Daniel McNerny, B.S. Ph.D. candidate in the Department of Chemical Engineering Dan McNerny received his B.S. in Chemical Engineering and Biomedical Engineering from Carnegie Mellon Univeristy in 2005 and M.S. in Chemical Engineering at UM in 2007. Dan's research within the M-NIMBS involves synthesizing bi-functional delivery platforms utilizing PAMAM dendrons.

Douglas Mullen, BSE PhD program in the Macromolecular Science and Engineering Doug did his undergraduate BSE degree in Mechanical Engineering and Materials Science at Duke University in 2005. At Duke University, Doug did research in the Atomic Force Microscopy and Nanomechanics Lab at the Center for Biologically Inspired Materials and Material Systems. Doug currently pursues a PhD degree in the Macromolecular Science and Engineering Program.

For his graduate work at Michigan, he is working witihin the M-NIMBS on the development of targeted chemotherapeutic agents that can be employed in a combinatorial manner to provide a wide array of functional materials.

Paul Makidon, DVM Ph.D. Candidate in Biomedical Engineering While earning his DVM degree (1998) at Michigan State University (MSU), Paul Makidon worked on research projects at the Laboratory of Comparative Orthopedic Research and the Endocrinology Section of the Animal Health Diagnostics Laboratory at MSU. He then worked in a clinical practice setting for several years. However, recognizing his deep interest in research, he started the PhD program at the Department of Biomedical Engineering at the University of

Michigan (UM) in Fall 2005 and earned candidacy in Fall 2007. He works under mentorship of Dr. James R. Baker Jr., Director of the Michigan Nanotechnology Institute for Medicine and Biological Sciences (M-NIMBS). He is concurrently a research fellow with the Unit for Laboratory Animal Medicine (ULAM) at UM where he is funded from a NIH/NCRR T-32 grant.

Paul is interested in biomedical applications of nanotechnology. He has been actively involved in development of nanoemulsion based, needle-free, nasal spray adjuvant vaccine development for Hepatitis B. His doctoral research project focuses on the development of an antimicrobial nanoemulsion based inhalation therapeutic to prevent infection or treat antibiotic resistant infections in patients with Cystic Fibrosis, a disease that affects more than 53,000 children worldwide. He will continue this research to complete his Ph.D. degree and then hopes to start an academic research career that is similarly clinically oriented and further examines treatment options that will improve the health status of Cystic Fibrosis patients.

Christopher Kelly, B.S. Ph.D. Candidate in Applied Physics Christopher graduated with high honors in Physics from Oberlin College in 2003.  After working for a year at NASA Glenn Research Center on thin film solar cells, Christopher started graduate work at University of Michigan with Professors Orr and Banaszak Holl in 2004.  Christopher earned his Masters in Electrical Engineering in 2007 and is working towards his Ph.D.

in Applied Physics, focusing on the molecular details of the dendrimer-plasma membrane interaction.  Christopher has been awarded the Biophysics Training Grant and is a graduate fellow of the Graham Institute for Environmental Sustainability.

Bernell Williams, M.S. Doctoral Candidate, Biomedical Engineering Michigan Nanotechnology Institute for Medicine and Biological Science University of Michigan Bernell Williams graduated summa cum laude with a B.S. in Biology and Chemistry and a B.A in Mathematics from Oakwood College in 2001. He continued his studies at the University of Michigan where he received a M.S. in Biomedical Engineering in 2002 and is

currently a Ph.D. candidate. Bernell's research focuses on the targeted delivery of diagnostics and therapeutics to prostate cancer using a polyvalent dendrimer platform.

Becky Lahti, B.S. University of Michigan Ph.D. program in Chemistry Becky graduated with high distinction from the University of Illinois at Urbana-Champaign in 2007 with a B.S. in Chemistry. At UIUC, she did research with Dr. Scott K. Silverman investigating DNA as a catalyst for bio-organic chemical reactions. Becky is currently pursuing a Ph.D. in Chemistry within M-NiMBS under the guidance of Professor Mark Banaszak-Holl.

