I want to thank the CBST staff for this great opportunity to be part of the summer
internship. It was a wonderful experience that was both educational and fun. I was skeptical and nervous at the beginning about the people I would meet and the project that I would be working on, but within the first week, I became friends with the other interns and grad students and it felt as if we knew each other for a long time. I worked in Dr. Huser’s lab under the mentorship of Deanna Thompson and Greg McNerney along with co-intern
Amanda. Both mentors were very kind, and they patiently introduced me, as well as guided
me, through the HIV-1 project. From the first day I started in this program I was working
in the lab looking at virological synapses using the deconvolution microscope. One of the
challenges I experienced at the beginning was reading all those articles. But thanks to the
weekly seminars, I became more comfortable reading and understanding the articles. I was
also fortunate enough to participate in the CBST retreat. I met many new people, attended
some interesting talks, and of course had lots of fun during the free time. Again, I would like to thank all of the people who made this summer so interesting and unforgettable.
Being part of the CBST program was a wonderful experience. The care the CBST family has for the interns shines through all of the bonding activities and seminars they organized for us. The first week intensive was full of interactive activities to learn about our peers and their life’s experiences. It was a privilege to form bonds with so many talented people, but above all with such warm hearts.
This program is unique in that interns are placed in labs that allow students to take on their own projects and work independently when comfortable. I was able to learn about the many challenges the world of research comes with, and it was exciting to see the results after much hard work. I am truly thankful for this opportunity and I hope many others take the chance to be part of the CBST program in the future.
The CBST Summer Internship Program during the summer of 2010 was a great experience. It started out with a first week intensive where we learned a lot about our fellow interns and participated in many meaningful games that taught me a lot about myself. I greatly enjoyed every minute of the first week intensive and was excited to get back into the lab. I was an unofficial intern for the same PI, Dr. Henderson the summer before so I had lab experience and was very excited to get started on my project. When I finally got to meet with Dr. Henderson to discuss my project for the summer I found out that I was doing a totally different project, which was very exciting and scary at the same time. I met my main mentor Wei He and started learning how to do the work required for the project. I also got the chance to work in another lab, Dr. Kermit Carraway’s lab, learning how to do Western Blots with Matt Saldana. I greatly enjoyed my summer experience in both labs and was blessed to meet many different people that would help me in the future with job opportunities or references. I had a great summer experience and hope to get more opportunities like this in the future.
There are approximately 1.7 million cases of traumatic brain injury (TBI) annually in the United States leading to over 50,000 deaths and 250,000 patients with long-term disability. In order to optimally treat our patients we must first understand the aftermath/consequences of TBI. One recently discovered phenomenon following TBI is autophagy. Autophagy occurs when a cell is deprived of nutrients, or is in a stressful environment for example post-TBI. When autophagy is stimulated organelles are packaged into autophagosomes, broken down by lysosomes, and supply the cell with amino acids promoting cell survival. In this study we will compare the use of deconvolution microscopy with standard epi-fluorescence microscopy to detect autophagy in rat cortical cell cultures. Initially we will determine whether autophagy occurs following both mechanical strain injury as well as glutamate toxicity by quantifying autophagosomes 6 or 24 hours post-injury. We predict that autophagy will occur following injury thus providing us with an in-vitro model to identify the mechanisms and consequences of autophagy in injured neurons. Future studies will determine whether autophagy is beneficial to long term cell survival and function. Additionally we will determine whether pharmacologically increasing autophagy can improve outcome post-injury. Ultimately, developing in-vitro models to better understand the complex nature of TBI will help to design more efficacious therapies.
The one-bead-one compound combinational library, discovered by Dr. Kit Lam, is used as a means of synthesizing millions of compounds within days via the “split-mix” scheme for screening against a variety of targets using onbead binding or other functional assays. These compounds have been used to form libraries which have been instrumental in identifying protein kinase protease substrates inhibitors and ligands for cell surface receptors. One particular library of interest is the WH-05 LLP2A based ligand that has a strong affinity for the α4β1 integrin that is found in most lymphoma cell lines but the α4β1 integrin activates many pathways within the tumor cell and it is still unclear as to which exact pathway the α4β1 integrin activates. Here, we are trying to identify the activated pathway(s) upon binding of ligands in the WH-05 library to the α4β1 integrin. One particular pathway we believe is activated is the ERK1/2 pathway. The ERK1/2 kinase is a well known cellular pathway that is involved with apoptosis, proliferation and more importantly, differentiation and survival. In order to identify the pathway for differentiation, we have chosen to begin with the ERK1/2 pathway. We used the MOLT-4 lymphoblastic leukemia cell line, which is known to express the α4β1 integrin, to screen for the ligands that activate this pathway. In order to test for this particular pathway, the cells were allowed to bind and subsequently stained for ERK1/2. Over time, we hope to identify the peptides in the WH-05 library that activates pathways in lymphoma cells.
The CBST summer internship has definitely been a very unique and helpful experience. I have done two internships before when I was at community college but this program was definitely different. I learned how to write an abstract and participated in weekly lab meetings and I especially loved the weekly CBST meetings to discuss career paths, resumes, and networking skills. Another aspect that sets this internship apart from my past ones is the unique personalities that I met during my eight week experience. I have met many people from different countries and backgrounds. They opened my eyes to the different possibilities and outcomes there can be in life. However, the actual lab work was the most critical aspect of the program. I had the privilege to work with Dr. Kit Lam as my primary mentor and Diana Lac as my secondary mentor. I had definitely learned to use my critical thinking skills during the course of the summer with every trial and tribulation that could and did come up. I was so used to the success and perfection in my lab work that I didn’t know how to accept failure but Dr. Lam and Diana helped my through it all and taught me that life in a lab is not always perfect and harmonious. They taught me to me persistent and determined with my experiments and to never give up. I thank the CBST for giving me a meaningful summer as I transition from community college to UC Davis.
Two photon, photoacoustic and ultrasonic imaging systems in combination show the advantages of both optical and ultrasonic in vivo imaging. The two photon system has higher resolution and requires less excitation energy, so the longer wavelength can be used to excite tissues of interest. The longer wavelength light can penetrate deeper into the tissue. Also, the acoustic signal can travel in tissue with very low distortion. As the result, the combination imaging system will be able to image deeper in tissue with higher resolution. We want to model the beam profile of laser in tissue which facilitates the design of two photon and photoacoustic system. Monte Carlo is a stochastic dynamic discrete model which is a powerful tool to model light propagation in turbid tissue. In the literature, there is a program to simulate light propagation in the multilayer turbid medium. In this program, one photon travels in the turbid medium and is absorbed or scattered in its pathway. At each step, the angle of deflection and step size of the photon are based on a random number with uniform distributions, and the absorption and transmittance are recorded. Then, the absorption values are used to calculate the intensity distribution in any portion of the tissue. The process is repeated many times in order to obtain reliable statistical results. Several adaptations are made in this code for applying to our setup. The initial position and direction of each photon are randomly generated in a range to simulate the laser beam. We got some results with the computational model, but future works need to be done to validate the result.
