Ralph Weissleder, MD, PhD
Professor, Harvard Medical School
Director, Center for Molecular Imaging Research
Director, Center for Systems Biology

Phone: 617-643-3220
Email: rweissleder@mgh.harvard.edu

My primary research interests lie in the field of in vivo molecular imaging. Specific research interests over the last 10 years have included the development of novel molecular probes for MR imaging, methods to image cell trafficking and homing, imaging of gene expression in vivo and development of novel imaging technologies, in particular different magnetic resonance and optical imaging methods. These basic research interests go hand-in hand with my clinical interests in interventional and oncologic imaging. Specific examples of translational research have included the development of novel magnetic nanoparticles for MR imaging; the development of enzyme activatable probes for the detection of early cancers by minimally invasive techniques such as laparoscopy; and clinical testing of long circulating polymers for angiogenesis imaging.

Molecular libraries and screens: One of the current areas of interest is the creation and use of entire libraries of imaging agents and their screening to identify hits for molecular targets of interest. Using this approach we have identified unique molecules and nanomaterials with specificity for activated and resting macrophages, subsets of endothelial cells and specific tumor cells.

Nanomaterials: Another area of interest is the exploration of novel nanomaterials to develop novel diagnostic and therapeutic agents. We have developed a series of new nanomaterials for specific applications in cancer and cardiovascular disease.

Stem cells: Another long standing research interest has been the imaging and tracking of individual cell populations in vivo especially stem cells. While we developed methods of superparamagnetic cell labeling over 10 years ago, it has not been until very recently that the use of membrane translocation signals has afforded the much required higher loading capacity of cells. Having the necessary tools at hand, we are now interested in exploring how the localization and retrieval of cell populations in vivo will enable detailed analysis of specific stem cell and organ interactions critical for advancing the therapeutic use of stem cells. Another area of interest is the identification of new affinity ligands for different stem cell types to allow their visualization in vivo.



