Newswise — WASHINGTON, D.C., February 13, 2017 -- Symptoms of dry eye syndrome -- dry, red, itchy, gritty, sore eyes -- are more common among contact lens wearers. But relief may be on the horizon, thanks to a group of Stanford University researchers and their work exploring the mechanical interactions between the eye surface, the cornea and contact lenses.

Ultimately, the group’s goal is to create better contact lenses that maximize comfort and alleviate dry eye symptoms. When developing biomaterial-based devices that are in direct contact with cells, like contact lenses, their mechanical interaction with cells, biomaterial adhesion to cells and biocompatibility are all extremely important factors. During the 88th Annual Meeting of The Society of Rheology, being held Feb. 12-16, in Tampa, Florida, Juho Pokki, a postdoctoral research fellow in the chemical engineering department at Stanford University will present the group’s work to enable accurately quantifying cell mechanics and the adhesion between cells and the biomaterial.

“Our system, a live-cell monolayer rheometer, is built on a standard inverted microscope for cell biology,” Pokki said. “It can simultaneously observe the cells and test cell mechanisms and adhesion.”

Additionally, the group created an automated system to enable controllable experiments at the microscale.

Cornea cell surfaces consist of a mechanically complex, soft material which you can think of, according to Pokki, as nature’s “smart material.”

“[It has] properties that depend on stress-strain conditions and time,” he said. “Corneal cell mechanics and cell adhesion are altered for different corneal surface conditions, such as changes caused by disease, and different contact lenses.”

By measuring mechanics and cellular or bacterial adhesion-related information, the group can compare biocompatible materials that are most suitable for contact lenses or for developing new biomedical devices such as prosthetic electronic skin. To date, one of the group’s key findings is that corneal surface cells, which have adapted to protect the eye surface, are mechanically complex.

“Their effective mechanical behavior is different between small and large strain conditions,” Pokki said. This behavior may be caused by changes within the cells which the group plans to study in the future.

In terms of applications, Pokki said, “beyond developing better contact lenses, our system can be used to screen and find optimal contact lens solutions or eye drops for people who have dry eye symptoms. This would allow people with dry eye syndrome to use contact lenses while maintaining corneal mechanics and adhesion similar to those of users without dry eye symptoms.”

The presentation BA5 "Mechanical characterization of corneal cells for investigating their conformability with contact lenses," by Juho Pokki, Maria C. Merola, Emily C. Hollenbeck, Namita Nabar and Gerald G. Fuller, will take place during a session beginning at 11:40 a.m. on Monday, Feb. 13, 2017 in Track 2/Room Audubon DEF at the Grand Hyatt Tampa Bay.

ABSTRACT: https://www.rheology.org/SoR172/ViewPaper?ID=100

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ABOUT THE MEETING

The Annual Meeting of The Society of Rheology is typically held in mid-October. The meetings ordinarily last three to four days and are open to both members and non-members. Every effort is made to stimulate and encourage fruitful discussion during the technical sessions, with 25 minutes normally allotted to the presentation and discussion of each paper. There are normally no more than four simultaneous sessions, and the program includes plenary lectures, special symposia, informal evening discussions, and instrument exhibits. A banquet is held to honor the recipients of the Society's awards: the Bingham Medal, the Journal of Rheology Publication Award, and the Distinguished Service Award, all for outstanding contributions to rheology. The Annual Meeting for those years during which an International Congress of Rheology occurs (2004, 2008, etc.) is held early in the following year (except when the ICR is held in the United States).

NEWS RELEASES

Embargoed press releases describing in detail some of the breakthroughs to be discussed at the meeting are available on Newswise and Alpha Galileo or by contacting the Media Line at the American Institute of Physics at [email protected] or 301-209-3090.

QUICK LINKS

88th Annual Society of Rheology Meeting, Feb. 12-16, 2017 in Tampa, FloridaMeeting Main Meeting Page: http://www.rheology.org/sor/annual_meeting/2017Feb/default.htm

ABOUT THE SOCIETY

Rheology, a branch of mechanics, is the study of those properties of materials which determine their response to mechanical force. The word rheology was coined in the 1920's to represent the science of the deformation and flow of matter, and The Society of Rheology was officially formed on December 9, 1929. Meetings of The Society have been held at least annually since that time. The Society has sponsored publication of technical and scientific papers in this field in various journals, currently in its own Journal of Rheology.

Rheology enters in some form into almost every study of material properties, and many physicists, chemists, engineers, biologists and mathematicians find a common meeting ground in The Society's meetings and publications. It is a small society compared to many others, membership currently being about 1,700. The membership represents a wide spectrum of individuals from academic, industrial, and governmental institutions whose activities include both phenomenological and molecular theories, instrumentation, the study of many types of materials such as polymers, metals, petroleum products, rubber, paint, printing ink, ceramics and glass, foods, biological materials, floor preparations and cosmetics, and a wide range of practical applications.

The Society of Rheology is one of the five founding members of the American Institute of Physics. By virtue of this affiliation, all Members of The Society receive the Institute's monthly publication Physics Today without extra charge, and join with other physicists in sponsoring the many general activities of the Institute including publication, translation, manpower studies, and projects on the history of physics. The Society is also affiliated with the U.S. National Committee on Theoretical and Applied Mechanics. The Society is also a member of the International Committee on Rheology, which organizes the International Congress on Rheology, held every four years.

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