Blake Erickson, B.S. University of Michigan Ph.D. degree program in Biophysics Blake graduated with in 2006 from the College of Creative Studies at the University of California, Santa Barbara with degrees in Physics and Literature. His undergraduate research, with Prof. Paul Hansma, focused on fracture mechanics of trabecular bone.   Blake started graduate work  at the University of Michigan with Professors Orr and Banaszak Holl in 2006 in the Biophysics program. Blake's research focuses on the mechanisms of dendrimer internalization into cells. Blake has been awarded the Biophysics Training Grant.

Outside of the lab, Blake travels to various ballroom dance competitions around the country.

Rahul Rattan, M.S. University of Michigan Ph.D. degree program Biomedical Engineering Rahul graduated from Panjab University, India in 2006 with a BE in Biotechnology. He is currently pursuing MS in Biomedical Engineering.   He is characterizing the impact of dendrimer based drug delivery on mammalian cells specifically the way these interact with cell membranes and unraveling the intricacies of how dendrimers based on their charge, size, hydrodynamics etc enter

a mammalian cell and eventually be able to model the loaded dendrimer’s interaction with specific cell types.

Ajdin Kavara, B.S. Ph.D. Candidate in Chemistry Ajdin is from Capljina, Bosnia & Hercegovinia.  He moved to Grand Rapids, Michigan in 1997 and earned his B.S. in chemistry from Grand Valley State University in 2004.  He did undergraduate research with Prof. Kovacs on heterogeneously catalyzed breakdown of sugars.  His PhD work is focused on CH-activation chemistry using Sn, applications of the products to cross-coupling chemistry, and novel approaches to natural products.

Tin Mediated CH-Activation and Cross-Coupling in a Single Flask.  J. M. Bartolin, A. Kavara, J. Kampf, M. M. Banaszak Holl.  Organometallics 2006, 25, 4738-4740.

Song Ge, B.S. University of Michigan PhD program in Physics Song Ge obtained his B.S. from Shandong University in China. His research work employs SQUID imaging of magnetic nanoparticles as part of a larger project developing nanotherapeutics for cancer therapy.

Jiumei Chen, M.S. Ph.D. program in Macromolecular Science and Engineering Jiumei earned a double major at Tianjin University with a Bachelors of Engineering in Polymer Materials and Engineering and a Bachelors of Arts in English.  She then earned an MS in Materials Science and Engineering from Wayne State University.  She is now using patch clamp techniques to study the interactions between nanoparticles and biological membranes.  This work will

help to provide an understanding of nanoparticle toxicity and the mechanism of DNA transfection. In October 2006, Jiumei won the prestigious Materials Incorporated Award in recognition of her academic excellence in the Macromolecular Science and Engineering Center. The award was presented at the banquet of the annual symposium.

Damian Khan, B.S. University of Michigan PhD program in Applied Physics   Damian Khan received a B.S. in physics from Morehouse College and an M.S. in physics from Clark Atlanta University. He is currently an applied physics graduate student working with the Orr group and Banaszak Holl groups where he does STM imaging of coated gold surfaces.

Recent Ph.D. Program Graduates

Kevin Landmark, Ph.D. University of Michigan PhD program in Applied Physics Kevin graduated summa cum laude from Michigan Technological University with a B.S. in Physics in 2000, advised by Dr. Robert Weidman. He then spent two years as a test engineer with Visteon, a Tier-1 automotive components supplier, gaining practical industrial experience before deciding to return to academia.

