Comparison of the capsule biocompatibility of three types of intraocular lenses in vitro

Background Researchers showed that posterior capsule opacification (PCO) may be associated with the materials of intraocular lenses (IOLs). However, there have long been controversies about the influence of IOLs materials on PCO pathogenesis. Objective This study was to compare the capsule biocompatibility of different materials of IOLs by observing the biological behavior of human lens epithelial cells (LECs) on the surface of IOLs, including adhesion, proliferation, epithelial mesenchymal transition (EMT) and the secretion of transforming growth factor-β2(TGF-β2), interleukin-6 (IL-6), matrix metalloproteinase-2 (MMP-2) and MMP-9 in vitro. Methods Human lens epithelial cell line (HLE-B3) was cultured on the surface of hydrophobic acrylic (Acrysof SA60AT) IOLs, silicone (Crystalens HD) IOLs and polymethyl methacrylate (PMMA) IOLs for 6 hours and 24 hours, respectively.The number and morphology of HLE-B3 cells on the surface of IOLs were observed under the optical microscope.The proliferation states of the cells on the IOL surface were detected with cell counting kit-8 (CCK-8). The expression of α-smooth muscle actin (α-SMA), a mesenchymal cell marker, in the cells was detected by immunofluorescence technology, and the EMT rates of HLE-B3 cells were calculated.The contents of TGF-β2, IL-6, MMP-2 and MMP-9 in the medium of IOL surface were measured by ELISA assay.The examination results were compared among different IOLs. Results Six hours after cultured, attached cells showed polygon and round in shape on the surface of Acrysof IOLs and Crystalens IOLs, while those on the PMMA IOLs showed the fusiform.Twenty-four hours after cultured, the cells extended obviously.On the surface of Acrysof IOLs and Crystalens IOLs, the adherent cells showed less cobble-stone like and more spindle shape; while those on the PMMA IOLs showed the typical fiber and some cells clustered the pearl rolls.The number of the cells on the Acrysof IOLs, Crystalens IOLs and PMMA IOLs was 0.238 4±0.007 1, 0.178 1±0.006 6 and 0.158 9±0.006 9 respectively, showing a significant difference among the three types of IOLs (F=475.947, P=0.000), and the number of the cells was much more on the Acrysof IOLs than that on the Crystalens IOLs or PMMA IOLs (both at P 0.05). Conclusions The hydrophobic acrylic IOLs have the best capsule biocompatibility followed by the silicone IOLs and then the PMMA IOLs. Key words: Biocompatible materials; Capsule opacification/etiology; Lenses, intraocular/adverse effects; Posterior capsule of the lens/pathology; Epithelial cells, lens; Human