The Biological Safety Evaluation Of Nano-copper/low Density Polyethylene Composite Intrauterine Device

Partâ… Experiment in vitroExperiment one Study of the Cytotoxicity of nano-copper/low density polyethylene composite intrauterine deviceObjective: To evaluate the cytotoxicity of nano-copper/low density polyethylene composite with mouse fibroblast cells.Methods: According to the experimental principle and method of biological appraising standard (GB/T 16886) on medical apparatus, leaching liquors of nano-copper/low density polyethylene composite and TCu220C were prepared with simulated uterine solution. The mouse fibroblast cells (L-929) were cultured with leaching liquors. The proliferation of L-929 cells was measured by tetrazolium colorimetric assay (MTT), and the morphology of the cells were observed by scanning electron microscope (SEM).Results: The relative growth rate of L-929 cells showed significant difference between nano-copper composite group and TCu220C group. The cytotoxicity of nano-copper composite group was 1, but the TCu220C group was 4. The morphology of L-929 cells was normal and the proliferative number of L-929 cells were increased in nano-copper composite group during culture period. The number of L-929 cells were decreased obviously and the morphology of most cells was damaged in TCu220C group.Conclusions: Nano-copper/low density polyethylene composite IUD present no cytotoxicity.Partâ…¡Experiment in vivo Experiment two Cutaneous stimulation test of nano-copper/low density polyethylene composite intrauterine deviceObjective: To evaluate the cutaneous stimulation of nano-copper/low density polyethylene composite intrauterine device.Methods: According to the experimental principle and method of biological appraising standard (GB/T16886) on medical apparatus, leaching liquors of nano-copper/low density polyethylene composite and TCu220C were prepared with simulated uterine solution. The extracts of two materials were used to stimulate the regional skin of healthy white rabbit spine. The skin stimulus reaction was observed within 72 hours after stimulation.Results: Animals had no exceptional actions during experimental period. No erythema, eschar or edema appeared in the regional skin of rabbits within 72 hours after being stimulated by the extracts of two materials. According to the standard of skin reaction of GB/T16886, the score of both IUDs in this test were 0.Conclusions: Nano-copper/low density polyethylene composite IUD present no skin stimulation.Experiment three Skin sensitization test of nano-copper/low density polyethylene composite intrauterine device Objective: To evaluate the skin sensitization of nano-copper/low density polyethylene composite intrauterine device.Methods: According to the experimental principle and method of biological appraising standard (GB/T16886) on medical apparatus, leaching liquor of nano-copper/low density polyethylene composite was prepared with simulated uterine solution. The extract was used to stimulate the regional skin of guinea pig by maximum dose method which contained initial induction and challenge phases. The skin sensitization reaction was observed at 24h and 48h after challenge phases.Results: Edema and erythema in the skin of guinea pig were observed at 24h in positive control group(1% 2-4-dinitrochlorphene), but those reaction was palliated at 48h. According to the standard of skin reaction of GB/T16886, positive control group was in 2~4 grade, and the allergy rate was 100%. Edema and erythema in the skin of guinea pig were not observed at 24h and 48h in nano-copper composite group and blank group (simulated uterine solution).Conclusions: Nano-copper/low density polyethylene composite IUD present no skin sensitization.Experiment four Muscle embedding test of nano-copper/low density polyethylene composite intrauterine deviceObjective: To evaluate the biocompatibility of nano-copper/low density polyethylene composite with myoideum.Methods: According to the six part of biological appraising standard (GB/T16886) on medical apparatus, two materials of copper/low density polyethylene nanocomposite and TCu220C were inserted into myoideum after sterilization. The reaction of myoideum surrounding the embedding part was observed at the first week, the fourth week and the twelfth week by macroscopic observation and tissue slice observation.Results: Animals had no exceptional actions during experimental period. The wounds during embedding stage had no manifestation of flare and diapyesis. In two groups, the myoideum was showed serious inflammatory reaction and capsule walls were not formed at first week. At fourth week, inflammatory reaction of the myoideum palliated, and fibrous capsule was formed. The inflammatory reaction of the myoideum and fibrous capsule were both inâ… grade at the twelfth week.Conclusions: Nano-copper/low density polyethylene composite present no adverse reaction in myoiduem. It proved good histocompatibility.