| 1. |
- Barreto Henriksson, Helena, et al.
(author)
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Determination of mechanical and rheological properties of a cell-loaded peptide gel during ECM production
- 2019
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In: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 563, s. 437-444
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Journal article (peer-reviewed)abstract
- The development of an injectable biomaterial that supports cell survival and maintains or promotes nucleus pulposus (NP) phenotype could aid delivery of cells to degenerated NPs causing low back pain. Mesenchymal cells were loaded and grown in a synthetic peptide gel, PuraMatrix (R). Cells were observed within the gels over 0-28 days, and accumulation of glycosaminoglycans were detected by histological staining. The mechanical properties of the cell-loaded constructs, and the change of the mechanical properties were studied using stress relaxation of the gels under compression and confinement. The PuraMatrix (R) gel was shown to relax fast on compression indicating that the fluid could easily flow out of the gel, and thus indicating the presence of large pores/voids. The presence of these pores/voids was further supported by high mobility of dextran molecules, determined using fluorescence recovery after photo bleaching. The stress required to deform the cell-loaded constructs to a specific strain increases at day 21, at which point the presence of glycosaminoglycans within the cell-loaded constructs was also observed. The results provide evidence of changes in mechanical properties of the PuraMatrix (R) matrix upon excretion of the extracellular matrix by the cells.
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| 2. |
- Barreto Henriksson, Helena, et al.
(author)
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Indications of that migration of stem cells is influenced by the extra cellular matrix architecture in the mammalian intervertebral disc region
- 2015
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In: Tissue & Cell. - : Elsevier BV. - 0040-8166 .- 1532-3072. ; 47:5, s. 439-455
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Journal article (peer-reviewed)abstract
- Disc-degeneration is believed a major cause for lumbar pain. Previously, potential stem cell niches in the intervertebral disc (IVD) region, located adjacent to epiphyseal plate was reported. The aim of the study was to examine migration of mesenchymal stem cells (MSCs), extracellular matrix (ECM) architecture in a potential cellular migration route (CMR; area located between the niche and IVD) and in the IVD in non-degenerated lapine- and in human degenerated IVD tissues. Human MSCs (n = 3), human degenerated IVD tissues (n = 10) and lapine IVDs (n = 10) were collected. The samples were examined by immunohistochemistry for stem cell markers; CD90, OCT3/4, pre-chondrocytic marker; GDF5, catabolic markers; MMP9, MMP13, inflammatory marker; IL1R, cellular migration markers; SNAI1, SNAI2, adhesion markers; β1-INTEGRIN and DDR2. In addition, gene-expression analyses (Real time PCR) were performed on additional samples. Further, time lapse studies were performed with hMSCs cultured on aligned COLL-I-fibers-coated glass-slides in DMEM-LG, 10% human serum containing fibroblast growth factor (bFGF). Results: Presence of stem cells (CD90+, OCT3/4 + ), pre-chondocytic cells (GDF5 + )and cells positive for migration markers (SNAI1+, SNAI2 + ), catabolic markers (MMP9+, MMP13 + ), inflammatory marker (IL1R + ), adhesion markers (DDR2+, B1-INTEGRIN + ) were detected (gene- and protein level) in investigated CMR and IVD regions. In the time lapse studies, MSCs alignment and protrusions were observed orientated in the same direction as collagen fibres. Results displays influence of ECM collagen architecture and collagen fiber spatial direction on migration of stem cells. The results can be useful when developing tissue-engineering strategies for disc-degeneration.
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| 3. |
- Barreto Henriksson, Helena, et al.
(author)
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The Traceability of Mesenchymal Stromal Cells After Injection Into Degenerated Discs in Patients with Low Back Pain.
