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Home People Faculty Faculty James Dunn, M.D., Ph.D.

James Dunn, M.D., Ph.D.

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Professor
Department of Bioengineering
Department of Surgery, Division of Pediatric Surgery

Bioengineering Office: 4121J Engineering V
Surgery Office: CHS 72-140
jdunn@mednet.ucla.edu

 

Education

  • B.S., California Institute of Technology
  • Ph.D., Massachusetts Institute of Technology
  • M.D., Harvard Medical School, 1992


CV


Research Interests

  • Tissue Engineering of Internal Organs
    1. Intestinal Tissue Engineering
    2. Adrenal Cortical Stem Cells
    3. Mass Transfer in Tissue Engineering
    4. Mechanical Forces in Tissue Engineering
    5. Intracellular Signaling in Tissue Engineering

  • Intestinal Tissue Engineering

Postdoctoral Fellow:

  • Jinyoung Park, M.D., pediatric surgeon, Tengu, Korea
  • Min Lee, B.S., M.S. in Materials Science and Engineering, Yonsei University, Seoul, Korea, Currently Ph.D. student in Bioengineering
  • Prof. Ben Wu, Department of Bioengineering

Short bowel syndrome occurs in children with an inadequate length of intestine to maintain normal digestion and absorption. These children are dependent on intravenous nutrition to sustain normal growth, however, this is associated with significant cost ($100,000 per patient per year) and morbidity, including infection and liver cirrhosis. Although intestinal transplantation for these patients is possible, outcomes are marginal and there are significant side effects associated with life-long immunosuppression. The long-term objective of this project is to engineer functional intestinal tissue that can be used to treat patients with short-bowel syndrome. Specifically, this project will focus on developing a genetically modified intestinal cell that can be grown on a bio-engineered scaffolding and ultimately, implanted into an animal model. The project can be broken down into three specific goals:

  1. Developing a genetically-modified intestinal stem cell line.
  2. Examining the effect of engineered scaffolds on the functions of these intestinal cells.
  3. Following the fate of these intestinal cells after they have been implanted in an animal model.

(Funded by UCLA Chancellor’s Border Crossing Initiative, Stein Oppenheimer Award, American Surgical Association Foundation)

  • Adrenal Cortical Stem Cells

Student:

  • Yinting Chu, B.S., in Molecular Biology, Taiwan University, Taipei, Taiwan, Currently Ph.D. student in Bioengineering

Collaborators:

  • Prof. Ben Wu, Department of Bioengineering
  • Prof. Ed McCabe, Department of Pediatrics and Human Genetics

The research project is focused on identifying molecular markers to isolate and transplant adrenal cortical progenitor cells as a potential treatment of adrenal insufficiency. A transgenic mouse that expresses the green fluorescent protein in adrenal cortical cells is used as the animal model. The first specific aim employs two strategies to identify candidate adrenal cortical progenitor cell markers: microarray analysis of adrenal cortical cell lines that differentiate in response to temperature change and screening of known stem cell surface markers during the ontogeny of the adrenal cortex. The second specific aim utilizes flow cytometry to sort primary adrenal cortical cells into subpopulations based on their differential expression of surface receptors. These potential adrenal cortical progenitor cells are transplanted under the renal capsule to determine their regenerative potential. These studies will lead to better understanding of the development of the adrenal cortex, as well as a new therapy to treat adrenal insufficiency in a more physiological fashion.\

The Dunn Lab

Members

  • Ziyad Jabaji

dunnmemberzZiyadJabaji is a 3rd year resident in the General Surgery residency training program at UCLA.  Prior to starting at UCLA, he studied Chemistry at Stanford and finished medical school at UC San Diego in 2009.Ziyad is currently spending his third and fourth years in the lab with Dr. Dunn and collaborators, focusing on aspects of tissue culture and bioengineering relevant to the future treatment of Short Gut Syndrome.  Specifically, his project employs an in-vitro culture modelutilizing mouse and human intestinal epithelial units in order to make progress towards the goal of a totally tissue-engineered intestine.  The model lends itself to answering many of the relevant questions in this effort – what are the relevant cells and how do they interact, how can we best support the expansion of a small amount of starting material, and how can we begin to utilize the results of this recently burgeoning field of research in the treatment of human disease?Ziyad can be reached for questions at

zjabaji@gmail.com
  • Chris Walthers

chriswalthersChris Walthers is a 4th year Graduate student in Biomedical Engineering here at UCLA.  In 2009, Chris received his Masters in Biomedical Engineering from UCLA after finishing a B.S. in Biomedical Engineering at the University of North Carolina at Chapel Hill. Chris has focused on studying the smooth muscle layer and its relationship with intestinal disease, in particular Crohn’s and colitis.  More specifically, Chris has studied the effect of cyclical mechanical stress, such as those seen in the body, on the behavior of smooth muscle cells.  In order to generate functional smooth muscle, Chris has developed a novel, disposable bioreactor system that replicates mechanical stresses seen in the healthy body.  Recently Chris’s project has led to the creation of a thick, well-vascularized muscle implant using a novel laser cut scaffold in conjunction with the bioreactor.  Ultimately he hopes to develop an implantable replacement for intestinal tissues lost to disease.  Chris can be reached at walthers@ucla.edu

