| 1. |
- di Summa, Pietro G, et al.
(författare)
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Adipose-derived stem cells enhance peripheral nerve regeneration
- 2010
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Ingår i: Journal of plastic, reconstructive and aesthetic surgery. - : Elsevier. - 1878-0539 .- 1748-6815. ; 63:9, s. 1544-1552
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic injuries resulting in peripheral nerve lesions often require a graft to bridge the gap. Although autologous nerve auto-graft is still the first-choice strategy in reconstructions, it has the severe disadvantage of the sacrifice of a functional nerve. Cell transplantation in a bioartificial conduit is an alternative strategy to create a favourable environment for nerve regeneration. We decided to test new fibrin nerve conduits seeded with various cell types (primary Schwann cells and adult stem cells differentiated to a Schwann cell-like phenotype) for repair of sciatic nerve injury. Two weeks after implantation, the conduits were removed and examined by immunohistochemistry for axonal regeneration (evaluated by PGP 9.5 expression) and Schwann cell presence (detected by S100 expression). The results show a significant increase in axonal regeneration in the group of fibrin seeded with Schwann cells compared with the empty fibrin conduit. Differentiated adipose-derived stem cells also enhanced regeneration distance in a similar manner to differentiated bone marrow mesenchymal stem cells. These observations suggest that adipose-derived stem cells may provide an effective cell population, without the limitations of the donor-site morbidity associated with isolation of Schwann cells, and could be a clinically translatable route towards new methods to enhance peripheral nerve repair.
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| 2. |
- Kalbermatten, Daniel F, 1969-, et al.
(författare)
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Fibrin matrix for suspension of regenerative cells in an artificial nerve conduit
- 2008
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Ingår i: Journal of plastic, reconstructive and aesthetic surgery. - : Elsevier BV. - 1878-0539 .- 1748-6815. ; 61:6, s. 669-675
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Tidskriftsartikel (refereegranskat)abstract
- Peripheral nerve injury presents with specific problems of neuronal reconstructions, and from a clinical viewpoint a tissue engineering approach would facilitate the process of repair and regeneration. We have previously used artificial nerve conduits made from bioresorbable poly-3-hydroxybutyrate (PHB) in order to refine the ways in which peripheral nerves are repaired and reconnected to the target muscles and skin. The addition of Schwann cells (SC) or differentiated mesenchymal stem cells (dMSC) to the conduits enhances regeneration. In this study, we have used a matrix based on fibrin (Tisseel) to fill optimally the nerve-conduits with cells. In vitro analysis showed that both SC and MSC adhered significantly better to PHB in the presence of fibrin and cells continued to maintain their differentiated state. Cells were more optimally distributed throughout the conduit when seeded in fibrin than by delivery in growth medium alone. Transplantation of the nerve conduits in vivo showed that cells in combination with fibrin matrix significantly increased nerve regeneration distance (using PGP9.5 and S100 distal and proximal immunohistochemistry) when compared with empty PHB conduits. This study shows the beneficial combinatory effect of an optimised matrix, cells and conduit material as a step towards bridging nerve gaps which should ultimately lead to improved functional recovery following nerve injury.
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| 3. |
- Kalbermatten, Daniel F, 1969-, et al.
(författare)
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New fibrin conduit for peripheral nerve repair
- 2009
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Ingår i: Journal of reconstructive microsurgery. - : Georg Thieme Verlag KG. - 0743-684X .- 1098-8947. ; 25:1, s. 27-33
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Tidskriftsartikel (refereegranskat)abstract
- An ideal substitute to treat a nerve gap has not been found. Initially, silicone conduits were employed. Later, conduits were fabricated from collagen or polyesters carbonates. More recently, it has been shown that a bioresorbable material, poly-3-hydroxybutyrate (PHB), can enhance nerve repair. The present investigation shows the use of fibrin as a conduit to guide nerve regeneration and bridge nerve defects. In this study we prepared and investigated a novel nerve conduit made from fibrin glue. Using a rodent sciatic nerve injury model (10-mm gap), we compared the extent of nerve regeneration through the new fibrin conduits versus established PHB conduits. After 2 and 4 weeks, conduits containing proximal and distal stumps were harvested. We evaluated the initial axon and Schwann cell stimulation using immunohistochemistry. The conduits presented full tissue integration and were completely intact. Axons crossed the gap after 1 month. Immunohistochemistry using the axonal marker PGP 9.5 showed a superior nerve regeneration distance in the fibrin conduit compared with PHB (4.1 mm versus 1.9 mm). Schwann cell intrusion (S100 staining) was similarly enhanced in the fibrin conduits, both from the proximal (4.2 mm versus 2.1 mm) and distal ends (3.2 mm versus 1.7 mm). These findings suggest an advantage of the new fibrin conduit for the important initial phase of peripheral nerve regeneration. The use of fibrin glue as a conduit is a step toward a usable graft to bridge peripheral nerve lesions. This might be clinically interesting, given the widespread acceptance of fibrin glue among the surgical community.
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| 4. |
- Kalbermatten, Daniel F, 1969-, et al.
