The subtle allure of materials science and engineering

You know what’s funny?

If you were to have asked me during my senior year of high school what Materials Science and Engineering (MSE) was, I wouldn’t have the slightest clue how to answer. Now, less than five years later, I’m sitting here writing this as a first-year MSE PhD student, and were I to be asked that question now, I could go on for hours about how it is one of the coolest, most interdisciplinary fields anyone could get themselves into.

MSE is often an overlooked discipline due to it not being a “major” (read: Mechanical, Chemical, Electrical) engineering discipline. What most people don’t realize, however, is that practically everything you do and take advantage of on a day-to-day basis, you have a materials engineer to thank for. That iPhone of yours you stare at for over an hour a day? It’s a materials masterpiece.

Consider how many times you’ve accidentally dropped your phone (whether it be on the ground or on your face while you’re laying in bed) without the screen cracking. You have the engineers at Corning to thank for that. Corning’s Gorilla Glass is no ordinary day-to-day window glass; it’s a special aluminosilicate glass that has undergone a process called ion exchange. Basically, what happens is you dip a sodium-containing glass into a hot bath of potassium ions, where a literal exchange happens between the sodium and the potassium atoms. Since potassium is ever so slightly larger than sodium, the glass is put under compression. If anyone wants to break this glass, they must first overcome the genius behind its reinforcement. You can read more about how gorilla glass is made [here].

gorillaglass

A sample of corning’s Gorilla Glass put under a three-point bending test.

The materials genius behind the iPhone isn’t limited to just its screen. The production of the hardware that makes your phone so fast was also a materials problem—getting those two billion transistors to fit on a chip inside your iPhone took literal decades of work.

Problems like these are what brought me to take on MSE as my undergraduate major, but the interdisciplinary nature of the field is what convinced me to stay.

My “Intro to MSE” professor (and my eventual undergraduate research advisor), Dr. Laura Fabris, would often tell us about her research. She worked on the production of gold nanoparticles (?!) that could be used for disease/biological marker detection. Her research fascinated me, and was what originally got me interested in the region where materials and biology overlap. The more that I read about what was being done, the more I longed to be a part of it. These desires have brought me to the Johns Hopkins University for my graduate studies, and ultimately the Institute for NanoBioTechnology so that I could gain further insight and training on what is being done at the forefront of my field.

goldnanorods

Transmission Electron Micrograph of Gold Nanorods in solution.

Now that I’m here at Hopkins, I’ve found myself working on the synthesis and self-assembly of polymeric nanoparticles used for biomedical applications. Did you know that most drugs on the market that are used for treatment of diseases such as cancer are hydrophobic? Now, consider the fact that your body is about 60% water… This makes delivering drugs to certain areas of your body a huge problem, and has posed a challenge for hundreds of scientists and engineers. Using the polymeric nanoparticles my lab synthesizes, we can store these drugs in a safe “vehicle” so that they may safely arrive wherever they are needed. Cool, huh?

With that, I’d like to leave you with the video from Corning that truly was the tipping point to my choosing MSE. Although it no longer lines up with the direction I’m taking myself, it shows how the future lies in the hands of engineers who believe in the power of materials, and I hope I have inspired you to consider the impact materials make in both our everyday lives and the (not-so-distant) future.

Lazaro Pacheco is a first year PhD student in the Materials Science and Engineering department at the Johns Hopkins University. He is a member of the Herrera Lab, and he is currently working on measuring the polydispersity of polymer chains that are ‘grafted from’ a central polymeric backbone.

Media inquires about INBT should be directed to Mary Spiro at mspiro@jhu.edu.

Researchers honored with Presidential career awards

Two Johns Hopkins researchers were honored by the White House for their research achievements, including one biomedical engineer affiliated with Johns Hopkins Institute for NanoBioTechnology (INBT).

