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Publications (10 of 12) Show all publications
Newman, D. K., New, P. W., Heriseanu, R., Petronis, S., Håkansson, J., Håkansson, M. Å. & Lee, B. B. (2020). Intermittent catheterization with single- or multiple-reuse catheters: clinical study on safety and impact on quality of life.. International Urology and Nephrology
Open this publication in new window or tab >>Intermittent catheterization with single- or multiple-reuse catheters: clinical study on safety and impact on quality of life.
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2020 (English)In: International Urology and Nephrology, ISSN 0301-1623, E-ISSN 1573-2584Article in journal (Refereed) Epub ahead of print
Abstract [en]

PURPOSE: Intermittent catheterization (IC) is a proven effective long-term bladder management strategy for individuals who have lower urinary tract dysfunction. This study provides clinical evidence about multiple-reuse versus single-use catheterization techniques and if catheter choice can have an impact on health-related quality of life (HRQoL).

METHOD: A prospective, multi-center, clinical trial studied patients who currently practiced catheter reuse, and who agreed to prospectively evaluate single-use hydrophilic-coated (HC) (i.e. LoFric) catheters for 4 weeks. A validated Intermittent Self-Catheterization Questionnaire (ISC-Q) was used to obtain HRQoL. Reused catheters were collected and studied with regard to microbial and debris contamination.

RESULTS: The study included 39 patients who had practiced IC for a mean of 10 years, 6 times daily. At inclusion, all patients reused catheters for a mean of 21 days (SD = 48) per catheter. 36 patients completed the prospective test period and the mean ISC-Q score increased from 58.0 (SD = 22.6) to 67.2 (SD = 17.7) when patients switched to the single-use HC catheters (p = 0.0101). At the end of the study, 83% (95% CI [67-94%]) preferred to continue using single-use HC catheters. All collected reused catheters (100%) were contaminated by debris and 74% (95% CI [58-87%]) were contaminated by microorganisms, some with biofilm.

CONCLUSION: Single-use HC catheters improved HRQoL and were preferred over catheter reuse among people practicing IC. Catheter multiple-reuse may pose a potential safety concern due to colonization by microorganisms as well as having reduced acceptance compared to single use.

TRIAL REGISTRY NUMBER: ClinicalTrials.gov NCT02129738.

Keywords
Catheter-associated urinary tract infection (CAUTI), Clean intermittent catheterization, Lower urinary tract dysfunction (LUTD), Neurogenic lower urinary tract dysfunction (NLUTD), Urinary catheter
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-44561 (URN)10.1007/s11255-020-02435-9 (DOI)32172456 (PubMedID)
Available from: 2020-03-24 Created: 2020-03-24 Last updated: 2020-03-24Bibliographically approved
Landberg, G., Fitzpatrick, P., Isakson, P., Jonasson, E., Karlsson, J., Larsson, E., . . . Ståhlberg, A. (2020). Patient-derived scaffolds uncover breast cancer promoting properties of the microenvironment. Biomaterials, 235, Article ID 119705.
Open this publication in new window or tab >>Patient-derived scaffolds uncover breast cancer promoting properties of the microenvironment
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2020 (English)In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 235, article id 119705Article in journal (Refereed) Published
Abstract [en]

Tumor cells interact with the microenvironment that specifically supports and promotes tumor development. Key components in the tumor environment have been linked to various aggressive cancer features and can further influence the presence of subpopulations of cancer cells with specific functions, including cancer stem cells and migratory cells. To model and further understand the influence of specific microenvironments we have developed an experimental platform using cell-free patient-derived scaffolds (PDSs) from primary breast cancers infiltrated with standardized breast cancer cell lines. This PDS culture system induced a series of orchestrated changes in differentiation, epithelial-mesenchymal transition, stemness and proliferation of the cancer cell population, where an increased cancer stem cell pool was confirmed using functional assays. Furthermore, global gene expression profiling showed that PDS cultures were similar to xenograft cultures. Mass spectrometry analyses of cell-free PDSs identified subgroups based on their protein composition that were linked to clinical properties, including tumor grade. Finally, we observed that an induction of epithelial-mesenchymal transition-related genes in cancer cells growing on the PDSs were significantly associated with clinical disease recurrences in breast cancer patients. Patient-derived scaffolds thus mimics in vivo-like growth conditions and uncovers unique information about the malignancy-inducing properties of tumor microenvironment. © 2019 The Authors

