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)

Nanoparticles slip through mucus barrier to protect against herpes virus

“Thick, sticky mucus layers limit effectiveness of drug delivery to mucosal tissues. Mucus-penetrating particles or MPPs (in red) are able to penetrate mucus, covering the entire surface of the mouse vagina (in blue). Improved distribution and retention of MPPs led to significantly increased protection in a mouse model for herpes simplex virus infection. Image by Laura Ensign.

Johns Hopkins researchers say they have demonstrated for the first time, in animals, that nanoparticles can slip through mucus to deliver drugs directly to tissue surfaces in need of protection.

The researchers used these mucus-penetrating particles, or MPPs, to protect against vaginal herpes infections in mice. The goal is to create similar MPPs to deliver drugs that protect humans against sexually transmitted diseases or even treat cancer.

“This is the first in vivo proof that MPPs can improve distribution, retention, and protection by a drug applied to a mucosal surface, said Justin Hanes, Ph.D., a professor of ophthalmology at the Johns Hopkins Wilmer Eye Institute and director of the Center for Nanomedicine at the Johns Hopkins University School of Medicine.

Hanes also is a principal investigator with the Johns Hopkins Center of Cancer Nanotechnology Excellence. Results of his team’s experiments are described in the June 13 issue of the journal Science Translational Medicine.

The moist mucosal surfaces of the body, like the eyes, lungs, intestines and genital tract, are protected from pathogens and toxins by layers of moist sticky mucus that is constantly secreted and shed, forming our outermost protective barrier.

“Although many people associate mucus with disgusting cold and cough symptoms, mucus is in fact a sticky barrier that helps keep you healthy,” says Laura Ensign, a doctoral student affiliated with the Center for Nanomedicine at the School of Medicine and with the Department of Chemical and Biomolecular Engineering at Johns Hopkins’ Whiting School of Engineering. She is the lead author of the journal report.

Unfortunately, Ensign noted, mucus barriers also stop helpful drug delivery, especially conventional nanoparticles intended for sustained drug delivery. In a Johns Hopkins laboratory, researchers developed nanoparticles that do not stick to mucus so they can slip through to reach the cells on the mucosal surface, in this case the surface of the mouse vagina, she added.

Ensign explained that conventional nanoparticles actually stick to mucus before releasing their drug payload and are then removed when the mucus is replenished, often within minutes to hours. Working with researchers in the laboratory of Richard Cone, Ph.D., in the Department of Biophysics in the university’s Krieger School of Arts and Sciences, the Hanes team fabricated particles with surface chemistry that mimics a key feature of viruses that readily infect mucosal surfaces.

“Richard Cone’s lab found that viruses, such as the human papilloma virus, could diffuse through human cervical mucus as fast as they diffuse through water. These ‘slippery viruses’ have surfaces that are ‘water-loving,’ ” Hanes said. “In contrast, many nanoparticles intended to deliver drugs to mucosal surfaces are ‘mucoadhesive’ and ‘oil-loving,’ but these nanoparticles stick to the superficial layers of the mucus barrier, the layers that are most rapidly removed.”

To make their mucus-penetrating particles, the team transformed conventional ‘oil-loving’ nanoparticles by coating them with a substance used in many commercial pharmaceutical products: polyethylene glycol. PEG makes the particles “water-loving,” like the viruses that slip right through mucus.

“The key is that the nanoparticles, like viruses, have to be small enough to go through the openings in the mucus mesh, and also have surfaces that mucus can’t stick to. If you think about it,” said Ensign, “mucus sticks to almost everything.”

“Viruses have evolved over millions of years to become slippery pathogens that readily penetrate our protective mucus barriers,” said Cone, “and engineering nanoparticles that penetrate the mucus barrier just like viruses is proving to be a clever way to deliver drugs.”

Hanes emphasized that the MPPs provided greatly improved protective efficacy while at the same time reducing the effective dose of drug needed 10-fold. Furthermore, Hanes added, the MPPs “continue to supply drug for at least a day and provide nearly 100 percent coverage of the mucosal surface of the vagina and ectocervix” in their laboratory mice.

“We’ve shown that mucus-penetrating particles are safe for vaginal administration in mice. Our next move will be to show that they are safe for vaginal administration in humans,” Ensign said. “Now our laboratory currently is working on an MPP formulation of a drug that protects against HIV infection that we hope will be tested in humans.”