Namandje Bumpus, Ph.D., and Jordan Green, Ph.D., of the Johns Hopkins University School of Medicine are among 105 winners of Presidential Early Career Awards for Scientists and Engineers, which were announced by the White House on Feb. 18. The awards recognize young researchers who are employed or funded by federal agencies “whose early accomplishments show the greatest promise for assuring America’s pre-eminence in science and engineering and contributing to the awarding agencies’ missions,” according to a White House statement.

“These early-career scientists are leading the way in our efforts to confront and understand challenges from climate change to our health and wellness,” President Barack Obama said in the statement. “We congratulate these accomplished individuals and encourage them to continue to serve as an example of the incredible promise and ingenuity of the American people.”

Namandje Bumpus, left, and Jordan Green. CREDIT Keith Weller, Johns Hopkins Medicine

Namandje Bumpus, left, and Jordan Green.
CREDIT
Keith Weller, Johns Hopkins Medicine

Bumpus, an associate professor of medicine and of pharmacology and molecular sciences, also serves as the school of medicine’s associate dean for institutional and student equity. Her research focuses on how the body processes HIV medications, converting them into different molecules, and the actions of those molecules. In recent studies, she has found genetic differences in how people process popular HIV drugs, suggesting genetic testing should have a greater role to play in combating the virus. “Since joining Johns Hopkins in 2010, Namandje has made tremendous progress toward ultimately making HIV treatment more personalized and effective,” says Mark Anderson, M.D., Ph.D., director of the Department of Medicine. “This is a well-deserved recognition of her work, and I look forward to seeing how she will continue to advance the field.”

Green, an associate professor of biomedical engineering, neurosurgery, oncology and ophthalmology, and a member of INBT, was named one of Popular Science’s Brilliant Ten in 2014. He develops nanoparticles that could potentially deliver therapeutics to the precise place in the body where they’re needed — to make tumor cells self-destruct, for example, while leaving healthy cells intact. “Jordan’s innovations and productivity are exceptional, and his findings have very exciting implications for patients,” says Leslie Tung, Ph.D., interim director of the Department of Biomedical Engineering. “He is truly an extraordinary and exemplary early-career scientist, and a wonderful colleague as well.”

The 105 award winners will be recognized at a White House ceremony this spring.

Source: Johns Hopkins Medicine

Symposium speakers 2015: Jordan Green

Neuro X is the title and theme for the May 1 symposium hosted by Johns Hopkins Institute for NanoBioTechnology. The event kicks off with a continental breakfast at 8 a.m. in the Owens Auditorium, between CRB I and CRB II on the Johns Hopkins University medical campus. Talks begin at 9 a.m. Posters featuring multidisciplinary research from across many Hopkins divisions and departments will be on display from 1 p.m. to 4 p.m.

One of this year’s speakers is Jordan J. Green, PhD.

Jordan Green, PhD

Jordan Green, PhD

Jordan Green is an associate professor in the Department of Biomedical Engineering at Johns Hopkins University. He graduated from Carnegie Mellon University with a bachelor’s degree in Biomedical Engineering, Chemical Engineering and then attended Massachusetts Institute of Technology to earn his doctorate in Biological Engineering. Green joined the Johns Hopkins faculty in 2008 His research focuses on cellular engineering and nanobiotechnology, with special interests in biomaterials, controlled drug delivery, and gene therapy. The potential of gene therapy and genetic medicine to benefit human health is tremendous as almost all human diseases have a genetic component, from cancer to cardiovascular disease. Methods for drug and gene delivery that are both safe and effective have remained elusive. New insights into understanding and controlling the mechanisms of delivery are required to further advance the field. To accomplish this, Green’s research team is developing a framework where biomaterials and nanoparticles can be rationally designed and computationally modeled. These same biomedical insights can also be used more broadly in the fields of regenerative medicine and nanomedicine.

