| 1. |
- Brisby, Helena, 1965, et al.
(författare)
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The presence of local mesenchymal progenitor cells in human degenerated intervertebral discs and possibilities to influence these in vitro: A descriptive study in humans
- 2013
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 22:5, s. 804-814
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Tidskriftsartikel (refereegranskat)abstract
- Low back pain is common and degenerated discs are believed to be a major cause. In non-degenerated intervertebral discs(IVDs) presence of stem-/progenitor cells was recently reported in different mammals (rabbit,rat,pig). Understanding processes of disc degeneration and regenerative mechanisms within degenerated discs(DDs) is important. The aim of the study was to examine presence of local stem-/progenitor cells in human DDs and if these cell-populations could respond to paracrin stimulation in vitro. Tissue biopsies from the IVD region (L3-S1) was collected from 15 patients, age 34-69 years, undergoing surgery (spinal fusion) and mesenchymal stem cells (MSCs)(iliac crest) from two donors. Non-degenerated disc cells were collected from one donor(scoliosis) and chordoma tissue was obtained from(positive control, stem cell markers) two donors. The IVD biopsies were investigated for gene- and protein expression of: OCT3/4, CD105, CD90, STRO-1 and NOTCH1. DD cell cultures(pellet mass) were performed with conditioned media from MSCs and non-degenerated IVD cells. Pellets were investigated after 7, 14, 28 days for the same stem cell markers as above. Gene expression of OCT3/4 and STRO-1 was detected in 13/15 patient samples, CD105 in 14/15 samples and CD90 and NOTCH1 was detected 15/15 samples. Immunohistochemistry analysis supported findings on protein level, in cells sparsely distributed in DDs tissues. DDs cell-cultures displayed more undifferentiated appearance with increased expression of CD105, CD90, STRO-1, OCT3/4, NOTCH1 and JAGGED1 which was observed when cultured in conditioned cell-culture media from MSC compared to cell-cultures cultured with conditioned media from non-degenerated disc cells. Expression of OCT3/4(multipotency marker) and NOTCH1(regulator of cell fate), MSC- markers CD105, CD90 and STRO-1 indicate that primitive cell populations are present within DDs. Furthermore, the possibility to influence cells from DDs by by paracrin signalling /soluble factors from MSCs and from non-degenerated IVD cells was observed in vitro indicating that repair processes within human degenerated discs may be stimulated.
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| 2. |
- Nicolaos, Papadimitriou, 1972, et al.
(författare)
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Cell Viability and Chondrogenic Differentiation Capability of Human Mesenchymal Stem Cells After Iron Labeling with Iron Sucrose
- 2014
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 23:21, s. 2568-2580
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Tidskriftsartikel (refereegranskat)abstract
- For evaluation of cell therapy strategies using human mesenchymal stem cells (hMSCs) it is important to be able to trace transplanted cells and their distribution in tissues e.g. cartilage over time. The aim with the study was to determine effects on cell viability, traceability and chondrogenic differentiation of hMSCs after iron labelling with iron sucrose. HMSCs were collected (7 donors, 13-57 years), undergoing spinal surgery. Two sub-sets of experiments were performed. 1)Iron labelling of hMSCs: 1 mg/mL Venofer®(iron sucrose) was added(16 hours) to cultures. hMSCs were examined for uptake of iron sucrose(Preussian blue staining) and cell viability(flow cytometry). 2)Iron labelled hMSCs(passage 4)(n=4, pellet-mass), 200 000 cells/tube were cultured(DMEM-HG) with 10 ng/mL TGFβ and compared to controls(from each donor). The pellets were harvested day 7, 14 and 28. Real time-PCR, IHC and histology were used to evaluate SOX9, ACAN, C6S and COL2A1 expression. Results; mean number of cells containing iron deposits was 98.1 % and mean cell viability 92.7 % (no significant difference compared to unlabelled control cells). Pellets containing iron labelled cells expressed COL2A1 on protein level(all time points), in similar levels as controls and glycosaminoglycan accumulation was observed in iron labelled pellets(day 14 or day 28). Results were supported expression of chondrogenic genes, SOX9, ACAN and COL2A1. The results in vitro indicate that iron sucrose can be used as a cell tracer, for evaluation of cellular distribution in vivo after transplantation of MSCs and thus contribute with important knowledge when exploring new treatment strategies for degenerated cartilaginous tissues.
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| 3. |
- Åberg, Jonas, 1982-, et al.
(författare)
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Biocompatibility and resorption of a radiopaque premixed calcium phosphate cement
- 2012
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 100A:5, s. 1269-1278
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Tidskriftsartikel (refereegranskat)abstract
- Calcium phosphate cements (CPC) are used as bone void filler in various orthopedic indications; however, there are some major drawbacks regarding mixing, transfer, and injection of traditional CPC. By using glycerol as mixing liquid, a premixed calcium phosphate cement (pCPC), some of these difficulties can be overcome. In the treatment of vertebral fractures the handling characteristics need to be excellent including a high radio-opacity for optimal control during injection. The aim of this study is to evaluate a radiopaque pCPC regarding its resorption behavior and biocompatibility in vivo. pCPC and a water-based CPC were injected into a circle divide 4-mm drilled femur defect in rabbits. The rabbits were sacrificed after 2 and 12 weeks. Cross sections of the defects were evaluated using histology, electron microscopy, and immunohistochemical analysis. Signs of inflammation were evaluated both locally and systemically. The results showed a higher bone formation in the pCPC compared to the water-based CPC after 2 weeks by expression of RUNX-2. After 12 weeks most of the cement had been resorbed in both groups. Both materials were considered to have a high biocompatibility since no marked immunological response was induced and extensive bone ingrowth was observed. The conclusion from the study was that pCPC with ZrO2 radiopacifier is a promising alternative regarding bone replacement material and may be suggested for treatment of, for example, vertebral fractures based on its high biocompatibility, fast bone ingrowth, and good handling properties.
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