- 2019
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In: Stem cells and development. - : Mary Ann Liebert Inc. - 1557-8534 .- 1547-3287. ; 28:17, s. 1203-1211
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Journal article (peer-reviewed)abstract
- Low back pain is a major health issue and one main cause to this condition is believed to be intervertebral disc (IVD) degeneration. Stem cell therapy for degenerated discs using mesenchymal stromal cells (MSCs) has been suggested. The aim of the study was to investigate the presence and distribution pattern of autologous MSCs transplanted into degenerated IVDs in patients and explanted posttransplantation. IVD tissues from four patients (41, 45, 47, and 47 years of age) participating in a clinical feasibility study on MSC transplantation to degenerative discs were investigated. Three patients decided to undergo fusion surgery at time points 8 months and one patient at 28 months posttransplantation. Pretransplantation, MSCs from bone marrow aspirate were isolated by centrifugation in FICOLL® test tubes and cultured (passage 1). Before transplantation, MSCs were labeled with 1mg/mL iron sucrose (Venofer®) and 1×106 MSCs were transplanted into degenerated IVDs. At the time point of surgery, IVD tissues were collected. IVD tissue samples were fixated, embedded in paraffin, and sections prepared. IVD samples were stained with Prussian Blue, by which iron deposits are visualized and examined (light microscopy). Immunohistochemistry (IHC), including SOX9 (sex determining region Y box 9), Coll2A1 (collagen 2A1), and cell viability (TUNEL) were performed. Cells positive for iron deposits were observed in IVD tissues (3/4 patients). The cells/iron deposits were observed in clusters and/or as solitary cells in regions in IVD tissue samples [regions of interest (ROIs)]. By IHC, SOX9- and Coll2A1-positive cells were detected in the same regions as the detected cells/iron deposits. A few nonviable cells were detected by TUNEL assay in ROIs. Results demonstrated that MSCs, labeled with iron sucrose, transplanted into degenerated IVDs were detectable 8 months posttransplantation. The detected cellular activity indicates that MSCs have differentiated into chondrocyte-like cells and that the injected MSCs and/or their progeny have survived since the cells were found in large cluster and as solitary cells which were distributed at different parts of the IVD.
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| 4. |
- Hansson, A., et al.
(author)
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The direction of human mesenchymal stem cells into the chondrogenic lineage is influenced by the features of hydrogel carriers
- 2017
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In: Tissue and Cell. - : Elsevier BV. - 1532-3072 .- 0040-8166. ; 49:1, s. 35-44
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Journal article (peer-reviewed)abstract
- Low back pain is a major public health issue in the Western world, one main cause is believed to be intervertebral disc (IVD) degeneration. To halt/diminish IVD degeneration, cell therapy using different biomaterials e.g. hydrogels as cell carriers has been suggested. In this study, two different hydrogels were examined (in vitro) as potential cell carriers for human mesenchymal stem cells (hMSCs) intended for IVD transplantation. The aim was to investigate cell- survival and chondrogenic differentiation of hMSCs when cultured in hydrogels Puramatrix((R)) or Hydromatrix((R)) and potential effects of stimulation with growth hormone (GH). hMSCs/hydrogel cultures were investigated for cell-viability, attachment, gene expressionof chondrogenic markers SOX9, COL2A1, ACAN and accumulation of extracellular matrix (ECM). In both hydrogel types, hMSCs were viable for 28 days, expressed integrin beta 1 which indicates adhesion of hMSCs. Differentiation was observed into chondrocyte-like cells, in a higher extent in hMSCs/Hydromatrix((R)) cultures when compared to hMSCs/Puramatrix ((R)) hydrogel cultures. Gene expression analyses of chondrogenic markers verified results. hMSCs/hydrogel cultures stimulated with GH displayed no significant effects on chondrogenesis. In conclusion, both hydrogels, especially Hydromatrix((R)) was demonstrated as a promising cell carrier in vitro for hMSCs, when directed into chondrogenesis. This knowledge could be useful in biological approaches for regeneration of degenerated human IVDs.
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| 5. |
- Hingert, Daphne, et al.
(author)
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Human mesenchymal stem cells pre-treated with IL-1β and stimulated with BMP-3 enhance chondrogenesis.
- 2018
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In: Tissue engineering. Part A. - 1937-335X. ; 24:9-10
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Journal article (peer-reviewed)abstract
- Low back pain is one of the most common ailments in western countries afflicting more than 80% of the population and the main cause is considered to be degeneration of intervertebral discs (IVDs). IL-1β is a vital inflammatory cytokine found in abundance in degenerated disc environment whereas BMP-3 is believed to promote chondrogenesis through TGF-β pathway.The aim was to study the effects of BMP-3, IL-1β and combination (pre-treatment with IL-1β) on hMSCs encapsulated in PuraMatrix™ hydrogel (Phg) especially in the absence of TGF-β in order to investigate the proliferation, and differentiation ability of hMSCs over 28 days period.100µL of hMSCs cell suspension was encapsulated between two layers of 100 µL hydrogels forming a sandwich-like structure. The encapsulated hMSCs were cultured in two sets of media, chondrogenic (C) and non-chondrogenic (nC) media along with addition of BMP-3 (10ng/mL) and IL-1β (10ng/mL). To study the combined effects of BMP-3 and IL-1β, the encapsulated hMSCs were first pre-treated with relevant media containing IL-1β for 24 hours, and then the media was replaced by media containing BMP-3 for the remaining experimental time period. IL-1β pre-treatment was carried out in both C and nC media. The samples were collected at day 7, 14, and 28.Proliferation and differentiation of hMSCs into chondrocyte-like cells was observed in all samples. Proteoglycans accumulation was observed in pre-treatment samples in C media. The protein and gene expression of Sox-9 and COL2A1 respectively, showed the occurrence of chondrogenesis in all samples.High cell viability, proliferation and differentiation was achieved in this in vitro model confirming that BMP-3 alone in the absence of TGF-β could drive hMSCs into chondrogenic lineage. Pre-treatment with IL-1β followed by BMP-3 stimulation resulted in high proteoglycans accumulation compared to stimulation with growth factors or cytokine alone. This suggests that pre-treatment with a pro-inflammatory cytokine before driving them into a chondrogeneic lineage might be of importance also in vivo.