As a member of the M-NiMBS team, Kevin has successfully synthesized and characterized dendrimer-functionalized magnetic nanoparticles for use as targeted contrast agents. Targeted uptake of the devices was verified using visible fluorescence from dye labels on the dendrimers as well as X-ray fluorescence from iron in the iron oxide cores. The latter experiments were conducted at the Advanced Photon Source, Argonne National Lab. This work has been published in ACS Nano: Landmark, K. J.; DiMaggio, S.; Ward, J.; Kelly, C.; Vogt, S.; Hong, S.; Kotlyar, A.; Myc, A.; Thomas, T. P.; Penner-Hahn, J. E.; Baker, J. R., Jr.; Banaszak Holl, M. M.; Orr, B. G. Synthesis, Characterization, and in Vitro Testing of Superparamagnetic Iron Oxide Nanoparticles Targeted Using Folic Acid-Conjugated Dendrimers. ACS Nano 2008, 2, (4), 773-783.

Kevin's Thesis:

DENDRIMER-COATED IRON OXIDE NANOPARTICLES AS TARGETED MRI CONTRAST AGENTS

by Kevin J. Landmark

Friday, May 16, 8:30 am, 335 West Hall

Co-Chairs: Mark M. Banaszak Holl and Bradford G. Orr

Other committee members: James R. Baker, Jr. and Roy Clarke

Targeted MRI contrast agents are anticipated to be critical tools in realizing the dream of predictive and preventative medicine.  Many approaches have been documented regarding superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents and the use of various ligands to actively target them to specific tissues.  This dissertation explores SPIONs coated and targeted by functionalized dendrimers for specific uptake by cancer cells via the folic acid receptor (FAR).

Monodisperse SPIONs were first prepared in organic solvents (OC-SPIONs).  Amine-terminated generation 5 poly(amidoamine) (G5-PAMAM) dendrimers were conjugated with an average of five folic acid (FA) moieties for targeting and three 6-TAMRA (6T) dye molecules for tracking by optical fluorescence.  To minimize nonspecific interactions, the remaining amino groups were neutralized by capping with acetyl (Ac) groups.  The resulting polymer units, G5-Ac(102)-FA(5)-6T(3), were used to transfer OC-SPIONs from organic to aqueous media, imparting protection, biocompatibility, optical tracking and targeting in a single step.  Following phase transfer, the dendrimer-coated SPIONs (DC-SPIONs) exhibited key properties for effective contrast agents: they retained their size and shape uniformity and exhibited a high saturation magnetization.

The ability of the dendrimer-coated SPIONs (DC-SPIONs) to be specifically internalized by cancer cells overexpressing the FAR was confirmed and quantified in vitro.  Targeted uptake of the dendrimer coatings and SPION cores was independently verified by two distinct but complementary techniques: flow cytometry for the dendrimers (6-TAMRA signal) and X-ray fluorescence (XRF) microscopy for the SPIONs (elemental iron signal).  Using XRF microscopy is unique because it enables quantification of iron uptake at the single-cell level versus analysis on bulk cell samples.  The XRF microscopy data reveal a wide variation in iron uptake that correlates well with the uptake distribution from flow cytometry and is consistent with the variability in uptake observed for neat G5-Ac(102)-FA(5)-6T(3).

Eric Tkaczyk University of Michigan MD/PhD program Eric Tkaczyk graduated magna cum laude with degrees in mathematics and Electrical Engineering from Purdue University and minors in German and French. Now, he is a fellow in the University of Michigan MD/PhD program.  His research interests include flow cytometry, pulse-shaping, coherent control, ultrafast optics, multiphoton microscopy, and their medical applications.  Previously, he pursued quantum chemistry

research in Estonia and multiphoton microscopy in France. In 2006, Tkaczyk won the International Biomedical Optics Society Best Student Paper Award at the Photonics West conference.  Estonia and multiphoton microscopy in France.  In 2007, he won first prize in the Student Paper Competition at the IEEE International Summer School and Symposium on Medical Devices and Biosensors in Cambridge, England.

