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Piotr Walczak, M.D., Ph.D.

Photo of Dr. Piotr Walczak, M.D., Ph.D.
  • Associate Professor of Radiology and Radiological Science

Research Interests

MRI-guided cell therapy, neurological disorders, demyelinating diseases


Dr. Piotr Walczak is an Assistant Professor in the Johns Hopkins Medicine Department of Radiology and Radiological Science. He specializes in magnetic resonance research and neuroradiology, with an emphasis on stem and progenitor cell transplantation.

Dr. Walczak received his M.D. in 2002 from the Medical University of Warsaw in Poland. He then completed a research fellowship in cell-based therapy for neurodegenerative disorders at the University of South Florida. After a fellowship in cellular imaging at Johns Hopkins University School of Medicine, Dr. Walczak joined the faculty of Johns Hopkins in 2008.

He is an affiliated faculty member at the Kennedy Krieger Institute’s F.M. Kirby Research Center. more


  • Associate Professor of Radiology and Radiological Science

Departments / Divisions

Centers & Institutes



  • Ph.D., University of Warmia and Mazury (Poland) (2012)
  • M.D., Warsaw University School of Medicine (Poland) (2002)

Research & Publications

Research Summary

Dr. Walczak is an expert in molecular imaging of stem cell transplantation. His training includes cell tracking and his work is focused on using non-invasive imaging technology to advance cell-based therapy for neurodegenerative diseases. He contributes in bioluminescent cellular imaging, analysis and interpretation of cellular imaging data.


Dr. Walczak’s lab develops cell-based therapies for the treatment of neurological disorders by using myelinating glial progenitor cells. These cells are capable of replenishing dysfunctional or lost myelin in disorders like multiple sclerosis, congenital dysmyelination and stroke. Primary glial progenitors derived from human fetal tissue show great therapeutic potential in dysmyelinated mice because of their extensive myelination and extended survival. However, Walczak’s team is investigating the use of induced pluripotent stem cells instead as a more plentiful source of glial progenitors. By developing new strategies for efficient intravascular, MRI-guided delivery of progenitor cells to brain lesions and applying non-invasive imaging technology to monitor survival and functional integration of the transplanted cells, the research group hopes to develop successful therapeutics for demyelinating diseases.

Selected Publications

View all on Pubmed

  1. Bar-Shir A, Liu G, Chan KW, Oskolkov N, Song X, Yadav NN, Walczak P, McMahon MT, van Zijl PC, Bulte JW, Gilad AA. "Human Protamine-1 as an MRI reporter gene based on chemical exchange." ACS Chem Biol. 2013 Oct 25. [Epub ahead of print]
  2. Barczewska M, Wojtkiewicz J, Habich A, Janowski M, Adamiak Z, Holak P, Matyjasik H, Bulte JW, Maksymowicz W, Walczak P. "MR monitoring of minimally invasive delivery of mesenchymal stem cells into the porcine intervertebral disc." PLoS One. 2013 Sep 13;8(9):e74658. doi: 10.1371/journal.pone.0074658.
  3. Liang Y, Walczak P, Bulte JW. "The survival of engrafted neural stem cells within hyaluronic acid hydrogels." Biomaterials. 2013 Jul; 34(22):5521-9. doi: 10.1016/j.biomaterials.2013.03.095. Epub 2013 Apr 25.
  4. Liang Y, Agren L, Lyczek A, Walczak P, Bulte JW. "Neural progenitor cell survival in mouse brain can be improved by co-transplantation of helper cells expressing bFGF under doxycycline control." Exp Neurol. 2013 Sep; 247:73-9. doi: 10.1016/j.expneurol.2013.04.001. Epub 2013 Apr 6.
  5. Janowski M, Lyczek A, Engels C, Xu J, Lukomska B, Bulte JW, Walczak P. "Cell size and velocity of injection are major determinants of the safety of intracarotid stem cell transplantation." J Cereb Blood Flow Metab. 2013 Jun;3 3(6):921-7. doi: 10.1038/jcbfm.2013.32. Epub 2013 Mar 13.

Contact for Research Inquiries

Phone: 443-287-5615

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