| AVS 63rd International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI+PB-TuP |
| Session: | Biomaterial Interfaces Poster Session (preceded by Oral Flash Presentations) |
| Presenter: | Nicole Herbots, SiO2 NanoTech LLC |
| Authors: | N.X. Herbots, SiO2 NanoTech LLC C.F. Watson, SiO2 NanoTech LLC/Arizona State University Physics Dpt EJ. Culbertson, University of California at Los Angeles PR. Thilmany, SiO2 NanoTech LLC IPO. Martins, SiO2 NanoTech LLC |
| Correspondent: | Click to Email |
Laparoscopes, arthroscopes, and laryngoscopes lenses are hydrophobic and fog during closed body surgery, due to bodily fluids and differences between body and operating room temperatures [1,2]. Surgeons must repeatedly remove, clean, and reinsert scopes obscured by fog. Hencesurgery duration, infection risks, and scarring from air exposure increase. Methods to address fogging introduce other complications [3]. Alcohol-based coatings scar tissue and quickly evaporate, heated lenses require reheating every 5 to 20 minutes. A non-toxic, super-hydrophilic, anti-fog coating that is pH neutral (7.2-7.4), long-lasting has been developed VitreOx™ . [4] VitreOx™ can be used wet or dry, without alcohol, heat, or fluid evacuation. When applied in liquid form, it easily espouses a lens’s surface and edges, and dries within seconds to form a permanently super-hydrophilic surface on silica and most polymer surfaces . VitreOx™ avoids current shortfalls by foregoing frequent reapplications.
VitreOx™'s anti - fog properties can be explained by nucleation and growth theory, and the three mechanisms for condensation: 1) 3-D droplets, resulting in fogging; 2) 2-D sheets resulting in a flat transparent film . ; or 3) mixed, resulting in optical distortion. On hydrophobic surfaces (e.g. optical lenses ), condensation occurs with fogging via spherical 3-D droplets (Volmer-Weber model). 3 - D droplets scatter light in all directions through refraction yielding opaque or translucent films, or fog. VitreOx™ applied to hydrophobic lenses renders them super-hydrophilic. Similar to the 2-D Frank Van-der-Merwe growth mode, condensation with uniform wetting yields transparent 2-D films that don’t distort light.
In-vitro and in-vivo animal studies of VitreOx™ were conducted to measure performance and duration of anti-fog effectiveness and bio-compatibility. In-vitro testing spanned from 3 to 72 hours over a 3-year range. Side-by-side in-vivo gastro-endoscopies were conducted using a lens coated with VitreOxTM and a Covidien Clearify ™ warmer with anti-fog, on Yucatan™ swine for 90 minutes . The VitreOx™ coating lasted without fogging nor reapplication, while Covidien Clearify™ only l ast ed at for 38 minutes without fogging, and required retreatment and reapplication . No adverse reaction was observed on swine in surgery, and in the 18 months that follows.
[1] Knuth A et al “ Anaesthesist. 2012 Dec;61(12):1036-44.
[2] Lawrentschuk N, et al “Laparoscopic Lens Fogging” (2010). Journal of Endourology. 24(6):905-913
[3] US Pat. 5,518,502 (1994) and its 129 cites.
[4] Herbots N, Watson CF, patents pending