Through the summer internship, I have learned a lot. In the community college, I have had chances to work in the lab, but this is the first time I experienced working in the real lab with professionals and big projects. Thanks to the internship, the door that leads to scientific research field has opened for me. There were many things I could learn from it. I learned how to incorporate what I studied to work and find the solutions for any problem. I also learned how reading the journals could lead me to answers of many of my questions during solving problems. I really liked and enjoyed the CBST annual retreat. At the retreat, not only I explored more knowledge in science, I also did rock climbing. It was very excited when I could climb on a high cliff and see the beautiful sight of Lake Tahoe. I never thought balancing between working, studying and playing was that amazing. During the internship, I attended all the presentations where I could meet numerous famous professionals in their fields. They have achieved wonderful results in their studies and research which inspired me to keep doing what I wanted to accomplish. I will never give up when facing any challenge.
Scientific Abstract
THIOL LIGAND QUANTIFICATION ON THE SURFACE OF GOLD NANOPARTICLES
Jasmine Mojica, Matthew Auyoung, and Ting Guo
Attaching hydrophilic thiols to the surface of gold nanoparticles is a practical method to produce water-soluble gold nanoparticles (AuNPs) for cancer therapeutics. Therefore, there must be a way to determine the number of thiol ligands on the surface of gold AuNPs. Ellman’s Reagent (5,5’- dithiobis(2 -nitrobenzoic acid)) is a chemical used for thiol ligand quantification. When Ellman’s Reagent is introduced to AuNPs, surfaceattached with thiols, ligand exchange occurs. This results in measurable anions, which can be detected using a spectrophotometer. In this experiment, excess Ellman’s Reagent is introduced into a solution of citrate-reduced AuNPs whose surface is coated with polyethylene glycol (PEG). The reaction is allowed to reach equilibrium and the solution is then probed with an excess of free thiolated PEG in order to verify ligand exchange occurrence with Ellman’s Reagent and the surface-attached thiol ligands. In our case, no anions could be detected, confirming that no ligand exchange took place, and Ellman’s Reagent alone could not be used for thiol ligand quantification of AuNPs with PEG attached to surface. Further studies are under way to investigate the effect of the length of the ligand on ligand exchange.
Personal Statement
I came into the CBST Summer Internship Program as a community college transfer, having not done a research internship in my life. I thought I was coming in with a disadvantage because I didn’t know what to expect, I had no idea how to conduct research, and most of my fellow summer interns had done previous research projects, unlike me. I was put out of my comfort zone and was placed into a world I knew modestly about. Little did I know that what I thought were my disadvantages were actually advantages. Advantages because I learned more than I could ever imagine, and I was privileged to have met incredibly wonderful people that have made this summer unforgettable. This program has also opened my eyes to many pathways and careers I’ve never considered before. The lesson I take from having done this summer program is “Get out there. It’s okay to be timid and afraid, but don’t let it stop you from taking advantages of what the world has to offer.”
Jazmyn F. Wright
UNDERGRADUATE INSTITUTION
Solano Community College
Major: Neurobiology
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Robert H. Fairclough
Secondary Mentors: Vu Trinh
Scientific Abstract
THE POTENTIAL TRIGGER THAT BREAKS IMMUNE PRIVILEGE IN MYASTHENIA GRAVIS
Jazmyn F. Wright, Vu Trinh, and Robert H. Fairclough
Human myasthenia gravis (MG) is an autoimmune disease characterized by antibody-mediated destruction of neuromuscular postsynaptic membrane folds with concomitant decrease in acetylcholine receptor (AChR) density, causing increased muscle fatigability. Experimental autoimmune myasthenia gravis (EAMG) is a rat animal model derived from immunizing rats with Torpedo electric organ AChR. The rats develop anti-Torpedo AChR antibodies (Ab) that cross-react with the rat AChR, resulting in MG symptoms. Some autoimmune rheumatoid arthritis patients, treated with the free sulfhydryl compound D-penicillamine (D-P), have also developed MG with an anti-AChR Ab response that clears upon discontinuing D-P. The Penn lab has shown that D-P covalently modifies the α-subunit cys192- 193 disulfide, blocking acetylcholine (ACh) binding. The Fairclough lab has shown that the free sulfhydryl peptide, glutathione (GSH), also modifies the α-subunit cys192-193 disulfide inactivating the ACh response in oocytes expressing AChRs. We hypothesize that in MG, GSH modifies AChRs producing the trigger that breaks immune tolerance to the AChR. We have observed a 1.3 factor increase in anti-GSH binding activity in 17 of 19 MG patient sera versus control sera. However, EAMG rat serum lacks this anti-GSH binding activity. To test the hypothesis that GSH is the potential trigger of MG, we have immunized rats with GSH cross-linked to BSA via SPDP. We are currently assessing the anti-GSH activity of the immunized rat sera versus control rat serum. Once anti-GSH activity is observed, we will attempt to induce MG fatigue and anti-AChR Abs by injection of GSH into the rat’s muscle controlling grasping reflex.
Personal Statement
Interning this summer with CBST has been the most amazing experience. Every
aspect of the internship was great—from the lab, to the other interns, to the Lake
Tahoe retreat. During the First Week Intensive, it was exciting to interact with
many different students who had interesting and diverse backgrounds. I am extremely grateful for the opportunity CBST gave me to intern in Dr. Robert Fairclough’s lab. It was an incredible experience to work one-on-one with my PI on a fascinating and unique research project. He has been an amazing mentor who continues to encourage me every step of the way. I am also appreciative to Dr. Corbacho and Dr. Gurkoff for the mentoring I received
from them as well. This opportunity has brought me one step closer to my eventual
goals, and for that I am particularly thankful.
