Dariusz Szarek

Wroclaw Medical University, Vrotslav, Lower Silesian Voivodeship, Poland

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Publications (13)17.9 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Great potential of cellular therapies has generated extensive research in the field of cells harvesting and culturing. Transplantation of cell cultures has been used in a variety of therapeutic programs but in many cases it appeared that biomaterial scaffold or sheath would enhance cells regenerative potential.
    Bio-medical materials and engineering 01/2014; 24(3):1625-37. · 1.09 Impact Factor
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    ABSTRACT: Central nervous system of reptiles has the ability to grow and regenerate during adult life of the animal. Therefore, cells creating CNS of this animal class should compound substances or molecules enabling neuroregeneration. Cells directly involved in this process have not been clearly characterized, especially in cell culture environment. Morphology of reptilian glial adherent cells should be known better to find any differences from mammalian CNS cells. We isolated glial cells from olfactory bulb and cerebrum from gecko (Eublepharis macularius) and cultured separately. We have observed populations of cells with proliferative capacity in both types of cultures. Also, we have detected lipid molecules deposits within their cytoplasm, which localization was correlated with mitochondria position. This information can be helpful in searching new bioactive substances involved in regeneration of central nervous system.
    International Journal of Morphology 12/2013; 31(3):826-831. · 0.21 Impact Factor
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    International Journal of Morphology 09/2013; 31(3):826-831. · 0.21 Impact Factor
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    ABSTRACT: Recently, we described the influence of sodium alginate on the inflammatory infiltrate during neuroregeneration in tube nerve grafts. It was noticeable that there was the coexistence of inflammatory cells, including neutrophils, plasma cells, and macrophages with Schwann cells and axons. This may indicate a beneficial interaction between alginates and the infiltrate and the additional beneficial effect of the cells on the neuroregeneration process in the inflammatory infiltrates. In this study, we have performed in vivo evaluation of our novel tubular implant prepared by a polyurethane/polylactide blend filled with alginate fibers. The influence of filling the lumen of the tubes with sodium and calcium alginates on the regeneration process of the rat sciatic nerve was investigated. The neuroregeneration process was assessed by detailed histomorphometric studies, axon counting, and calculating the regenerative indexes. It was observed that calcium alginate had a supportive effect on nerve regeneration similar to nerve autotransplant.
    Biotechnology and Applied Biochemistry 08/2013; · 1.35 Impact Factor
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    ABSTRACT: OBJECTIVE:Numerous studies in animals have shown the unique property of olfactory ensheathing cells tostimulate regeneration of lesioned axons in the spinal cord. In a Phase I clinical trial, weassessed the safety and feasibility of transplantation of autologous mucosal olfactoryensheathing cells and olfactory nerve fibroblasts in patients with complete spinal cord injury.METHODS:Six patients with chronic thoracic paraplegia (American Spinal Injury Association class AASIA A) were enrolled for the study. Three patients were operated and three served as acontrol group. The trial protocol consisted of pre- and postoperative neuro-rehabilitation,olfactory mucosal biopsy, culture of olfactory ensheathing cells, and intraspinal cell grafting.Patient's clinical state was evaluated by clinical, neurophysiological and radiological tests.RESULTS:There were no adverse findings related to olfactory mucosa biopsy or transplantation of olfactory ensheathing cells at one year after surgery. There was no evidence of neurologicaldeterioration, neuropathic pain, neuroinfection or tumorigenesis. In one cell-grafted patient an asymptomatic syringomyelia was observed. Neurological improvement was observed only intransplant recipients. The first 2 operated patients improved from ASIA A to ASIA C andASIA B. Diffusion tensor imaging showed restitution of continuity of some white mattertracts throughout the focus of spinal cord injury in these patients. The third operated patientalthough remained ASIA A, showed improved motor and sensory function of the first spinalcords segments below the level of injury. Neurophysiological examinations showedimprovement in spinal cord transmission and activity of lower extremity muscles in surgicallytreated patients but not in patients receiving only neuro-rehabilitation.CONCLUSIONS:Observations at 1 year indicate that the obtaining, culture and intraspinal transplantation ofautologous olfactory ensheathing cells was safe and feasible. The significance of theneurological improvement in the transplant recipients and the extent to which the celltransplants contributed to it will require larger numbers of patients.
