Piotr Holak

Dr. Piotr Holak

Department of Surgery and Roentgenology, Faculty of Veterinary Medicine in Olsztyn
orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2016 in Journal of Cerebral Blood Flow & Metabolism
Verified
Journal Article
Closed access
Piotr WalczakPiotr Walczak
Piotr Walczak
JWJoanna Wojtkiewicz
Joanna Wojtkiewicz
ANAdam Nowakowski
Adam Nowakowski
AHAleksandra Habich
Aleksandra Habich
PHPiotr Holak
Piotr Holak
MJMiroslaw Janowski
Miroslaw Janowski
Stem cell therapy for neurological disorders reached a pivotal point when the efficacy of several cell types was demonstrated in small animal models. Translation of stem cell therapy is contingent upon overcoming the challenge of effective cell delivery to the human brain, which has a volume ∼1000 times larger than that of the mouse. Intra-arterial injection can achieve a broad, global, but also on-demand spatially targeted biodistribution; however, its utility has been limited by unpredictable cell destination and homing as dictated by the vascular territory, as well as by safety concerns. We show here that high-speed MRI can be used to visualize the intravascular distribution of a superparamagnetic iron oxide contrast agent and can thus be used to accurately predict the distribution of intra-arterial administered stem cells. Moreover, high-speed MRI enables the real-time visualization of cell homing, providing the opportunity for immediate intervention in the case of undesired biodistribution.

13 September 2013 in PLOS ONE
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Journal Article
Open access
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MBMonika Barczewska
Monika Barczewska
JWJoanna Wojtkiewicz
Joanna Wojtkiewicz
AHAleksandra Habich
Aleksandra Habich
MJMiroslaw Janowski
Miroslaw Janowski
ZAZbigniew Adamiak
Zbigniew Adamiak
Piotr WalczakPiotr Walczak
Piotr Walczak
Bone marrow stem cell therapy is a new, attractive therapeutic approach for treatment of intervertebral disc (IVD) degeneration; however, leakage and backflow of transplanted cells into the structures surrounding the disc may lead to the formation of undesirable osteophytes. The purpose of this study was to develop a technique for minimally invasive and accurate delivery of stem cells. Porcine mesenchymal stem cells (MSCs) were labeled with superparamagnetic iron oxide nanoparticles (SPIO, Molday ION rhodamine) and first injected into the explanted swine lumbar IVD, followed by ex vivo 3T MRI. After having determined sufficient sensitivity, IVD degeneration was then induced in swine (n=3) by laser-evaporation. 3 x 106 SPIO-labeled cells embedded within hydrogel were injected in 2 doses using a transcutaneous cannula and an epidural anesthesia catheter. T2-weighted MR images were obtained at 3T before and immediately after cell infusion. Two weeks after injection, histological examination was performed for detection of transplanted cells. MSCs were efficiently labeled with Molday ION rhodamine. Cells could be readily detected in the injected vertebral tissue explants as distinct hypointensities with sufficient sensitivity. MR monitoring indicated that the MSCs were successfully delivered into the IVD in vivo, which was confirmed by iron-positive Prussian Blue staining of the tissue within the IVD. We have developed a technique for non-invasive monitoring of minimally invasive stem delivery into the IVD at 3T. By using a large animal model mimicking the anatomy of IVD in humans, the present results indicate that this procedure may be clinically feasible.

7 November 2018 in Scientific Reports
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Journal Article
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ICIzabela Malysz - Cymborska
Izabela Malysz - Cymborska
DGDominika Golubczyk
Dominika Golubczyk
LKLukasz Kalkowski
Lukasz Kalkowski
ABAdam Burczyk
Adam Burczyk
MJMiroslaw Janowski
Miroslaw Janowski
Piotr WalczakPiotr Walczak
Piotr Walczak
Disseminated diseases of the central nervous system such as amyotrophic lateral sclerosis (ALS) require that therapeutic agents are delivered and distributed broadly. Intrathecal route is attractive in that respect, but to date there was no methodology available allowing for optimization of this technique to assure safety and efficacy in a clinically relevant setting. Here, we report on interventional, MRI-guided approach for delivery of hydrogel-embedded glial progenitor cells facilitating cell placement over extended surface of the spinal cord in pigs and in naturally occurring ALS-like disease in dogs. Glial progenitors used as therapeutic agent were embedded in injectable hyaluronic acid-based hydrogel to support their survival and prevent sedimentation or removal. Intrathecal space was reached through lumbar puncture and the catheter was advanced under X-ray guidance to the cervical part of the spine. Animals were then transferred to MRI suite for MRI-guided injection. Interventional and follow-up MRI as well as histopathology demonstrated successful and predictable placement of embedded cells and safety of the procedure.

1 January 2018 in Folia Neuropathologica
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Journal Article
Open access
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MBMonika Barczewska
Monika Barczewska
KJKatarzyna Jezierska-Wozniak
Katarzyna Jezierska-Wozniak
AHAleksandra Habich
Aleksandra Habich
Seweryn LipińskiSeweryn Lipiński
Seweryn Lipiński
PHPiotr Holak
Piotr Holak
JWJoanna Wojtkiewicz
Joanna Wojtkiewicz
Introduction The pathophysiology of degenerative disc disease (DDD) is complex and not fully understood. While surgical treatment and appropriate rehabilitation offer relief of acute symptoms, there is a need to find tissue engineering strategies for intervertebral disc repair to restore...

22 June 2021 in Cells
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Journal Article
Open access
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LGLeszek Gromadziński
Leszek Gromadziński
LPLukasz Paukszto
Lukasz Paukszto
ASAgnieszka Skowronska
Agnieszka Skowronska
PHPiotr Holak
Piotr Holak
MSMichał Smoliński
Michał Smoliński
MMMarta Majewska
Marta Majewska
Deep vein thrombosis (DVT) is a severe disease affecting the human venous system, accompanied by high morbidity and mortality rates caused by early and late complications. The study aimed at analyzing the changes in the transcriptome of the femoral vein caused by DVT in the porcine model based on the formation of the thrombus in vivo. The study was performed on 11 castrated male pigs: A thrombus was formed in each left femoral vein in six animals; the remaining five served as a control group. Total RNA was isolated from the left femoral veins of the experimental and control animals. High-throughput RNA sequencing was used to analyze the global changes in the transcriptome of veins with induced DVT. Applied multistep bioinformatics revealed 1474 differentially expressed genes (DEGs): 1019 upregulated and 455 downregulated. Functional Gene Ontology annotated 1220 of DEGs into 225 biological processes, 30 molecular functions and 40 cellular components categories. KEGG analysis disclosed TNF, NF-κB and apoptosis pathways’ overexpression in DVT samples. A thorough analysis of the detected DEGs indicated that a dysregulated inflammatory response and disturbed balance between clotting and anti-clotting factors play a crucial role in the process of DVT.

25 September 2016 in Anatomia, Histologia, Embryologia
Verified
Journal Article
Closed access
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PZPaulina Przyborowska- Zhalniarovich
Paulina Przyborowska- Zhalniarovich
ZAZbigniew Adamiak
Zbigniew Adamiak
PHPiotr Holak
Piotr Holak
YZYauheni Zhalniarovich
Yauheni Zhalniarovich