Their technology could lead to a once-daily treatment for preventing sexually transmitted diseases, for contraception and for treatment of cervico-vaginal disorders, Ensign said.

Ensign added that MPP technology has the potential to prevent a wide range of mucosal diseases and infections, including chronic obstructive pulmonary disease, lung cancer, and cystic fibrosis,” Ensign said.

Additional authors on the paper include postdoctoral fellow Ying-Ying Wang and research specialist Timothy Hoen from the Department of Biophysics; former master’s student Terence Tse from the Department of Chemical and Biomolecular Engineering; and Benjamin Tang, formerly of Johns Hopkins School of Medicine and currently at the Massachusetts Institute of Technology.

Under a licensing agreement between Kala Pharmaceuticals and the Johns Hopkins University, Hanes is entitled to a share of royalties received by the university on sales of products used in the study.

Hanes and the university own Kala Pharmaceuticals stock, which is subject to certain restrictions under university policy. Hanes is also a founder, a director and a paid consultant to Kala Pharmaceuticals. The terms of this arrangement are being managed by The Johns Hopkins University in accordance with its conflict of interest policies.”

Story by Mary Spiro

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

Phys.org

WYPR: The Mucus Ruse

Scientific American

 

Biodegradable nanoparticles ideal carrier for drug delivery

Johns Hopkins University researchers have created biodegradable nanosized particles that can easily slip through the body’s sticky and viscous mucus secretions to deliver a sustained-release medication cargo. The researchers say that these nanoparticles, which degrade over time into harmless components, could one day carry life-saving drugs to patients suffering from dozens of health conditions, including diseases of the eye, lung, gut or female reproductive tract.

The mucus-penetrating biodegradable nanoparticles were developed by an interdisciplinary team led by Justin Hanes, a professor of chemical and biomolecular engineering in Johns Hopkins’ Whiting School of Engineering*. The team’s work was reported recently in the Proceedings of the National Academy of Sciences. Hanes’ collaborators included cystic fibrosis expert Pamela Zeitlin, a professor of pediatrics at the Johns Hopkins School of Medicine and director of Pediatric Pulmonary Medicine at Johns Hopkins Children’s Center.

Individual biodegradable nanoparticle developed by the Justin Hanes Lab at Johns Hopkins University (shown here at microscale for easier imaging) displaying polymer coating as a red fluorescent glow. Hanes' biodegradable nanoparticles have the ability to penetrate mucus barriers in the body to deliver drugs. (Photo by Jie Fu/JHU)

Individual biodegradable nanoparticle developed by the Justin Hanes Lab at Johns Hopkins University (shown here at microscale for easier imaging) displaying polymer coating as a red fluorescent glow. Hanes’ biodegradable nanoparticles have the ability to penetrate mucus barriers in the body to deliver drugs. (Photo by Jie Fu/JHU)

These nanoparticles, Zeitlin said, could be an ideal means of delivering drugs to people with cystic fibrosis, a disease that kills children and adults by altering the mucus barriers in the lung and gut. “Cystic fibrosis mucus is notoriously thick and sticky and represents a huge barrier to aerosolized drug delivery,” she said. “In our study, the nanoparticles were engineered to travel through cystic fibrosis mucus at a much greater velocity than ever before, thereby improving drug delivery. This work is critically important to moving forward with the next generation of small molecule– and gene-based therapies.”

Beyond their potential applications for cystic fibrosis patients, the nanoparticles also could be used to help treat disorders such as lung and cervical cancer and inflammation of the sinuses, eyes, lungs and gastrointestinal tract, said Benjamin C. Tang, lead author of the journal article and a postdoctoral fellow in the Department of Chemical and Biomolecular Engineering. “Chemotherapy is typically given to the whole body and has many undesired side effects,” he said. “If drugs are encapsulated in these nanoparticles and inhaled directly into the lungs of lung cancer patients, drugs may reach lung tumors more effectively and improved outcomes may be achieved, especially for patients diagnosed with early stage non–small cell lung cancer.”

“If drugs are encapsulated in these nanoparticles and inhaled directly into the lungs of lung cancer patients, drugs may reach lung tumors more effectively and improved outcomes may be achieved, especially for patients diagnosed with early stage non–small cell lung cancer.” ~ Ben Tang

In the lungs, eyes, gastrointestinal tract and other areas, the human body produces layers of mucus to protect sensitive tissue. But an undesirable side effect is that these mucus barriers can also keep helpful medications away.

