywords
Fibrinogen, ellipsometry, coupling chemistry, protein adsorption
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-19707 (URN)10.1016/j.colsurfb.2009.09.013 (DOI)000276921900004 ()
Note
Original Publication: Torun Berlind, Michal Poksinski, Pentti Tengvall and Hans Arwin, Formation and cross-linking of fibrinogen layers monitored with in situ spectroscopic ellipsometry, Colloids and Surfaces B: Biointerfaces, 2010, (75), 2, 410-417. http://dx.doi.org/10.1016/j.colsurfb.2009.09.013 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/ Available from: 2009-07-16 Created: 2009-07-16 Last updated: 2017-12-13Bibliographically approved
Linderbäck, P., Areva, S., Aspenberg, P. & Tengvall, P. (2010). Sol-gel derived titania coating with immobilized bisphosphonate enhances screw fixation in rat tibia. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, 94A(2), 389-395
Open this publication in new window or tab >>Sol-gel derived titania coating with immobilized bisphosphonate enhances screw fixation in rat tibia
2010 (English)In: JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, ISSN 1549-3296, Vol. 94A, no 2, p. 389-395Article in journal (Refereed) Published
Abstract [en]

A variety of surface modifications have been tested for the enhancement of screw fixation in bone, and locally delivered anti-osteoporosis drugs such as bisphosphonates (BP) are then of interest. In this in vivo study, the impact of surface immobilized BP was compared with systemic BP delivery and screws with no BP. After due in vitro characterization, differently treated stainless steel (SS) screws were divided into four groups with 10 rats each. Three of the groups received screws coated with sol gel derived TiO2 and calcium phosphate (SS+TiO2+CaP). One of these had no further treatment, one had alendronate (BP) adsorbed to calcium phosphate mineral, and one received systemic BP treatment. The fourth group received uncoated SS screws and no BP (control). The screw pullout force was measured after 4 weeks of implantation in rat tibiae. The immobilized amount and release rate of alendronate could be controlled by different immersion times. The SS+TiO2+CaP coating did not increase the pullout force compared to SS alone. Surface delivered alendronate enhanced the pullout force by 93% [p = 0.000; 95% Confidence Interval (CI): 67-118%] compared to SS, and by 39% (p = 0.044; 95% CI: 7-71%) compared to systemic alendronate delivery. Both surface immobilized and systemically delivered alendronate improved implant fixation. Also, locally delivered, that is, surface immobilized alendronate showed a better fixation than systemically delivered. Using sot gel derived TiO2 as a platform, it is possible to administer controllable amounts of a variety of BPs.

Place, publisher, year, edition, pages
John Wiley and Sons, Ltd, 2010
Keywords
screw; bone; bisphosphonates; sol-gel; rat
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-58262 (URN)10.1002/jbm.a.32708 (DOI)000279482600006 ()
Available from: 2010-08-10 Created: 2010-08-09 Last updated: 2011-10-10
Andersson, T., Agholme, F., Aspenberg, P. & Tengvall, P. (2010). Surface immobilized zoledronate improves screw fixation in rat bone: A new method for the coating of metal implants. JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 21(11), 3029-3037
Open this publication in new window or tab >>Surface immobilized zoledronate improves screw fixation in rat bone: A new method for the coating of metal implants
2010 (English)In: JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, ISSN 0957-4530, Vol. 21, no 11, p. 3029-3037Article in journal (Refereed) Published
Abstract [en]

Previous studies show that surface immobilized bisphosphonates improve the fixation of stainless steel screws in rat tibia after 2-8 weeks of implantation. We report here about the immobilization of a potent bisphosphonate, zoledronate, to crosslinked fibrinogen by the use of another technique, i.e. ethyl-dimethyl-aminopropylcarbodiimide (EDC)/imidazole immobilization. Bone fixation of zoledronate-coated screws was compared to screws coated with crosslinked fibrinogen only and ditto with EDC/N-hydroxy-succinimide immobilized pamidronate. Fixation in rat tibia was evaluated by a pull-out test at either 2 or 6 weeks after implantation. Both bisphosphonate coatings increased the pull-out force at both time points, and zoledronate showed a significantly higher pull-out force than pamidronate. To further evaluate the new coating technique we also performed a morphometric study, focusing on the area surrounding the implant. The zoledronate coating resulted in an increased bone density around the screws compared to controls. No pronounced increase was seen around the pamidronate coated screws. Together, the results demonstrate the possibility of obtaining a significant local therapeutic effect with minute amounts of surface immobilized zoledronate.

Place, publisher, year, edition, pages
Springer Science Business Media, 2010
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-63148 (URN)10.1007/s10856-010-4154-x (DOI)000284074500014 ()
Note
The original publication is available at www.springerlink.com: Therese Andersson, Fredrik Agholme, Per Aspenberg and Pentti Tengvall, Surface immobilized zoledronate improves screw fixation in rat bone: A new method for the coating of metal implants, 2010, JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, (21), 11, 3029-3037. http://dx.doi.org/10.1007/s10856-010-4154-x Copyright: Springer Science Business Media http://www.springerlink.com/ Available from: 2010-12-13 Created: 2010-12-13 Last updated: 2010-12-30
Ericsson, E., Faxälv, L., Weissenrieder, A., Askendal, A., Lindahl, T. & Tengvall, P. (2009). Glycerol monooleate-blood interactions. Colloids and Surfaces B: Biointerfaces, 68(1), 20-26
Open this publication in new window or tab >>Glycerol monooleate-blood interactions
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2009 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 68, no 1, p. 20-26Article in journal (Refereed) Published
Abstract [en]

In the present study the initial blood compatibility of glycerol monooleate (GMO)-coated surfaces was evaluated after deposition to surfaces and in bulk. The model surface was silica onto which multiple layers of fibrinogen or human serum albumin (HSA) was immobilized. The protein-coated surfaces were subsequently dip-coated in GMO in ethanol and used for blood plasma and whole blood experiments. The characterization methods included null ellipsometry, scanning electron microscopy, imaging of coagulation, hemolysis test and whole blood coagulation time by free oscillation rheometry.

The results showed a GMO film thickness of approximately 350 angstrom (similar to 4 mu g/cm(2)) upon dip-coating in ethanolic solution. A major part of the deposited layer detached in aqueous solutions, especially during shear conditions. The coagulation time on GMO was significantly prolonged compared to that on HSA coated silica. Whole blood tests showed that GMO is a very weak hemolytic agent. Deposited GMO detached easily from surfaces upon rinsing or shearing, although a stable layer with undefined phase structure and a thickness of 50-70 angstrom remained on HSA and fibrinogen precoated surfaces. This indicates that GMO has stronger adhesive forces to its substrate compared to the cohesive forces acting within the bulk GMO. The ability of GMO to detach from itself and tentatively form micelles or lipid bilayers when subjected to flowing blood may be of use in extravascular applications. It is concluded that GMO results in weak blood activation, and the material may in spite of this be suitable in selected biomaterial applications, especially as a biosealant and in colloidal dispersions.

Keywords
Glycerol monooleate, Blood compatibility, Shear, Ellipsometry
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-16356 (URN)10.1016/j.colsurfb.2008.09.016 (DOI)
Available from: 2009-01-16 Created: 2009-01-16 Last updated: 2017-12-14Bibliographically approved
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