Ultraviolet Disinfection of Contact Lenses

Harris, Michael G.; Fluss, Larry; Lem, Anita; Leong, Hou

doi:10.1097/00006324-199310000-00011

Cited by 15 publications

(6 citation statements)

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“…This trend in z values for test bacteria under high and low RH conditions of present study is consistent with results of previous studies . Besides, the z values in the water were 0.12 and 0.014 m 2 /J observed by Oguma et al and Harris et al for E coli and S epidermidis respectively, which are lower than that in the air. Because UV susceptibility in the water closes to that in the air at ~100% relative humidity, it also confirmed that there is a decreasing trend in z values as the increase in RH.…”

Section: Resultssupporting

confidence: 93%

Disinfection by in‐duct ultraviolet lamps under different environmental conditions in turbulent airflows

et al. 2020

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In this study, we investigated the effects of environmental factors such as airflow velocity, relative humidity (RH), temperature, and duct reflectance on the performance of in‐duct UVC lamps. Staphylococcus epidermidis, Pseudomonas alcaligenes, and Escherichia coli were used as the test bacteria. The UV irradiance, disinfection efficacy, and UV susceptibility constant (Z value) of the test bacteria were experimentally determined. The results showed that the UV disinfection efficacy decreased as the airflow velocity and RH increased. The maximum UV disinfection efficacy was obtained at temperature of 20‐21°C compared with the performance at lower temperature (15‐16°C) and higher temperature (25‐26°C). When the RH increased from 50% to 90%, the Z values of airborne bacteria reduced by 40%, 60%, and 38% for S epidermidis, P alcaligenes, and E coli, respectively. Besides, susceptibility constants had lower values under both cooling temperature (15‐16°C) and heating temperature (25‐26°C) compared with that under the temperature of 20‐21°C. It was observed that S epidermidis generally had the highest resistance to the UV irradiance. The results also showed that the UV disinfection efficacy was lower in the duct with a black surface than in the clean duct.

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Section: Resultssupporting

confidence: 93%

Disinfection by in‐duct ultraviolet lamps under different environmental conditions in turbulent airflows

et al. 2020

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“…UV light can be divided into three categories: UVA (315–400 nm), UVB (280–315 nm) and UVC (100–280 nm). UVB and UVC light are capable of inducing direct DNA damage and are often used for sterilization[ 2 – 5 ], while UVA may induce indirect DNA damage through the production of free radicals given the right environment and intensity[ 6 ]. Nearly all cell-based applications of photochemistry use light sources with UVA wavelengths (or longer) because they generally balance the energy requirements to achieve photoreactions with cell compatibility.…”

Section: Introductionmentioning

confidence: 99%

Low-Dose, Long-Wave UV Light Does Not Affect Gene Expression of Human Mesenchymal Stem Cells

2015

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Light is a non-invasive tool that is widely used in a range of biomedical applications. Techniques such as photopolymerization, photodegradation, and photouncaging can be used to alter the chemical and physical properties of biomaterials in the presence of live cells. Long-wave UV light (315 nm–400 nm) is an easily accessible and commonly used energy source for triggering biomaterial changes. Although exposure to low doses of long-wave UV light is generally accepted as biocompatible, most studies employing this wavelength only establish cell viability, ignoring other possible (non-toxic) effects. Since light exposure of wavelengths longer than 315 nm may potentially induce changes in cell behavior, we examined changes in gene expression of human mesenchymal stem cells exposed to light under both 2D and 3D culture conditions, including two different hydrogel fabrication techniques, decoupling UV exposure and radical generation. While exposure to long-wave UV light did not induce significant changes in gene expression regardless of culture conditions, significant changes were observed due to scaffold fabrication chemistry and between cells plated in 2D versus encapsulated in 3D scaffolds. In order to facilitate others in searching for more specific changes between the many conditions, the full data set is available on Gene Expression Omnibus for querying.

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“…The SCLs was treated with oxygen plasma (Branson IPC 3000 O2 Asher) for one minute each side to make the lens surface hydrophilic and soaked in PVP360 solution for one minute (Lai et al, 1996). The drug-loaded contact lens was ultra-violet (UV) radiated using a UV-C lamp (TUV T8, Philips, Amsterdam, Netherlands) at a peak 253.7 nm for 30 minutes (Harris et al, 1993).…”

Section: Fabrication Of Pfd-pva Film Embedded Silicone Contact Lensesmentioning

confidence: 99%

Controllable release of pirfenidone by polyvinyl alcohol film embedded soft contact lenses in vitro and in vivo

Chong

et al. 2021

Drug Delivery

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To increase the amount of pirfenidone (PFD) loaded in polyvinyl alcohol (PVA) film embedded soft contact lens (SCL), and evaluate its function of sustaining delivery of drug in vitro and in vivo . Drug loading efficiency within PVA film and SCLs, drug release from SCLs in vitro , and the effects of parameters of SCLs and external environment on drug release in vitro were evaluated by ultraviolet–visible spectrophotometer at 312 nm. Safety of SCLs was evaluated in vitro by transformed human corneal epithelial cell. Safety in vivo was determined by optical coherence tomography and histology of anterior segment of rabbits. Drug release study in tear fluid and aqueous humor were measured by ultra-performance liquid chromatography. SCLs had smooth surface and were fit for experimental rabbits. Amount of PFD in PVA film and SCLs were 153.515 μg ± 12.508 and 127.438 μg ± 19.674, respectively, PFD in PVA film was significantly higher than SCLs ( p =.006) and closed to 150 μg (targeting amount of PFD to be loaded). Thickness of SCLs, molecular weight of PVA, and amount of PVA used in SCLs affected drug release in vitro significantly. Thickness of PVA film and amount of drug in SCLs had no effect on drug release rate in vitro . SCLs were safe in vitro and in vivo , PFD released from SCLs could be detected around 12 hours in tears and aqueous humor, and the concentration of drug was higher than eye drop at all detected time points while amount of PFD in SCLs was lower than eye drop. Drug loaded PVA film embedded SCLs may be a promising ocular drug delivery system.

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Ultraviolet Disinfection of Contact Lenses

Cited by 15 publications

References 0 publications

Disinfection by in‐duct ultraviolet lamps under different environmental conditions in turbulent airflows

Disinfection by in‐duct ultraviolet lamps under different environmental conditions in turbulent airflows

Low-Dose, Long-Wave UV Light Does Not Affect Gene Expression of Human Mesenchymal Stem Cells

Controllable release of pirfenidone by polyvinyl alcohol film embedded soft contact lenses in vitro and in vivo

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