Original research article The antifertility effectiveness of copper/low-density polyethylene nanocomposite and its influence on the endometrial environment in rats B

Purpose: The study was conducted to investigate the antifertility effectiveness of copper/low-density polyethylene nanocomposite (nano-Cu/ LDPE) and its influence on the endometrial environment in rats. Methods: One hundred and seventy sexually mature female Sprague–Dawley (SD) rats were randomly divided into five groups: shamoperated control group (SO group, n=10), bulk copper group (Cu group, n=40), LDPE group (n=40), and nano-Cu/LDPE groups I (n=40) and II (n=40). Twenty rats in each group except for the SO group were mated with male rats of proven fertility, from 30 days after insertion, and the antifertility rates (ATs) were observed at Day 11 of pregnancy. The concentrations of prostaglandin E2 (PGE2) and tissue plasminogen activator (tPA) in the endometrium of the remaining rats in each group were measured by using ELISA at the 30th and 60th day after insertion, respectively. Results: ATs in the Cu group and nano-Cu/LDPE groups I and II (100%) were significantly higher than those in the LDPE group (pb.05). Compared with those in the SO group, the concentrations of PGE2 and tPA in all experimental groups except for PGE2 levels in the LDPE group were significantly increased at Day 30 after insertion, and these parameters in the nano-Cu/LDPE groups were significantly lower than in the Cu group (pb.05). At Day 60 after insertion, tPA levels were still higher in the Cu and nano-Cu/LDPE groups, but there was no difference in PGE2 levels in all groups except for the Cu group. Conclusion: Nano-Cu/LDPE exhibits satisfactory contraceptive efficacy with less influence on the endometrium PGE2 and tPA levels. D 2007 Elsevier Inc. All right reserved.