Assistant professor of chemical engineering at Carnegie Mellon University in Pittsburgh, PA, Kathryn Whitehead has synthesized and tested nearly 5,000 nanoparticle delivery vehicles in order to identify a select few that can potently shuttle drugs into exactly the right cells.
Her approach to nanoparticle research and her development of systems for the oral delivery of macromolecules has led her to be named one of the top ten “brightest young minds reshaping science” in Popular Science’s 2015 Brilliant Ten list.
in-Pharmatechnologist spoke to her on this achievement and the current trends in drug delivery:
What are the major drug delivery issues which are currently challenging the industry?
It’s hard to pick only a few, but I’d say there are three major challenges: Protein delivery strategies, personalized medicine and targeted drug delivery.
Can you elaborate?
We can now generate sufficient quantities of protein drugs for therapeutic purposes with the advancement of recombinant protein expression technologies, but methods to deliver proteins beyond IV injection are extremely limited.
Personalized medicine is increasingly becoming reality, and the need for DNA/RNA/CRISPR delivery technology capable of treating the precise genetic abnormalities of individuals has never been more pressing.
Meanwhile, maximizing delivery to diseased organs and tissue, while minimizing delivery to healthy organs (targeted drug delivery) is an incredibly difficult problem. If we can crack this one, cancer will be a thing of the past.
How can nanoparticle delivery vehicles help?
The advantage of nanoparticles, as the name implies, is their size. Many tissues are accessible only through blood and lymphatic vessels that are on the order of 100 nm, so nanoparticles are properly sized to take drugs to these locations.
Which companies do you see leading the way in this field?
Alnylam Pharmaceuticals is a leader in siRNA delivery and has several nanoparticle based siRNA drugs in Phase II and III clinical trials. Results look extremely promising, and I anticipate that Alnylam will put forth the first FDA approved siRNA therapeutic in the years ahead.
Alnylam’s work has been exciting and validating for those in the siRNA delivery field, because it shows that a long-term commitment to a challenging therapeutic platform can result in new therapies for patients in need.
You developed a patented oral delivery system being used by Entrega. Can you briefly explain how this system works and what implications it could have for the drug industry?
As a graduate student, I developed intestinal patches for oral protein delivery. These patches are made of compressed mucoadhesive polymers and drug, and we’ve shown that they effectively adhere to intestinal epithelium and can systemically deliver protein drugs, including insulin and salmon calcitonin. This work is being continued both at Entrega and in the lab of my Ph.D. advisor, Samir Mitragotri, at UC Santa Barbara.
You have already achieved so much in your career and this award recognises this, but how do you hope to build your innovative work on drug delivery systems going forward?
There are plenty of outstanding challenges in drug delivery that require solutions. I like to look at an area that may be relatively stagnant and to ask what I can do differently - ignoring ‘conventional wisdom’ is one of my favourite things to do. Conventional wisdom typically yields only conventional outcomes.
Is there a lack of investment in drug delivery?
As with all industries, the pharmaceutical industry in the US is driven by profit and return on investment. As such, it’s often more prudent for pharma companies to invest in therapeutics that don’t require delivery vehicles - vehicles are an extra component that add extra cost and sometimes insurmountable complication at the FDA stage.
So yes, I wish there was more money in place to treat diseases with drugs that require vehicles. I also wish that industry and government agencies were willing to invest more money in young scientists and engineers. Young people, despite not having decades of experience in drug development, can have some very good ideas as well as the grit needed to see them through.
If resources were limitless, which direction would you like the future of drug delivery to go in?
In the perfect future, drug delivery will enable personalized medicine. Once the biologists have figured out the genetic underpinnings of each individual's disease, drug delivery scientists will deliver the customized drugs needed to modify pathological genetics and epigenetics in only the diseased cells, sparing healthy tissue.
If you could have had a career in any other field, what would you have chosen and why?
It was tough enough to pick a first career! If I could suddenly fall into a lot of cash, I’d choose to be a professional philanthropist. There is so much joy in giving.