(författare)
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Schwann cell strip for peripheral nerve repair
- 2008
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Ingår i: Journal of Hand Surgery - British and European Volume. - : SAGE Publications. - 0266-7681 .- 1532-2211. ; 33:5, s. 587-594
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Tidskriftsartikel (refereegranskat)abstract
- Many strategies have been investigated to provide an ideal substitute to treat a nerve gap injury. Initially, silicone conduits were used and more recently conduits fabricated from natural materials such as poly-3-hydroxybutyrate (PHB) showed good results but still have their limitations. Surgically, a new concept optimising harvested autologous nerve graft has been introduced as the single fascicle method. It has been shown that a single fascicle repair of nerve grafting is successful. We investigated a new approach using a PHB strip seeded with Schwann cells to mimic a small nerve fascicle. Schwann cells were attached to the PHB strip using diluted fibrin glue and used to bridge a 10-mm sciatic nerve gap in rats. Comparison was made with a group using conventional PHB conduit tubes filled with Schwann cells and fibrin glue. After 2 weeks, the nerve samples were harvested and investigated for axonal and Schwann cell markers. PGP9.5 immunohistochemistry showed a superior nerve regeneration distance in the PHB strip group versus the PHB tube group (> 10 mm, crossed versus 3.17+/- 0.32 mm respectively, P<0.05) as well as superior Schwann cell intrusion (S100 staining) from proximal (> 10 mm, crossed versus 3.40+/- 0.36 mm, P<0.01) and distal (> 10 mm, crossed versus 2.91+/- 0.31 mm, P<0.001) ends. These findings suggest a significant advantage of a strip in rapidly connecting a nerve gap lesion and imply that single fascicle nerve grafting is advantageous for nerve repair in rats.
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| 5. |
- Kalbermatten, Daniel, 1969-
(författare)
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Nerve gap repair by the use of artificial conduits and cultured cells
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Peripheral nerve injuries are often associated with loss of nerve tissue and require autologous nerve grafts to provide a physical substrate for axonal growth. This thesis investigates the use of fibrin as both a tubular conduit to guide nerve regeneration and also as a matrix material to suspend various regenerative cell types within/on poly-3-hydroxybutyrate (PHB) nerve conduits. Adipose derived stem cells (ASC) are found in abundant quantities. In this thesis the ability of rat ASC to differentiate into Schwann cells was determined and a preliminary study of the neurotrophic potential of human ASC was also investigated. Rat sciatic nerve axotomy was performed proximally in the thigh to create a 10-mm gap between the nerve stumps and the gap was bridged using the various conduits. At early time points the nerve grafts were harvested and investigated for axonal and Schwann cell markers. After 16 weeks the regenerative response from sensory and motor neurons was also evaluated following retrograde labelling with Fast Blue fluorescent tracer. Stem cells were treated with a mixture of glial growth factors and after 2 weeks in vitro the expression of Schwann cell markers was analysed by immunocytochemistry and Western blotting. ASC were cocultured with the NG108-15 neuronal cell line to determine their ability to promote neurite outgrowth. Human ASC were isolated from the deep and superficial layers of abdominal fat tissue obtained during abdominoplasty procedures. RT-PCR was used to investigate the expression of neurotrophic factors. Immunohistochemistry showed a superior nerve regeneration distance in the fibrin conduit compared with PHB. The fibrin conduit promoted regeneration of 60% of sensory neurones and 52% of motor neurones when compared with an autograft group at 16 weeks. The total number of myelinated axons in the distal nerve stump in the fibrin-conduit group reached 86% of the graft and the weight of gastrocnemius and soleus muscles recovered to 82% and 89% of the controls, respectively. In vitro studies showed that rat ASC could be differentiated to a Schwann cell phenotype. These treated cells enhanced both the number of NG108-15 cells expressing neurites and neurite length. In the same coculture model system, human superficial fat layer ASC induced significantly enhanced neurite outgrowth when compared with the deep layer fat cells. RT-PCR analysis showed ASC isolated from both layers expressed neurotrophic factors. These results indicate that a tubular fibrin conduit can be used to promote neuronal regeneration following peripheral nerve injury. There was also a beneficial effect of using a fibrin matrix to seed cells within/on PHB conduits which should ultimately lead to improved functional recovery following nerve injury. There might also be an advantage to use a simple strip of PHB rather than a conventional tube-like structure implying that single fascicle nerve grafting could be advantageous for nerve repair. The results of in vitro experiments indicate adipose tissue contains a pool of regenerative stem cells which can be differentiated to a Schwann cell phenotype and given that human ASC express a range of neurotrophic factors they are likely to be of clinical benefit for treatment of peripheral nerve injuries.
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| 6. |
- Kalbermatten, Daniel, 1969-, et al.
