A New Method Of Cell Function Regulation Based On Acoustomagnetoelectric Effect

In recent years,the use of physical energy to treat tumors with minimally invasive or noninvasive methods attracted increasing attention in the field of cancer treatment,such as ultrasound,light,magnetic field and so on.With the gradual revealing of the biological effects of ultrasound and magnetic field,how to combine the advantages of ultrasound and magnetic field to develop a new type of tumor treatment technology has received much attention.Therefore,this study is based on the sonomagnetoeletric effect that using ultrasound combine with magnetic field to generate Lorentz force and then induce charge separation.Innovatively propose a tumor cell regulation technique which combined with the advantages of ultrasonic millimeter resolution and sonomagnetic noninvasive physical field.This new technology has been verified and studied at the level of living cells.The sonomagnetoeletric stimulation system was designed in this subject is mainly composed of high intensity focused ultrasound transducer?center frequency is 1.1MHz,negative sound pressure is 1.1 or 2.2MPa,pulse width is 45?s,pulse repetition frequency is1kHz?,parallel static magnetic field?the form of a single magnet is 50×50×30 mm³,magnetic field strength is 680±20mT?and a self-designed living cell sample dish which has acoustic and magnetic compatibility.In order to semi-quantitatively measure the change of living cell's function,they are labeled with corresponding fluorescent probe.Furthermore,the membrane potential,biochemical signals and growth of the cells were recorded using an inverted fluorescence microscope.Finally,the feasibility and effectiveness of sonomagnetoeletric effect in the regulation of cell function were verified by microscope image analysis software and statistical analysis software.In terms of cell membrane potential regulation,we found that the intensity of the DiBAC₄?3?fluorescent probe which is label the membrane potential was decreased after sonomagnetic stimulation,indicating that the membrane potential was hyperpolarized.Furthermore,the amplitude of the fluorescence intensity caused by ultrasonic pressure at2.2MPa?change 57.92%±1.04%?under sonomagnetic stimulation was larger than that caused by ultrasonic pressure at 1.1MPa?change 47.89%±1.14%?.However,both the ultrasonic stimulation alone and the magnetic stimulation alone all didn't cause a large change,which confirmed the availability of sonomagnetic stimulation in regulating membrane potential.We further researched the slow accumulation effect of sonomagnetic stimulation on membrane hyperpolarization from 0 to 10 minutes and found that longer stimulation times would lead to greater hyperpolarization of cell membrane potential.We found that sonomagnetic stimulation promoted different types of cells'membrane potential to more hyperpolarized states,and the degree of cell membrane hyperpolarization was cell-type dependent.At the organelle level,we researched the changes of mitochondrial membrane potential after sonomagnetic stimulation.The results were consistent with the response of membrane potential,and the degree of hyperpolarization was positively correlated with the ultrasonic pressure.In the regulation of cell biochemical signals,we found that sonomagnetic stimulation leads to a significant increase in the intracellular concentration of Ca²⁺and NO which were two important signaling molecules in the cell.In addition,the level of ROS?reactive oxygen?was also increased after sonomagnetic stimulation,which is associated with mitochondrial state.Particularly,we found that sonomagnetic stimulation can also increase the concentration of H⁺in the cytoplasm,so that the intracellular pH was decreased,and the intracellular acidification was observed.In terms of cell growth regulation,we found that sonomagnetic stimulation?10 min/day for a total of 3 days?effectively reduced the growth rate of N2a tumor cells by 48.64%.However,after sonomagnetic stimulationin combine with5-aminolevulinic acid?5-ALA?,Retinoit Acid?RA?and Doxorubicin?DOX?respectively,only sonomagnetic stimulation combine with RA can inhibite the growth rate of N2a together.This study verifies that sonomagnetic stimulation can effectively regulate the membrane potential,signal level and growth rate of tumor cells.The method of sonomagnetic stimulation has great potential in the field of tumor physiotherapy,and it's expected to become a new type of tumor treatment method to provide technical support for clinical treatment of tumors.