Would you be happy, sleeping on plastic?
Maybe you traveled to visit family for the holidays this year. And maybe you weren’t the only one staying at that family members’ house, so the guest room was taken. And maybe, just maybe, you were the one that got the short end of the stick and slept on an air mattress in your parents’ office where there was barely enough room to walk around once it was inflated, and even the tiniest movement was followed by the obnoxious sound only a very large piece of plastic filled with air can make. Or maybe, that was just me – but you feel my pain.
It was lovely to visit my parents for the holidays, but I would be remiss not to mention that I felt pretty grumpy and not like my normal self after a few nights on that air mattress. It turns out, the very same thing happens to cells in the lab when scientists force them to sleep on the hard and unforgiving plastic of a petri dish.
As a bioengineer, I care A LOT about understanding how the body works when it’s healthy and when it’s suffering from disease. The best tool to understand this in the lab is to study the different cells that make up the body. But of course, in the lab, I can’t study these cells while they are still in the body, I have to study them outside of their natural habitat.
Historically, scientists have thrown cells into petri dishes, expecting them to act as they would in the human body despite being in a completely different environment. Within the body, cells are packed tightly together in three dimensions and encased in a meshwork of proteins, sugars, and more that holds everything together. In a petri dish, however, cells are met by plastic on one side and liquid cell food on the other. Just like me, when I was sleeping on an air mattress instead of in my own comfy bed, cells get pretty grumpy in a petri dish. And they don’t behave as they typically would in the body.
Over the years, scientists have discovered new ways to grow cells that better mimic their natural habitat, providing new and more accurate ways of understanding cell behavior and disease. To do this, they use Jell-O-like materials called hydrogels. Hydrogels are soft and squishy and filled with water, just like your body! This makes hydrogels great mimics of human tissues, and cell are much happier growing in them. And just like Jell-O, hydrogels come in many different flavors. The latest and greatest flavor is “smart” hydrogels.
Smart hydrogels are engineered to respond to various stimuli. For example, a hydrogel may be engineered to break down at cooler temperatures or to release loaded cargo in response to light. Smart hydrogels have equipped scientists with new ways to carefully control the cells’ environment. These controlled environmental changes can alter cell behavior, allowing scientists to study the ways that cells respond. Understanding the cells’ response can be used to gain insight into how these cells would respond to similar changes in the body.
There are still seemingly endless opportunities for the development of new smart hydrogels with unique properties. And each one can be the key to help unlock new understanding of cell function in the body. So remember, for humans and cells alike, everything is better when you don’t have to sleep on plastic.
Nicole Gregorio is a second year PhD student in bioengineering at the University of Washington. She is developing new, Jell-O-like materials that help us better understand cells and disease. These materials are also a key part of improving disease treatments that help the body regenerate itself.