| 1. |
- Ahmed, Tamer A. E., et al.
(författare)
-
Fibrin Glues in Combination with Mesenchymal Stem Cells to Develop a Tissue-Engineered Cartilage Substitute
- 2011
-
Ingår i: Tissue Engineering. Parts A, B and C. - : Mary Ann Liebert Inc. - 2152-4947 .- 2152-4955. ; 17:3-4, s. 323-335
-
Tidskriftsartikel (refereegranskat)abstract
- Damage of cartilage due to traumatic or pathological conditions results in disability and severe pain. Regenerative medicine, using tissue engineering-based constructs to enhance cartilage repair by mobilizing chondrogenic cells, is a promising approach for restoration of structure and function. Fresh fibrin (FG) and platelet-rich fibrin (PR-FG) glues produced by the CryoSeal (R) FS System, in combination with human bone marrow-derived mesenchymal stem cells (BM-hMSCs), were evaluated in this study. We additionally tested the incorporation of heparin-based delivery system (HBDS) into these scaffolds to immobilize endogenous growth factors as well as exogenous transforming growth factor-beta(2). Strongly, CD90+ and CD105+ hMSCs were encapsulated into FG and PR-FG with and without HBDS. Encapsulation of hMSCs in PR-FG led to increased expression of collagen II gene at 2.5 weeks; however, no difference was observed between FG and PR-FG at 5 weeks. The incorporation of HBDS prevented the enhancement of collagen II gene expression. BM-hMSCs in FG initially displayed enhanced aggrecan gene expression and increased accumulation of Alcian blue-positive extracellular matrix; incorporation of HBDS into these glues did not improve aggrecan gene expression and extracellular matrix accumulation. The most significant effect on cartilage marker gene expression and accumulation was observed after encapsulation of hMSCs in FG. We conclude that FG is more promising than PR-FG as a scaffold for chondrogenic differentiation of hMSCs; however, immobilization of growth factors inside these fibrin scaffolds with the HBDS system has a negative impact on this process. In addition, BM-hMSCs are valid and potentially superior alternatives to chondrocytes for tissue engineering of articular cartilage.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Ananta, M, et al.
(författare)
-
A Poly(Lactic Acid-Co-Caprolactone)–Collagen Hybrid for Tissue Engineering Applications
- 2009
-
Ingår i: Tissue engineering Part A. - : Mary Ann Liebert, Inc.. - 1937-3341 .- 1937-335X. ; 15:7, s. 1667-1675
-
Tidskriftsartikel (refereegranskat)abstract
- A biodegradable hybrid scaffold consisting of a synthetic polymer, poly(lactic acid-co-caprolactone) (PLACL), and a naturally derived polymer, collagen, was constructed by plastic compressing hyperhydrated collagen gels onto a flat warp-knitted PLACL mesh. The collagen compaction process was characterized, and it was found that the duration, rather than the applied load under the test conditions in the plastic compression, was the determining factor of the collagen and cell density in the cell-carrying component. Cells were spatially distributed in three different setups and statically cultured for a period of 7 days. Short-term biocompatibility of the hybrid construct was quantitatively assessed with AlamarBlue and qualitatively with fluorescence staining and confocal microscopy. No significant cell death was observed after the plastic compression of the interstitial equivalents, confirming previous reports of good cell viability retention. The interstitial, epithelial, and composite tissue equivalents showed no macroscopic signs of contraction and good cell proliferation with a two- to threefold increase in cell number over 7 days. Quantitative analysis showed a homogenous cell distribution and good biocompatibility. The results indicate that viable and proliferating multilayered tissue equivalents can be engineered using the PLACL-collagen hybrid construct in the space of several hours.
|
|
| 5. |
|
|
| 6. |
- Banerjee, Debashish, et al.
(författare)
-
Characterization of Decellularized Implants for Extracellular Matrix Integrity and Immune Response Elicitation
- 2022
-
Ingår i: Tissue Engineering Part A. - : Mary Ann Liebert Inc. - 1937-3341 .- 1937-335X. ; 28:13-14, s. 621-639
-
Tidskriftsartikel (refereegranskat)abstract
- Biological scaffold is a popular choice for the preparation of tissue-engineered organs and has the potential to address donor shortages in clinics. However, biological scaffolds prepared by physical or chemical agents cause damage to the extracellular matrix (ECM) by potentially inducing immune responses after implantation. The current study explores the fate of the decellularized (DC) scaffolds using a cocktail of chemicals following implantation without using immunosuppressants. Using the syngeneic (Lewis male-Lewis female) and allogeneic (Brown Norway male-Lewis female) models and different tissue routes (subcutaneous vs. omentum) for implantation, we applied in-depth quantitative proteomics, genomics along with histology and quantitative image analysis tools to comprehensively describe and compare the proteins following DC and postimplantation. Our data helped to identify any alteration postdecullarization as well implantation. We could also monitor route-specific modulation of the ECM and regulation of the immune responses (macrophage and T cells) following implantation. The current approach opens up the possibility to monitor the fate of biological scaffolds in terms of the ECM and immune response against the implants. In addition, the identification of different routes helped us to identify differential immune responses against the implants. This study opens up the potential to identify the changes associated with chemical DC both pre- and postimplantation, which could further help to promote research in this direction. Impact StatementThe development of a biological scaffold helps in the preparation of a functional organ in the clinics. In the current study, we develop a strategy for chemical decellularization and explored two different routes to understand the differential responses elicited postimplantation. The use of sensitive protein and genomic tools to study the changes creates a favorable environment for similar efforts to develop and characterize biological scaffolds before further trials in the clinics. The current study, which was carried out without any immunosuppressive agents, could help to establish (a) appropriate chemical strategies for preparing biological scaffolds as well as (b) identify putative implantable routes to circumvent any adverse immune reactions, which will ultimately decide the outcome for acceptance or rejection of the scaffold/implant.
|
|
| 7. |
- Bartaula-Brevik, Sushma, et al.
