| The high incidence and mortality rate of cancer have seriously threatened human health.The clinical treatment methods for cancer are mainly surgical resection,chemotherapy,and radiotherapy.However,in addition to large-scale defects caused by surgical operations,there is also the risk of cancer recurrence due to residual cancer cells.However,chemotherapy and radiotherapy have obvious side effects which is great harm to the human body and poor prognosis.Ultraound and light supplemented by sono-/photo-responsive nanoparticles can be used for photodynamic and sonodynamic therapy.Because of the non-invasiveness and the focus on tumor tissue without damaging normal tissues,it provides a new method for cancer treatment.Therefore,to improve the efficiency of tumor treatment and avoid the side effects of traditional therapies,the development of a highly effective anti-tumor acousto-optic responsive nanoparticle has become an effective approach for tumor treatment.Perovskite-type inorganic piezoelectric nanoparticles are a class of functional materials with sono-/photo-responsiveness,which can generate active oxygen to kill cancer cells under light or ultrasound.This subject studied the killing effect of perovskite-type inorganic piezoelectric nanoparticles with sono-/photo-responsiveness on cancer cells under the light or ultrasound and its death mechanism.The main contents of this subject are as follows:(1)Based on the recent research of low cancer treatment efficiency of sono-/photoresponsive nanoparticles under ultrasound or light,we constructed synergistic sono-photoresponsive nanoparticles to realize synergistic sono-phototherapy to kill melanoma cells.The sono-photo-responsive potassium sodium niobate piezoelectric nanoparticles were prepared by solid-phase reaction method,mechanochemical method and external electric field polarization.Characterization of the optical and electrical properties of the piezoelectric nanoparticles were separately detected by UV-vis absorption spectroscopy and electrical signal detection under ultrasound.Comparing the degradation efficiency of methyl blue under single ultrasound,single light and the combination of ultrasound and light,among them,the degradation rate under a single stimulation was about 40%,and the degradation rate under the synergistic stimulation was as high as 70%,which showed the synergistic sono-photo-responsiveness of the nanoparticles.The effect of the piezoelectric nanoparticles on melanoma cells under the combination of ultrasound and light was studied.The mortality rate of cancer cells under the combination of ultrasound and light was as high as 81%,which is higher than the effect of a single stimulation.Cell endocytosis,intracellular reactive oxygen species and reduced glutathione levels revealed the mechanism of interaction between the material and cancer cells.After cells uptaking the piezoelectric nanoparticles,the intracellular reactive oxygen species level significantly increased and the reduced glutathione level significantly decreased under the combination of ultrasound and light,breaking the dynamic balance of both and thus killing cancer cells.In vivo animal experiments further showed that the piezoelectric nanoparticles had a better anti-tumor effect under the combination of ultrasound and light than a single stimulation.(2)Based on the recent research of sonodynamic therapy,heterojunction enhancing active oxygen generation capacity and bismuth metal element in the biomedical field,we constructed sono-responsive bismuth/barium titanate heterojunction piezoelectric nanoparticles to enhance the efficiency of killing breast cancer cells.The fluorescence intensity detection of reactive oxygen species in solution showed that both barium titanate and bismuth/barium titanate piezoelectric nanoparticles could generate a large amount of reactive oxygen species under ultrasound irradiation.Compared with barium titanate,the reactive oxygen species level of bismuth/barium titanate was nearly doubled,which indicated bismuth could enhance the ultrasonic responsiveness of barium titanate.The mortality of cancer cells of barium titanate and bismuth/barium titanate under ultrasound irradiation were about 43% and 70%,respectively,which indicated that the bismuth enhanced the anti-breast cancer cell effect of barium titanate.The analysis of apoptosis and necrosis and the level of intracellular reactive oxygen species showed that the nanoparticles generated reactive oxygen species under ultrasound irradiation and then induce apoptosis of cancer cells. |
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