Facile multifunctional IOL surface modification via poly(PEGMA-co-GMA) grafting for posterior capsular opacification inhibition

Posterior capsule opacification (PCO) is a significant complication of intraocular lens (IOL) implantation in cataract surgery, in which the adhesion and proliferation of lens epithelial cells (LECs) on the implanted IOL surface play an important role. The surface modification of IOL to prevent LEC adhesion and proliferation is a practical way to reduce the incidence of PCO. In this study, a multifunctional binary copolymer of poly(ethylene glycol) methacrylate (PEGMA) and glycidyl methacrylate (GMA) was synthesized (poly(PEGMA-co-GMA), PPG) and chemically grafted onto the aminolyzed IOL surface, utilizing the coupling reaction of epoxy and amino groups. Doxorubicin (DOX) was subsequently immobilized on the surface coating via the reaction of epoxy and amino groups as well. Taking advantages of the hydrophilicity of the PEG segments in the copolymer coating and the anti-proliferative effects of the DOX, a multifunctional surface coating was easily established by the synthesized copolymer PPG. Such anti-proliferative drug immobilized hydrophilic coating modification may effectively reduce the cell adhesion and proliferation and thus it is hypothesized to have great potential in PCO inhibition. The synthesis of PPG was confirmed by proton nuclear magnetic resonance spectroscopy ((1)H-NMR) and Fourier transform infrared spectroscopy (FTIR). The surface coating immobilization was demonstrated by X-ray photoelectron spectroscopy (XPS). The in vitro drug release profiles and the cell behaviors were also investigated to validate the multifunctional coating inhibition effect on cellular adhesion and antiproliferation. Finally, the in vivo ocular implantation was carried out on rabbit eyes to evaluate the effect of the coating modified IOL on the inhibition of postoperative PCO. It followed that such multifunctional coating modification can effectively inhibit the adhesion and proliferation of LECs and significantly reduce the incidence of PCO. All these results reveal that such PPG copolymer modification provides a facile yet effective way to inhibit PCO formation after IOL implantation.