Jesse J. Garcia
UNDERGRADUATE INSTITUTION
Skyline College
Major: Biochemistry
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Kit Lam
Secondary Mentors: Lorenzo Bertil
Scientific Abstract
OPTIMIZATION OF LOADING LEVELS AND STABILITY OF MAGNETIC COMPLEXES BETWEEN SINGLE STRANDED DNA (SS DNA) AND IRON OXIDE NANOPARTICLES FOR ANTISENSE CANCER THERAPY
Jesse J. Garcia, Lorenzo Berti1, and Kit S. Lam
The interest in magnetic nanoparticles as drug delivery vehicles is rising steadily because the unique properties of these materials show great promise for targeted drug delivery, cancer diagnosis and real-time tumor imaging. Several shortcomings are however impairing the development of practical applications of nanoparticle-based antisense delivery systems in the clinical settings. In particular, a pressing issue is the development of synthetic methodologies permitting the maximization of the amount of DNA loaded while retaining a benign pharmacokinetic profile. In this study, we are investigating a new synthetic procedure for obtaining stable ssDNA:iron oxide nanoparticle magnetic complexes. This procedure relies on the electrostatic complex formation between poly(ethyleneimine)-coated positively charged iron oxide nanoparticles with the negatively charged ssDNA. Through a combination of tools (Dynamic Light Scattering, UV-Vis and Fluorescence Spectrophotometry), we are investigating how the ssDNA:iron oxide ratio, the size of the nanoparticle and the ionic strength of the complexing environment affect the loading levels and the stability of the resulting complex. Co-loading the ssDNA in the presence of increasing amounts of negatively charged block copolymer of poly(ethyleneglycol) (PEG) tailed with poly(glutamic acid) resulted in stabilization of the ssDNA:iron oxide complex but also in lower ssDNA loading levels due to competitive displacement. However, through systematic screening of multiple experimental conditions we have determined an optimal ssDNA:PEG:iron oxide formulation yielding stable nanoparticles at high ssDNA loading levels. We are currently in the process of testing the silencing efficiency of this nanoparticle formulation on a cell model system by targeting the GFP expression on GFP- transfected pancreatic cancer cells.
Personal Statement
A long and exciting summer has gone in a flash. The first week felt as if I was a movie star
with the cameras recording our daily events. Jumping into Dr. Lam’s lab was a wonderful
and thrilling experience that can be described as amazing. I began to learn about cancer from
my mentor Lorenzo Berti and also had to think back to my chemistry class to solve some lab
problems. I felt like a real scientist trying to help solve problems to further enhance cancer
treatment. Soon after we went on the summer retreat of a lifetime. The seminars were great
but the people were even better. I met Dr. Lydia Howell who smiled and laughed along with
me during a career path exercise at the retreat. Back at CBST in the lab we had a weekly
presentation meeting, which helped me understand and improve my own presentation. As the
weeks went on I gathered data however was frustrated with the results. The ideal mechanism was not forming as I hoped, so I began to try other variables. Eureka! I finally succeeded! It was a great moment to enjoy with my mentor. I learned that persistence would pay off with hard work. I did not give up nor did my mentor let me give up. Presenting my work after just a few weeks was nerve wrecking however necessary to grow and understand that people will help you along the way. I was a small part of big group and I cherish all the moments, failures, and success I had in contributing to the team. It has been the greatest summer of my life.
Jonathan Santos
UNDERGRADUATE INSTITUTION
American River College
Major: Biomedical Engineering
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Ramsey Badawi
Scientific Abstract
TRACING SOFTWARE FOR PHASE II STUDY OF BEVACIZUMAB (AVASTIN) AND BCNU FOR TREATMENT OF RELAPSED, HIGH-GRADE GILIOMAS
Jonathan Santos, Ramsey Badawi
This project entails the development of a GUI based application aiming to facilitate the tracing of tumors for the Phase II Study of Bevacizumab (Avastin) and Carmustine (BCNU), a new treatment that is being tested for relapsed, high-grade gliomas. The purpose of this study is to determine the 6 month progression-free survival of patients with high-grade gliomas that have relapsed or become progressive after radiation therapy and are currently being treated on this study with BCNU and bevacizumab. The radiographic response to therapy is evaluated using MRI and PET with image fusion. This computer application was developed as a user friendly tool to outline gliomas on different image slices from different modalities/contrast, without sacrificing accuracy so that the tumor size can be properly assessed. Current progress of the program allows for outlining of MRI/CT data sets. This application can be expanded to other medical applications that require the use of tracing.
Personal Statement
Being part of CBST and ET-CURE for the past two years has been a life changing experience for
me. It has given me a complete new outlook on research as a whole. I consider myself very lucky to be part of this cutting-edge program. It has been a great experience and pleasure working under Dr. Badawi for a second year, along with all the other researchers and staff from the Badawi lab. I’ve learned that working in research is not just sitting behind a desk and putting together results and data, but to collaborate and share thoughts and opinions with other scientists, work along with other labs and look for resources where no one has looked before.
Throughout my stay in Dr. Badawi’s lab, I experienced many of the different aspects of
research, from writing grants, to working on initial data to get a project started, building
scientific tools to manipulate results, translating research from one field to another and multi-
tasking on different projects. I‘ve been exposed to different branches of science and medicine,
from basic physics and biology, to working in nuclear medicine and giant cluster systems.
I had gotten great satisfaction knowing that research and developments that I have been
involved with have been put to use by field professionals. I owe all of this to the Center
of Biophotonics Science and Technology for putting together this awesome program.
Larissa K. Miyachi
UNDERGRADUATE INSTITUTION
Yuba Community College
Major: Biochemistry
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Ting Guo
Secondary Mentors: Neal Cheng and Zane Starkewolfe
Scientific Abstract
ENHANCEMENT OF RADIATION-INDUCED HYDROXYL RADICAL GENERATION IN THE
PRESENCE OF GOLD NANOPARTICLES
Larissa Miyachi, Neal Cheng, Zane Starkewolfe, and Ting Guo
When irradiated with x-rays, gold nanoparticles (AuNPs) release electrons which can interact with nearby water molecules to generate highly-reactive hydroxyl radicals. As these radicals can cause DNA strand breaks, the use of AuNPs to enhance radiation-induced hydroxyl radical production holds potential for cancer therapeutics and merits thorough investigation. Currently, it is unknown whether this enhancement is due to increased radiation absorption by gold (physical enhancement) or from reactions occurring on the surface of the gold nanoparticles (chemical enhancement). As chemical enhancement is proportional to surface while physical enhancement is proportional to mass, nanoparticles with varying surface-to-volume ratios can be used to isolate and investigate both forms of enhancement. Small AuNPs were used for investigating chemical enhancement and large AuNPs were used for investigating physical enhancement. Nonfluorescent probe molecules (NFPM), which form a fluorescent hydroxylated product that can be measured using fluorometry, were utilized as a probe for hydroxyl radicals. Solutions containing AuNPs and NFPM were irradiated with hard x-rays and fluorescence intensities were then measured using a fluorometer. Enhanced hydroxyl radical generation was observed for small AuNPs, indicating the presence of a surface-chemical effect in AuNP radical enhancement. The role of physical enhancement is presently inconclusive as AuNP radical scavenging obscured the results obtained for large AuNPs, and further studies must be performed. As there is immense potential for the use of AuNPs in cancer therapeutics, these studies will continue to elucidate the conditions by which enhanced radical generation occurs.