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| 6. |
- Hingert, Daphne, et al.
(author)
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Pathological Effects of Cortisol on Intervertebral Disc Cells and Mesenchymal Stem Cells from Lower Back Pain Patients
- 2019
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In: Cells Tissues Organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 207:1, s. 34-45
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Journal article (peer-reviewed)abstract
- In western countries, lower back pain (LBP) is one of the most common disorders, experienced by more than 80% of the population. Chronic LBP due to disc degeneration has been linked to ongoing inflammatory processes in the disc and endplates. Pain effects the body in different ways, inducing a general stress response in which the body responds by releasing the stress hormone cortisol. Little is known about the impact of pain-induced stress on the progression of disc degeneration. Thus, the effects of cortisol on disc cells (DCs) and human mesenchymal stem cells (hMSCs) were explored in vitro with the objective of investigating the repercussions of cortisol on these cell types involved in de- and regenerative mechanisms of the disc. DC and hMSC pellet cultures were exposed to cortisol at two concentrations (150 and 300 ng/mL) for 28 days to simulate pain-induced stress. Cell viability, histological staining, and GAG DNA, along with apo-ptotic assays were conducted. Detection of OCT4, SOX9, IL-1R, and CXCR2 expressions was performed by immunohistochemistry. With cortisol treatment, restricted cell proliferation and less GAG production in both DCs and hMSCs were observed. Suppression of the differentiation and immunomodulatory efficacy of hMSCs was also detected. Moreover, elevated expressions of IL-1R and CXCR2 were detected in both cell types. To conclude, constant exposure to cortisol even at a physiological level enhanced pathological cellular processes in both DCs and hMSCs, which further jeopardized chondrogenesis. This suggests that cortisol resulting from pain-induced stress is a contributing component of intervertebral disc degeneration and may negatively affect regenerative attempts of the disc.
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| 7. |
- Vukusic, Kristina, 1979, et al.
(author)
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Physical exercise affects slow cycling cells in the rat heart and reveals a new potential niche area in the atrioventricular junction
- 2015
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In: Journal of Molecular Histology. - : Springer Science and Business Media LLC. - 1567-2379 .- 1567-2387. ; 46:4, s. 387-398
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Journal article (peer-reviewed)abstract
- Physical exercise has several beneficial effects on the heart. In other tissues it has been shown to activate endogenous stem cells. There is however a lack of knowledge how exercise affects the distribution of progenitor cells as well as overall cell turnover within the heart. Therefore, proliferating cells were identified using BrdU DNA labeling in a rat exercise model. Slow cycling cells were identified by label retention. BrdU+ nuclei were counted in apex, ventricle and atrioventricular junction (AV junction), as well as in skin tissue where label retaining cells (LRC) have been described previously. After 13 weeks of chasing, the cells with the highest intensity were identified and considered as LRC. Heart tissue showed slower proliferation compared to skin. The highest number of BrdU+ cells was found in the AV junction. Here, a sub region in close proximity to the valvular insertion point was observed, where density of BrdU+ cells was high at all time points. Physical exercise increased proliferation in AV junction at the early stage. Furthermore, the sub region was found to harbor a significant higher number of LRC compared to other regions of the heart in the exercised animals. Progenitor markers MDR1 and Sca-1 were detected in the same area by immunohistochemistry. In conclusions, our data shows that physical exercise affects cell turnover and distribution of LRC in the heart. Furthermore, it reveals a region within the AV junction of the heart that shows features of a stem cell niche.
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| 8. |
- Andersson Shams Hakimi, Caroline, et al.
(author)
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The Effect of Ex Vivo Factor XIII Supplementation on Clot Formation in Blood Samples From Cardiac and Scoliosis Surgery Patients.