Dr. Green is working at the chemistry/biology/engineering interface to answer fundamental scientific questions and create innovative technologies and therapeutics that can directly benefit human health. In 2014, Dr. Green was named one of Popular Science magazine’s “Brilliant Ten” list, highlighting young scientists who are revolutionizing their fields. He is also a member of the USA Science and Engineering Festival’s Nifty Fifty, which includes 200 of the most dynamic scientists and engineers in the United States who were selected for their unique ability to inspire the next generation of students to pursue careers in the STEM fields. He and Dr. Alfredo Quiñones-Hinojosa recently won a BioMaryland Center Biotechnology Development Award to advance their work on a biodegradable nanoparticle therapy enabling effective transfection of a patient’s stem cells derived from adipose tissue that are applied directly to the post-operative site of brain cancer.

Additional speakers will be profiled in the next few weeks. To register your poster and for more details visit http://inbt.jhu.edu/news/symposium/

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, mspiro@jhu.edu or 410-516-4802.

 

 

 

Podcast: Shaping polymers for biomedical use

In this edition of the Johns Hopkins Institute for NanoBioTechnology Nanobyte podcast, Hai-Quan Mao, professor of materials science and engineering at Johns Hopkins University, discusses his work with polymers and their potential applications for medicine.

Slide1 In the Mao lab, researchers are using multi-molecule structures called polymers and forming them into different shapes for biomedical applications such as tissue engineering, nerve regeneration, and drug delivery. Mao uses natural models, such virus, as shape templates for designing nanoparticles with specific capabilities.

Listen to the podcast on Mixcloud here.

Visit the Mao Research Group here.

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, mspiro@jhu.edu or 410-516-4802.

Definition: What is Brownian Motion?

Not all bumper cars are created equal. Somehow I always pick the one with a sticky gas pedal and become the object of torment for my opponents. This is essentially what happens to microscopic particles when you stick them in a jar of water. The microscopic particle is a massive bumper car stuck in the middle of the rink surrounded by a bunch of tiny super-charged bumper cars, water molecules. The water molecules are all crashing into the poor, defenseless particle at once, and this makes it move. If you were to watch the particle, it would look like it’s moving in random directions for no apparent reason. A botanist named Robert Brown (hence the name Brownian Motion) watched pollen grains doing this in water with a microscope almost 200 years ago.

Click on this image to watch "Dark Field Video Microscopy of 100 nm Gold Nanoparticles"

Click on this image to watch “Dark Field Video Microscopy of 100 nm Gold Nanoparticles” by Gregg Duncan

It turns out actually that this process isn’t entirely random. How fast particles jiggle around is dependent on a few things. As the particles get bigger, they will move slower because more water molecules have to gang up on it to push it around. We can also give the water molecules more energy by increasing the temperature. At higher temperatures, the water molecules will move around faster and bang into the particle with more force that will make the particle move more quickly. It’s also important what kind of fluid the particle is immersed in, as you may or may not know from experience, it’s a lot easier to swim through water then something more viscous, or “thicker” like molasses. So if you take these few things into consideration, we can predict how big the random jumps particles make pretty accurately.

So then how do we measure how fast they move? Well, you need some way to watch the particles move around and this is still done the same way Robert Brown did back in the day with a microscope. Then you can watch the particle for awhile and write down where it went over time. You’ll see that if given x amount of time, the particle on average moves about the same distance. In fact, if you plot the average distance the particle moves versus time, it’s a straight line. The slope of that line is what we use to figure out the diffusion coefficient of the particle, and this tells us how fast or slow the particles will move.

Luckily in my lab, we have fancy cameras attached to our microscopes to make movies of particles moving around. I have a video here I took recently of some gold particles I was messing around with. I used a technique called dark field microscopy, which is a nice way to image really, really tiny particles like these that can’t be seen in normal microscopes. We’ve also written particle tracking software that does all the number crunching for us to figure out how fast the particles are moving. It is important for us to know how fast particles are moving as they approach each other for instance, when we try to build crystals out of them or as they approach a surface, like a cancer cell.

Story by Gregg Duncan, a Ph.D. student in the Department of Chemical and Biomolecular Engineering with interests in nanoparticle-based biosensing and drug delivery.

