Welcome to the B(E)log! Here you can find posts about BMES, the BE department, or Bioengineering in general.
Mimicking the Rabies Virus to Fight Brian Cancer
It seems unlikely that a virus that kills thousands every year would give scientists new insights into effective cancer treatment, but that is exactly what researchers have done with the rabies virus. Brain tumors are difficult to treat because the blood brain barrier, a membrane that controls what reaches the brain, stops cancer fighting drugs from reaching brain rumors. It is estimated that about 17,000 people die of brain tumors each year. The rabies virus has the unique ability to pass through the blood brain barrier, giving cancer researchers the opportunity to treat brain cancer by mimicking the rabies virus.
Yu Seok Youn has led a team of researchers at Sungkyunkwan University in Suwon, South Korea in repurposing the rod-like structure that allows the rabies virus to penetrate the brain to fight cancer. The researchers used rod-shaped, gold nanoparticles that are able to use nerve cell receptors as a method of entering the brain. These nanoparticles then become concentrated at the brain tumor and are able to absorb heat to kill the cancerous tissue. Because the nanoparticles are made of gold, they are able to absorb infrared light and radiate enough heat to kill surrounding cells while other brain tissue is spared. This method of tumor treatment has worked in mice, but has not yet been attempted in humans. Here is the scientific journal article describing the methods used.
There is some dissension among the scientific community about the true potential of this treatment method. Some believe that the results of this study are not accurate because rabies usually takes longer to bind than was reported in the study. Another expert has expressed that it may be possible that the nanoparticles do not all accumulating around the cancer cells, leading to damage of healthy tissue as well as cancerous tissue. It is apparent that more work must be done to determine the effectiveness of this treatment; however, utilizing the attributes of a deadly virus to fight cancer is an example of an innovative strategy that will push the medical field forward in the future.
Here is an article is Science that provides more information on Youn’s study.
Multiple Oscillators Drive Forward Locomotion in C. elegans
Shelly Teng, Anthony Fouad, & Dr. Christopher Fang-Yen
This summer, I worked in the Fang-Yen lab to study the neural circuit of the microscopic nematode, Caenorhabditis elegans (C. elegans). In particular, our project closely studied how its neural network was able to control behavioral locomotion and movement. Previous studies have shown that locomotion is primarily driven by some combination of spontaneous rhythmic oscillators and the propagation of this signal through the rest of the worm’s body. By using optogenetic techniques, we were able to manipulate various neurons within the worm’s forward locomotion circuit and behaviorally assess how changing a certain neuron had an effect on the worm’s ability to propagate rhythmic movements. Data were analyzed using MATLAB and various worm segmentation software. Results from the study showed that the worm’s forward locomotion circuit is most likely comprised of multiple oscillators that are present through the entire length of the body. These oscillators have the ability to generate spontaneous undulations, and they have some sort of entrainment property that allows them to have specific effects on each other.
In the future, we plan to continue our work in elucidating the functional relation and connectivity of the neural circuit and forward locomotion. Through this project, we hope to better understand the nature of rhythmic locomotion in animals, as it is also relevant to many more complex organisms.
Potential Future Organ Transplants From Human-Animal Chimeras
Lack of available organs for organ transplants leads to the death of thousands every year. A potential solution has made its way into the spotlight with a paper published in January of 2017: organs from human-animal hybrids. In this article, Researchers from the Salk Institute detail the insights they gained from their efforts to cross the cells of two different organisms, and allow them to grow into a hybrid animal, otherwise known as a chimera.
The researchers of the Salk Institute created mouse-rat chimeras and human-pig chimeras by injecting the embryo of one organism with stem cells from another organism. Under the right conditions, embryos were then able to grow into a hybrid organism with the cells of both organisms growing together. Mice embryos injected with rat stem cells grew into adult chimeras with traits of mice and rats, some even growing gall bladders which have been absent in mice for millions of years. The human-pig chimera embryos were allowed to develop for three to four weeks before they were taken out of the pigs for analysis. It was concluded that the human-pig chimeras were developing with about one human cell per every hundred thousand pig cells.
These chimera organs clearly would not be usable in organ transplants due to the high ratio of pig cells; however, the potential for more human hybrid organs exists in the future. Researchers conducting this study utilized the CRISPR Cas9 system to delete traits from the host embryo that would prevent the injected cells from growing, demonstrating the utility of CRISPR Cas9. Another insight gained from this study was the delicate developmental timing of injecting stem cells when creating chimeras. There are complicated moral issues associated with combining human and animal cells into one organism; however, the idea of growing usable human organs for life-saving transplants is exciting.
Here is a National Geographic Article outlining the findings and implications of the study discussed.
A Topic in Bioethics: Bioweapons Event Summary
On Tuesday, 3/24/15, Dr. Matthew Hersch and Dr. Jonathan Moreno led a group of students in a discussion on the ethics of bioweapons. This is an issue that has become increasingly crucial as new technologies are developed, and the accessibility and lethality of bioweapons increases. Dr. Hersch and Dr. Moreno talked about topics that ranged from the various types of bioweapons to the United States’ preparedness for a bioweapons attack against the USA. They also briefly discussed their similarities with chemical and nuclear weapons.
