Research On The Absorption And Transportation Mechanisms Of Copper Oxide Nanoparticles In Caco-2Cells And The Chicken Intestine

Nano copper oxide (nano CuO) is the new nano trace element additives, with theadvantages of high bioavailability, improvement of immune function in animals, notantagonizing other trace elements, etc. This project aims to investigate the absorptionof nano CuO by the intestine in chickens in vivo model, and reveal the absorption andtransport mechanisms of nano CuO from the molecular and cellular levels.By founding Caco-2cell model, this project investigates the effects of nano CuO,micron CuO and CuSO4on cell growth, and LDH, AKP, and SOD activity. Theresults showed that CuSO4, micron CuO and nano CuO had few effects on Caco-2cells grown (24h). With increasing copper concentration and incubation time, alarge of cell were dead. Effect of nano CuO on Caco-2cells was similar with CuSO4.The culture copper ion concentration of nano CuO was between CuSO4and micronCuO, suggesting part of nano CuO was dissolved in the culture.By comparing the different sources of copper absorption transport in Caco-2cells, the researcher found out that Micron CuO was transported by passive diffusionin Caco-2cells, and the absorption was poor. CuSO4and nano CuO had betterabsorption in Caco-2cells, and there is active transport mechanism in transit. CuSO4was a concentration-dependent and saturated in transit. Nano CuO was aconcentration-dependent in transit, but did not show absorption saturation. By usingendocytosis inhibitors to research the uptake path of nano CuO in Caco-2cells, theresearcher found that the process of nano CuO into the cell was energy-dependent,and nano CuO entered the cells by the action of a variety of endocytic pathway.By comparing the effects of different sources of copper on Ctr1, ATP7A, ATP7B,MT and DMT1protein in Caco-2cells, the results showed that nano-CuO affects bothcopper transporter gene expression and protein. It suggested that nano CuO wastransported absorption by copper transport protein regulation in Caco-2cells. The effects of CuSO4, micron CuO and nano CuO on the expression of copper transportproteins and the genes encoding these proteins differed considerably. Nano CuO has adifferent transport mechanism in Caco-2cells to those of CuSO4and micron CuO.In summary, nano CuO was partially dissolved in the culture. which is absorbedand transported by the cells in the ways of copper ions and nanoparticles, Thetransport processes are coordinately regulated by a variety of copper ion transportproteins and the number of endocytosis pathway.Animal experiments showed that adding nano CuO could improve the chickenweight gain, and could significantly increase the activity of SOD, CP, CCO in plasma.Through the study of copper transporter gene expression in the intestinal of chickens,the researcher found that nano CuO was mainly absorbed in the duodenum andjejunum, which suggests nano CuO absorbed mainly in the form of copper iontransport in duodenum, and absorbed mainly in the form of nanoparticles transport injejunum.