1,731 research outputs found
Supplemental Material - Cellular and Site-Specific Mitochondrial Characterization of Vital Human Amniotic Membrane
No full textSupplemental Material for Cellular and Site-Specific Mitochondrial Characterization of Vital Human Amniotic Membrane by Asmita Banerjee, Andrea Lindenmair, Simone Hennerbichler, Philipp Steindorf, Ralf Steinborn, Andrey V. Kozlov, Heinz Redl, Susanne Wolbank, and Adelheid Weidinger in Cell Transplantation</p
DS_10.1177_0363546518818792 – Supplemental material for Osteointegration of a Novel Silk Fiber–Based ACL Scaffold by Formation of a Ligament-Bone Interface
No full textSupplemental material, DS_10.1177_0363546518818792 for Osteointegration of a Novel Silk Fiber–Based ACL Scaffold by Formation of a Ligament-Bone Interface by Andreas Herbert Teuschl, Stefan Tangl, Patrick Heimel, Uwe Yacine Schwarze, Xavier Monforte, Heinz Redl and Thomas Nau in The American Journal of Sports Medicine</p
Bone-marrow-derived mesenchymal stromal cells: from basic biology to applications in bone tissue engineering and bone regeneration
No full textBone marrow provides a rich source of mesenchymal stromal cells (MSCs), which have the remarkable capacity for cell and tissue regeneration. Since their initial discovery in the guinea pig almost 50 years ago, bone-marrow-derived MSCs have been extensively studied in animals and humans. Several subpopulations have been characterized with the aim to isolate, enrich, and identify the cells with stem-cell properties and immunomodulatory actions, which are important for regenerative medicine. In this chapter, we review the properties of bone-marrow-derived MSCs with a focus on the preclinical setting and discuss their applications for bone tissue engineering and bone regeneration
Structural analysis of Heinz Isler’s bubble shell
Full text linkThis paper presents a detailed structural analysis of a bubble shell engineered by Heinz Isler. Through 3Dscanning the geometry of this shell structure has become available to the authors. Structural analysis has notbeen possible before since the geometry of the shell was not available. The bubble shell was Isler’s most builttype of shell. In the paperfirst the process of reverse engineering the geometry of the shell is described. Second,the effect of pre-stress in the edge beams is described. Third, the load distribution throughout the shell and themembrane behaviour relative to bending behaviour is assessed
Ansätze der Geweberegeneration zur Verbesserung der peripheren Nervenregeneration
Full text linkPeripheral nerve injuries show a prevalence of about 5% of traumatic injuries (approximately 300.000 cases per year in Europe) and are a frequent cause of hospitalization, displaying a major burden to patients, and the social health-care systems and the economy. Injuries to peripheral nerves often result in large defects in the continuity of the severed nerve. Bridging of a large defect with an autologous interfascicular nerve graft is considered to be the gold standard. Albeit it is best available treatment, transplantation of an autologous nerve graft does not always provide a satisfactory outcome. In this thesis several alternative approaches have been developed to improve peripheral nerve regeneration. Schwann cells are a crucial factor in peripheral nerve regeneration. Isolation, culture and re-implantation to the defect site have been proven to be challenging. Alternatives to native cultures are mesenchymal stem cells differentiated into Schwann cell-like cells. Chapter I illustrates the method -Extracorporeal Shockwave Treatment- to facilitate native Schwann cell isolation and culture, and to improve differentiation of mesenchymal stem cells into Schwann cell-like cells. Nerve conduit luminal fillers have been topic of discussion for many years. Ideas of an ideal luminal filler range from gels, to single fibres of different diameters and number, to composite gel/fibre fillers, multiple channels containing different growth factors and/or cells. In chapter II we investigated electrospinning as a method to align fibrin/PGLA fibres to create a biomimicking tissue-like material seeded with Schwann cell-like cells in vitro for potential use as an in vivo scaffold. Chapter III focuses on a novel nerve conduit material, its fabrication and functionalization. Due to its excellent biocompatibility silk fibroin has attracted considerable interest as a biomaterial for use as a conduit in peripheral nerve regeneration. We describe a novel procedure to produce silk fibroin nerve conduits: a braided tubular structure of raw Bombyx mori silk is subsequently degummed with a borate buffer system and processed with the ternary solvent CaCl2/H2O/ethanol, formic acid and methanol to improve its mechanical and topographical characteristics. Furthermore a protocol has been established to covalently bind laminin to silk fibroin utilizing carbodiimide chemistry, resulting in improved adhesion, viability and proliferation of Schwann cells
