Synthetic Polymeric Materials for Ocular Applications
At A Glance
Researchers at CSU have incorporated hyaluronan into a silicone polymer for use in ocular applications (such as contact lenses). Silicone provides excellent oxygen permeability and mechanical properties.
The incorporation of the hyalruonan:
- Increases lubricity and wettability;
- Reduces foreign body response while maintaining a preocular tear film;
- Increases the hydrophilicity of the lens surface to enhance spreading of mucin to cornea;
- Imparts antimicrobial properties to the silicone.
It is anticipated that the characteristics of these hyaluronan enhanced silicones may also improve intraocular lens technology.
It is estimated that there are over 30 million contact lens wearers in the United States. In addition to vision correction, a contact lens should:
- Maintain stable, continuous tear film for clear vision
- Resist deposition of tear film components
- Sustain normal hydration
- Permeable to oxygen enabling corneal metabolism
- Permeable to ions to maintain movement
- Non-irritating and comfortable
- Neither hydrophobic nor lipophilic
The current state-of-the-art enables high-volume, low-cost production of corrective lenses. These often Siloxane-containing hydrogels, have addressed need for Oxygen transmission, critical as the cornea is avascular. While effective, there are common complaints from contact lens wearers, including lens deposits and resulting eye inflammation.
Researchers at CSU have developed a bio-polymer incorporating hyaluronan into a silicone polymer. Silicone increases Oxygen permeability and mechanical properties. This enables non-vascularized cornea to obtain oxygen. The incorporation of the hyalruonan increases lubricity and wettability, reduces foreign body reponse while maintaining a preocular tear film, and the hydrophilic capacity of the lens enhances spread of mucin to cornea
Importantly, these researchers demonstrate the ability to manufacture block copolymers consisting of silicone blocks and polyethylene oxide blocks as well as those block polymers modified with hyaluronic acid.
- Able to control shape and composition of block copolymer
- Improved manufacturing process resulting in more durable HA content when compared to surface modification and cross-linking techniques
The effectiveness of these ophthalmic lenses have evaluated the hydrophobicity and optical transparency, the protein absorbtion and monocyte adhesion to demonstrate these new lenses as suitable for ophthalmic application. The novel mechanism of manufacture mark an improvement to currently available contact lenses, and enter the “next frontier” in lens manufacture.
Last updated on October 7, 2019.
Sue James, Susan P. James, Susan James