Dr. Matthew Hersch, professor of Engineering Ethics, received his B.S. from MIT in Political Science and his Ph.D. from Penn. A Penn professor since 2009, Hersch has taught 8 courses at Penn, published over 30 conference papers, and won a multitude of prizes. Dr. Hersch is joining the faculty at Harvard University beginning July 2015.
Dr. Jonathan Moreno is a professor of medical ethics and health policy at Penn Medicine. He received his B.A. from Hofstra University, and later his Ph.D. from Washington University. Dr. Moreno has published 21 books and more than 500 papers, book chapters, reviews and op eds. Moreno is an elected member of several national and international bioethics committees. He was also a senior staff member multiple presidential advisory commissions.
Resume Workshop Event Summary
This year, Engineering Week at Penn was held February 23rd-27th. On Monday the 23rd, BMES hosted a resumé/cover letter workshop with guest speaker Rosette Pyne from Career Services. Pyne walked students through the steps to writing a cover letter and building a resume tailored to different applications. She even included memorable anecdotes from past students’ experiences, particularly about proofreading and using one’s own words, to reiterate her points.
For the second half of the event, as they munched on Federal Donuts, attendees broke off into one-on-one resume checks with upperclassmen from BMES and Theta Tau. All in all, Mrs.Pyne’s presentation combined with these resume critique sessions ensured that the event was an informative, yet interactive experience for the mostly freshman and sophomore attendees.
The Degradation and Mechanical Properties of Hydrogels
James Howard, Ryan Wade & Dr. Jason Burdick
Our first Research Spotlight was written by James Howard, a junior working in Dr. Jason Burdick’s lab. If you would like to learn more about his work or the other research being conducted by the Burdick lab, feel free to visit their lab website.
The goal of the research was to form a mathematical model that related the strength of hydrogels with a hyaluronic acid (HA) backbone to the enzymatic degradation rate of that hydrogel. Ultimately, this model could be used for future studies that apply to cell culturing, cell delivery, and growth factor delivery.
In degradation analysis, hydrogels were tagged with a fluorescent molecule before cross-linking, and after gelation, these gels were put in varying concentrations of Type II collagenase, which contains matrix metalloproteinases. Every other day, the gels were refreshed with collagenase or buffer, and the supernatant was collected to determine HA release from the network (fluorometric analysis). The results showed that the 4 wt% gels were mechanically stronger than the 2 wt% gels because a larger weight percent corresponds to an increase in cross-linking density, causing the gels to be stronger. The degradable hydrogels completely degraded in response to collagenase because the peptide sequences within the gel are recognized. In contrast, non-degradable gels remained intact in collagenase as the peptide cross-linkers were not recognized by collagenase.
The next step in developing this mathematical model is to measure the Michaelis-Menten degradation parameters of single degradable and non-degradable peptides to incorporate into a statistical model of degradation.
This semester, we will be posting Research Spotlights to give BE undergraduates who are working in a research lab the opportunity to share their work with the BE community. We hope the Spotlights will promote discussions and well as introduce readers to areas of study outside of their own.
If you work in a lab that does biomedical-related research at Penn and would like to write a short summary of the lab’s activities, please email the BMES Board at firstname.lastname@example.org. If you plan to work in a lab over the summer, let us know, and you can submit at article at the beginning of the Fall 2015 semester. Remember to first get permission from your PI!
Plans for Next Semester
We are very excited for the spring semester, as we have a lot in the pipeline which we believe will benefit the BE community.
Our first event of the semester was a talk by Eric Esch, a PhD student in the Huh Lab. He worked as an engineering consultant for MPR Associates, and spoke to members of the BE Mentoring program about important lessons he learned as an undergrad. The talk took place on Thursday, 1/22/15 in Raisler Lounge from 12-1pm.
The mentoring program will continue to hold small events to encourage the mentor/mentee relationships that began in the first semester. We are hoping to hold a spring semester kickoff event in the near future for members to reconnect with each other after the long winter break.
Semester in Review
BMES would like to welcome you back to what is sure to be another fun and fulfilling semester at Penn.
The Fall 2014 semester was a very successful one for us. We won the BMES Outstanding Outreach Award from the national BMES organization for our efforts in spreading awareness about bioengineering to the surrounding community. We also organized a variety of events focused on professional development, community service and academics. One of our biggest events was the BE Alumni Reception. Taking place in the Glandt Forum of the Singh Center for Nanotechnology, undergraduate BE students had the opportunity to speak with alumni about their undergraduate experiences and the careers they are currently pursuing with their BE degrees. Another event was the Healthcare Consulting Panel, hosted in partnership with the M&T Club. The panel consisted of representatives from ZS Associates, PwC, and Simon-Kucher & Partners. It was a great way for students to learn more about healthcare consulting from professionals in the field. In November, we organized a registry drive with Be The Match to allow BE students to join a bone marrow registry and get the opportunity to save the lives of blood cancer patients. We are planning on holding another drive this semester to give even more people the chance to register.