D Peng - Research Update

I realized I haven't written about my research yet, so here's an update. I work in the Functional Nanosystems (FNS) group at imec, a group of very friendly graduate/postdoctoral students.

Scientists at imec have been interested in inorganic nanoparticles, namely gold and iron oxide particles, for the application of hyperthermia therapy of cancer. Gold nanoparticles can be optically heated because they have a surface plasmon resonance. These particles can be adjusted to absorb near infrared (NIR) light, which provides penetration through tissue with minimal absorption by hemoglobin and water, allowing for selective photothermal therapy of cancer. Similarly, superparamagnetic iron oxide nanoparticles can be remotely heated using an alternating magnetic field. These particles have further potential in that magnetic fields can penetrate deeper in vivo than near infrared light, and can also be imaged using magnetic resonance.

MDA-231 are triple negative human cancer cells with no effective treatment, which motivates this collaboration between Green's lab and imec to develop a local, controllable drug delivery system for dual cancer therapy by encapsulating these particles in thermo-sensitive polymer gels. Poly(ester amine)s are promising drug delivery vehicles due to their degradability and can serve as reservoirs for delivery of encapsulated drugs, sensors, or inorganic particles. Diacrylate-terminated poly(ester amine)s can be UV-crosslinked using acrylate-functionalized monomers and oligomers (PEG-diacrylate) and a photoinitiator to form polymer gels.

I've been synthesizing gels and characterizing them for their mechanical and retention/release properties. I've also been testing the inorganic nanoparticles with their respective hyperthermia set-ups, and synthesizing gels with particles inside. So far, I've been able to demonstrate that a gels with encapsulated inorganic nanoparticles can heat up to 16C, which is very promising for triggering drug release.

Experimenting with the laser-hyperthermia set up has been especially interesting. Powering on the system will turn on a sign saying "Verboden Toegang Laserstraling," to warn other scientists that the Class IV laser is on. I also have to close black curtains around the set-up to prevent any exposure to the rest of the lab. Here's a picture!

Curtains enclosing the laser-hyperthermia set up

It's also been a really great experience being able to meet imec employees who work in the different labs. In Biolab 1, I use DLS and do all my chemical experiments. In Biolab 3, I do dark field imaging, use the UV-Vis spectrometer, and the magnetic hyperthermia set-up. In the Convergence lab, I use the laser hyperthermia set-up. In the Neuro-Electronics lab, I use the plate reader and will do tissue culture as my project reaches its final stages. Finally, in the Remo lab, I do all my UV-crosslinking. It's been nice that imec's resources have fit so well with my project.

I will be giving my second presentation to the FNS group this coming week. An interesting story from my first presentation a couple weeks ago: 20 minutes into the powerpoint, two of the scientists started a discussion about a detail in my presentation. As the discussion got heated, they both switched from English to Dutch for more natural fluency. As the only non-Dutch speaker at the front of the room, this became a bit awkward for me for the following 15 minutes. We laughed it off later on.

Aside from this project, I've also been busy writing paper drafts for my characterization research back in Dr. Green's lab, organizing and preparing for this year's annual Biomedical Engineering Society (BMES) conference in Hartford, discussing and having Google+ "hangouts" (video chats) with my upcoming design team, and attempting to study for the GRE.

I've been happy with my overall experience at imec so far - it's been enriching both culturally and academically. I'll try to update more before the internship ends!

D. Peng


Sorry for the delay with posting. The three of us have been working hard getting results and, well, being in Europe. But this blog will be updated with our adventures and progress soon, we promise! Our second long weekend (6/11-6/13) was spent in Paris, France. It was a quick 1.5 hour train ride from our Leuven train station with a transfer at Brussels train station.

Paris was a lot of fun for all of us and the subway system made it convenient to get around. We hit the following attractions: the Louvre Museum (twice, because once wasn't enough for us), the Arc de Triomphe, and the Eiffel Tower.

I'll let pictures show you the rest!

Daniel touching the tip of the pyramid in front of the Louvre

Lauren celebrating making it to Paris

Joanna posing in front of a statue display in the museum

Crowd of visitors fighting to get a closer picture of the Mona Lisa

View from inside of the museum

The Venus de Milo

Bridge filled with "love padlocks"

The three of us in front of the Arc de Triomphe

View from the top of the Arc de Triomphe

Joanna and Lauren posing in front of the Eiffel Tower from the roof of the Arc de Triomphe

Close-up picture of the Eiffel Tower

A delicious crepe spread with nutella and filled with sliced bananas

That's all for now!
- Daniel


Hello from Leuven, Belgium! I was so excited when I found out my project proposal had been accepted by the INBT/IRES program, and I can hardly believe we're here with the opportunity to work at IMEC! We've been so busy getting settled and starting work on our projects, but we've had a little time to explore the weekends. We arrived on May 31st, a day early for our June 1st orientation. Ascension, a Belgian national holiday, was observed on June 2nd, and since it fell on a Thursday, the following Friday was also generally not considered a work day. For us, this meant we had time to adjust to the time difference, which was made especially difficult by the long daylight hours here--the sun generally rises around 6:00 am, and it doesn't get dark until 10:00 pm! (We're six hours ahead of Baltimore, and twelve hours ahead of my hometown: Honolulu, Hawaii.)

Fiesta Europa, an organized festival that invites vendors from different European countries to set up an open market style event, happened to be in Leuven that weekend. It was set up in the center of the town at Ladeuzeplein, the large square behind the Katholieke University Library. At night there were pyrotechnic performances, fireworks, and a drum performance! The next day, we stumbled upon Circus & Co. in the park just North of the square just in time to watch some of the acrobatic performances. One of the routines we saw was entirely in Dutch, but humorous nonetheless.