Personal Statement
I am grateful that I had the opportunity to participate in this internship, as it allowed me to experience science at a greater depth than ever before. Working under Dr. Ting Guo in his research lab was a remarkable experience; I was able to learn many new skills, such as how to synthesize gold nanoparticles, operate a rotary evaporator, and care for cell cultures, as well as hone skills I previously learned in my college science courses. Dr. Ana Corbacho has organized an excellent internship that provides a solid introduction to research and to the scientific community. Through activities such as the first week intensive, weekly seminars, and get-togethers, I had many occasions to connect with my
fellow interns, thus becoming part of a community of young adults who are pursuing science-related goals. In addition to helping me connect with other students, this program provided opportunities for improving my journal reading and comprehension skills through a weekly journal club guided by Dr. Gene Gurkoff. My experiences in this internship have further motivated my desire to study science, as the challenges I have encountered in research have inspired me to learn more. I would recommend the CBST internship to anyone interested in research, as it builds both skills and relationships and gives greater purpose to the years spent at college.
Laura Ramirez
UNDERGRADUATE INSTITUTION
California State University Sacramento
Major: General Sciences
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Kit S. Lam
Secondary Mentors: David Olivos
Scientific Abstract
Nanotherapeutic Targeting Agents for Ovarian Cancer
Laura Ramirez, David Olivos, and Kit S. Lam
The designing, synthesizing and screening of one-bead-one-compound (OBOC) combinatorial chemistry libraries against a single target ligand has been well developed. Recently, novel cholesterol/peptide hybrid combinatorial One-Bead-One-Compound (OBOC) combinatorial libraries have been developed and synthesized with self folding capabilities. The library design strategy was based on a similar pentamer and hexamer self-folding branched tricylic libraries previously developed. The cholic acid on the side chain of the carboxyl lysine is believed to interact with fixed hydrophobic amino acids at the amino-termini (position 5) of the twin branched L-amino acid arms and self-fold into a tricyclic molecule. The newly synthesized library has arginine (R) and Lysine (K) down-proportioned to 10 % for each position to decrease the probability of positive charge nonspecific binding. Thirty L-, D-, and unnatural amino acids were used in each position as building blocks. Hydrophobicity was fixed at position 5 with hydrophobic L amino acids and unnatural amino acids. The bead interior, contained nitrotyrosine to reduce tentagel bead auto fluorescence, and a coding tag for identification via Edman sequencing. These libraries were screened against several ovarian cancer cell lines. The peptides were screened in competition inhibition assays with the presence of our best ovarian targeting ligands. Select peptides were tested against patient tumor and normal sample cells. The ovarian cancer targeting agents identified from this series of novel libraries may serve as a highly efficient delivery vehicle for drug-loaded nanoparticles into tumor endothelial cells and cancer cells.The designing, synthesizing and screening of one-bead-one-compound (OBOC) combinatorial chemistry libraries against a single target ligand has been well developed. Recently, novel cholesterol/peptide hybrid combinatorial One-Bead-One-Compound (OBOC) combinatorial libraries have been developed and synthesized with self folding capabilities. The library design strategy was based on a similar pentamer and hexamer self-folding branched tricylic libraries previously developed. The cholic acid on the side chain of the carboxyl lysine is believed to interact with fixed hydrophobic amino acids at the amino-termini (position 5) of the twin branched L-amino acid arms and self-fold into a tricyclic molecule. The newly synthesized library has arginine (R) and Lysine (K) down-proportioned to 10 % for each position to decrease the probability of positive charge nonspecific binding. Thirty L-, D-, and unnatural amino acids were used in each position as building blocks. Hydrophobicity was fixed at position 5 with hydrophobic L amino acids and unnatural amino acids. The bead interior, contained nitrotyrosine to reduce tentagel bead auto fluorescence, and a coding tag for identification via Edman sequencing. These libraries were screened against several ovarian cancer cell lines. The peptides were screened in competition inhibition assays with the presence of our best ovarian targeting ligands. Select peptides were tested against patient tumor and normal sample cells. The ovarian cancer targeting agents identified from this series of novel libraries may serve as a highly efficient delivery vehicle for drug-loaded nanoparticles into tumor endothelial cells and cancer cells.
Personal Statement
@font-face { font-family: "Calibri"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } @font-face { font-family: "Arial"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }
This summer has been one of the most rewarding experiences by far. Being part of the ET-CURE and CBST programs for a second summer has truly been a great opportunity. I continue to learn and put disciplines together in order to solve problems. The Lam Lab is truly multidisciplinary and provides an environment that allows me to continuously grow and gain invaluable skills that are crucial for my future in research. The mentorship I received has continued to exceed my expectations and the people that surrounded me in the lab were very helpful. Overall this is a great experience for any student considering a career in research and I am extremely grateful for taking part in this summer’s CBST research program.
Leng K. Mut
UNDERGRADUATE INSTITUTION
Sacramento City College
Major: Chemical Engineering
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Thomas Huser
Secondary Mentor: Latevi Lawson
Scientific Abstract
INVESTIGATION OF 3,7-DIMERCAPTO-2-NAPHTHOIC ACID AS A NOVEL PH SENSITIVE REPORTER
Leng Mut, Latevi Lawson and Thomas Huser
Cells tend to acidify their environment as a function of normal cell metabolism. Cells that experience ligand-mediated activation can acidify their environment up to 3000 times more rapidly than resting cells. Therefore, cellular activation can be monitored as a function of pH. Currently, bulk measurements of cellular pH and fluorescent dyes are used to monitor cellular pH as a function of external stimuli. The primary goal of this project is to develop improved pH-sensitive, Raman-active nanoprobes utilizing surface-enhanced Raman spectroscopy (SERS). Earlier work has shown that by binding 4-Mercaptobenzoic acid (4-MBA) to silver and gold nanoparticles, the pH-sensitive vibrations of 4-MBA can be probed more sensitively and efficiently against the naturally occurring autofluorescence background in vivo. However, in otherwise uncontrolled nanoparticles the SERS enhancement is largely unpredictable. Interestingly, it was found to be greatest at the junction of two or more nanoparticles. Thus, we synthesized 3,7-dimercapto-2-naphtoic acid (3,7-DM-2-NA), a pH-sensitive molecule capable of actively linking two nanoparticles, creating a SERS hotspot. To verify the correct synthesis of the compound, we utilized Raman, and IR Spectroscopy. UV-Vis absorption spectroscopy was used to determine the
extinction coefficient (3840/[M*cm]) of our reporter and to verify that the reporter caused both Ag and Au colloidal nanoparticles to aggregate. Both results from Raman and IR signals confirmed that we have successfully synthesized 3,7-DM-2-NA. The UV-Vis of Ag and Au in the presence of 3,7-DM-2-NA showed significant red shifts indicating aggregation of the nanoparticles.
Personal Statement
I had an excellent opportunity to get involved in the 2009 Winter Internship and 2009 and
2010 summer internships at the Center for Biophotonics Science and Technology (CBST).