    Cell Transplantation 04/2013; · 4.42 Impact Factor
  • Cell Transplantation 04/2013; · 4.42 Impact Factor
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    ABSTRACT: Numerous studies in animals have shown the unique property of olfactory ensheathing cells to stimulate regeneration of lesioned axons in the spinal cord. In a Phase I clinical trial, we assessed the safety and feasibility of transplantation of autologous mucosal olfactory ensheathing cells and olfactory nerve fibroblasts in patients with complete spinal cord injury. Six patients with chronic thoracic paraplegia (American Spinal Injury Association class A-ASIA A) were enrolled for the study. Three patients were operated, and three served as a control group. The trial protocol consisted of pre- and postoperative neurorehabilitation, olfactory mucosal biopsy, culture of olfactory ensheathing cells, and intraspinal cell grafting. Patient's clinical state was evaluated by clinical, neurophysiological, and radiological tests. There were no adverse findings related to olfactory mucosa biopsy or transplantation of olfactory ensheathing cells at 1 year after surgery. There was no evidence of neurological deterioration, neuropathic pain, neuroinfection, or tumorigenesis. In one cell-grafted patient, an asymptomatic syringomyelia was observed. Neurological improvement was observed only in transplant recipients. The first two operated patients improved from ASIA A to ASIA C and ASIA B. Diffusion tensor imaging showed restitution of continuity of some white matter tracts throughout the focus of spinal cord injury in these patients. The third operated patient, although remaining ASIA A, showed improved motor and sensory function of the first spinal cords segments below the level of injury. Neurophysiological examinations showed improvement in spinal cord transmission and activity of lower extremity muscles in surgically treated patients but not in patients receiving only neurorehabilitation. Observations at 1 year indicate that the obtaining, culture, and intraspinal transplantation of autologous olfactory ensheathing cells were safe and feasible. The significance of the neurological improvement in the transplant recipients and the extent to which the cell transplants contributed to it will require larger numbers of patients.
    Cell Transplantation 01/2013; 22(9):1591-612. · 4.42 Impact Factor
  • Anna Lis, Dariusz Szarek, Jadwiga Laska
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    ABSTRACT: Traumatic spinal cord injuries are very serious burden for the organism of affected human population, and are more critical because mostly touching the young cluster of population. Physical, emotional and economic problems caused by traumatic spinal cord injuries as a general rule significantly limit the individual patient functionality and are burden for the society. The spinal cord has considerable lack of ability for spontaneous and functional regeneration, hence the spinal cord injury cause a solemn and frequently permanent disabilities. The pathophysiology of spinal cord injury is the results of sequential two phenomena, primary physical and biochemical secondary mechanisms of injury. After physical injury, the spinal cord undergoes a sequential progression in biochemical pathologic deviations increasing after injury, that are mutually deteriorating and cause further damage in the spinal cord. Consequently series of pathological processes lead to haemorrhage, oedema, neuronal necrosis, axonal fragmentation, demyelination of the remaining axons, and formation of ultimately cyst. Furthermore spinal cord injuries can immediately result in neural cells death and cause disruption of the blood supply to the site of the injury. The most important difference between peripheral and central nervous system is the fact that in the spinal cord the neuronal cell bodies are damaged, while in the peripheral nervous system only axons are injured. In the surroundings of the spinal cord, one of the major factors hampering regeneration is the glial scar expansion. The spreading of densely packed astrocytes on the site of injuries effectively inhibit axon growth through the nerve grow blocking. Glial scar, which consists mainly of overactive astrocytes and fibroblasts, as well as the presence of growth-inhibitor molecules such as chondroitin sulphate proteoglycans (derived from the breakdown of damaged nerve cells) form a physicochemical barrier for effective regenerating axons. The recent scientific progress in medicine, biology and biomaterials engineering, and predominantly in the fields of neurosurgery, cell culture and tissue engineering, creates the opportunity for the development of new therapies, which support healing of the effects of traumatic spinal cord injuries and prevent further neurodegenerative processes. The most promising effects so far have been obtained using well-designed polymer scaffold as structural support for axon regeneration combined with drug delivery system or therapeutic cell line and neurotrophic factors. This review article focuses on the application of selected biomaterials for the regeneration of traumatic spinal cord injuries. First, the basic anatomical structure of the spinal cord has been described. Then the injury and neurodegenerative mechanisms within the peripheral and central nervous system have been compared. The pathophysiology of the spinal cord damage has been referred to the current strategy of biomaterials engineering in experimental therapies supporting neuroregeneration processes. In the summary, the promising interdisciplinary therapeutic strategies aimed at the regeneration of the spinal cord have been highlighted.