In general, Leuven is a small city, the center of which is enclosed by a circular highway. Everywhere is reachable by bike, and for many of the large student population here (including ourselves), that's the primary mode of transportation. We bike to work, to go grocery shopping, and pretty much anytime we need to get around. After only two weeks here, I can't imagine not having my lime-green bike, and am very glad my Dad taught me to ride when I was little!

I'm on the JHU Fencing team, and in order to continue training thorughout the summer, I've found a fencing club in Leuven! At open fencing the other day, I learned that streets ending in 'straat' (street) refer to the part of that street that is inside the circular highway, and those ending in 'steenweg' refer to streets outside of the circle. 'Steenweg' comes from 'stone road', refering to roads that were not paved. It's little things like this that make me love Leuven more and more. Language has been an adjustment, but most people in Leuven are bilingual, speaking both Dutch and English, so we haven't encountered many problems. Many of the signs and labels, however, are dutch only, which leads to interesting grocery purchases. We've bought buttermilk and Speculoos, mistaking them for milk and peanut butter respectively. Speculoos is very good gingerbread spread, but a bit surprise if you're not expecting it!

Orientation consisted of a tour of the four buildings, as well as basic safety training. The exterior of IMEC is very pretty in summer. Sheltered by glass coverings, the open walkways connecting the buildings are flanked by greenery on either side. The inside of the IMEC facilities is nothing short of impressive. We work mainly at IMEC One, which houses offices, labs, and the research clean room. To get to lab every morning after stopping at our desks, we walk through the support floor of the clean room--an overwhelming labyrinth of pipes, valves, and gauges to supply the various manufacturing machines housed above.

The clean rooms are amazing: giant ballrooms filled with researchers quietly preparing silicon wafers for patterning amongst machines the size of an average bedroom. Protective, light plastic clothing, rubber shoe coverings, and eye protection is de riguer as they perform precisely choreographed protocols. One clean room is a Class 1 (One particle per cubic meter) while another more recently set up clean room is rated Class 1000. However, this is because the equipment is nearly completely automatic, and does not require the wafers to be exposed to the clean room environment while being transferred into the machine.

At IMEC, lab access is controlled by your keycard, or badge. The majority of the first week consisted of required safety training in the Convergence lab and Neuroelectronics lab to be given access, as well as training in tissue culture, confocal microscopy, and fluorescent microscopy. In order to use any equipment, you must first be granted access by the 'lab responsible', the person in charge of that tool.

My project here at IMEC is a continuation of work previously performed by Professor Sharon Gerecht's lab at JHU. I will be microcontact printing silicon micropillar substrates manufactured here at IMEC with components of the extracellular matrix, fibronectin and type IV collagen, in parallel patterns. Endothelial cells will first be cultured on the substrates, and then transferred to fibrin and type I collagen gels respectively via inversion of the substrates. The goal of the project is to enhance and control tubulogenesis.

Last week consisted mainly of test prints and optimization of the protocol to make sure the printing and fluorescent staining process were consistent. Joanna and I are using the same cell lines, and we thawed a vial of each this past week. Hopefully they will be confluent (Will have a cell density high enough that we can use them in experiments and pass them to a new flask to continue the culture) early next week, which means I could test the entire process!

I can't wait to see more of the city, and hopefully will be traveling more on weekends! I'd love to have more pictures to share with you!

Tot ziens voor nu,
(Bye for now)



I didn't want to repeat anything that Daniel or Lauren wrote so this time, I only wrote about my research here.

My project here at IMEC is a collaboration combining the research that I have done at the Gerecht Lab (http://www.jhu.edu/chembe/gerecht/) at Hopkins with some of the research done here. The Gerecht lab has previously examined the effect of micropatterned fibronectin on 2D glass substrates on endothelial tube formation. Research at IMEC has used stiff silicon processed nail beds and examined their effect on both mature and endothelial cell culture. This summer, I hope to continue and combine the research done by both institutions by fabricating soft 3D substrates from PDMS and examining their effect on endothelial tube formation.

Last week, I began to optimize PDMS conditions in order to best create the soft substrates, as well as familiarizing myself with IMEC's facilities and protocols. This week, I hope to perform some of the controls for the project.


Looks like we'll be blogging on here this summer - the three of us (Lauren, Joanna, and me) are undergraduates from the Johns Hopkins INBT (Institute for NanoBioTechnology) IRES (International Research Experience for Students) program. Long name, I know, but in short we're all working on collaboration projects between our labs at Hopkins and imec. I'm an incoming junior at Hopkins majoring in biomedical engineering.

Back at Hopkins I work in Dr. Jordan Green's lab(http://web1.johnshopkins.edu/greengroup/). In the Green Group I am trying to optimize polymers for properties such as degradation rate, buffer capacity, particle size, and binding affinity for effective gene delivery. I'm crosslinking some of these polymers into gel reservoirs to store drugs and combining the gels with nanoparticles worked on at imec that can be optically or magnetically heated for a controlled drug delivery system. I'll detail my summer project at imec in a later post.

A little delayed, but we arrived safely in the cozy city of Leuven, Belgium 2 weeks ago! After unpacking, the first thing we did was rent bikes for the next 10 weeks, since the majority of Leuven residents bike. Our apartment is a 15-minute bike ride to imec, so like many other imec employees, that's how we get to work! The first weekend (4-day weekend) we spent here happened to be Fiesta Europa, an international festival in Leuven which consisted of a weekend-long farmer's market, fire-related shows, and some circus performances.

Fireworks kicking off Fiesta Europa

An array of candy at the farmer's market

Acrobatics performers

Lamp circus performer

Belgian boy being hugged by a chair

Fire performer

Joanna and Lauren posing next to a fresh pork sandwich advertisement

Until Later,
D. Peng