The relaxed learning environment made it easy for me to meet many fine friends from these
internships. I enjoyed the games during First Week Intensive because they allowed fellow
interns and me an opportunity to get to know each other well before we were divided into labs. I especially enjoyed the CBST Annual Retreat at Squaw Creek Resort because we had so much fun together while we learned from each of the presentations. By attending a career panel and listening to many professionals from different backgrounds who have diverse careers, I found out what I want to do as my career. I would like to thank to Dr. Ana Corbacho for organizing many of these fun informative activities and Dr. Gene Gurkoff for organizing the weekly journal club. Attending this club helped me hone my presentation skills while simultaneously showing me how to extract pertinent information from different journal articles. These internships have been a wonderful opportunity to receive an introduction to my professional life as an engineer. I believe this has been the beginning of a productive career in which I look forward to making contributions to the betterment of the human condition and to humanity in general.
M. Hiram Dominguez Cruz
UNDERGRADUATE INSTITUTION
Merced Community College
Major: Biology
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Rob Berman
Secondary Mentors: Gene Gurkoff
Scientific Abstract
NOVEL PARADIGMS FOR ASSESSING BEHAVIOR DEFICITS FOLLOWING LATERAL FLUID PERCUSSION INJURY IN RATS
Hiram Dominguez-Cruz, Gene Gurkoff, and Rob Berman
Traumatic brain injury (TBI) is a significant problem in the United States with over 1.7 million cases reported each year. 50,000 of these cases result in death, while an additional 250,000 patients are left with some form of disability after brain injury. One of the consequences of TBI that is seen in a subset of patients is a deficit in learning and memory. In this study, we examine the role of TBI on rat performance in two different behavioral tests of learning and memory: metric and topological object tests. Rats were tested in each of these two behavioral paradigms ten days following either TBI or sham injury. The metric task tests the ability to process changes in spatial distance between objects; whereas, the topological task tests the ability to process changes in the relative location of objects in space. While we predicted that TBI would affect behavioral performance in both tasks, preliminary data suggests that injured animals are functionally impaired in the metric task but not in the topological task. If injured animals do have a statistical deficit in behavior, these tests will serve as important tools to test the efficacy of treatment paradigms on improving cognitive performance in rat models of TBI. In our lab, we are interested in investigating neuroprotective qualities of the drug SNX-111, a voltage-gated calcium channel (VCGG) blocker. If we demonstrate that this drug improves cognitive function in rodent models, we hope to translate our findings into treating patients suffering from learning and memory deficits following TBI.
Personal Statement
The CBST Summer Internship is nothing short of amazing. I spent three months as an
intern in the UC Davis Department of Neurological Surgery, where Dr. Rob Berman
and Dr. Gene Gurkoff were my primary and secondary mentors, respectively. In simple
terms, my research project involved working with rodents to conduct research on learning
and memory deficits. My mentors and other lab members were very available and
helpful to answer all my questions and provide guidance day in and day out. I truly
enjoyed working in Dr. Berman’s lab. This experience solidified my interest in my major
and provided a foundation for future research experiences I plan on pursuing. I can’t
think of a better way to spend a summer. In addition to working in a research lab, summer interns attended the Journal Club and other workshops, lectures, interactive presentations, and even a three day biophotonics research conference. We also had the opportunity to present our research projects at the end of the eight weeks. These experiences allowed us to grow professionally by leaps and bounds. Furthermore, the fantastic crowd that were the 30 or so interns, had the opportunity to form friendships that will hopefully last a lifetime. Most of us started out as strangers, but before we knew it, we were planning fun social activities: from
playing soccer, to visiting the Davis Farmer’s Market, to riding go-karts after work. I am proud to be part of the biophotonics family and am thankful for the opportunity to participate in this incredible summer research program. The investment CBST makes on us students is worth much more than I can explain with words.
Moses Evbuomwan
UNDERGRADUATE INSTITUTION
University of California, Berkeley
Major: Molecular and Cell Biology
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Kit Lam
Secondary Mentors: Pappanaicken Kumaresan
Scientific Abstract
IMMUNOTHERAPY APPROACH TO CANCER TREATMENT
Moses Evbuomwan, Anastaia Warde, Angela Echeverri, Kit Lam and
Pappanaicken Kumaresan
The absence of curative therapies for recurrent forms of metastatic cancer has prompted a vigorous search for novel treatment strategies. Cancer immunotherapy uses the host immune system, either directly or indirectly, to combat cancer. The more successful cancer immunotherapies are antibody-based. In this study, we hypothesized that a chemical antibody (chembody) with an intact Fc region can be constructed by conjugating tumor cell specific peptidomimetic agents (ligands) to the Fab region of human IgG (hIgG). We used ligand which binds effectively to αVβ3 integrins expressed on MDA-MB-231, U87-MG, K562, and K562-αVβ3transfected cell lines. And ligand which binds to α4β1 integrins expressed on MOLT-4 cell line. The resultant chembody will bind to the tumor cells and elicit host immune response against cancer cells by recruiting the immune effector cells. In this study, we (1) conjugate naïve hIgG with the ligand, (2) verify ligand conjugation, and (3) test the efficacy of the chembody. We used the Traut’s reagent to conjugate the ligand to naïve hIgG. We performed Western blot analysis, MALDI-MS assay and Cell Binding assay to verify the successful conjugation. Antibody Dependent Cellular Cytotoxicity (ADCC) assay is being employ to test the efficacy of the chembody. We expect chembodies with intact Fc region to be tumor specific, and actively recruit immune effector cells to the tumor site and have low immunogenicity. This novel individualized medicine approach in cancer immunotherapy can be very effective in eliminating the minimal residual cells (MRD) responsible for relapse after chemotherapy or radiotherapy.
Personal Statement
It was a privilege to participate in the Center for Biophotonics, Science and Technology (CBST) Summer Program these past two summers through the Emerging Technologies Continuing Umbrella of Research Experience (ET-CURE) Program. The invaluable skills and mentorship I gained while in the program would always be pivotal to my future endeavors in science and research. And I’m extremely grateful for the opportunity and also to the people I had the chance to interact with on a daily basis during the internship. I urge all undergraduates to take advantage of the ample opportunities provided by the program.
