Study Of Bovine Capsular Bag Culture In Ocular Tissue And Inhibition Of Arsenic Trioxide Of Bovine Lens Epithelial Cells

With the development of modern micrurgy, extracapsular cataract extraction (ECCE) and phacoemulsification, the surgical therapy of cataract is not a problem. But posterior capsule opacification (PCO) is a significant long-term complication that leads to visual acuity decrease again. The incidence of PCO is 30%⁵0% in adults and 100% in children of patients within 2 months to 5 years after ECCE. Nd:YAG posterior capsulotomy is easy but isn't safe and the complication of capsulotomy include injuring the IOL, high intraocular tension, cystoid macular edema and retinal detachment. If the head couldn't be fixed the capusulotomy wouldn't apply. In PCO, residual LECs in the anterior and equatorial regions of the lens capsule after surgery proliferate and migrate onto the previously acellular posterior capsule. There cells form a multiplayer, take on a fibroblast-like appearance, contract, and secrete extra cellular matrix.A lot of model of PCO in vitro had been established. From origin culture of BLEC to passage BLEC, tissue culture of BLEC and three dimensionally culture of BLEC we have had a series of study. The report of capsular bag culture is seldom in domestic. The report of capsular bag culture only in ocular tissue is never seen. In order to find out the mechanism of PCO formation, replicate the pattern of in vivo growth as closely as possible we designed the model of capsular bag culture only in ocular tissue. In this research, we observed the effect of ocular on BLEC without serum.Arsenic trioxide is effective element of Chinese traditional medicine arsenic which has been used to treat acute primyelocytic leukemia (PAL) in clinic and achieved significant effect. It mainly induced apoptosis of tumor cells. Arsenic trioxide is changing the cellular chromosome structure, restraining cellular activity, disturbing cellular metabolize and inducing cancer cells apoptosis. Our study firstly investigates the effect of arsenic trioxide restraining proliferation and inducing apoptosis on BLEC cultured in vitro. What's more, the medical sensitivity is different in different growth state. Our study provides experiment data to prevent PCO with arsenic trioxide by ocular local application in clinic.1. Study of bovine capsular bag culture in ocular tissueMethods The bovine capsular bags were dissected from zonules and cultured by different ocular tissue in condition of 37℃, 5% CO₂ incubator for 5 weeks. To retain itscircular shape the capsular bags were implanted a glass ring. On-going observations were by phase-contrast microscopy and Giemsa-staining.Results The fresh capsular bag is transparent. Apoptosis of BLEC within capsular bags were seen after 1 week in aqueous humor. All cells were completely apoptosis after 5 weeks. Proliferation, differentiation and fibrosis of BLEC were seen in lens cortex, vitreous humor. The lens epithelial cells migrate and proliferate on posterior capsule from equatorial region to the center. The posterior capsule cell confluence time is different from different ocular tissue. The time is 13d¹6d in lens cortex, 9d¹0d in vitreous humor and 5d⁷d in 2%DMEM.2. The inhibition effects of arsenic trioxideMethod: BLECs were isolated and cultured. The passage BLECs were placed in 24-well tissue culture plates and incubated for 24 hours or 48 hours. The absorbencies of the cells were tested by using MTT assay.Results: Arsenic trioxide significantly suppressed the proliferation of BLEs in vitro, showing dose-dependent and time-dependent manner. The medical sensitivity is different in different growth state. The inhibition effect of arsenic trioxide is strongerwith serum than without. It possibly can be used to inhibit the after cataract. 3. Conclusion(1) The capsular bag culture in ocular tissue in vitro is a kind of efficient method to model PCO. The capsule bag in ocular tissue culture can replicate in vivo growth of LEC as closely as possible.(2) The capsular bag culture model in ocular tissue shows either lens cortex or vitreous humor can format PCO. The role of vitreous humor is significant in the formation of PCO. The aqueous humor inhibits the proliferation of LEC, induces apoptosis of LEC and inhibits the formation of PCO.(3) Arsenic trioxide can make the BLEC apoptosis in vitro. It can be used to inhibit the after cataract.