  •  Masae Kobayashi

masaeMasae Kobayashi is a graduate student with the Biomedical Engineering department at UCLA. She majored in Bioengineering at UC Berkeley as an undergraduate and developed strong interests in tissue engineering and regenerative medicine. To contribute to the goal of tissue engineering in a functional small intestine, her project focuses on studying intrinsic and extrinsic strategies to induce contractile activities in intestinal smooth muscle cells. Other than doing research, she enjoys dancing, eating, and sleeping. Masae can be reached at (mkobayashi2006@gmail.com)

  • Nan Ye (Francisco) Lei

Nan Ye (Francisco) Lei is a 1st year masters student in the Biomedical Engineering department at UCLA. He received his BS in bioengineering at UCLA and subsequently has worked with Dr. Dunn and collaborators on projects investigating intestinal tissue engineering and regeneration for application in Short Bowel Syndrome. Some of his previous work includes developing a therapy for improving intestinal adaptation and refining the intestinal epithelial stem cell niche. He is currently working on a delayed release drug delivery system to be used for delivering growth factors to tissue engineered implants in vivo. He can be contacted at nlei@ucla.edu.

  •  Connie Martin

martinConnie Martin is a Staff Research Associate in the Dunn lab. She received her B.S. in Biology at UC Riverside, and will be matriculating into medical school in the fall of 2012. She is assisting in several projects with Dr. Dunn and collaborators. Connie can be reached at conniemartin@mednet.ucla.edu.




  •  Elvin Chiang

elvinElvin Chiang is a Staff Research Associate with the Dunn Lab. He received his BS in Human Biology from UC San Diego in 2010. He is currently working Dr. Dunn and collaborators in several projects. Elvin can be reached at ekchiang@mednet.ucla.edu

 Recent Papers

  1. Lahar N., Lei N.Y., Wang J., Jabaji Z., Tung S.C., Joshi V., Lewis M., Stelzner M., Martin M.G., Dunn J.C., "Intestinal Subepithelial Myofibroblasts Support in vitro and in vivo Growth of Human Small Intestinal Epithelium," PLoS One. 2011;6(11):e26898. Epub 2011 Nov 17.
  2. McClellan E.B., Shew S.B., Lee S.S., Dunn J.C., Deugarte D.A., "Liver herniation in gastroschisis: incidence and prognosis," J Pediatr Surg. 2011 Nov;46(11):2115-8.
  3. Qin H.H., Dunn J.C., "Small intestinal submucosa seeded with intestinal smooth muscle cells in a rodent jejunal interposition model," J Surg Res. 2011 Nov;171(1):e21-6. Epub 2011 Aug 27.
  4. Lei N.Y., Ma G., Zupekan T., Stark R., Puder M., Dunn J.C., "Controlled release of vascular endothelial growth factor enhances intestinal adaptation in rats with extensive small intestinal resection," Surgery. 2011 Aug;150(2):186-90. Epub 2011 Jun 29.
  5. Geisbauer C.L,. Wu B.M., Dunn J.C., "Transplantation of Enteric Cells in to the Aganglionic Rodent Small Intestines," J Srug REs. 2011 Jun 7. (Epub ahead of print)
  6. Zupekan, T., Dunn J.C., "Adrenocortical cell transplantation reverses a murine model of adrenal failure," J Pediatr Surg. 2011 Jun;45(6):1208-13.
  7. Singh S., Wu B.M., Dunn J.C., "Accelerating vascularization in polycaprolactone scaffolds by endothelial progenitor cells," Tissue Eng Part A. 2011 Jul;17(13-14):1819-30. Epub 2011 May 6.
  8. Geisbauer C.L., Chapin J.C., Wu B.M., Dunn J.C., "Transplantation of Enteric Cells Expressing p75 in the Rodent Stomach," J Surg Res. 2011 Jan 8. (Epub ahead of print).
  9. Singh S., Wu B.M., Dunn J.C., "The enhancement of VEGF-medited angiogenesis by polycaprolactone scaffolds with surface cross-linked heparin," Biomaterials. 2011 Mar;32(8):2059-69. Epub 2010 Dec 13.
  10. Qin H.H., Lei N., Mendoza J., Dunn J.C., "Benzalkonium chloride-treated anorectums mimicked endothelin-3-deficient aganglionic anorectums on manometry," J Pediatr Surg. 2010 Dec;45(12):2408-11.

 

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