Roque Troz
UNDERGRADUATE INSTITUTION
Contra Costa Community College
Major: Chemistry
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Delmar Larsen
Secondary Mentor: Elizabeth Carroll
Scientific Abstract
MOLECULAR MECHANISMS OF PRIMARY SIGNAL TRANSDUCTION IN THE CYANOBACTERIAL PHYTOCHROME CPH1
Roque Troz, Dr. Elizabeth Carroll, and Dr. Delmar Larsen
Magnetic nanoparticles hold incredible potential for advancing the diagnosis, imaging, and treatment of cancer. The characteristics of Superparamagnetic Iron Oxide nanoparticles (SPIO) make them valuable tools for MRI enhancement, magnetic targeting, and delivery of anticancer drugs. SPIO can also convert electromagnetic energy into heat that is strong enough to disassemble complementary oligonucleotides bound to their surface. Our goal is to show that conjugating double-stranded oligonucleotide sequences to SPIO represents a superior delivery system for the powerful chemotherapy agent Doxorubicin (DOX). We want to demonstrate that this delivery system can improve drug efficacy and reduce the deleterious side-effects associated with non-specific chemotherapy treatments. In our project, we developed a synthetic scheme, based on disulfide exchange chemistry, allowing the easy access to the DOX nanocarrier . Bioconjugation of dsDNA to SPIO allows for loading of DOX through intercalation. Our initial results showed the efficient conjugation of DNA to SPIO (1200 to 1900 strands of DNA per SPIO) and a reasonable loading of DOX to DNA. Conjugation of DNA was confirmed by dynamic light scattering, where an increase in hydrodynamic radius was observed, and by agarose gel electrophoresis. DOX release curves where obtained indicating that the SPIO-dsDNA-DOX conjugates retain the drug more effectively than SPIO only. Next we will (i) explore the release of DOX by application of an alternating magnetic field and (ii) start in vitro cytotoxic experiments on representative cancer cell lines. We envision that the combination of hyperthermia and localized delivery of DOX might increase anti-tumor effects by sensitizing preferentially cancer cells to chemotherapy.
Personal Statement
p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }
The CBST internship was one of the most intriguing, yet wonderful experiences I ever had. It allowed me to grow in various aspects including as a person, scientist and professional. Throughout the summer, my research, the workshops I attended and the summer retreat to Squaw Valley helped me to look at life with a reformed perspective. My summer experience was full of revelations: I have the ability to work at a lab, I can live alone, and I am no longer confined to one career path based on the exposure I had to the diversity of careers available in the field of science. In addition to learning about new subject material, I learned how integrated science is and that many of the things learned in school resurfaced during the summer. To see applications of material I learned was personally gratifying. I appreciated the opportunity to be a part of this program as it reemphasized the importance of education and introduced me to various career paths. It was an invaluable experience that I will be part of my future. Additionally I have learned the importance of networking and so I also am glad for the opportunity to encounter all the people I have met and who have helped me this summer.
Rosa M. Serrano
UNDERGRADUATE INSTITUTION
University of California Davis
Major: Engineering
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Sashi Kunnath
Scientific Abstract
A SEISMIC EVALUATION AND BUILDING CODE ASSESSMENT USING THE SAP-2000 COMPUTER SOFTWARE
Rosa Serrano and Sashi Kunnath
Building codes have been established in order for engineers to have a standard set of guidelines to perform a building design. Since earthquakes cannot be predicted, buildings are designed according to the provisions in current codes such as ASCE-7 (American Society of Civil Engineers) and IBC (International Building Code). Damage to structures in recent earthquakes provides the need for evaluations to be done on buildings designed by earlier codes. A building evaluation will provide an assessment of how the structure would perform during earthquakes as well as information on the adequacy of code-based structural design. In this study, a steel moment frame constructed in 1976 was chosen to conduct a seismic evaluation. The six story symmetrical building was designed in Southern California according to the 1973 code. The building was analyzed to determine if the structure would be adequate when compared against the most recent code, ASCE 2007. A dynamic analysis was conducted on the building using the computer software (SAP-2000) to determine the seismic performance of the existing building. Various earthquake accelerations were then applied to the steel building frame to determine the critical earthquake magnitude that would have the most significant effect on the structure. Once a critical earthquake has been selected, the earthquake’s intensity will be increased until the building reaches a failure point. With the obtained results decisions could be made on appropriate seismic retrofitting and on necessary adjustments to the building code.
Personal Statement
I could have never predicted what I experienced in the Summer CBST Internship.
There was not a single moment in the internship in which I was not learning: from the
First Week Intensive activities to the Journal Club Meetings, to the weekly Seminars,
to the Retreat, and finally to the Symposium Presentations. Being a civil engineer and
not having the biology or chemistry background did not impede my ability to absorb
countless amounts of information from the internship.
The First Week Intensive activities allowed me to comfortably open up to my
peers and to cope with different issues that exist in real world situations. Although at
times reading the Journal Club articles was tedious and difficult, at the end, I was able
to apply those skills to my own research which is in a completely different field. I was
surprised when the seminars brought new interviewing skills and tips to my attention
that I had not learned in my four college years. The CBST retreat allowed me to further
develop professional and personal relationships with other interns and members of
the scientific community. One of the most nerve wrecking, yet enjoyable learning
experiences was the Research Symposium. I was astounded of the research my peers
were doing, and was thrilled when my peers informed me their enjoyment in listening to
my presentation.
I am extremely grateful to every one who contributed to the path leading to this
internship and to all who made this experience one of the most memorable.
Ryan S. Harake
UNDERGRADUATE INSTITUTION
University of California, Davis
Major: Biomedical Engineering
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Tingrui Pan
Scientific Abstract
REVERSIBLY BONDED PDMS MICROFLUIDICS
Ryan S. Harake and Tingrui Pan
Microfluidic devices, a subset of microelectromechanical systems (MEMS), allow for the precise control of fluids while requiring fewer reagents, making them appealing for “lab-on-a-chip” (LOC) applications. This makes LOC devices suitable for use in medicine, such as in diagnostics and drug delivery, where accuracy, safety and cost reduction are paramount. Newly developed fabrication methods reduce the necessary resources needed compared to traditional photolithographic MEMS fabrication by using a computercontrolled, high-resolution CO2 laser engraving system. This process provides a way to create microfluidic channels from bulk materials. Polydimethylsiloxane (PDMS), a commonly employed biocompatible and optically transparent silicon-based elastomer, is used in conjunction with this laser system to create a platform in which inexpensive and rapid prototyping is achieved. Typically after fabrication, PDMS microfluidic chips are packaged by using O2 plasma treatment, resulting in an irreversible bond with a substrate which may not be desirable for certain biological assays where the contents of the chip are to be retrieved for further analysis. In this work, a novel technique for creating reversibly bonded PDMS microfluidic chips is developed using a laser engraving system. Unlike other reversible bonding methods that are based on weak physical bonding, this new technique utilizes mechanical forces to form a PDMS-PDMS bond, allowing the user to open and close the same chip numerous times while still maintaining the functionality of the resealed device.
Personal Statement
I am very glad I spent my summer as a CBST intern. The research experience in the lab
was wonderful but there were also many other components that made this an excellent program. I really enjoyed meeting and working with other students from so many different places who shared similar scientific interests. Weekly workshops taught us important skills such as reading scientific journal articles, writing scientific abstracts, the importance of professional networking, building an effective résumé, being a productive researcher, preparing for interviews, as well as valuable information about graduate school. The annual retreat in Lake Tahoe provided us with great exposure to many fascinating talks about biophotonics, which proved to be very helpful at the end of the program when we each gave our own research presentations. It is clear from the final presentations that everyone who took part in the program was directly involved with very interesting and cutting-edge research. I feel very blessed to have served this internship and know that what I learned from it will greatly benefit me in achieving my professional aspirations. I would like to thank everyone at the CBST for all their hard work in organizing this excellent program as well as the members of my lab group for all of their daily guidance and mentorship.