(författare)
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Neurotrophic activity of human adipose stem cells isolated from deep and superficial layers of abdominal fat
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- New approaches to the clinical treatment of traumatic nerve injuries may one day utilize stem cells to enhance nerve regeneration. Adipose derived stem cells (ASC) are found in abundant quantities and can be harvested by minimally invasive procedures which should facilitate their use in such regenerative applications. In this study, we have analyzed the properties of human ASC isolated from the deep and superficial layers of abdominal fat tissue obtained during abdominoplasty procedures. Cells from the superficial layer proliferated significantly faster than those from the deep layer. Both in the deep and superficial layers, ASC expressed the pluripotent stem cell markers oct4 and nanog and also the stro-1 cell surface antigen. Superficial layer ASC induced significantly enhanced neurite outgrowth from NG108-15 motor neuron like cells when compared with the deep layer cells. However, RT-PCR analysis showed that ASC isolated from both layers expressed similar levels of the neurotrophic factors NGF, BDNF, GDNF and NT-3. These results indicate that human ASC have promising potential for the treatment of traumatic nerve injuries and that superficial layer ASC might represent the more optimal cell type for such applications.
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| 7. |
- Pettersson, Jonas, 1979-, et al.
(författare)
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Biodegradable fibrin conduit promotes long-term regeneration after peripheral nerve injury in adult rats
- 2010
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Ingår i: Journal of Plastic, Reconstructive & Aesthetic Surgery. - : Elsevier. - 1748-6815 .- 1878-0539. ; 63:11, s. 1893-1899
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Tidskriftsartikel (refereegranskat)abstract
- Peripheral nerve injuries are often associated with loss of nerve tissue and require autologous nerve grafts to provide a physical substrate for axonal growth. Biosynthetic neural conduits could be an alternative treatment strategy in such injuries. The present study investigates the long-term effects of a tubular fibrin conduit on neuronal regeneration, axonal sprouting and recovery of muscle weight following peripheral nerve injury and repair in adult rats. Sciatic axotomy was performed proximally in the thigh to create a 10-mm gap between the nerve stumps. The injury gap was bridged by using a 14-mm-long fibrin glue conduit, entubulating 2mm of the nerve stump at each end. A reversed autologous nerve graft was used as a control. The regenerative response from sensory and motor neurones was evaluated following retrograde labelling with Fast Blue fluorescent tracer. In control experiments, at 16 weeks following peripheral nerve grafting, 5184 (+/-574 standard error of mean (SEM)) sensory dorsal root ganglion neurones and 1001 (+/-37 SEM) spinal motor neurones regenerated across the distal nerve-graft interface. The fibrin conduit promoted regeneration of 60% of sensory neurones and 52% of motor neurones when compared to the control group. The total number of myelinated axons in the distal nerve stump in the fibrin-conduit group reached 86% of the control and the weight of gastrocnemius and soleus muscles recovered to 82% and 89% of the controls, respectively. The present results suggest that a tubular fibrin conduit can be used to promote neuronal regeneration following peripheral nerve injury.
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| 8. |
- Schaakxs, Dominique, 1979-, et al.
(författare)
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Intramuscular Stem Cell Injection in Combination with Bioengineered Nerve Repair or Nerve Grafting Reduces Muscle Atrophy
- 2022
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Ingår i: Plastic and reconstructive surgery (1963). - : Lippincott Williams & Wilkins. - 0032-1052 .- 1529-4242. ; 149:5, s. 905E-913E
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Tidskriftsartikel (refereegranskat)abstract
- Background: Peripheral nerve injuries represent a clinical challenge, especially when they are accompanied by loss of neural tissue. In this study, the authors attempted to attain a better outcome after a peripheral nerve injury by both repairing the nerve lesion and treating the denervated muscle at the same time.Methods: Rat sciatic nerves were transected to create 10-mm gaps. Repair was performed in five groups (n = 5 rats for each), as follows: group 1, nerve repair using poly-3-hydroxybutyrate strips to connect the proximal and distal stumps, in combination with control growth medium injection in the gastrocnemius muscle; group 2, nerve repair with poly-3-hydroxybutyrate strip seeded with Schwann cell-like differentiated adipose stem cells (differentiated adipose stem cell strip) in combination with growth medium intramuscular injection; group 3, differentiated adipose stem cell strip in combination with intramuscular injection of differentiated adipose stem cells; group 4, repair using autograft (reverse sciatic nerve graft) in combination with intramuscular injection of growth medium; and group 5, autograft in combination with intramuscular injection of differentiated adipose stem cells. Six weeks after nerve injury, the effects of the stem cells on muscle atrophy were assessed.Results: Poly-3-hydroxybutyrate strips seeded with differentiated adipose stem cells showed a high number of βIII-tubulin-positive axons entering the distal stump and abundant endothelial cells. Group 1 animals exhibited more muscle atrophy than all the other groups, and group 5 animals had the greatest muscle weights and muscle fibers size.Conclusion: Bioengineering nerve repair in combination with intramuscular stem cell injection is a promising technique to treat nerve lesions and associated muscle atrophy. Clinical Relevance Statement: Nerve injuries and resulting muscle atrophy are a clinical challenge. To optimize functional recovery after a nerve lesion, the authors treated the nerve and muscle at the same time by using regenerative medicine with adipose stem cells and obtained encouraging results for future clinical applications.
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