Finding the right fit in terms of teaching and research is an important component of a faculty member’s ability to make a contribution in academia – and it’s often a daunting task, particularly for those who are beginning their careers. For Allan David, it was all about finding an academic home that mirrored his interest in nanomaterials that have applications in the field of biomedical engineering.
He was excited, then, when he arrived in Minneapolis for the American Institute of Chemical Engineer’s annual meeting in 2011. A graduate from the University of Maryland with a bachelor’s and doctoral degree in chemical engineering, he had been running a pharmaceutical sciences lab at the University of Michigan, first as a post doc and then as a member of the research faculty.
Earlier in the week he had received an email from then chemical engineering chair (and now, dean), Christopher Roberts, suggesting they talk Sunday evening about opportunities on the Auburn faculty. It would be before the conference began in earnest the following morning, and David was eager to follow the lead, if a little unsure about the career move.
“I was looking for a tenure track position in engineering, but didn’t really know much about Auburn, even though ‘it had a name’,” David explains. “I thought I knew where it was, which is to say it was in Georgia, and just about on the Alabama state line.”
As he approached Roberts, he saw Elizabeth Lipke and his heart sank, if only a little, to think that he was not the only candidate the department had invited to chat with the chemical engineering chair from Auburn. It rose when he discovered that she was in fact already on the faculty, and he had a clear shot.
“The three of us sat down together,” he recalls. “When we got up, Auburn became my first choice, with anything else a distant second. Dr. Roberts’ comments were such that I knew the campus not only had everything I was looking for, but also that there was energy and enthusiasm.”
He would join the faculty in 2012 as the John W. Brown assistant professor of chemical engineering.
“I wanted to make a difference, not a name,” David recalls, “with people that I would be excited to work with, and in an environment that encouraged collaboration. I also saw in Auburn the opportunity to work in a growing department with unique opportunities, such as the presence of state-of-the-art MRI scanners.”
David has since put into place a nanoparticle and nanocomposite lab that is focused on highly selective drug targeting to enhance cancer therapy.
“Our work is not too difficult to explain,” he points out. “What we are trying to do is target cancer cells in a highly selective way so that the therapeutic goes to the diseased site and does not interfere with healthy cells in the rest of the body.”
For example, achieving a therapeutic concentration in a tumor could require gram-level doses of a drug that distributes through the entire body.
The ‘smart nano’ approach, David explains, places the drugs where they can be effective. They are contained within nanoparticles and nanocomposites that target, and ‘stick’ to the cells that need to be treated. It’s an approach that will allow for much greater treatment efficacy at lower delivery doses, and a resulting reduction in side effects.
He cites as an example pH responsive nanoparticle-based carriers that can be guided to certain sections of the stomach or intestines, and deliver drugs into a limited area at high concentrations.
“A good example of where this can be effective is in the treatment of peptic ulcers, which are bacterial infections in the stomach,” David notes. “In current treatment, patients are given oral antibiotics that are ingested, move through the stomach, and into the intestines where they are absorbed into the bloodstream.
“The bloodstream then moves the drug back to the site in the stomach, but only a small portion, since the balance is distributed throughout the body. In fact, these antibiotics also end up destroying a lot of ‘good’ bacteria in the gut, which results in side effects such as diarrhea in the patient.
“So what we are looking at here is to encapsulate such antibiotics in ‘smart’ nanotechnology-based carriers that are responsive to the microenvironment in the stomach, where the drugs can be specifically targeted.”
He adds this area holds great promise for insulin therapies in diabetics, since insulin cannot be delivered orally and must therefore be injected.
“It degrades in the acidic environment that it would have to move through, as well as other factors,” David explains. “However, if we protect it with a nano-based carrier, we may be able to deliver insulin orally in the future, which has many advantages.”
David notes that the benefits of nanotechnology will ultimately lead to what is called personalized medicine – targeted therapies that reduce dosage amounts and frequency, which results in better treatment at lower cost. It is also anticipated that patients treated in this way will recover more quickly, and become productive again in a shorter amount of time.
“We are also focusing on magnetic nano particles, which act as contrast agents in MRI scans,” David notes. “This approach is very helpful in diagnostics, and we are using it in a Department of Defense grant to track prostate cancers.
“Some of these cancers grow very slowly, while others are very aggressive. We can potentially monitor how smart materials change due to the biological activity within a tumor. This would allow us to quantify what is happening – that is, determine how quickly the tumor is growing – by mapping its volume non-invasively.”
David notes that the research in his laboratory is often collaborative, and has included peers within his department, such as Elizabeth Lipke, but also faculty from curricula outside the College of Engineering, including Robert Arnold in the School of Pharmacy, and Valery Petrenko in the College of Veterinary Medicine.
“And, of course, we are involved with the Auburn University Research Initiative in Cancer as well as faculty members such as Tom Denney and Ron Beyers at the Magnetic Resonance Imaging Research Center,” David adds. “I find this kind of interdisciplinary mix not only a very exciting way to conduct research, but absolutely imperative if we are to challenge the health care issues that are facing us.”
Nanoparticles: tiny fighters
In addition to research into targeted drug delivery, David’s team is also working on nanoparticles that illustrate how promising – and varied – this field can be. Janus particles represent one such area.
They are so named from the Roman god often depicted in art with two faces, one looking to the left and the other to the right, or more temporally, one looking forward and one looking back (think of January in the calendar). These particles can, for example, exhibit both hydrophilic and hydrophobic action, that is, they both attract and repel water at the same time.
“These kinds of nanomaterials may be able to act as antimicrobial barriers because of these properties,” David explains. “Research has indicated that some nanoparticles have proven effective against bacteria, so it represents a logical direction to take as we look to move forward with nanotechnology applications.”
The technology can be taken a step further in the energy and biomedical sectors by ultimately changing how self-assembled materials are manufactured.
“We are really at the forefront of this technology,” David notes. “The direction we can take is almost limitless.”