Bee blight and a honeycomb of funding possibilities

by Holly Occhipinti http://www.flickr.com/photos/pinti1/5519458297/

by Holly Occhipinti http://www.flickr.com/photos/pinti1/5519458297/

Time Magazine had an issue recently where the front cover asked, “What would the world be like without bees”? (1) This might seem like a rather small loss to the global ecology; how could bees play that large of a role in our daily lives? Actually, bees are rather important for us as human beings and for our food sources. The article estimated that the loss of bee pollination of plants would cost several billion dollars annually. This is perhaps the reason why a funding source we as scientists might not be accustomed to thinking about, the U.S. Department of Agriculture through the Agricultural Research Services (ARS), is looking to fund research to protect bees. (2) I believe that this could provide a unique source of funding for labs interested in studying and preventing the spread of Bee Blight.

What is Bee Blight then and why is it threatening bees?  As the source from above writes, Bee Blight is a poorly understood phenomenon, which is causing a change in worker bee behavior to have them leave their hives.  This decreases the overall population of bees and the effectiveness of the bee hive at producing honey and pollinating.  It is speculated that a combination of pesticides and fungicides that are currently in use are somehow poisoning the honey bees and causing them to exhibit this strange behavior.  Due to the fact that this concepts is very poorly understood, there are a multitude of efforts being made to find solutions to the problem of Bee Blight.

We as scientists at Johns Hopkins University have an opportunity to help research this problem and, in terms of funding, gain access to the resources that the ARS and other groups is providing.  Recently, a Harvard Lab was provided almost ten million dollars from the NSF to study how to make a hive of robotic bees to replace the ones found in nature. (3)  As someone whose research project is based on studying Melittin, the key component of Bee Honey Venom, and who is also an amateur entomologist, I believe that the solution might not need to be that exotic.  How many of us work on nanoparticles that are supposed to have very specific properties in very specific environments?  How many of us work on creating coatings for devices that kill off bacteria and other harmful diseases?  How many of us work in the public health department and know the impact that proper food management has on people’s health?  I believe that there are many other options, from better crops to better pesticides, that we at Hopkins have the ability to investigate and that this provides a new source of funding for our efforts.

  1. Time Magazine, August 2013
  2. Kaplan K. (2013, March 7). Honey Bees and Colony Collapse Disorder.  ARS website. Retrieved 9/9/2013 from <http://www.ars.usda.gov/News/docs.htm?docid=15572>
  3. Robobees Lab. (2013). Home Page. Robobees Lab Website. Retrieved 9/9/2013 from <http://robobees.seas.harvard.edu/>

By Gregory Wiedman, a graduate student from the Materials Science Department who is altering natural peptides from Bee Honey venom to improve drug delivery.

Overcoming drug delivery barriers

Editor’s Note: The following is a summary of one of the talks from the 2013 Nano-bio Symposium hosted by Johns Hopkins Institute for NanoBioTechnology held May 17. This summary was written by Randall Meyer, a doctoral candidate in the biomedical engineering and a member of the Cancer Nanotechnology Training Center. Look for other symposium summaries on the INBT blog.

Nanotechnology bears a multitude of possibilities to systematically and specifically treat many well-characterized and currently untreatable diseases.  Despite this, there exist multiple barriers to its development including challenges related to delivery in the human body.

justin_hanes

Justin Hanes, a professor of Chemical and Biomolecular Engineering at Johns Hopkins University, highlighted some of the exciting advances that his laboratory has developed to overcoming these challenges.  According to Hanes, one of the primary functions of nanobiotechnology is to enable a therapy to be delivered to a specific location and only remain there for as long as it is needed.  He likened this idea to applying weed poison to a rose garden.  You only want to apply a little bit of poison to a targeted area, not flood the whole garden.  Unfortunately conventional cancer chemotherapy is like flooding the garden, but only 1 percent of the drug reaches the tumor.  Hanes stated the goal of his work is to flip that so that all but 1 percent of the drug makes it to the site of delivery.

