Purpose. To validate the biocompatibility and transmittance properties of contact lenses bearing intact liposomes. These liposomal lenses loaded with therapeutics can be used as ophthalmic drug delivery systems.
Methods. The biocompatibility of soft contact lenses, coated with liposomes was evaluated through in vitro direct and indirect cytocompatibility assays on human corneal epithelial cells, on reconstructed human corneas and on ex vivo rabbit corneas. The direct and indirect transmission spectra of liposome-covered lenses were also evaluated to test if they transmit all wavelengths of the ultraviolet-visible spectrum, to thereby fulfill their optical function, without gross alteration of the colors perception and with a minimum of light dispersion.
Results. Contact lenses bearing layers of stable liposomes did not induce any significant changes in cell viability and in cell growth, compared with lenses bearing no liposome. Elution assays revealed that no cytotoxic compound leaks from the lenses whether bearing liposomes or not. Histological analyses of reconstructed human corneas and ex vivo rabbit corneas directly exposed to liposomal lenses revealed neither alteration to the cell nor to the tissue structures. Contact lenses bearing layers of liposomes did not significantly affect light transmission compared with control lenses without liposome at the wavelength of maximal photopic sensitivity, i.e., 550 nm. In addition, the contact lenses afford more eye protection in the ultraviolet spectrum, compared with the control lenses.
Conclusions. Liposomal contact lenses are biocompatible and their transmittance properties are not affected in the visible light range.
Laboratoire de Bioingénierie et de Biophysique de l’Université de Sherbrooke, Department of Chemical Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada (AD, PV), Research Centre on Aging, Institut universitaire de gériatrie de Sherbrooke, Sherbrooke, Québec, Canada (AD, PV), Oncology and Molecular Endocrinology Research Center, CHUL’s Research Center, CHUQ, Québec, Québec, Canada (CJD, RP), École d’optométrie, Université de Montréal, Montréal, Québec, Canada (CJG, SD, PS), Laboratoire d’Organogenèse Expérimentale (LOEX), and CHA Pavilllon Saint-Sacrement and Département d’ORL-ophtalmologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada (CJG, SD, PS)
This work was supported by the NSERC through an Idea-to-Innovation grant (PV and CJD), by the Canada Foundation for Innovation (CJG and PV), and by the Canadian Optometric Trust Fund (CJG). The contact lenses were kindly supplied by Robert Mercure from Les Laboratories Opti-Centre (Sherbrooke, Québec, Canada).
Some of these results were originally presented as a poster at the annual meeting of the American Academy of Optometry; December 8, 2006; Denver, CO.
Received December 2, 2006; accepted May 7, 2007.