    Polimery w medycynie 01/2013; 43(2):59-80.
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    ABSTRACT: In this study, scanning electron microscopy (SEM) has been applied for instantaneous assessment of processes occurring at the site of regenerating nerve. The technique proved to be especially useful when an artificial implant should have been observed but have not yet been extensively investigated before for assessment of nerve tissue. For in vivo studies, evaluation of implant's morphology and its neuroregenerative properties is of great importance when new prototype is developed. However, the usually applied histological techniques require separate and differently prepared samples, and therefore, the results are never a 100% comparable. In our research, we found SEM as a technique providing detailed data both on an implant behavior and the nerve regeneration process inside the implant. Observations were carried out during 12-week period on rat sciatic nerve injury model reconstructed with nerve autografts and different tube nerve grafts. Samples were analyzed with haematoxylin-eosin (HE), immunocytochemical staining for neurofillament and S-100 protein, SEM, TEM, and the results were compared. SEM studies enabled to obtain characteristic pictures of the regeneration process similarly to TEM and histological studies. Schwann cell transformation and communication as well as axonal outgrowth were identified, newly created and matured axons could be recognized. Concurrent analysis of biomaterial changes in the implant (degradation, collapsing of the tube wall, migration of alginate gel) was possible. This study provides the groundwork for further use of the described technique in the nerve regeneration studies. SCANNING 00: 1-14, 2012. © 2012 Wiley Periodicals, Inc.
    Scanning 10/2012; · 1.29 Impact Factor
  • Współczesna myśl techniczna w naukach medycznych i biologicznych : III sympozjum : Inżynieria biomedyczna motorem rozwoju Dolnego Śląska : Wrocław, 25–26 Maja 2012; 05/2012
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    ABSTRACT: Bilateral chronic subdural haemorrhage accompanying meningioma is a very rare clinical condition. We present a case of a 69-year-old female patient with large meningioma completely obliterating the posterior third part of the superior sagittal sinus with accompanying bilateral chronic subdural haematomas. Three anatomical zones of venous collateral circulation were revealed by the preoperative digital subtraction angiography. The tumour and haematomas were removed completely with no major complications. The most likely pathomechanism of the development of bilateral chronic subdural haematomas was venous hypertension caused by an occlusion of major cerebral venous trunks. As a result of a minor thrombotic incident or insignificant head injury, the distended veins of collateral circulation that were volumetrically burdened could have been damaged. Patients with large tumours occluding the superior sagittal sinus, who did not qualify for or refused surgery, should be carefully monitored clinically and neuroradiologically because of possibly increased risk of an intracranial haemorrhage.
    Neurologia i neurochirurgia polska 01/2011; 45(5):500-4. · 0.49 Impact Factor
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  • Anna Lis, Dariusz Szarek, Jadwiga Laska
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    ABSTRACT: Neurological disorders and injuries such as ischemic or haemorrhagic strokes or traumatic brain injuries result in the damage of cerebral parenchyma structures and in consequence, the loss of neurological functions. The current clinical strategies for the treatment of the brain nervous tissue disruptions are limited. The aforementioned methods can reduce the tissue degeneration or mitigate the subsequent symptoms, but do not alter the fact that many of the affected people are incapable of returning to the condition before the accident and they need long-lasting rehabilitation. Regenerative strategies based on the cell therapies and the use of polymeric scaffolds seem to be very promising for many patients. Polymer scaffolds may provide an opportunity to enhance the probability of cell therapy success by creating an artificial extracellular matrix which further facilitates cell survival, proliferation, differentiation, and promotes integrity of transplanted as well as endogenous cells. This paper presents selected forms of the polymeric scaffolds, which have been tested for the restoration processes within brain tissue and their potential clinical applications of scaffolds in both the treatment of posttraumatic neuronal loss and the neurodegenerative disorders.
    Polimery w medycynie 43(4):302-312.