With that in mind, Hanes summarized two stories from his lab of ideas that are successfully being translated from bench to bedside.  One therapy involves the use of custom designed nanoparticles that are capable of penetrating the mucus layers of various human tissues to enable a controlled release of drug into the body.  The second therapy involves the use of injectable particles to the eye that inhibit blood vessel formation,  which is related to diseases such as macular degeneration.

These therapies are being developed by biotech companies launched by Hanes, GrayBug and Kala Pharmaceuticals.

Nanotech checks on transplanted cell survival

Researchers at Johns Hopkins are using nanotechnology to track the survival and location of transplanted cells. The device, based on nanoscale ph sensors and imaging via magnetic resonance, could help improve outcomes from cell replacement therapies used for conditions such as liver disease or type 1 diabetes.

Cartoon showing nanoscale probe used to detect pH change caused by death of transplanted cell. (McMahon/Nature Materials)

Cartoon showing nanoscale probe used to detect pH change caused by death of transplanted cell. (McMahon/Nature Materials)

“This technology has the potential to turn the human body into less of a black box and tell us if transplanted cells are still alive,” says Mike McMahon, Ph.D., an associate professor of radiology at the Johns Hopkins University School of Medicine principal investigator on the study. “That information will be invaluable in fine-tuning therapies.”

Transplanted cells often fall victim to assault from the body’s immune system, which sees the news cells as foreign invaders. Says McMahon,  “once you put the cells in, you really have no idea how long they survive.”

When cells die there is a change in the acidity nearby. Using this fact, the researchers developed a nanoparticle sensor that could both sense the change in pH and be detected via MRI. The team tested the sensors on mice and found they they were able to track the location of surviving transplanted cells and determine the proportion that had survived.

“It was exciting to see that this works so well in a living body,” says research fellow Kannie Chan, Ph.D., the lead author on the study, which was published in Nature Materials. This should take a lot of the guesswork out of cell transplantation by letting doctors see whether the cells survive, and if not, when they die,” Chan says. “That way they may be able to figure out what’s killing the cells, and how to prevent it.”

Chan works in the laboratory of Jeff Bulte, Ph.D., the director of cellular imaging at Johns Hopkins’ Institute for Cell Engineering. Bulte and McMahon collaborated on the study. Additional authors include Guanshu Liu, Xiaolei Song, Heechul Kim, Tao Yu, Dian R. Arifin, Assaf A. Gilad, Justin Hanes, Piotr Walczak and Peter C. M. van Zijl, all of the Johns Hopkins University School of Medicine. McMahan, Bulte, Gilad, Hanes and van Zijl are all affiliated faculty members of Johns Hopkins Institute for NanoBioTechnology.

Funding for this study was provided by the National Institute of Biomedical Imaging and Bioengineering (grant numbers R01 EB012590, EB015031, EB015032 and EB007825).

Follow this link to read the paper, MRI-detectable pH nanosensors incorporated into hydrogels for in vivo sensing of transplanted-cell viability, in Nature Materials online http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat3525.html

DNA folded into shapes offers alternative gene delivery vehicle

DNA molecules (light green) packaged into nanoparticles of different shapes using a polymer with two different segments. Cartoon illustrations created by Wei Qu, Northwestern University and Martin Rietveld, Johns Hopkins /INBT. Microscopic images created by Xuan Jiang, Johns Hopkins University.

Using snippets of DNA as building blocks to create nanoscale rods, worms and spheres, researchers at Johns Hopkins and Northwestern universities have devised a means of delivering gene therapy that avoids some of the undesirable aspects of using viruses to deliver genes to treat disease. The shape and size of the DNA-based nanoparticle also affected how well the genes were delivered.

Worm shapes, for example, were particularly effective.