Publications
Weissleder R, Pittet MJ
Imaging in the era of molecular oncology
Nature. 2008;452:580-589
Lee H, Sun E, Ham D, Weissleder R
Chip-NMR biosensor for detection and molecular analysis of cells.
Nat Med. 2008;:ePub
Wurdinger T, Badr C, Pike L, de Kleine R, Weissleder R, Breakefield XO, Tannous BA
A secreted luciferase for ex vivo monitoring of in vivo processes.
Nat Methods. 2008;5:171-173
Nahrendorf M, Zhang H, Hembrador S, Panizzi P, Sosnovik D, Aikawa E, Libby P, Swirski F, Weissleder R.
Nanoparticle PET-CT imaging of macrophages in inflammatory atherosclerosis
Circulation. 2008;117:379-387
Nahrendorf M, Sosnovik D, Chen JW, Panizzi P, Figueiredo JL, Aikawa E, Libby P, Swirski FK, Weissleder R
Activatable Magnetic Resonance Imaging Agent Reports Myeloperoxidase Activity in Healing Infarcts and Noninvasively Detects the Antiinflammatory Effects of Atorvastatin on Ischemia-Reperfusion Injury.
Circulation. 2008;117(9):1153-60
Kircher M, Grimm J, Swirski FK, Libby P, Gerszten R, Allport J, Weissleder R
Noninvasive in vivo imaging of monocyte trafficking to atherosclerotic lesions.
Circulation. 2008;117:388-395
Kelly KA, Bardeesy N, Anbazhagan R, Gurumurthy S, Berger J, Alencar H, Depinho RA, Mahmood U, Weissleder R
Targeted Nanoparticles for Imaging Incipient Pancreatic Ductal Adenocarcinoma.
PLoS Med. 2008;5(4):e85
Korosoglou G, Weiss RG, Kedziorek DA, Walczak P, Gilson WD, Schar M, Sosnovik DE, Kraitchman DL, Boston RC, Bulte JW, Weissleder R, Stuber M
Noninvasive detection of macrophage-rich atherosclerotic plaque in hyperlipidemic rabbits using positive contrast magnetic resonance imaging.
J Am Coll Cardiol. 2008;52:483-91
Koh I, Hong R, Weissleder R, Josephson L
Sensitive NMR Sensors Detect Antibodies to Influenza.
Angew Chem Int Edit. 2008;47(22):4119-4121
Shaw SY, Westly EC, Pittet MJ, Subramanian A, Schreiber SL, Weissleder R
Perturbational profiling of nanomaterial biologic activity.
P Natl Acad Sci U S A. 2008;105:7387-7392
Chen JW, Breckwoldt MO, Aikawa E, Chiang G, Weissleder R
Myeloperoxidase-targeted imaging of active inflammatory lesions in murine experimental autoimmune encephalomyelitis.
Brain. 2008;131(Pt 4):1123-33
McCarthy JR, Weissleder R
Multifunctional magnetic nanoparticles for targeted imaging and therapy.
Adv Drug Deliv Rev. 2008;60:1241-1251
Kelly KA, Setlur SR, Ross R, Anbazhagan R, Waterman P, Rubin MA, Weissleder R
Detection of early prostate cancer using a hepsin-targeted imaging agent.
Cancer Res. 2008;68(7):2286-91
Shah K, Hingtgen S, Kasmieh R, Figueiredo JL, Garcia-Garcia E, Martinez-Serrano A, Breakefield X, Weissleder R
Bimodal viral vectors and in vivo imaging reveal the fate of human neural stem cells in experimental glioma model.
J Neurosci. 2008;28:4406-13
Nahrendorf M, Aikawa E, Figueiredo JL, Stangenberg L, van den Borne S, Blankesteijn M, Sosnovik D, Jaffer F, Tung CH, Weissleder R
Transglutaminase activity in acute infarcts predicts healing outcome and let ventricular remodelling : implications for FXIII therapy and antithrombin use in myocardial infarction
Eur Heart J. 2008;29:445-454
Gee MS, Upadhyay R, Bergquist H, Alencar H, Reynolds F, Maricevich M, Weissleder R, Josephson L, Mahmood U
Human Breast Cancer Tumor Models: Molecular Imaging of Drug Susceptibility and Dosing during HER2/neu-targeted Therapy.
Radiology. 2008;:ePub
Blois J, Yuan H, Smith A, Pacold ME, Weissleder R, Cantley LC, Josephson L
Slow Self-Activation Enhances The Potency of Viridin Prodrugs.
J Med Chem. 2008;:ePub
Sosnovik DE, Nahrendorf M, Weissleder R
Targeted imaging of myocardial damage.
Nat Clin Pract Card. 2008;5 Suppl 2:S63-70
Hilderbrand SA, Kelly KA, Niedre M, Weissleder R
Near Infrared Fluorescence-Based Bacteriophage Particles for Ratiometric pH Imaging.
Bioconjug Chem. 2008;:ePub
Barnes KR, Blois J, Smith A, Yuan H, Reynolds F, Weissleder R, Cantley LC, Josephson L
Fate of a Bioactive Fluorescent Wortmannin Derivative in Cells.
Bioconjug Chem. 2008;19:130-137
Sosnovik DE, Nahrendorf M, Weissleder R
Magnetic nanoparticles for MR imaging: agents, techniques and cardiovascular applications.
Basic Res Cardiol. 2008;103(2):122-30
Nahrendorf M, Sosnovik DE, Weissleder R
MR-optical imaging of cardiovascular molecular targets.
Basic Res Cardiol. 2008;103:87-94
Figueiredo JL, Passerotti CC, Sponholtz T, Nguyen HT, Weissleder R
A Novel Method of Imaging Calcium Urolithiasis Using Fluorescence.
J Urol. 2008;179:1610-1614
Taktak S, Weissleder R, Josephson L
Electrode Chemistry Yields a Nanoparticle-Based NMR Sensor for Calcium.
Langmuir. 2008;24 (14):7596-7598
Hong R, Cima MJ, Weissleder R, Josephson L
Magnetic microparticle aggregation for viscosity determination by MR.
Magn Reson Med. 2008;59:515-520
Korosoglou G, Tang L, Kedziorek D, Cosby K, Gilson WD, Vonken EJ, Schar M, Sosnovik D, Kraitchman DL, Weiss RG, Weissleder R, Stuber M
Positive contrast MR-lymphography using inversion recovery with ON-resonant water suppression (IRON).
J Magn Reson Imaging. 2008;27(5):1175-1180
Guimaraes AR, Tabatabei S, Dahl D, McDougal WS, Weissleder R, Harisinghani MG
Pilot Study Evaluating Use of Lymphotrophic Nanoparticle-Enhanced Magnetic Resonance Imaging for Assessing Lymph Nodes in Renal Cell Cancer.
Urology. 2008;71(4):708-12
Rusanescu G, Weissleder R, Aikawa E
Notch Signaling in Cardiovascular Disease and Calcification
Curr Cardiol Review. 2008;4(3):148-156
Gounaris E, Tung CH, Restaino C, Maehr R, Kohler R, Joyce JA, Plough HL, Barrett TA, Weissleder R, Khazaie K
Live imaging of cysteine-cathepsin activity reveals dynamics of focal inflammation, angiogenesis, and polyp growth.
PLoS ONE. 2008;3:e2916
Lin KY, Maricevich M, Bardeesy N, Weissleder R, Mahmood U
In vivo quantitative microvasculature phenotype imaging of healthy and malignant tissues using a fiber-optic confocal laser microprobe.
Transl Oncol. 2008;1:84-94