title: The antifertility effectiveness of copper/low-density polyethylene nanocomposite and its influence on the endometrial environment in rats.
abstract: OBJECTIVE
  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: sham-operated 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 E(2) (PGE(2)) 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 (p<.05). Compared with those in the SO group, the concentrations of PGE(2) and tPA in all experimental groups except for PGE(2) 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 (p<.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 PGE(2) levels in all groups except for the Cu group.
  
  
  CONCLUSIONS
  Nano-Cu/LDPE exhibits satisfactory contraceptive efficacy with less influence on the endometrium PGE(2) and tPA levels.
authors.affiliation: Family Planning Research Institute, TongJi Medical College, Huazhong University of Science and Technology, Wuhan 430030, RP China.
authors.forename: He-Fang
authors.initials: HF
authors.lastname: Liu
authors.forename: Zi-Long
authors.initials: ZL
authors.lastname: Liu
authors.forename: Chang-Sheng
authors.initials: CS
authors.lastname: Xie
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Chang-Hong
authors.initials: CH
authors.lastname: Zhu
mesh_terms: D000818:Animals; D003300:Copper / Q000008:administration & dosage / Q000494:pharmacology*; D015232:Dinoprostone / Q000378:metabolism; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D007435:Intrauterine Devices, Copper; D053761:Nanocomposites; D020959:Polyethylene / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D010959:Tissue Plasminogen Activator / Q000378:metabolism
chemical_list: D003300:Copper; D020959:Polyethylene; D010959:Tissue Plasminogen Activator; D015232:Dinoprostone