- 2018
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In: Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. - : SAGE Publications. - 1938-2723. ; 24:4, s. 677-683
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Journal article (peer-reviewed)abstract
- Excessive perioperative bleeding remains a substantial problem. Factor XIII (FXIII) contributes to clot stability, and it has therefore been suggested that supplementation with FXIII concentrate may improve perioperative hemostasis. We evaluated the effects of increasing doses of FXIII, alone or in combination with fibrinogen or platelet concentrate, in blood samples from 2 considerably different groups of surgical patients: cardiac and scoliosis surgery patients. Whole-blood samples were collected immediately after operation from cardiac and scoliosis surgery patients. The samples were supplemented with 3 clinically relevant doses of FXIII concentrate (+20%, +40%, and +60%), alone or in combination with a fixed dose of fibrinogen concentrate (+1.0 g/L) or fresh apheresis platelets (+92 × 10(9)/L). Clot formation was assessed with rotational thromboelastometry (ROTEM). When the highest dose of FXIII concentrate was added, EXTEM clotting time was shortened by 10% in both cardiac and scoliosis surgery patients (95% confidence intervals: 2.4%-17% and 3.3%-17%, respectively), and FIBTEM maximum clot firmness was increased by 25% (9.3%-41%) in cardiac patients, relative to baseline. When fibrinogen was added, the dose-dependent effect of FXIII on clot stability was maintained, but the total effect was markedly greater than with FXIII alone, +150% (100%-200%) and +160% (130%-200%) for the highest FXIII dose in cardiac and scoliosis patients, respectively. Ex vivo supplementation with clinically relevant doses of FXIII improved clot formation moderately in blood samples from cardiac and scoliosis surgery patients, both alone and when given in combination with fibrinogen or platelet concentrate.
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| 9. |
- Angelini, Eva, 1964, et al.
(author)
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Patients' Experiences of Pain Have an Impact on Their Pain Management Attitudes and Strategies
- 2018
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In: Pain Management Nursing. - : Elsevier BV. - 1524-9042. ; 19:5, s. 464-473
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Journal article (peer-reviewed)abstract
- Objectives: Postoperative pain remains undermanaged in orthopedic surgery. To identify areas of improvement for future structural changes in pain management, patients' experiences of pain and pain management when undergoing elective lumbar spine surgery were explored, using a qualitative method with focus group interviews. Setting: The study setting was an orthopedic spine surgery department at a University Hospital in Sweden. Methods: This study consisted of two focus group interviews with patients (n = 6/group, a total of 12 patients) who had undergone lumbar spine surgery 4 days to 5 weeks prior to the focus group interviews. The interviews were semi-structured, and the analysis was performed using qualitative content analysis. Results: The main result of this study revealed that patients' experiences of pain influenced their attitudes and strategies for pain management. Three main categories emerged from the focus group interviews: I. Coping with pain while waiting for surgery; II. Using different pain-relieving strategies after surgery; and III. How organizational structures influence the pain experiences. Conclusions: In conclusion the results from this study acknowledge that postoperative pain experiences and coping strategies after spine surgery are highly diverse and individual. This calls for staff having a more personalized approach to pain management in order to optimize pain relief, which was stressed as highly valued by the patients. (C) 2018 by the American Society for Pain Management Nursing
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| 10. |
- Baranto, Adad, 1966, et al.
(author)
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Interspinous Process Implants Causes Wear of the Spinous Processes in Patients Treated for Spinal Stenosis—An Experimental Biomechanical Study with Comparison to Clinical Cases
- 2016
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In: Open Journal of Orthopedics. - : Scientific Research Publishing, Inc.. - 2164-3008 .- 2164-3016. ; :6, s. 201-210
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Journal article (peer-reviewed)abstract
- There are few biomechanical studies on Interspinous Process Implants (IPD); however none investigate the amount of wear on spinous processes. Therefore the objective of the present study was to investigate the effect of repetitive loading of the IPD Aperius on the spinous processes in a biomechanical porcine model. For comparison, three patients treated surgically with the same device have been followed for one to two years clinically and with image analyses (X-rays, MRI, CT-scans). Four lumbar spines from 6 months old porcine were divided into seven segments, which received IPD. The segments were exposed to 20,000 cyclical loads. Afterwards the deformation (wear) of the segments was registered. The wear of the spinous processes was measured in mm on a following CT-scan. Additionally, the wear of the ex-vivo was compared to that of the spinous processes investigated by CT-scans or X-ray in three patients treated surgically with the same interspinous implant. The mean maximal deformation of porcine specimens was 1.79 mm (SD 0.25) with the largest deformation occurring in the first quarter of the loading (<5000 cycles). The mean wear of the spinous processes after loading was 6.57 mm. A similar level of wear (mean 12.7 mm) of the spinous processes was detected in the patients. The Aperius IPD creates significant wear on the spinous processes in an experimental biomechanical study. Similar wear of the spinous pro-
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