Steve Huerta
UNDERGRADUATE INSTITUTION
University of California, Davis
Major: Biochemistry
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Hsing-Jien Kung
Secondary Mentors: Mel Campbell and Yoshihiro Izumiya
Scientific Abstract
MAPPING OF KSHV LANA PRC2 COMPLEX BINDING SITE
Steve Huerta, Mel Campbell, Yoshihiro Izumiya, Hsing-Jien Kung
The Kaposi sarcoma-associated herpesvirus (KSHV) has been discovered to contribute to the development of Kaposi’s sarcoma among other serious diseases. KSHV maintains a latent state in most infected cells, during which a very restricted portion of the viral genome is expressed. This latent state has been shown to be controlled at both genetic and epigenetic levels. Latency-associated nuclear antigen (LANA), a viral protein expressed during latency, is a key player in KSHV latency establishment and maintenance. LANA has been found to interact with Polycomb Repressive Complex 2 (PRC2), an important complex involved in chromatin silencing. Preliminary studies have shown the C-terminus of LANA to be highly involved in PRC2 interaction. This experiment was designed to further elucidate the LANAPRC2 interaction site in detail. GST pull-down of several fragments within the C-terminus of LANA was followed by western blotting for PRC2 complex core members in order to narrow down the region of LANA-PRC2 interaction. The results suggested the presence of two independent regions of LANA that interact with PRC2. In addition, in order to elucidate a more specific interaction region, missense mutations in LANA are being used to obtain a LANA mutant that no longer binds to PRC2. These research efforts are focused on exploring the role of LANA-PRC2 interaction in the epigenetic regulation of KSHV latency.
Personal Statement
This was my second experience working with the CBST internship mentors, in addition I was part of the ET-CURE program run by the CBST education team. The team of summer mentors, led by Dr. Ana Corbacho, once again did an outstanding job keeping a lively and professional environment during the intern meetings and activities. My time in the lab was phenomenal; I was able to build on my current skills and learn new techniques such as genetic cloning, GST pull-down, chromatin immuno-precipitation (ChIP), and indirect fluorescence antibody (IFA) protocols. After my first summer doing this internship, I felt that I had seen and learned a great deal. Little did I know there was still so much room for growth. I worked once again with Dr. Kung's lab team, and I was able to engage with far more depth into the various projects ongoing in the lab. In addition, I was invited to speak about my research at the CBST annual retreat at Lake Tahoe. This was indeed a rewarding experience in which I was both excited and honored to be involved. This internship has truly opened up so many doors for me and my education. Through my experiences in the lab, propelled by the CBST, I was able to apply for a supplement grant which was awarded by the NIH. I have gained a great deal from this internship, and I'm extremely glad that I took that first step and applied.
Sven M. Strombom
UNDERGRADUATE INSTITUTION
Cabrillo College
Major: Chemical Engineering
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Sebastian Wachsmann-Hogiu
Secondary Mentors: Zackary Smith
Scientific Abstract
APPARATUS FOR COLLECTION OF KERR GATED RAMAN SPECTRA USING A DIGITAL MICROMIROR DEVICE AND A PHOTO MULTIPLIER TUBE DETECTOR
Sven Strombom, Zackary Smith, and Sebastian Wachsmann-Hogiu
Raman spectroscopy is a powerful analytical tool for identifying molecular structure, but Raman emission tends to be weak in comparison to the fluorescent emission present in most biological material. One method for reducing the fluorescent emission that is collected is to use a Kerr gate operated with ultrafast laser pulses, thus allowing the Raman emission through while blocking the fluorescent emission which has a slower response time. Phase-sensitive (lock-in) detection can take advantage of the periodic nature of the weak Raman signals and improve the signal-to-noise ratio. However, the charge-coupled devices (CCDs) commonly used to collect spectral emission cannot operate at the high frequencies required for effective lock-in detection. Here we report the development of a phase-sensitive detection scheme for time-gated Raman spectroscopy. This apparatus, which includes a spectrometer, a micromirror device, a single point detector, and a lock-in amplifier, has the ability to help with fast measurements of Raman signals (and other spectroscopic signals) by operating in several different modes, such as selective and multipeak recording, Hadamard and Fourier transform measurements. Combining this apparatus with a time-gating Raman setup will result in a powerful instrument capable of performing
time-resolved, noninvasive spectroscopy on biological samples.
Personal Statement
I had an excellent time as an intern at CBST. Coming from a community college this was my first experience in a research lab. From the start I felt welcomed by all of the researchers and students at CBST. Right from the beginning my mentors were helpful and devoted much of their time to get me going on my own project. They were always available to answer my questions, but at the same time they allowed me the freedom to work on my own. Through the various events (first week intensive, retreat, journal club) I got to know the over interns many of whom are also headed to Davis in the Fall. Through this internship I not only learned about the science surrounding my project but also the nature of research labs, the way that academic faculty interact, and what graduate school holds in store.
Vanessa N. Atkinson
UNDERGRADUATE INSTITUTION
University of California, Davis
Major: Neurobiology, Physiology, and Behavior
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Bruce Lyeth
Secondary Mentors: Gene Gurkoff
Scientific Abstract
DEVELOPING A NOVEL BEHAVIORAL TASK, THE BARNES MAZE, TO ASSESS COGNITIVE FUNCTION IN RATS FOLLOWING TRAUMATIC BRAIN INJURY
Venessa Atkinson, Dr. Gene Gurkoff, Dr. Bruce Lyeth
Fragile X-associated Tremor Ataxia Syndrome (FXTAS) is a neurodegenerative disorder resulting from a 55-200 long CGG tri-nucleotide repeat within the 5’ untranslated region of the x-linked FMR1 gene. FXTAS patients development tremors, ataxia, Parkinsonism, cognitive impairments, as well as ubiquitin-positive intranuclear inclusions later in life. Most studies have focused on males with FXTAS because symptoms of FXTAS are generally less severe in females due to x-inactivation. Recently a CGG knock-in (KI) mouse model of FXTAS has been developed which recapitulates many of the features of clinical FXTAS, including motor dysfunction and cognitive deficits. As with human studies, relatively little is known about pathology in female CGG KI mice. Therefore we examined the brains of female CGG KI mice for the presence and distribution of intranuclear inclusions, the hallmark neuropathology of FXTAS. Brains of 7 female heterozygous mice with CGG repeat expansions between 150 and 170, and 14 mice with expansions between 211 and 264 were formalin-fixed, sectioned, and examined using H&E, immunocytochemical and immunofluorescent staining methods. Female KI mice with 143-179 CGG repeats showed numerous intranuclear inclusions in several brains regions, including the amygdala, hippocampus and cortex. In contrast to a previous study, we also found intranuclear inclusions throughout the brains of female mice with greater than 230 CGG repeats. In conclusion, female heterozygous KI mice show intranuclear inclusions similar to that seen in male KI mice, indicating that x-inactivation does not protect female mice from FXTAS-associated neuropathology, and that inclusions are also found in female mice with long (>230) expansions.