Place, publisher, year, edition, pages
Elsevier Ltd, 2020
Keywords
Breast cancer, Cancer stem cells, Differentiation, Infiltration, Malignancy, Scaffold, Cell culture, Cell proliferation, Differentiation (calculus), Diseases, Gene expression, Mass spectrometry, Scaffolds, Stem cells, Tumors, Epithelial-mesenchymal transition, Experimental platform, Gene expression profiling, Mass spectrometry analysis, Tumor microenvironment, Scaffolds (biology)
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-43392 (URN)10.1016/j.biomaterials.2019.119705 (DOI)2-s2.0-85077985377 (Scopus ID)
Note

Funding details: Västra Götalandsregionen; Funding details: Barncancerfonden, 2017-0043; Funding details: Vetenskapsrådet, VR, 2016-01530, 2017-01392; Funding details: VINNOVA, 2017-03737; Funding details: Stiftelsen för Strategisk Forskning, SSF; Funding details: Swedish Cancer Foundation, 2016-438, 2016-486, PjF 20 0306; Funding details: Knut och Alice Wallenbergs Stiftelse; Funding details: American Liver Foundation, ALF, 721091, 716321; Funding details: Göteborgs Universitet; Funding details: Stiftelsen Assar Gabrielssons Fond, AG Fond; Funding text 1: We thank the people at Departments of Pathology and Surgery, Sahlgrenska University Hospital for technical assistance handling breast cancer samples and Gothenburg University Proteomics Core Facility for their support. This work was supported by grants from Assar Gabrielssons Research Foundation ; BioCARE National Strategic Research Program at University of Gothenburg; Johan Jansson Foundation for Cancer Research; Knut and Alice Wallenberg Foundation, Wallenberg Center for Molecular and Translational Medicine, University of Gothenburg, Sweden; Region Västra Götaland; Swedish Cancer Foundation (PjF 20 0306 , 2016-438 and 2016-486 ); Swedish Foundation for Strategic Research ; Swedish Research Council ( 2017-01392 and 2016-01530 ); Swedish Childhood Cancer Foundation ( 2017-0043) ; the Swedish state under the agreement between the Swedish government and the county councils, the ALF agreement ( 716321 and 721091 ); Wilhelm and Martina Lundgren Foundation for Scientific Research and VINNOVA ( 2017-03737 ). Appendix A

Available from: 2020-01-31 Created: 2020-01-31 Last updated: 2020-01-31Bibliographically approved
Tasiopoulos, C., Petronis, S., Sahlin, H. & Hedhammar, M. (2020). Surface Functionalization of PTFE Membranes Intended for Guided Bone Regeneration Using Recombinant Spider Silk. ACS Applied Bio Materials, 3(1), 577-583
Open this publication in new window or tab >>Surface Functionalization of PTFE Membranes Intended for Guided Bone Regeneration Using Recombinant Spider Silk
2020 (English)In: ACS Applied Bio Materials, ISSN 2576-6422, Vol. 3, no 1, p. 577-583Article in journal (Refereed) Published
Abstract [en]

