Releasing of Cupric Ion of Three types of Copper-bearing Intrauterine Contraceptive Device in Simulated UterineFluid

Objective To compare the cupric ion releasing in vitro o.f the three IUDs. Methods The stability o.f cupric ion releasing o.f IUDs including TCu 380.4 IUD （TCu 380A）, Multiload Cu375 IUD （MCu 375） and Yuangong 365 copper-bearing indomethacin-releasing IUD （Yuangong 365） by the determination of cupric ion releasing in simulated uterine fluid. The simulated uterine fluid was used for releasing media. Copper ion was determined by flame atomic absorption spectrometer. Results The cupric ion releasing of three IUDs were instable at the beginning and tend to be stable gradually. In the stable phase, the average level of cupric ion releasing of TCu380A, MCu375 and Yuangong 365 were 4.25±2.71-7.62±6.42 μg, 4.92±1.23 -8.62±3.08 μg and 2.19±0.40-4.68±1.66 μg, respectively. TCu380A had higher instable releasing level than those of Yuangong 365 （P〈0. 05）. Conclusion TCu 380.4 and MCu 375 showed a ＂burst release＂ during the first few days and the.former was of great significance（P〈0.05）. The initial cupric ion releasing of Yuangong 365 appeared to be the lowest, followed by MCu375 and TCu380A in a releasing order

Cytotoxicity of six copper-bearing intrauterine devices on Chinese hamster ovary cells: the influence of frame, shape and copper surface area

Objective To evaluate the cytotoxicity of six commonly used copper-bearing intrauterine devices （Cu-IUDs） on Chinese hamster ovary （CHO-K1） cells and to investigate the influence of frame, shape and copper surface area of Cu-IUDs on cell toxicity.Methods Cu-IUDs were incubated in 10% FBS-DMEM/F12 culture medium at 37 ℃ for 24 h. The extracts were analyzed by flame atomic absorption spectrometer and were then diluted into different concentrations with culture medium. Finally, cytotoxicity of these original and diluted extracts on CHO-K1 cells was detected by cell counting kit-8 （CCK-8） assay.Results The viabilities of cells treated with the original extracts of six Cu-IUDs （TCu220C bulb, TCu220C, GCu220, GCu300, Yuangong Cu270 and Yuangong Ⅱ- 300） were all below 10% and the cupric ion concentrations in these extracts were 28.22 mg/L, 31.80 mg/L, 92.80 mg/L, 99.74 mg/L, 114.90 mg/L and 119.20 mg/L, respectively. After these original extracts were diluted, significant differences in cytotoxicity were exhibited. IUDs with larger copper surface areas （GCu300 and Yuangong Ⅱ-300） showed more cytotoxicity than those with smaller areas （GCu220 and Yuangong Cu270） respectively; When different shapes of Cu-IUDs were compared, TCu220C bulb showed lower cytotoxicity than TCu220C, and GCu300 exhibited higher toxicity than Yuangong Ⅱ-300; TCu220C displayed significantly lower cytotoxicity than GCu220 due to their differences in frames.Conclusion We presented evidence on the cytotoxic effects of copper ions released from Cu-IUDs on CHO-K1 cells and found that shape, frame together with copper surface area of Cu-IUDs had obvious influence on the cytotoxicity.