Abstract
Abstract: :
Purpose: After cataract surgery, posterior capsular opacification incidence depends mostly on the type of biomaterials used for intraocular lenses (IOLs). Our purpose was to evaluate biocompatibility-cytotoxicity induced by different biomaterials on human lens epithelial cells (HLECs). Methods: Biomaterials studied are acrylics (hydrophobic: MA60BM (Alcon), hydrophilic: ACR6D), polymethylmethacrylate (CP65T), and silicone (SM575) (Corneal). Positive and negative controls were latex and high density polyethylene. We used a standardized elution technique (ISO 10993-5): medical devices were placed in DMEM during 48 hours to release residual chemicals from polymeric biomaterials; HLECs (SRA 01/04) were treated with the eluted solutions. Cellular responses were assessing with fluorescent probes: neutral red (ISO 10993-5), to assess membrane integrity and DNA probe, Hoechst 33342, as proliferation probe. Both signals are interpreted to distinguish inertia from necrosis, apoptosis, hormesis and cellular proliferation. Fluorescent signals are performed directly in 96 wells microplates using cold light cytofluorometry. Qualitative control could easily be practiced with invert fluorescent microscopy. Morphology of cells could be analysed by confocal fluorescent microscopy after staining with phalloïdine and propidium iodide. Results: Validity of this cytotoxic test is confirmed by controls: latex and polyethylene respectively induced apopto-necrosis and inertia. Hydrophilic acrylic induced hormesis, polymethylmethacrylate and silicone were inert and hydrophobic acrylic tended to induce apoptosis. Conclusions: These results confirm the sensibility of the elution technique and the interest of DNA probe to study IOLs cytotoxicity on adherent HLECs. Our in vitro data may be compared with clinical incidence of PCO and show that cytotoxic phenomena induced by biomaterials on residual HLECs after cataract extraction could play an important role in capsular biocompatibility of IOLs.
Keywords: cataract • posterior capsular opacification (PCO) • apoptosis/cell death