Kontrastverstärktes μCT von peripheren Nerven und Rückenmark
Full text linkSpinal cord and peripheral nerve injury are a common result of traumatic injury. The treatment options are still limited and consequences of these injuries can be severe and may result in permanent disability and reduction in quality of life. There is an urgent need for research into new treatment options. Novel imaging modalities may provide new insights into the mechanisms of injury and regeneration. Contrast enhanced computed tomography (CECT) allows the visualization of soft tissues with the use of contrast agents. In this work, we sought to investigate the viability of CECT for use in the context of peripheral nerve and spinal cord injury repair. We investigated the staining mechanisms of Lugol’s iodine staining on rat limbs by comparing repeated staining’s at various concentrations. The knowledge gained was employed to stain a peripheral nerve injury which was regenerated using a silk based nerve guidance conduit. Lugol’s iodine was further used to stain rat spinal cords after impact injury. We further investigated the staining of healthy and injured spinal cords using Lugol’s iodine, Accupaque and hafnium-substituted Wells-Dawson polyoxometalate (Hf-POM). Accupaque was then employed as a contrast agent in a rat spinal cord injury experiment. We were able to optimize Lugol’s iodine staining for a peripheral nerve and spinal cord injury regeneration context. The staining was successfully employed in studies on peripheral nerve and spinal cord injuries in rats. In the peripheral nerve, the degree of bridging and blood supply through macroscopic holes in the nerve guidance conduit could be evaluated. In the spinal cord, the geometry of the cysts and remaining healthy tissue were quantified on the CECT scans. We were further able to demonstrate the use of CECT in both the healthy and injured spinal cord in high resolution scans. In the Accupaque stained spinal cords, both the cyst and damaged tissue volume could be quantified in great detail. The CECT techniques demonstrated in this work enable non-destructive visualization of the healthy and injured spinal cord as well as injured peripheral nerve at a high level of detail. This new tool may provide new insights into the anatomy and injury mechanics of the spinal cord and peripheral nerves.Verletzungen des Rückenmarks und peripherer Nerven sind häufige Folgen von Unfalltraumata. Die verfügbaren Behandlungsmöglichkeiten sind weiterhin begrenzt. Verletzungen können schwerwiegende Folgen haben und eine dauerhafte Behinderung und eine erhebliche Einschränkung der Lebensqualität nach sich ziehen. Es besteht ein dringender Bedarf an Forschung zu neuen Behandlungsoptionen. Neue Bildgebungsverfahren könnten neue Einblicke in die Mechanismen von Verletzungen und Regeneration ermöglichen. Die kontrastverstärkte Computertomographie (CECT) erlaubt durch den Einsatz von Kontrastmitteln die Visualisierung von Weichgeweben. In dieser Arbeit untersuchten wir die Eignung der CECT im Kontext der Reparatur von peripheren Nerven- und Rückenmarksverletzungen. Wir analysierten die Färbemechanismen von Lugol’scher Jodlösung an den Gliedmaßen von Ratten, indem wir wiederholte Färbungen mit unterschiedlichen Konzentrationen verglichen. Das gewonnene Wissen wurde verwendet, um verletzte periphere Nerven zu färben, die mit einer seidenbasierten Nervenleitungsprothese regeneriert wurde. Zusätzlich wurde Lugol’scher Jodlösung zur Färbung von Rattenrückenmark nach einer traumatischen Verletzung eingesetzt. Wir untersuchten weiterhin die Färbung von gesundem und verletztem Rückenmark mit Lugol’scher Jodlösung, Accupaque und Hafnium-substituiertes Wells-Dawson-Polyoxometallat (Hf-POM). Accupaque wurde anschließend als Kontrastmittel in einem Experiment bei Rückenmarksverletzung in Ratten eingesetzt. Es gelang uns, die Kontrastierung mit Lugol’scher Jodlösung für die Anwendung im Kontext der Regeneration von peripheren Nerven- und Rückenmarksverletzungen zu optimieren. Die Färbung wurde erfolgreich in Studien zu peripheren Nerven- und Rückenmarksverletzungen bei Ratten angewendet. Im Bereich der peripheren Nerven konnten der Grad der Überbrückung sowie die Blutversorgung durch makroskopische Öffnungen in der Nervenleitungsprothese evaluiert werden. Im Rückenmark wurden Geometrie der Zysten und verbleibendes gesundes Gewebe auf den CECT-Scans quantifiziert. Darüber hinaus konnten wir die Anwendung der CECT bei gesundem und verletztem Rückenmark in hochauflösenden Scans demonstrieren. Bei den mit Accupaque gefärbten Rückenmarkproben konnten sowohl das Zystenvolumen als auch das Volumen des geschädigten Gewebes detailliert quantifiziert werden. Die in dieser Arbeit demonstrierten CECT-Techniken ermöglichen eine zerstörungsfreie Visualisierung des gesunden und verletzten Rückenmarks sowie des verletzten peripheren Nervs mit einem hohen Detailgrad. Dieses neue Werkzeug ermöglicht neue Einblicke in die Anatomie und Verletzungsmechanismen des Rückenmarks und der peripheren Nerven
