Biofilms on Contact Lenses: A Vision for Making Bacteria Uncomfortable

 a person putting a contact lens in her eye

April 29, 2016

Just like we care about the comfort of what we choose to wear and where we choose to live—so do bacteria. Unlike our friends and family, researchers would like to find ways to make bacteria less welcome on surfaces.

This is the objective of Professor Dacheng Ren, who recently was awarded a R21 grant from the National Institutes of Health (NIH) to study how bacteria grow on the surface of polymers with different levels of stiffness—particularly as it relates to bacterial growth on contact lenses.

“By using a common polymer material, that is used in many medical devices, it turns out that bacteria care a lot about stiffness,” said Ren. “When you change the stiffness, within the range of normal contact lenses, we see a big difference in terms of how much bacteria can attach. It also affects the physiology of attached cells, in terms of how fast they grow, and their sensitivity to antibiotics. Even the size of the cells tends to be different based on the stiffness.”

Through collaboration with Professor Jay Henderson, the team will be using cell-tracking software to look at how cells move on surfaces of varying stiffness and will measure quantitative and statistically significant differences based on the different materials.

Bacteria, like us, have environmental preferences. “It is not surprising that they prefer the soft surfaces used in our study because it is easier for them to attach. They seem to be happier too as the cells become longer and grow faster.”

Right now, a lot of people who wear contact lenses don’t think about bacterial growth and they do not often clean and change them in time. Some of these actions can cause chronic, permanent damage due to biofilm-associated eye infections. Ren is working in his lab to see if the contact lenses themselves could one day become a line of defense against eye infections.

This NIH R21 grant is funded by the National Eye Institute and entitled for $408,183 for two years. It will help understand the effects of material stiffness on bacterial biofilm formation and develop better contact lenses.