| Cataract is a main ocular disease in the world which leads to blindness. Up to date, extracapsular cataract extraction (ECCE) or phacoemulsification combined with artificial intraocular lens (IOL) implantation is considered to be the best treatment. However, posterior capsular opacification (PCO), the most common postoperative complication, may decrease the visual acuity again.Some studies suggest that posterior capsular opacification is mainly caused by the proliferation and migration of postoperative remnants of lens epithelial cells (LECs). 5-fluorouracil (5-FU), an anti-metabolic drug, has been showed effective in inhibiting lens epithelial cells proliferation in many experimental trials in vitro and in vivo. 5-FU in eye was cleared from anterior chamber by aqueous flow. Its clinical use is limited by instable ocular concentration and intolerable toxic side effects to other ocular tissues. Thus, it is imperative to find a new drug delivery system which can deliver a therapeutically effective dose to the LECs to selectively kill them and reduce the toxic side effects. It has very important clinical value to produce the drug delivery system of high polymer material or/and monoclonal antibody linked to anti-metabolic drugs, toxins and nuclein, which can selectively and long-time killed LECs for preventing PCO.we produced 5-FU-coated polyactic acid (PLA) nanoparticles (NPs) by double emulsion (water-in-oil-in-water, W/O/W) method and the particles were characterized for size, morphology, and structure by scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). 5-FU loading level and in vitro release-3-were also examined. Then we produced immunonanoparticles (INPs) by conjugating monoclonal antibody HILE6 with NPs via carbodiimide catalyzed reaction and measured the molar ratio of HILE6 and 5-FU and the INPs activity of the antibody in the conjugate by ELISA. We evaluated NPs and INPs effect on LECs proliferation by MTT colorimetry and observed the relevant morphological changes of LECs with light microscope and transmission electron microscope and the internalization of INPs by fluorescence microscopy. The main results are the following:1. The mean particle size was 191.0?.202nm, the drug loading was 8.1%, 5-FU release was sustained about 20 days. 5-FU NPs not only can keep inhibition on lens epithelial cells, but also be better than original 5-FU in some dose with the time.2. No cytotoxicity of the unloaded PLA-NPs was observed on LECs and cornea stroma cells (CSCs) following 72 hours of exposure. PLA-NPs were highly tolerated by the cells and can be used as drug carriers for treatment of ocular diseases.3. In the INPs, the immunological activity of antibody retained about 84% of the original HILE6 and each McAb could carry 1809 5-FU molecule. LECs were sensitive to INPs and 68.42% growth inhibition was achieved with a concentration of 240 H g/ml after 24 hours exposure.4. The INPs can find and adhere to lens epithelial cells in 30 minutes and enter the cytoplasm or/and nucleus in 4 hours, and the nucleus were the major compartment of their distribution. The NPs were delivered into the cells by antibody as an intact conjugate.We successfully prepared the immunonanoparticles of monocolonal antibody HILE6 linked with 5-FU polyactic acid nanoparticles and studied their character, cytotoxicity, immunological character and internalization. It laid a foundation of experiment in vivo furtherly for preventing PCO safely and effectively.
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