Isolation and ex-vivo activation of adipose-derived cells
Full text linkIn recent years stem cell research has become increasingly important for regenerative medicine and tissue engineering. The isolation of stem cells from adipose tissue evades ethical concerns with which embryonic stem cells and induces pluripotent stem cells (iPS) are afflicted,because of its declaration as clinical waste material. Tumescent liposuction is a minimally invasive procedure providing high amounts of adipose tissue rich in therapeutically relevantcells within a short time. The isolated stromal vascular fraction (SVF) and the adipose derived stromal/stem cells (ASC) contained there in show a high regenerative potential and have been successfully used in many clinical studies. Maintaining SVF cells in their natural environment and therefore providing the maximum possible regenerative potential of adipose tissue-derived cells is a prerequisite for successful autologous clinical application. With an improved gentle and fast isolation process by minor manipulation it is possible to obtain a therapeutically relevant cell population. A physical stimulus already used in clinics is the extracorporeal shockwave therapy (ESWT), shockwaves are characterized by their high rise in pressure within a very short time followed by cavitation wave with a negative amplitude. By applyinglow-energy ESWT on freshly obtained human liposuction material and isolated SVF cells (invitro) we aimed to equalize and enhance stem cell properties and their functionality. We were able to show an increased adenosine tri-phosphate (ATP) concentration after applying ESWT on adipose tissue as well as a significantly increased expression of single mesenchymal and vascular surface markers in comparison with the untreated group. Additionally, the protein secretion of insulin-like growth factor 1 (IGF-1) and placental growth factor (PLGF) was significantly enhanced. Further it was investigated if there is the same beneficial effect when applying ESWT on the adipose tissue harvest site before liposuction to improve cell propertiesin situ. We showed a significantly enhanced viability, ATP concentration and population doublings after 3 weeks in culture for cells isolated from ESW treated adipose tissue harvest site. Further the expression of mesenchymal and endothelial/pericytic markers was elevated collaborating with the increased angiogenic differentiation potential as well as the increased secretion of certain angiogenic proteins after ESWT in situ. Besides ESWT the effect of another physical stimulus on SVF/ASC cells was tested - Low level laser therapy (LLLT) has already shown beneficial effects. Therefore, we investigated effects of pulsed blue (475nm), green(516nm) and red (635nm) light from light-emitting diodes (LEDs) applied on freshly isolated SVF cells. Cells had a stronger capacity to vascular tube formation after exposure to greenand red light concomitant with an increased concentration of vascular endothelial growth factor(VEGF) in the secretome. In a side project during the PhD program the hormone-relatedwomens disease lipedema was investigated. The SVF cell properties of healthy and lipedemapatients were investigated and a significant enhancement in cell yield as well as a reduction in adipogenic differentiation capacity of lipedema SVF cells was revealed. Within this work different physical forces applied on adipose tissue and adipose tissue-derived cells were presented as well as an improved isolation method and characteristics of degenerated adiposetissue. This are promising applications for the clinical use in the field of regenerative medicine and tissue regeneration
Assessment of peripheral nerve regeneration across a 7mm gap in the delayed rat median nerve model : a comparative study of autologous nerve graft, muscle filled-in vein conduit, and extracellular vesicle-based therapies