“The worm-shaped particles resulted in 1,600 times more gene expression in the liver cells than the other shapes,” said Hai-Quan Mao, an associate professor ofmaterials science and engineering in Johns Hopkins’ Whiting School of Engineering. “This means that producing nanoparticles in this particular shape could be the more efficient way to deliver gene therapy to these cells.”

This study was published in the Oct. 12 online edition of Advanced Materials.

Initial funding for the research came from a seed grant provided by the Johns Hopkins Institute for NanoBioTechnology, of which Mao is an affiliate. The Johns Hopkins-Northwestern partnership research was supported by a National Institutes of Health grant.

Read the entire Johns Hopkins press release by Phil Sneiderman (JHU) and Megan Fellman (Northwestern) here.

 

 

Coated nanoparticles move easily into brain tissue

Real-time imaging of nanoparticles green) coated with polyethylene-glycol (PEG), a hydrophilic, non-toxic polymer, penetrate within normal rodent brain. Without the PEG coating, negatively charged, hydrophobic particles (red) of a similar size do not penetrate. Image by Elizabeth Nance, Kurt Sailor, Graeme Woodworth.

Johns Hopkins researchers report they are one step closer to having a drug-delivery system flexible enough to overcome some key challenges posed by brain cancer and perhaps other maladies affecting that organ. In a report published online Aug. 29 in Science Translational Medicine, the Johns Hopkins team says its bioengineers have designed nanoparticles that can safely and predictably infiltrate deep into the brain when tested in rodent and human tissue.

“We are pleased to have found a way to prevent drug-embedded particles from sticking to their surroundings so that they can spread once they are in the brain,” said Justin Hanes, Lewis J. Ort Professor of Ophthalmology and project leader in the Johns Hopkins Center of Cancer Nanotechnology Excellence.

Standard protocols following the removal of brain tumors include chemotherapy directly applied to the surgical site to kill any cancer cells left behind. This method, however, is only partially effective because it is hard to administer a dose of chemotherapy high enough to sufficiently penetrate the tissue to be effective and low enough to be safe for the patient and healthy tissue. Furthermore, previous versions of drug-loaded nanoparticles typically adhere to the surgical site and do not penetrate into the tissue.

These newly engineered nanoparticles overcome this challenge. Elizabeth Nance, a graduate student in chemical and biomolecular engineering, and Johns Hopkins neurosurgeon Graeme Woodworth, suspected that drug penetration might be improved if drug-delivery nanoparticles interacted minimally with their surroundings. Nance achieved this by coating nano-scale beads with a dense layer of PEG or poly(ethylene glycol). The team then injected the coated beads, which had been marked with a fluorescent tag,  into slices of rodent and human brain tissue. They found that a dense coating of PEG allowed larger beads to penetrate the tissue, even those beads that were nearly twice the size previously thought to be the maximum possible for penetration within the brain. They then tested these beads in live rodent brains and found the same results.

Elizabeth Nance. Photo by Ming Yang.

The results were similar when biodegradable nanoparticles carrying the chemotherapy drug paclitaxel and coated with PEG were used. “It’s really exciting that we now have particles that can carry five times more drug, release it for three times as long and penetrate farther into the brain than before,” said Nance. “The next step is to see if we can slow tumor growth or recurrence in rodents.”

Woodworth added that the team “also wants to optimize the particles and pair them with drugs to treat other brain diseases, like multiple sclerosis, stroke, traumatic brain injury, Alzheimer’s and Parkinson’s.” Another goal for the team is to be able to administer their nanoparticles intravenously, which is research they have already begun.

Additional authors on the paper include Kurt Sailor, Ting-Yu Shih, Qingguo Xu, Ganesh Swaminathan, Dennis Xiang, and Charles Eberhart, all from The Johns Hopkins University.

Story adapted from an original press release by Cathy Kolf.

 

Additional news coverage of this research can be found at the following links:

Nanotechnology/Bio & Medicine

Death and Taxes Mag

New Scientist Health

Nanotech Web

Portugese news release (in Portugese)

German Public Radio (in German)