Personal Statement
As a second year CBST summer intern, I am grateful for the opportunities and experiences this internship has provided me with. This internship has given me the opportunity to expand my knowledge in research and to learn a vast amount from my co-workers and fellow interns. The first week intensive allowed the interns to partake in team building activities and learn to work both as individuals and as a group. I really enjoyed all of the activities and research I got to be involved in this summer. This summer, I had the opportunity to proceed my work at the neurological surgery lab under the mentorship of Dr. Bruce Lyeth and Dr. Gene Gurkoff. My summer project focused on testing cognitive function in rats following an induced traumatic brain injury. I really enjoyed working on this project this summer and I look forward to continuing my work in the lab next year. I want to thank all the interns, my lab members, and all the staff at CBST for providing another summer filled with learning and fun.
Vinh Lam
UNDERGRADUATE INSTITUTION
University of California, Davis
Major: Biology
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Paul T. Henderson
Secondary Mentor: Chong-Xian Pan
Scientific Abstract
TARGETED BLADDER CANCER THERAPY AND IMAGING
Vinh Lam, Paul T. Henderson, and Chong-Xian Pan
Doxorubicin (DOX) is a commonly prescribed chemotherapy drug. DOX penetrates cells and binds to genomic DNA, which causes cell death in many tumor types. However, DOX kills many normal cell types resulting in toxic side effects and restriction in the maximum tolerated dose. My research aims to specifically target bladder cancer by attaching doxorubicin to a peptide carrier. The peptide of choice, called PLZ4, was developed at UC Davis and shows strong binding affinity and specificity for bladder cancer cells. PLZ4 binds to cell surface molecules called integrin receptors, which then transports the peptide inside the cell. Since the receptors that are targeted by PLZ4 are over expressed in bladder cancer cells compared to normal cells, PLZ4 may be able to ferry DOX to the site of the tumor and kill the cancer cells while reducing side effects compared to conventional DOX therapy. This summer I am synthesizing DOX conjugated to PLZ4 and testing the ability of the new molecule to penetrate and kill bladder cancer cells. Because DOX is a fluorescent molecule, I will use confocal microscopy with fluorescent imaging to quantify the uptake of PLZ-DOX conjugates into cultured bladder cancer cells. I will also test the ability of PLZ4-DOX to kill the cells in comparison with conventional DOX therapy. This research aims to eliminate the adverse effects of chemotherapy treatment by specifically targeting the cancer cells of the bladder by binding the PLZ4 to integrin receptors over expressed by the cancer.
Personal Statement
The CBST summer intern program gave me the opportunity of a life time. I applied
to this program not knowing too many details, but I was blown away by the caliber of
the experiences within the program. I didn’t think I would be able to work alongside
PhD’s and post docs to accomplish the same goal: to advance society within the science
and technology field. My primary mentor, Dr. Henderson, treated me as an equal or
even more like a co-worker. He gave me the opportunity to make my own decisions
independently and the opportunity to learn so much about my specific project. I also
enjoyed that the program emphasizes the importance of networking. I had a blast
meeting and hanging out with all of the interns. They made this program and my summer
much more enjoyable. Aside from the fun things, I was able to learn so much from the
workshops that Dr. Corbacho and Dr. Gurkoff provided. For example, the personal
statement and interview workshops were very eye opening and I was able to apply the
knowledge that I had gained to my personal life. Also, I am now fully equipped to tackle
a journal article. Overall, this program is awesome and I wouldn’t change it for anything.
Yulia I. Kostenko
UNDERGRADUATE INSTITUTION
Sacramento City College
Major: Bioengineering/Biotechnology
CBST 2010 SUMMER INTERNSHIP
Primary Mentor: Sebastian Wachsmann-Hogiu
Secondary Mentor: Cynthia Pagba
Scientific Abstract
SYNTHESIS AND CHARACTERIZATION OF NOVEL NONLINEAR MATERIAL FOR OPTICAL SWITCHING
Yulia I. Kostenko, Cynthia Pagba, and Sebastian Wachsmann-Hogiu
Ultrafast optical switching has a broad spectrum of applications in telecommunication and has great potential in the fields of bioimaging and biosensing. However, in order to become useful for these applications, more efficient optical switches are required which utilize less energy per pulse. This can be achieved with materials exhibiting high nonlinearity. Our goal
is to synthesize an organic compound, CuL2, which possesses an exceedingly high nonlinear refractive index of 4.6x10-12 cm2/W, is thermally stable, transparent in the visible range of the electromagnetic region, and nonfluorescent. The synthesis of CuL2 involves a five-step sequence and the progress is monitored by taking the Raman spectra of the products for each step. The Raman spectra of all the reagents/ materials used are also obtained for reference and comparison. The products are purified by column chromatography and the fractions are analyzed by Raman spectroscopy. One immediate application of this material is in the development of an ultrafast optical switch for the separation of the fast Raman signal from the much slower (and stronger) fluorescence background. This will enable Raman measurements in tissue and at wavelengths in the visible range, with potential for improved sensitivity and specificity of detection.
Personal Statement
To play a productive role in a scientific community, a person must be well-balanced and comprehensively developed in a variety of aspects. However, the “classroom education” is
oftentimes insufficient in the overall development due to its lack of hands-on experimentation that encourages critical thinking and discovery. That’s why I am very grateful to the
CBST for giving me a chance to participate in their summer internship program. The benefits of being a part of this program are innumerable. Nonetheless, I would say that the most valuable aspect of the internship is that I was immersed in the real- world scientific environment with all its challenges, frustrating and rewarding moments. This experience destroyed my preconceptions about research and stirred up my mindset in a way books never would. Every day spent at CBST was consistently filled with discoveries awaiting you everywhere. That is because all people at CBST – interns, graduate students, mentors, and staff members – are very helpful, supportive, intelligent, and enthusiastic. I had a privilege to work with Sebastian Wachsmann-Hogiu, PhD, and Cynthia Pagba, PhD, two amazing people who made my experience at CBST unforgettable. They patiently guided me throughout the internship inciting my desire to explore and broaden my horizons. In addition to that, frequent seminars, journal club meetings, and workshops made the internship very informative and enlightening. It exposed me to different educational paths and perspectives. I am profoundly convinced that the CBST internship made a great contribution to my education as well as my professional and personal development.