Full text linkPeriphere Nervenverletzungen stellen nach wie vor eine große klinische Herausforderung dar und führen trotz chirurgischer Eingriffe häufig zu einer unvollständigen funktionellen Wiederherstellung. Zuverlässige präklinische Modelle sind für die Bewertung von Reparaturstrategien und das Verständnis der biologischen Prozesse, die bei der Nervenreparatur eine Rolle spielen, von entscheidender Bedeutung. Diese Studie untersucht Behandlungsmethoden zur Verbesserung der Regeneration des Nervus medianus nach segmentalen Verletzungen bei Ratten, wobei der Schwerpunkt auf der verzögerten Nervenreparatur liegt. In dieser Studie wird die autologe Nerventransplantation (ANT) mit muskelfüllten Venenkonduits (MVCs) nach einer 8-wöchigen Reparaturverzögerung verglichen, mit oder ohne zusätzliche Behandlung mit extrazellulären Vesikeln (EVs), entweder Wildtyp-EVs oder modifizierten EVs zur Verbesserung der Laminin-Bindungsfunktion. Insgesamt 48 männliche Lewis-Ratten (Durchschnittsgewicht: 484 g) wurden gleichmäßig auf sechs Conduit-Typen und Behandlungsgruppen verteilt (MVC = 24, ANT = 24, davon: PBS = 8, modEVs = 8 und wtEVs = 8). Zwölf Wochen nach der Reparatur wurde die Nervenregeneration durch in-vivo-elektrophysiologische Aufzeichnungen und histologische Analysen bewertet. Die zusammengesetzten Muskelaktionspotenziale (CMAPs) wurden hinsichtlich Latenz, Dauer, Amplitude und Fläche unter der Kurve analysiert. Die Werte wurden mit histologischen Daten (H&E-, c-Jun-, GFAP-, MSB- und MBP-Färbung) verglichen. Ein wichtiges Ziel dieser Studie war es, eine standardisierte Pipeline für die quantitative Histomorphometrie unter Verwendung der MBP-Immunfärbung in Kombination mit AxonDeepSeg, einem automatisierten Segmentierungswerkzeug, zu etablieren. Diese Plattform ermöglichte eine konsistente Quantifizierung der Axon- und Myelin Strukturen. Während die EV-Behandlungen keine statistisch signifikanten Verbesserungen ergaben, was vor allem auf die Variabilität zwischen den Tieren zurückzuführen war, zeigten die ANT-Gruppen überlegene Regenerationsergebnisse, was durch höhere CMAP-Amplituden und größere Flächen unter der Kurve im Vergleich zu den MVC-Gruppen belegt wurde. Wichtig ist, dass starke lineare Korrelationen zwischen der Gesamtzahl der Nervenfasern und der CMAP-Amplitude (p = 0,0002) sowie der Fläche unter der Kurve (p = 0,0005) beobachtet wurden. Weitere signifikante Korrelationen wurden zwischen der CMAP-Dauer und dem Axondurchmesser (p = 0,0014), der Myelindicke (p = 0,0241) und dem g-Verhältnis (p = 0,0011) festgestellt. Diese Ergebnisse unterstreichen die verbesserte Regenerationsfähigkeit von ANT gegenüber MVC bei verzögerten Reparaturprozessen und bestätigen die Verwendung der MBP-Färbung mit AxonDeepSeg als robuste Methode für die histomorphometrische Analyse in Studien zu peripheren Nerven.Peripheral nerve injuries remain a major clinical challenge, often resulting in incomplete functional recovery despite surgical intervention. Reliable preclinical models are crucial for evaluating repair strategies and understanding the biological processes that play a role in nerve repair. This study investigates treatment modalities to enhance regeneration of the median nerve following segmental injury in rats, with a focus on delayed nerve repair. In this study the autologous nerve transplant (ANT) is compared to muscle filled-in vein conduit (MVCs) after an 8-week repair delay, with or without additional treatment using extracellular vesicles (EVs), either wild-type EVs or modified EVs to enhance laminin-binding functionality. A total of 48 male Lewis rats (mean weight: 484 g) were evenly distributed across six conduit type and treatment groups (MVC = 24, ANT= 24, of which: PBS= 8, modEVs= 8 and wtEVs= 8). Twelve weeks post-repair, nerve regeneration was assessed through in-vivo electrophysiological recordings and histological analyses. Compound muscle action potentials (CMAPs) were analyzed for latency, duration, amplitude, and area under the curve. The values were compared with histological data (H&E, c-Jun, GFAP, MSB, and MBP staining). A key objective of this study was to establish a standardized pipeline for quantitative histomorphometry using MBP immunostaining in combination with AxonDeepSeg, an automated segmentation tool. This platform enabled consistent quantification of axonal and myelin structures. While EV treatments did not yield statistically significant improvements, largely due to inter-animal variability, the ANT groups demonstrated superior regenerative outcomes, as evidence by higher CMAP amplitudes and larger areas under the curve compared to MVC groups. Importantly, strong linear correlations were observed between the total number of nerve fibers and CMAP amplitude (p = 0.0002) and area under the curve (p = 0.0005). Additional significant correlations were found between CMAP duration and axon diameter (p = 0.0014), myelin thickness (p = 0.0241), and g-ratio (p = 0.0011). These findings highlight the enhanced regenerative capacity of ANT over MVC in delayed repair scenarios and validate the use of MBP staining with AxonDeepSeg as a robust method for histomorphometric analysis in peripheral nerve studies
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