(författare)
-
Angiogenic and Immunomodulatory Properties of Endothelial and Mesenchymal Stem Cells
- 2016
-
Ingår i: Tissue Engineering. Part A. - : Mary Ann Liebert. - 1937-3341 .- 1937-335X. ; 22:3-4, s. 244-252
-
Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that the effect of implanted cells on the local environment is important when selecting the appropriate cell type for tissue regeneration. Our aim was to compare the local tissue response to implanted human mesenchymal stem cells (MSC) and human umbilical vein endothelial cells (EC). MSC and EC were cultured in poly(l-lactide-co-1,5-dioxepan-2-one) scaffolds for 1 week in a bioreactor system, after which they were implanted subcutaneously in NOD/SCID mice. After 3 weeks, scaffolds were retrieved, and the mRNA expression of selected genes involved in hypoxia and inflammation was examined by real-time reverse transcription polymerase chain reaction and correlated with immunofluorescent staining for corresponding proteins. The Toll-like receptor signaling pathway was examined by superarray hybridization. The expression of 53 angiogenesis-related proteins was investigated by a proteome profiler angiogenesis antibody array kit. Vascularization was quantified using immunohistochemistry for CD31. The expression of hypoxia-inducible factors and biomarkers for angiogenesis was more strongly upregulated in response to implanted EC than to MSC, suggesting a higher sensitivity to low oxygen tension among EC. Hypoxic signaling was increased after implantation of EC compared with MSC, leading to a prolonged acute inflammatory phase that promoted ingrowth of vascular cells and establishment of the circulation. Inflammatory cytokines were also differently expressed at the gene and protein levels in the two experimental groups, resulting in altered recruitment of acute and chronic inflammatory cells. The end result of these differences was increased vessel formation within the constructs in the EC group.
|
|
| 8. |
- Berg, Malin, 1976, et al.
(författare)
-
Replacement of a Tracheal Stenosis with a Tissue-Engineered Human Trachea Using Autologous Stem Cells: A Case Report
- 2014
-
Ingår i: Tissue Engineering. Part A. - 1937-3341 .- 1937-335X. ; 20:1-2, s. 389-397
-
Tidskriftsartikel (refereegranskat)abstract
- Cell-based therapies, involving tissue engineering represent interesting and potentially important strategies for treatment of patients with various disorders. Here, using a detergent-enzymatic method we prepared an intact 3-dimensional scaffold of an extracellular matrix (ECM) derived from a human cadaver donor trachea, which we repopulated with autologous stem cells and implanted into a 76-year old patient with tracheal stenosis including lower part of the larynx. Although the graft provided the patient with an open airway, a week after surgery, the mucous membrane of the graft was covered by a 1-2mm thick fungal infection, which was treated with local and systemic anti-fungal therapy. The airway lumen was postoperatively controlled by fiberbrandoscopy and found stable and sufficient. However, twenty-three days later the patient died due to cardiac arrest but with a patent, open, stable tracheal transplant and intact anastomoses. Histopathological results of the transplanted tracheal graft at autopsy showed a squamous but not ciliated epithelium, neovascularization, bundles of -sma positive muscle cells, serous glands and nerve fibres with S-100 positive nerve cells in the submucosa and intact chondrocytes in the cartilage. Our findings suggest that although autologous stem cells- engineered tracheal matrices may represent a tool for clinical tracheal replacement. Further preclinical studies are required for generating functional airway grafts and long term effects of such grafts.
|
|
| 9. |
- Bigdeli, Narmin, 1974, et al.
(författare)
-
Superior Osteogenic Capacity of Human Embryonic Stem Cells Adapted to Matrix-Free Growth Compared to Human Mesenchymal Stem Cells.
- 2010
-
Ingår i: Tissue engineering. Part A. - : Mary Ann Liebert Inc. - 1937-335X .- 1937-3341. ; 16:11, s. 3427-3440
-
Tidskriftsartikel (refereegranskat)abstract
- Human mesenchymal stem cells (hMSCs) represent a promising source of cells for bone tissue engineering. However, their low frequencies and limited proliferation restrict their clinical utility. An alternative is the use of human embryonic stem cells (hESCs), but labor-intensive expansion with the need for coating support limits their clinical use. We have previously derived a cell line from hESCs denoted matrix-free growth (MFG)-hESC that are independent of coating support for expansion, and we here compare its osteogenic capacity to that of hMSCs. Microarray analysis of hMSCs and MFG-hESCs revealed differential expression of genes involved in ossification. MFG-hESCs have significantly higher expression of secreted phosphoprotein 1 (SPP1) during osteogenic differentiation, whereas the opposite was true for alkaline phosphatase (ALPL), transforming growth factor, beta 1 (TGFB2), runt-related transcription factor 2 (RUNX2), and forkhead box C1 (FOXC1), as well as the activity of the ALPL enzyme, demonstrating that these two cell types differentiate into the osteogenic lineage using different signaling pathways. von Kossa staining, time-of-flight secondary ion mass spectrometry, and measurement of calcium and phosphate in the extracellular matrix demonstrated a superior ability of the MFG-hESCs to produce a mineralized matrix compared to hMSCs. The superior ability of the MFG-hESCs to form mineralized matrix compared to hMSCs demonstrates that MFG-hESCs are a promising alternative to the use of adult stem cells in future bone regenerative applications.
|
|
| 10. |
|
|
