Week Eight . . . The End

After eight weeks of living and working in Cambridge, MA, my time here has come to an end. My last few days at Harvard and MIT were quite eventful, so much in fact, that I slept a total of less than 14 hours during my last three nights! But I’ll start at the beginning . . .

On Monday, I spent nearly five hours extruding in the lab. Extrusion, if you remember from my last blog entry, is one method of forming liposomes of a desired size. The method is relatively simple; the solution containing the liposomes is filtered through screens of decreasing size using high pressure. The solution needs to be filtered through the larger filters three times, but through the smaller filters 12 times. So the process takes a long time when there are six filters involved. Also, in between each filtering cycle, the extruder needs to be disassembled and cleaned for any excess solution. I was standing during the whole process, so I was pretty tired by the end of the day.

On Tuesday, there were more presentations from college students in journal club. Topics included the creation of gels held in dialysis tubing for controlled release drug delivery and the development and evaluation of 3D gel constructs for vocal fold tissue engineering. Another student presented a paper on the dispersion of biofilms with engineered enzymatic bacteriophage. I enjoyed the two student research presentations, but had some difficulty with the content of the paper. Back in the lab, I weighed out synthetic lipids and cholesterol for Al and Hila’s future work with the liposomes.

Wednesday was my last day in the lab, and I spent it working alongside Al and Hila, freeze-thawing four different liposome compositions. Three of the samples had the toxic substance saxitoxin (STX) inside of them. STX is a naturally-occurring toxin that is a potent and extremely selective sodium-channel blocker. It is responsible for red tide and the subsequent harsh effects on humans. In fact, ingestion of 0.2 mg of STX is fatal to an average size human, so I was a little wary in handling the substance, even if it was safely enclosed in a plastic test tube. Other than the freeze-thawing, there was little for me to do around the lab, so I spent some time cleaning and saying good-byes before I left.

Meanwhile on campus, it was finals week for everyone. Monday night, I was up until 3:00 studying for my Tuesday exam. After only a few hours of sleep that night, Hila and Al gave me strict instructions to take a half day at the lab and go take a nap before my exam. The exam itself was okay. I was more relieved than anything after it was over, which my whole floor heard about while I danced in the hallway.

Wednesday was the last day on campus for most of my floormates, including myself. To celebrate, we had a gigantic sleepover (involving very little sleep), complete with 15 cartons of strawberries and more food than we could have ever possibly eaten. It was a fun way to spend my last night, even though I was scrambling to finish my packing on Thursday morning before my parents picked me up. The morning concluded with my last breakfast in Annenberg and even more goodbyes in my dorm before the ride home.

All in all, these last eight weeks have been pretty amazing. What I’ve learned most about research is that you can never predict how busy a lab will be and you should always prepare for the worst-case scenario. As for myself, I learned how to survive away from home and challenge myself in a class where it was impossible to know all the answers. Thank you to Mr. Palm, the Science Department at Brooks School, Harvard Summer School, and MIT’s Langer Lab for giving me the opportunity to have such a once-in-a-lifetime experience. I encourage other Brooks students to apply for future summer opportunities.

Have a great school year!

Week Seven . . . A Little Bit of This, A Little Bit of That

Seven weeks down, one to go. It’s scary to think that I have less than a week left in Cambridge. As far as busy weeks go, this was one of the busiest. I spent my week shadowing Al and Hila, mostly observing and learning about their work with liposomes.

Liposomes are another type of particles used in experimenting with drug delivery. The basic process of making liposomes, as Al explained to me, is as follows:

First, all the hydrophobic components (lipids, cholesterol) are dissolved in a chloroform: methanol solution. Then, the chloroform and methanol are evaporated, using a rotovap at a temperature above the melting point of the lipids. A rotovap is a machine that uses temperature and pressure as a means to evaporate and then remove liquids from a solution. When the chloroform and methanol are evaporated, all that is left is a film. An inorganic substance called t-butanol is used to dissolve the film, then the solution is frozen in liquid nitrogen. After 2-3 hours, the t-butanol is evaporated using the rotovap again and the remaining film is put on the lyopholizer overnight. Then, you add water and ammonium sulfide to return the frozen sample to an aqueous phase. At this point, the process for making liposomes diverges, depending on the size you desire. Extrusion, or filtering, is one method. The other method is to homogenize the sample for 10 mins, adjusting the speed based on the desired size for the liposomes. Then, the sample is freeze-thawed (transferred back and forth 12 times from liquid nitrogen to hot water). No matter which method is chosen, the final steps include dialysis to get rid of the ammonium sulfide, loading of the drug, and then dialysis to get rid of any outside remnant drug.

As you can see, making liposomes is a long process, but I was able to see the entire process at different points throughout the past week.

