Paper Number
BA5 

Session
Biorheology & Active Fluids

Title
Mechanical characterization of corneal cells for investigating their conformability with contact lenses

Presentation Date and Time
February 13, 2017 (Monday) 11:40

Track / Room
Track 2 / Audubon A

Authors (Click on name to view author profile)

1. Pokki, Juho (Stanford University, Chemical Engineering)
2. Merola, Maria C. (Stanford University, Chemical Engineering)
3. Hollenbeck, Emily C. (Stanford University, Chemical Engineering)
4. Nabar, Namita (Stanford University, Chemical Engineering)
5. Fuller, Gerald G. (Stanford University, Department of Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Juho Pokki, Maria C. Merola, Emily C. Hollenbeck, Namita Nabar, and Gerald G. Fuller
Department of Chemical Engineering, Stanford University, Stanford, CA 94305

Speaker / Presenter 
Pokki, Juho

Text of Abstract
The mechanical properties of cells, which are caused by complex intracellular structures, are modulated by biological processes and extracellular mechanical stimuli. Further, cells’ mechanical behavior affects on how cells maintain interactions with their environment during biological strains. These interactions (e.g., adhesion) are crucial for how cells adapt to the presence of artificial material, such as contact lenses or medical implants. A variety of technologies are used to investigate cell mechanics, such as atomic force microscopy (AFM) and microrheological methods, which provide localized information from single cells. To overcome the challenges with the biological variation between individual cells, new technologies are necessary to acquire enhanced statistics on cell mechanics in controlled conditions. We present measurements using a live-cell monolayer rheometer (LCMR) that can characterize averaged cell mechanics or averaged cell adhesion. The LCMR enables the investigation of biologically active layers: controlled amounts of live cells, extracellular components, or artificial material (e.g., contact lenses). In this work, cell mechanics of the ocular cornea are characterized to provide understanding on how these cells mechanically conform onto the artificial surface of a contact lens. To simulate physiological conditions, cell mechanics is quantified in experiments in which cells are sheared tangential to the cell layers. Time-dependent step-strain tests with strain sweeps are used to characterize the mechanical relaxation of the cell layers. The relaxation responses provide quantitative information of the cell interior rearrangements and cell-cell attachments. The quantification of cell mechanics using the LCMR has the potential for multiple biomedical applications, including disease diagnosis and drug-efficacy screening.