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Meet the Team

Nikki Posnack, Ph.D.
Assistant Professor,
Children’s National Heart Institute, Sheikh Zayed Institute for Pediatric Surgical Innovation: Children’s National Health System

Department of Pediatrics, Department of Pharmacology and Physiology: George Washington University, School of Medicine and Health Sciences

Ph.D., Department of Pharmacology and Physiology, George Washington University, 2009
B.S., Department of Biology, Department of Chemistry, Washington College, 2004

Research interests:
My research is broadly focused on how pharmacological and toxicological exposures affect cardiovascular function. Recently, our laboratory has been investigating the impact of biocompatibility and hospital-based chemical exposures (including phthalates and bisphenols) on cardiovascular health and autonomic regulation. Our laboratory also develops models to comprehensively screen medical device materials, additives and biocompatible device coatings for cardiotoxicity. Our research group is multidisciplinary, and includes individuals with expertise in cardiovascular physiology, pharmacology, toxicology and biomedical engineering. As such, our laboratory has specialized skills in cardiovascular models (neonatal and adult myocytes, human stem cell-derived myocytes, ex vivo perfused hearts, in vivo radiotelemetry, induced pluripotent stem cells), electrophysiology, imaging modalities (confocal, optical mapping, optical spectroscopy) and phenotypic assays (metabolic, gene expression arrays, calcium and voltage dyes).

nposnack@childrensnational.org  |  PI biopage


Rafael Jaimes 2017

Rafael Jaimes, Ph.D.             
Staff Scientist
Ph.D., Biomedical Engineering from George Washington University
B.S., M.S., Biomedical Engineering from Worcester Polytechnic Institute

rjaimes@childrensnational.org


Luther Swift

Luther Swift, Ph.D.
Staff Scientist
Ph.D., Molecular Medicine - George Washington University, Washington, D.C.
M.S., Microbiology - Texas Tech University, Lubbock, TX
B.A., Biology - Southwestern University, Georgetown, TX

lswift2@childrensnational.org


Manelle Ramadan

Manelle Ramadan
Research Technician
B.S., Biology - Pennsylvania State University

mramadan2@childrensnational.org


 Damon McCullough headshot 

Damon McCullough
Research Technician
B.S., Biomedical Engineering, George Washington University

dmccullough@childrensnational.org


 Devon Guerrelli headshot

Devon Guerrelli
Research Technician
B.S., Biomedical Engineering, George Washington University

dguerrelli@childrensnational.org


Morgan Burke
Research Assistant
B.S., Michigan State University

burkemt@gwu.edu


Chantel Bruno, D.O.
Critical Care Fellow
D.O., New York College of Osteopathic Medicine

cbruno@childrensnational.org


Bryan Seigel 2017

Bryan Siegel, M.D.
Cardiology Fellow
B.A., Dartmouth
M.D., New York University School of Medicine
Yale-New Haven Hospital Pediatric Residency
Children’s National Cardiology Fellowship

bsiegel@childrensnational.org


Ashika Chaluvadi
Research Assistant
B.S., Biology, George Mason University


Alumni

James Hiebert 2017

James Hiebert
Research Assistant
B.S., Biology, George Washington University
A.S., Medical Laboratory Science, George Washington University
Term: 2016-2018

jhibert1691@gwu.edu


Daniel McInerney 2017

Daniel McInerney
B.S., Biology, George Washington University
Term: 2017-2018

dmcinerney21@gwu.edu


 Meredith Sherman 2017 

Meredith Sherman
Tufts University
Term: 2015-2017