Alveolar bone loss is usually treated with guided bone regeneration, a dental procedure which utilizes a tissue-separation membrane. The barrier membrane prevents pathogens and epithelial cells to invade the bone augmentation site, thereby permitting osteoblasts to deposit minerals and build up bone. This study aims at adding bioactive properties to otherwise inert PTFE membranes in order to enhance cell adherence and promote proliferation. A prewetting by ethanol and stepwise hydration protocol was herein employed to overcome high surface tension of PTFE membranes and allow for a recombinant spider silk protein, functionalized with a cell-binding motif from fibronectin (FN-silk), to self-assemble into a nanofibrillar coating. HaCaT and U-2 OS cells were seeded onto soft and hard tissue sides, respectively, of membranes coated with FN-silk. The cells could firmly adhere as early as 1 h post seeding, as well as markedly grow in numbers when kept in culture for 7 days. Fluorescence and scanning electron microscopy images revealed that adherent cells could form a confluent monolayer and develop essential cell-cell contacts during 1 week of culture. Hence, functionalized PTFE membranes have a potential of better integration at the implantation site, with reduced risk of membrane displacement as well as exposure to oral pathogens.

Place, publisher, year, edition, pages
American Chemical Society, 2020
Keywords
cell adherence, guided bone regeneration, nonreinforced PTFE membranes, recombinant spider silk, surface functionalization, Calcium compounds, Cell adhesion, Cells, Membranes, Recombinant proteins, Scanning electron microscopy, Tissue, Tissue regeneration, PTFE membranes, Spider silks, Bone
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-43943 (URN)10.1021/acsabm.9b00972 (DOI)2-s2.0-85078675977 (Scopus ID)
Note

Funding details: VINNOVA; Funding details: VetenskapsrÃ¥det, VR; Funding text 1: This research was supported by Vinnova, Swedish Research Council and Knut & Alice Wallenberg foundation.

Available from: 2020-02-24 Created: 2020-02-24 Last updated: 2020-02-24Bibliographically approved
Flys, O., Jarlemark, P., Petronis, S., Stenlund, P. & Rosen, B.-G. -. (2018). Applicability of characterization techniques on fine scale surfaces. Surface Topography: Metrology and Properties, 6(3), Article ID 034015.
Open this publication in new window or tab >>Applicability of characterization techniques on fine scale surfaces
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2018 (English)In: Surface Topography: Metrology and Properties, ISSN 2051-672X, Vol. 6, no 3, article id 034015Article in journal (Refereed) Published
Abstract [en]

In this study, several surface topographies typical for dental implants were evaluated by different measurement techniques. The samples were prepared by machine turning, wet chemical etching and electrochemical polishing of titanium discs. The measurement techniques included an atomic force microscope (AFM), coherence scanning interferometer (CSI) and a 3D stereo scanning electron microscope (SEM). The aim was to demonstrate and discuss similarities and differences in the results provided by these techniques when analyzing submicron surface topographies. The estimated surface roughness parameters were not directly comparable since the techniques had different surface spatial wavelength band limits. However, the comparison was made possible by applying a 2D power spectral density (PSD) function. Furthermore, to simplify the comparison, all measurements were characterized using the ISO 25178 standard parameters. Additionally, a Fourier transform was applied to calculate the instrument transfer function in order to investigate the behavior of CSI at different wavelength ranges. The study showed that 3D stereo SEM results agreed well with AFM measurements for the studied surfaces. Analyzed surface parameter values were in general higher when measured by CSI in comparison to both AFM and 3D stereo SEM results. In addition, the PSD analysis showed a higher power spectrum density in the lower frequency range 10-2-10-1 μm-1 for the CSI compared with the other techniques.

