André Stevenson: Small particles with a huge impact--How nanoparticles can deliver drugs and heal the brain

The following story was written in April 2018 by Kendall Daniels in ​ENGL ​4824​: Science Writing ​as part of a collaborative project that included the English department, the Center for Communicating Science, ​the ​Fralin Life Science​ Institute​, and ​Technology-enhanced Learning and Online ​Strategies (TLOS).

André Stevenson’s passion for biomedical engineering began with a simple Google search. At the time, he was a high school student who was simply trying to find his calling.

    Fast forward to 2018: Stevenson has earned a Ph.D. studying nanoparticles, which are really, really small particles that have a variety of uses in the field of biomedicine. His passion for the trifecta of engineering, science, and biology that manifested in high school continues to motivate his work. He recently (and successfully) defended his dissertation, “Synthesis, Characterization and Performance of Gelatin Biopolymer based Nanoparticle Formulations for Molecule Encapsulations,” under the direction of Dr. Abby Whittington in materials science engineering at Virginia Tech.

    Stevenson's interest in nanoparticles stems from their ability to bind, absorb, and carry compounds with them, which makes them extremely useful in the human body.  He received an undergraduate degree in biomedical engineering with a minor in materials science at Vanderbilt University. His graduate research has focused on understanding polymer properties to develop materials for application in complex environments, including the human body. Stevenson's work ranges from gelatin nanoparticles, which carry potential therapeutic molecules to treat traumatic brain injuries, to synthetic polymers used for customized 3D printing of washing machine and dishwasher parts.

    One of the main goals in nanoscience is to integrate nanoparticles easily into the environment. Research in biomedical nanoscience has shown that there is less of an immune response when the body of an animal is injected with natural materials, such as gelatin and albumin. Essentially, the body is able to recognize and accept the particles as its own, compared to a synthetic material, like plastic, which the body would recognize to be foreign and would attempt to eliminate.

    Stevenson's current lab work revolves around nanoparticles and the gelatin from pigs and cows, which is derived from collagen–a protein found in skin and bones. He wants to make gelatin more translational, meaning he wants to apply his research directly from the laboratory bench to a clinical setting. Imagine someone’s own collagen–and subsequently gelatin–being made into a nanoparticle that can be used for  personalized drug delivery applications. These nanoparticles could be used to infiltrate the body and to deliver medicine to specific locations to help the body heal effectively and efficiently. This is the aim of his future work.

    To minimize the risk of rejection or a severe immune response, Stevenson suggests that we could derive particles or polymers from our own bodies. His device would involve taking skin or other bodily material and turning it into particles made from an individual’s own tissue to create personalized treatment.

    “It can be like a personalized nanodelivery device for each person–like a broadband, broadspectrum device,” he explained. This discovery would be beneficial because fewer particles would need to be injected and the nanoparticles could all be delivered to a specific location without being removed by the macrophages, a cellular version of Pac-Man that seeks out and gobble up invaders.

    Years of working as a graduate student has provided Stevenson his fair share of obstacles. He equates working in the lab to a “love-hate” relationship: “If something works out nicely, you love lab and you just want to be there seven days a week, you know. Then if something doesn’t work out in lab, you just want to give up and have a drink.”

    Experimentation, Stevenson pointed out, is not as simple as following a lab notebook but rather can be a long and grueling process that requires lots of trial and error.

    “When I say work out and not work out, I mean that when [I] do an experiment…and if I don’t have a certain nanoparticle size, I have to try and figure out, ‘If I change the experimental conditions, does that give me better control over certain properties?’” said Stevenson.

    Another obstacle, according to Stevenson, is that cutting-edge papers from around the world can cause more harm than good.

    “There are certain words or certain methods that are left out, [and] when you are trying to replicate a work, you don’t really know how to do it precisely,”  Stevenson said. When you are trying to replicate or “put your own spin” on an experiment, figuring out what conditions are critical or minor is an obstacle, he explained.

    Stevenson is both excited and hesitant about the future.

    “What keeps me up is thinking about what can be done in the future. Like ten years from now, what is going to be the big thing? There has to be a big discovery," he said. "How can I help that or how can nano[science] impact that?”

    He recently read an article about the discovery of microplastics in water bottles, and he said that the scariest part is that no one knew about these small particles other than the company until it was made public.

    Apparently the company is aware of this issue and simply states that the concentration is so miniscule that it won’t have an impact on humans. Stevenson, on the other hand, thinks that the nanoscience community needs to expand their research to environmental health hazards and manufacturing.

    “That has to happen, because if humans are ingesting these particles, then that is a very bad thing,” he said. In general, he believes that both the nanoparticle and the micro-particle communities are so invested in nanomedicine that they aren’t able to focus on other issues that threaten human health, such as environmental health hazards.

    “We have to broaden our interests,” he stated.

    When asked about how his work reflects Ut Prosim, “that I may serve,” Stevenson said that TBI, or traumatic brain injury, is a ubiquitous injury that occurs in sports, car accidents, and every area of life.

    “So if I can create some sort of help for that, [then] I think I can have a global impact–so that’s exciting,” he said.

    “I like that I am the only person in the world doing what I am doing right now. There are people of course–graduate students–all over that are doing bits and pieces of a project or a similar experiment, but the questions that I am trying to answer and the way that I am doing it is different, and that is what is particularly cool about what I do.”