Witihin the M-NIMBS, Eric is involved with two-photon, two-color in vivo flow cytometry to noninvasively monitor multiple circulating cell populations. See:

Eric R. Tkaczyk, Cheng Frank Zhong, Jing Yong Ye, Steve Katnik, Andrzej  Myc, Kathryn E. Luker, Gary D. Luker, James R. Baker, Jr., and Theodore B. Norris, "Two-photon, Two-color in Vivo Flow Cytometry to Noninvasively Monitor Multiple Circulating Cell Lines," Multiphoton Microscopy in the Biomedical Sciences VI, Proceedings of SPIE 6631, 2007.

Eric R. Tkaczyk, Cheng Frank Zhong, Jing Yong Ye, Andrzej Myc, Thommey Thomas, Zhengyi Cao, Raimon Duran-Struuck, Kathryn E. Luker, Gary D. Luker, Theodore B. Norris and James R. Baker, Jr.  In Vivo Monitoring of Multiple Circulating Cell Populations Using Two-photon Flow Cytometry. Optics Communication, 2008, In press.

Eric's Thesis:

FEMTOSECOND LASER PULSE OPTIMIZATION FOR MULTIPHOTON CYTOMETRY AND CONTROL OF FLUORESCENCE

by Eric Robert Tkaczyk

May 1, Thursday, 2pm, Duderstadt 1180

Chair: Theodore B. Norris

Other committee members are: Gary Luker, Jennifer Ogilvie, and Duncan Steel.

This body of work encompasses optimization of near infrared femtosecond laser pulses both for enhancement of flow cytometry as well as adaptive pulse shaping to control fluorescence. A two-photon system for in vivo flow cytometry is demonstrated, which allows noninvasive quantification of circulating cell populations in a single live mouse. We monitor fluorescently-labeled red blood cells for more than two weeks, and are also
able to noninvasively measure circulation times of two distinct populations of breast cancer cells simultaneously in a single mouse. We build a custom laser excitation source in the form of an extended cavity mode-locked oscillator, which enhances the two-photon signal strength several fold relative to a commercial laser. This enables superior detection in whole blood or saline of cell lines expressing fluorescent proteins including the green fluorescent protein (GFP), tdTomato and mPlum. A mathematical model explains unique features of the signals including: sub-square law scaling of unsaturated two-photon signal; a sigmoidal sensitivity curve for detection under varying excitation powers; and uncorrelated signal strengths in two detection channels.

The ability to distinguish different fluorescent species is central to simultaneous measurement of multiple molecular targets in high throughput applications including the multiphoton flow cytometer. We demonstrate that two dyes which are not distinguishable to one-photon measurements can be differentiated and in fact quantified in mixture via phase-shaped two-photon excitation pulses found by a genetic algorithm. We also selectively enhance or suppress two-photon fluorescence of numerous common dyes with tailored pulse shapes. Using a multiplicative (rather than ratiometric) fitness parameter, we are able to control the fluorescence while maintaining a strong signal. The importance of linear chirp and power scaling checks on the adaptive learning process is investigated in detail. With this method, we control the two-photon fluorescence of the blue fluorescent protein (BFP), which is of particular interest in investigations of protein-protein interactions, and has frustrated previous attempts of control. Implementing an acousto-optic interferometer, we use the same experimental setup to measure two-photon excitation cross-sections of dyes and prove that photon-photon interferences are the predominant mechanism of control.
This research establishes the basis for molecularly tailored pulse shaping in multiphoton flow cytometry, which will advance our ability to probe the biology of circulating cells during disease progression and response to therapy.

Undergraduate Students

Meghan Liroff Undergraduate Student, Deartment of Chemistry Meghan Liroff is a third-year undergraduate pre-medical student at the University of Michigan pursuing her B.A. in Women's Studies. Under the guidance of the Banaczak Holl-Orr Lab and Ph.D. candidate Chris Kelly, her M-NiMBS work concerns the complex interactions between model phospholipid membranes and dendrimers as studied by isothermal titration calorimetry.