Keywords
3D-stereo SEM, AFM, Coherence scanning interferometer, power spectral density, surface topography, transfer function, Atomic force microscopy, Chemical polishing, Dental prostheses, Interferometers, Scanning, Scanning electron microscopy, Spectral density, Surface roughness, Topography, Transfer functions, Wet etching, 3d stereos, Characterization techniques, Measurement techniques, Power spectrum density, Scanning interferometers, Spatial wavelengths, Surface roughness parameters, Wavelength ranges, Parameter estimation
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-35683 (URN)10.1088/2051-672X/aacf5e (DOI)2-s2.0-85055559461 (Scopus ID)
Available from: 2018-11-06 Created: 2018-11-06 Last updated: 2018-11-06Bibliographically approved
Granskog, V., García-Gallego, S., von Kieseritzky, J., Rosendahl, J., Stenlund, P., Zhang, Y., . . . Malkoch, M. (2018). High-Performance Thiol–Ene Composites Unveil a New Era of Adhesives Suited for Bone Repair. Advanced Functional Materials, 28(26), Article ID 1800372.
Open this publication in new window or tab >>High-Performance Thiol–Ene Composites Unveil a New Era of Adhesives Suited for Bone Repair
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2018 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 26, article id 1800372Article in journal (Refereed) Published
Abstract [en]

The use of adhesives for fracture fixation can revolutionize the surgical procedures toward more personalized bone repairs. However, there are still no commercially available adhesive solutions mainly due to the lack of biocompatibility, poor adhesive strength, or inadequate fixation protocols. Here, a surgically realizable adhesive system capitalizing on visible light thiol–ene coupling chemistry is presented. The adhesives are carefully designed and formulated from a novel class of chemical constituents influenced by dental resin composites and self-etch primers. Validation of the adhesive strength is conducted on wet bone substrates and accomplished via fiber-reinforced adhesive patch (FRAP) methodology. The results unravel, for the first time, on the promise of a thiol–ene adhesive with an unprecedented shear bond strength of 9.0 MPa and that surpasses, by 55%, the commercially available acrylate dental adhesive system Clearfil SE Bond of 5.8 MPa. Preclinical validation of FRAPs on rat femur fracture models details good adhesion to the bone throughout the healing process, and are found biocompatible not giving rise to any inflammatory response. Remarkably, the FRAPs are found to withstand loads up to 70 N for 1000 cycles on porcine metacarpal fractures outperforming clinically used K-wires and match metal plates and screw implants.

Keywords
adhesives, biomedical applications, composites, photochemistry, polymeric materials, Biocompatibility, Composite materials, Dental composites, Dental materials, Fracture, Fracture fixation, Functional polymers, Medical applications, Photochemical reactions, Polymeric implants, Polymers, Chemical constituents, Coupling chemistry, Dental adhesive system, Dental resin composites, Inflammatory response, Shear bond strengths, Surgical procedures, Bone
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33958 (URN)10.1002/adfm.201800372 (DOI)2-s2.0-85048981911 (Scopus ID)
Note

Funding details: KI, Karolinska Institutet; Funding details: MSCA-IF-2014-655649, MSCA, H2020 Marie Skłodowska-Curie Actions; Funding details: 2010-435; Funding details: 2014-03777; Funding details: 2012-0196, Knut och Alice Wallenbergs Stiftelse; 

Available from: 2018-07-03 Created: 2018-07-03 Last updated: 2019-08-19Bibliographically approved
Kuna, V. K., Padma, A. M., Håkansson, J., Nygren, J., Sjöback, R., Petronis, S. & Sumitran-Holgersson, S. (2017). Significantly accelerated wound healing of full-thickness skin using a novel composite gel of porcine acellular dermal matrix and human peripheral blood cells. Cell Transplantation, 26(2), 293-307
Open this publication in new window or tab >>Significantly accelerated wound healing of full-thickness skin using a novel composite gel of porcine acellular dermal matrix and human peripheral blood cells
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2017 (English)In: Cell Transplantation, ISSN 0963-6897, E-ISSN 1555-3892, Vol. 26, no 2, p. 293-307Article in journal (Refereed) Published
Abstract [en]

