Abstract
Purpose::
Intraocular application of silicone materials often causes cell migration and attachment to the surface of the implant. In intraocular lens (IOL)-implantation, the migration of epithelial cells into the optical axis reduces the patient’s visual outcome and is often associated with extensive after-care. We therefore studied cell growth and viability on a modified silicon surface with the aim to inhibit cell attachment without influencing cell viability.
Methods::
Silicon membranes with and without polyethyleneglycol (PEG)-coating as well as combined PEG and heparin coating were plasma-sterilized in 2-well chamber slides and degassed over night. ARPE 19 cells (obtained from ATCC depository) were cultured in a 1:1 mixture of Dulbeccos modified Eagles medium and Ham’s F 12 medium containing 20 % fetal calf serum (FCS) and incubated at 37 °C in 5 % CO2. After they reached confluence, cells were seeded onto the silicon membranes at a seeding density of 30.000 cells/ml and cultured as described above. A toxic membrane containing PVC, a biocompatible foil and a glass slide served as controls. Cell viability was measured after 24 h using an ethidiumbromid dye to detect defect cells and fluorescein diacetate (FDA) to dye intact cells. Cell proliferation was determined by fluorescence-microscopy of incorporated 5-bromo-2’-deoxyuridine (BrdU) using a fluorescein conjugated monoclonal antibody. Morphological cell changes were documented after haemalaun staining.
Results::
Cell adhesion and number of cells were highest on uncoated silicon membranes, biocompatible foil and the glass slide. Cells were viable but not as abundant on PEG- and PEG+heparine-coated membranes. BrdU-incorporation was best on uncoated membranes and highly decreased in both coating methods. There were no viable cells attached to toxic membranes. Morphology of tested cells appeared unchanged compared to controls (except for toxic membrane).
Conclusions::
PEG-coated silicone membranes showed high biocompatibility and reduced cell adhesion. There was no difference in PEG-coated versus PEG and heparine-coated silicone membranes. Since the coating process is easily applicable for pre-operative treatment of IOLs, our results are encouraging for further clinical trials with PEG-coated intraocular silicone lenses to reduce postoperative complications.
Keywords: cell membrane/membrane specializations • intraocular lens • microscopy: light/fluorescence/immunohistochemistry