In addition to the liposome work, I worked with Al to take pictures of embryonic stem cells in some of the HA hydrogels that Sarah and I had made. I also watched Hila perform a Live/Dead assay on the same cells. I finished the MTT assay for Sarah’s SBA-15 experiment, and my results showed that the supernatant alone had little to no effect on cell viability.

On Tuesday, and extra-early journal club consisted mostly of presentations from summer interns preparing to head back to their respective universities. Topics of discussion included targeted gene delivery of nanoparticles to MDA breast cancer cells and the creation of ‘patterned monolith structures for passive mixing in microfluidic channels.’ Later in the week I attended a poster session for other summer students, where they were able to present their research for the MIT community. I learned a lot, and I was surprised at how much I understood. Also at journal club, a graduate student presented a paper on continuous sensing with magnetic nanoswitches.

Wednesday, I met my aunt (who works only a street away from Langer Lab!) for lunch and we did some shopping in between my liposome work at the lab. Thursday was the Langer Lab beach party. However, because I had my last lecture of the summer session that night, I didn’t attend the party, but instead went on a college visit with my parents before coming back just in time for class. Our last lecture topics included the sexual transmission of HIV, development of a vaccine, and HIV in India.

This weekend I “visited” Harvard with my parents, attending an information session, but opting out of a tour, since I’ve seen nearly all of campus while living there. My final exam is Tuesday night at 6:15 pm, so I spent the remainder of my weekend studying anywhere and everywhere: my room, the library, the science center, the lawn in front of my dorm, the tutoring office, and the hallway. I did, however, make some time to support Jee Su at an orchestra performance and stop by the last dance of the summer.

With only three more days for me at the lab, a final exam, and all my packing to do before I leave on Thursday morning, these last few days in Cambridge will be stressful and busy as everything comes to a close. Wish me luck!

Week Six . . . Polymers, Buses, and YouTube—Oh My!

With my sixth week in Cambridge now behind me, I’m my time here is quickly ending. This was my last week with Sarah as my post-doctorate, and we spent most of the week finishing up things so that she could get ready for her trip to Canada. We did have a decent amount of lab work, but compared to some past weeks, it was much quieter and more relaxed around the lab.

This week we focused on polymers, a stark contrast to MTT assays. We made a PXC-ADH polymer again, following the same process of maintaining the pH while we added the materials, putting it on dialysis and then freeze-drying it. Later in the week, we dissolved the freeze-dried PXC-ADH along with several other polymers. We tried mixing different combinations of the polymers at different concentrations with a double-barreled syringe to see if any hydrogels formed. This process took most of the week, so I spent time cleaning up the lab bench and reading scientific journals as well.

For this week’s journal club, there were talks on the ‘disassembly of nanodiscs with cholate’ and the production of neural-controlled prosthetic devices for humans with tetraplegia. The first talk was way over my head, but I found the second topic quite interesting, especially the videos we were able to see of the working devices.

On Thursday, I plated mesothelial cells on my own for the first time. Dan Anderson, the head of our group at MIT, asked Sarah to perform a rough experiment on the effects of SBA-15 nanoparticles versus SBA-15 supernatant on mesothelial cells. Since Sarah won’t be around to finish the experiment next week, I was responsible for adding the substances to the cells on Friday and I will perform an MTT assay on them to determine what happened to the cells in the different environments.

In class this week, we discussed the human immune system: how it reacts to HIV infection and how HIV turns the immune system against itself during progression to AIDS. It was some of the hardest biology we’ve discussed so far; I even had to pull out my AP Biology book to review basic immune responses so that I could understand some of the more advanced concepts.

Friday night, Jon and I had our first adventure on the bus system in Cambridge, venturing to Mr. and Mrs. McCahill’s new home for dinner. We spent a few hours with them before heading back to campus. I was also home for part of the weekend, spending some time with friends and working on one of my community service projects for this school year.

Sunday night I received an urgent text message from a fellow Brooksian instructing me to return to campus in time for the Secondary School Talent Show at Harvard. So after gathering all my stuff in less than ten minutes and suddenly informing my parents that I had to go back to campus two hours earlier than anticipated, I was there to see five old and new friends perform—to a Backstreet Boys song. It was hilarious; they’ve now become campus celebrities and videos of their performance can already be found on YouTube. My weekend ended with an 11:30 pm ice cream run with a few friends who we convinced to stop by Harvard Square on their way home from Boston.

Next week I’m going to be working with Hila, a post-doc, and Al, a student at MIT. I’ll be shadowing the two of them and their work with liposomes in addition to completing Sarah’s experiment. I’ll be seeing a multitude of different things in the lab, so it will be a change from my current routine.

Enjoy your week!