Herein, we report the fabrication of a novel composite gel from decellularized gal-gal-knockout porcine skin and human peripheral blood mononuclear cells (hPBMC) for full-thickness skin wound healing. Decellularized skin extracellular matrix (ECM) powder was prepared via chemical treatment, freeze-drying and homogenization. The powder was mixed with culture medium containing hyaluronic acid to generate a pig skin gel (PSG). The effect of the gel in regeneration of full-thickness wound was studied in nude mice. We found significantly accelerated wound closure already on day 15 in animals treated with PSG only or PSG+hPBMC as compared to untreated and hyaluronic acid treated controls (p<0.05). Addition of the hPBMC to the gel resulted in marked increase of host blood vessels as well as the presence of human blood vessels. At day 25, histologically, the wounds in animals treated with PSG only or PSG+hPBMC were completely closed as compared to controls. Thus, the gel facilitated generation of new skin with well arranged epidermal cells and restored bilayer structure of the epidermis and dermis. These results suggest that porcine skin ECM gel together with human cells may be a novel and promising biomaterial for medical applications especially for patients with acute and chronic skin wounds.

Place, publisher, year, edition, pages
Cognizant Communication Corporation, 2017
National Category
Pharmacology and Toxicology Pharmaceutical Sciences Biomaterials Science
Identifiers
urn:nbn:se:ri:diva-27768 (URN)10.3727/096368916X692690 (DOI)27503828 (PubMedID)2-s2.0-85012224726 (Scopus ID)
Available from: 2017-01-06 Created: 2017-01-06 Last updated: 2019-01-10Bibliographically approved
Wetterskog, E., Castro, A., Zeng, L., Petronis, S., Heinke, D., Olsson, E., . . . Svedlindh, P. (2017). Size and property bimodality in magnetic nanoparticle dispersions: single domain particles vs. strongly coupled nanoclusters. Nanoscale, 9(12), 4227-4235
Open this publication in new window or tab >>Size and property bimodality in magnetic nanoparticle dispersions: single domain particles vs. strongly coupled nanoclusters
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2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 12, p. 4227-4235Article in journal (Refereed) Published
Abstract [en]

The widespread use of magnetic nanoparticles in the biotechnical sector puts new demands on fast and quantitative characterization techniques for nanoparticle dispersions. In this work, we report the use of asymmetric flow field-flow fractionation (AF4) and ferromagnetic resonance (FMR) to study the properties of a commercial magnetic nanoparticle dispersion. We demonstrate the effectiveness of both techniques when subjected to a dispersion with a bimodal size/magnetic property distribution: i.e., a small superparamagnetic fraction, and a larger blocked fraction of strongly coupled colloidal nanoclusters. We show that the oriented attachment of primary nanocrystals into colloidal nanoclusters drastically alters their static, dynamic, and magnetic resonance properties. Finally, we show how the FMR spectra are influenced by dynamical effects; agglomeration of the superparamagnetic fraction leads to reversible line-broadening; rotational alignment of the suspended nanoclusters results in shape-dependent resonance shifts. The AF4 and FMR measurements described herein are fast and simple, and therefore suitable for quality control procedures in commercial production of magnetic nanoparticles.

National Category
Nano Technology
Identifiers
urn:nbn:se:ri:diva-29219 (URN)10.1039/c7nr00023e (DOI)28290585 (PubMedID)2-s2.0-85016118237 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme
Available from: 2017-04-05 Created: 2017-04-05 Last updated: 2019-01-10Bibliographically approved
Wells, J., Kazakova, O., Posth, O., Steinhoff, U., Petronis, S., Bogart, L., . . . Johansson, C. (2017). Standardisation of magnetic nanoparticles in liquid suspension. Journal of Physics D: Applied Physics, 50(383003), 1-25
Open this publication in new window or tab >>Standardisation of magnetic nanoparticles in liquid suspension
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2017 (English)In: Journal of Physics D: Applied Physics, Vol. 50, no 383003, p. 1-25Article in journal (Refereed) Published
Abstract [en]

Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation,spanning a large number of industry sectors from imaging and actuation based applicationsin biomedicine and biotechnology, through large-scale environmental remediation uses suchas water purification, to engineering-based applications such as position-controlled lubricantsand soaps. Continuous advances in their manufacture have produced an ever-growing rangeof products, each with their own unique properties. At the same time, the characterisation ofmagnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpretthe measurement data. In many cases, the stringent requirements of the end-user technologiesdictate that magnetic nanoparticle products should be clearly defined, well characterised,consistent and safe; or to put it another way—standardised. The aims of this document areto outline the concepts and terminology necessary for discussion of magnetic nanoparticles,to examine the current state-of-the-art in characterisation methods necessary for the mostprominent applications of magnetic nanoparticle suspensions, to suggest a possible structurefor the future development of standardisation within the field, and to identify areas and topicswhich deserve to be the focus of future work items. We discuss potential roadmaps for thefuture standardisation of this developing industry, and the likely challenges to be encounteredalong the way.

National Category
Nano Technology
Identifiers
urn:nbn:se:ri:diva-32363 (URN)10.1088/1361-6463/aa7fa5 (DOI)2-s2.0-85029007133 (Scopus ID)
Projects
NanoMag
Available from: 2017-10-24 Created: 2017-10-24 Last updated: 2019-06-27Bibliographically approved
Karazisis, D., Petronis, S., Agheli, H., Emanuelsson, L., Norlindh, B., Johansson, A., . . . Omar, O. (2017). The influence of controlled surface nanotopography on the early biological events of osseointegration.. Acta Biomaterialia, 53, 559-571
Open this publication in new window or tab >>The influence of controlled surface nanotopography on the early biological events of osseointegration.
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2017 (English)In: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 53, p. 559-571Article in journal (Refereed) Published
Abstract [en]

The early cell and tissue interactions with nanopatterned titanium implants are insufficiently described in vivo. A limitation has been to transfer a pre-determined, well-controlled nanotopography to 3D titanium implants, without affecting other surface parameters, including surface microtopography and chemistry. This in vivo study aimed to investigate the early cellular and molecular events at the bone interface with screw-shaped titanium implants superimposed with controlled nanotopography. Polished and machined titanium implants were firstly patterned with 75-nm semispherical protrusions. Polished and machined implants without nano-patterns were designated as controls. Thereafter, all nanopatterned and control implants were sputter-coated with a 30nm titanium layer to unify the surface chemistry. The implants were inserted in rat tibiae and samples were harvested after 12h, 1d and 3d. In one group, the implants were unscrewed and the implant-adherent cells were analyzed using quantitative polymerase chain reaction. In another group, implants with surrounding bone were harvested en bloc for histology and immunohistochemistry. The results showed that nanotopography downregulated the expression of monocyte chemoattractant protein-1 (MCP-1), at 1d, and triggered the expression of osteocalcin (OC) at 3d. This was in parallel with a relatively lower number of recruited CD68-positive macrophages in the tissue surrounding the nanopatterned implants. Moreover, a higher proportion of newly formed osteoid and woven bone was found at the nanopatterned implants at 3d. It is concluded that nanotopography, per se, attenuates the inflammatory process and enhances the osteogenic response during the early phase of osseointegration. This nanotopography-induced effect appeared to be independent of the underlying microscale topography.

STATEMENT OF SIGNIFICANCE: This study provides a first line of evidence that pre-determined nanopatterns on clinically relevant, screw-shaped, titanium implants can be recognized by cells in the complex in vivo environment. Until now, most of the knowledge relating to cell interactions with nanopatterned surfaces has been acquired from in vitro studies involving mostly two-dimensional nanopatterned surfaces of varying chemical composition. We have managed to superimpose pre-determined nanoscale topography on polished and micro-rough, screw-shaped, implants, without changes in the microscale topography or chemistry. This was achieved by colloidal lithography in combination with a thin titanium film coating on top of both nanopatterned and control implants. The early events of osseointegration were evaluated at the bone interface to these implants. The results revealed that nanotopography, as such, elicits downregulatory effects on the early recruitment and activity of inflammatory cells while enhancing osteogenic activity and woven bone formation.

