Study On The Fabrication Of Selenium-doped Potassium Sodium Niobite Bioceramics And Its Antitumor Effect

Bone tumors and malignant melanoma seriously affect the life and health of patients.At present,the clinical treatments of these malignant tumors have three steps.Firstly,the patients are treated with chemotherapy or radiation to prevent tumor cell metastasis.Then surgical surgery is used to completely remove the tumor tissue.Lastly,postoperative adjuvant chemotherapy and radiation therapy are used to prevent residual and metastasis of tumor cells.But the side effects of chemotherapy and radiotherapy are very large.For bone tumors,clinical treatment can cause irreparable bone deects.Thereforfe,selenium-doped potassium sodium niobite biological ceramics with piezoelectric property was constructed to achieve the filling of bone defects.The piezoelectric properties of the ceramics and the release of Se were utilized to achieve the effective combination of electrotherapy and drug therapy to anticancer.For malignant melanoma,in clinical treatment,the cure rate of patients is very low.The selenium-doped potassium niobite biological ceramic with photocatalytic property was constructed.The photocatalytic properties of the ceramic and the release of Se can achieve the effective combination of photodynamic therapy and drug therapy to anticancer.The main research contents of this topic are as follows:（1）The selenium-doped potassium sodium niobate biological ceramics with piezoelectric property（KNN-Se）,combining the piezoelectric properties and Se element,were prepared as bone implant materials.The KNN-Se biological ceramics not only filled with bone defects,but also combined effectivly electrotherapy and drug therapy to anticancer.By analyzing the composition,structure and morphology of the ceramic sheet,it is proved that the Se element is successfully doped into the KNN crystal structure,resulting in the surface particle size of the ceramic sheet becoming larger.With the increase of the doping amount of Se element,the piezoelectric constant d₃₃ of the polarized ceramic piece rises from 80 pC/N to 120 pC/N,then drops to 80 pC/N,and the ceramic with selenium doping amount is 6%.The sheet is the highest,ie 120 pC/N,and the surface potential of the ceramic sheet after polarization is three times higher than before the polarization.The amount of Se released in the PBS before and after polarization was 1.5 times higher than that in PBS at pH 7.4,and the amount of Se released from the polarized ceramic sheet was higher than that before polarization.Increased.The effects of ceramic sheets before and after polarization on the activity of osteosarcoma cells,morphology of tumor cells,apoptosis and necrosis,and reactive oxygen species were studied.It was proved that the amount of Se doping after polarization was 6%for ceramic cells.The killing effect is the strongest,and its cell survival rate is half of that before polarization,which is 1/3 of the undoped Se element.Its active oxygen production is 2 times higher than before polarization and 4 times higher than undoped Se.And KNN-Se piezoelectric properties bioceramics have no obvious toxicity to normal osteoblasts.This study provides a new research idea for the treatment of bone tumors.（2）The 6%selenium-doped potassium sodium niobate biological ceramics with photosensitive property（KNN-6%Se）,combining the photocatalytic properties and Se element,were prepared to combine photodynamic therapy with drug therapy to anticancer.Through the analysis of the composition,structure and morphology of the ceramic powder,it is proved that the Se element is successfully doped into the crystal structure of the ceramic,which leads to the larger particle size of the KNN ceramic powder and the improvement of the photocatalytic performance of the powder.The amount of Se element released by selenium-doped ceramic powder in PBS at pH 5.0 was twice as high as that in PBS at pH7.4,and the amount of Se released under light conditions was increased under light-shielding conditions.The effects of ceramic powder on the activity,apoptosis and necrosis of malignant melanoma cells and reactive oxygen species under light and dark conditions were studied.The selenium-doped ceramic powder had the strongest killing effect on tumor cells under light conditions.The cell viability is half that in the dark,and is1/3 of the doped selenium.Its active oxygen production is 2 times higher than in the dark,and 6 times higher than the undoped Se element.The photocatalytic reaction of the ceramic powder under light conditions produces reactive oxygen species,which enter the cell and cause apoptosis of the tumor cells.The released selenium element enters the inside of the tumor cells and promotes the production of ROS,thereby causing apoptosis of the tumor cells.And the ceramic powder has no obvious toxicity to normal human umbilical vein endothelial cells.