In proof-of-concept experiments, previous research teams led by Hanes earlier demonstrated that latex particles coated with polyethylene glycol could slip past mucus coatings. But latex particles are not a practical material for delivering medication to human patients because they are not broken down by the body. In the new study, the researchers described how they took an important step forward in making new particles that biodegrade into harmless components while delivering their drug payload over time.

“The major advance here is that we were able to make biodegradable nanoparticles that can rapidly penetrate thick and sticky mucus secretions, and that these particles can transport a wide range of therapeutic molecules, from small molecules such as chemotherapeutics and steroids to macromolecules such as proteins and nucleic acids,” Hanes said. “Previously, we could not get these kinds of sustained-release treatments through the body’s sticky mucus layers effectively.”

The new biodegradable particles comprise two parts made of molecules routinely used in existing medications. An inner core, composed largely of polysebacic acid, or PSA, traps therapeutic agents inside. A particularly dense outer coating of polyethylene glycol, or PEG, molecules, which are linked to PSA, allows a particle to move through mucus nearly as easily as if it were moving through water and also permits the drug to remain in contact with affected tissues for an extended period of time.

In Hanes’ previous studies with mucus-penetrating particles, latex particles could be effectively coated with PEG but could not release drugs or biodegrade. Unlike latex, however, PSA can degrade into naturally occurring molecules that are broken down and flushed away by the body through the kidney, for example. As the particles break down, the drugs loaded inside are released.

This property of PSA enables the sustained release of drugs, said Samuel Lai, assistant research professor in the Department of Chemical and Biomolecular Engineering, while designing them for mucus penetration allows them to more readily reach inaccessible tissues.

Biodegradable nanoparticles produced by the Justin Hanes Lab at Johns Hopkins University visualized under a scanning electron microscope. (Photo by Ben Tang and Mark Koontz/JHU)

Biodegradable nanoparticles produced by the Justin Hanes Lab at Johns Hopkins University visualized under a scanning electron microscope. (Photo by Ben Tang and Mark Koontz/JHU)

Jie Fu, an assistant research professor, also from the Department of Chemical and Biomolecular Engineering, said, “As it degrades, the PSA comes off along with the drug over a controlled amount of time that can reach days to weeks.”

PEG acts as a shield to protect the particles from interacting with proteins in mucus that would cause them to be cleared before releasing their contents. In a related research report, the group showed that the particles can efficiently encapsulate several chemotherapeutics, and that a single dose of drug-loaded particles was able to limit tumor growth in a mouse model of lung cancer for up to 20 days.

Hanes, Zeitlin, Lai and Fu are all affiliated with the Johns Hopkins Institute for NanoBioTechnology. Other authors on the paper are Ying-Ying Wang, Jung Soo Suk and Ming Yang, doctoral students in the Johns Hopkins Department of Biomedical Engineering; Michael P. Boyle, an associate professor in Pulmonary and Critical Care Medicine at the Johns Hopkins School of Medicine; and Michelle Dawson, an assistant professor at the Georgia Institute of Technology.

This work was supported in part by funding from the National Institutes of Health, a National Center for Research Resources Clinical and Translational Science Award, the Cystic Fibrosis Foundation, the National Science Foundation and a Croucher Foundation Fellowship.

The technology described in the journal article is protected by patents managed by the Johns Hopkins Technology Transfer Office and is licensed exclusively by Kala Pharmaceuticals. Justin Hanes is a paid consultant to Kala Pharmaceuticals, a startup company in which he holds equity, and is a member of its board. The terms of these arrangements are being managed by The Johns Hopkins University in accordance with its conflict-of-interest policies.

(*At the time that this research was published, Hanes had his primary affiliation with the Whiting School of Engineering Department of Chemical and Biomolecular Engineering. Hanes’ current primary affiliation is with the Johns Hopkins School of Medicine Department of Ophthalmology.)

Related Links

Biodegradable polymer nanoparticles that rapidly penetrate the human mucus barrier. PNAS 2009 106:19268-19273; published online before print November 9, 2009.  [Institutional access required.]

Hanes Lab

Johns Hopkins Children’s Center

Institute for NanoBioTechnology

Story by Mary Spiro and Jacob Koskimaki with materials provided by Johns Hopkins Technology Transfer.

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