Keywords
Gene expression, In vivo, Nanotopography, Osseointegration, Titanium
National Category
Biomaterials Science
Identifiers
urn:nbn:se:ri:diva-29220 (URN)10.1016/j.actbio.2017.02.026 (DOI)28232253 (PubMedID)2-s2.0-85014028726 (Scopus ID)
Funder
VINNOVARegion Västra Götaland
Available from: 2017-04-05 Created: 2017-04-05 Last updated: 2019-01-03Bibliographically approved
Karazisis, D., Ballo, A. M., Petronis, S., Agheli, H., Emanuelsson, L., Thomsen, P. & Omar, O. (2016). The role of well-defined nanotopography of titanium implants on osseointegration: Cellular and molecular events in vivo. International Journal of Nanomedicine, 11, 1367-1382
Open this publication in new window or tab >>The role of well-defined nanotopography of titanium implants on osseointegration: Cellular and molecular events in vivo
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2016 (English)In: International Journal of Nanomedicine, ISSN 1176-9114, E-ISSN 1178-2013, Vol. 11, p. 1367-1382Article in journal (Refereed) Published
Abstract [en]

Purpose: Mechanisms governing the cellular interactions with well-defined nanotopography are not well described in vivo. This is partly due to the difficulty in isolating a particular effect of nanotopography from other surface properties. This study employed colloidal lithography for nanofabrication on titanium implants in combination with an in vivo sampling procedure and different analytical techniques. The aim was to elucidate the effect of well-defined nanotopography on the molecular, cellular, and structural events of osseointegration. Materials and methods: Titanium implants were nanopatterned (Nano) with semispherical protrusions using colloidal lithography. Implants, with and without nanotopography, were implanted in rat tibia and retrieved after 3, 6, and 28 days. Retrieved implants were evaluated using quantitative polymerase chain reaction, histology, immunohistochemistry, and energy dispersive X-ray spectroscopy (EDS). Results: Surface characterization showed that the nanotopography was well defined in terms of shape (semispherical), size (79±6 nm), and distribution (31±2 particles/μm2). EDS showed similar levels of titanium, oxygen, and carbon for test and control implants, confirming similar chemistry. The molecular analysis of the retrieved implants revealed that the expression levels of the inflammatory cytokine, TNF-α, and the osteoclastic marker, CatK, were reduced in cells adherent to the Nano implants. This was consistent with the observation of less CD163-positive macrophages in the tissue surrounding the Nano implant. Furthermore, periostin immunostaining was frequently detected around the Nano implant, indicating higher osteogenic activity. This was supported by the EDS analysis of the retrieved implants showing higher content of calcium and phosphate on the Nano implants. Conclusion: The results show that Nano implants elicit less periimplant macrophage infiltration and downregulate the early expression of inflammatory (TNF-α) and osteoclastic (CatK) genes. Immunostaining and elemental analyses show higher osteogenic activity at the Nano implant. It is concluded that an implant with the present range of well-defined nanocues attenuates the inflammatory response while enhancing mineralization during osseointegration.

Place, publisher, year, edition, pages
Dove Medical Press Ltd., 2016
Keywords
Bone formation, Energy dispersive X-ray spectroscopy, Gene expression, Immunohistochemistry, Inflammatory cytokines, Nanofabrication
National Category
Biomaterials Science Dentistry
Identifiers
urn:nbn:se:ri:diva-85 (URN)10.2147/IJN.S101294 (DOI)2-s2.0-84962737306 (Scopus ID)
Available from: 2016-05-24 Created: 2016-04-28 Last updated: 2019-06-19Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4592-5851

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