Design Of Ultrasound Responsive Polymer Nanosystem For Glioma Treatment

Glioma is a primary brain tumor among nervous system tumors.It has highly aggressive spread and diffuse invasion.It is currently one of the deadliest malignant intracranial tumors that need effective treatment.Its incidence is 40% of intracranial tumors.Among them,chemotherapy is currently a mature and effective treatment method for glioma.However,because glioma has physiological barriers such as bloodbrain barrier,blood-brain tumor barrier,and tight junctions between endothelial cells,chemotherapy drugs cannot be effective.Passing the blood-brain barrier to the site of glioma to achieve the concentration of drugs necessary to destroy glioma has brought a huge challenge to the use of chemotherapeutic drugs to treat glioma.Nanoparticles can be used as drug carriers to achieve drug delivery across the physiological barrier of glioma,and stimulus-responsive nanoparticles can achieve controlled release of drugs at the glioma site.Among the stimulus sources that nanoparticles respond to,ultrasound has the advantages of strong penetrating ability and no ionizing radiation.It has irreplaceable advantages for nanoparticles to release drugs in response to ultrasound to achieve controlled delivery.The research is based on the synthesis of ultrasonic-responsive block copolymers based on RAFT polymerization:poly(N,N-dimethylacrylamide-b-tetrahydropyranyl methacrylate)and poly(N,Ndimethylacrylamide-co-fluorescein acrylate-b-tetrahydro Pyranyl methacrylate)block copolymers,prepared by self-assembly method,can partially disassemble in response to ultrasound stimulation,and the hydrophobic fragments in response to ultrasound fall off,resulting in an increase in the proportion of hydrophilic fragments.We used ultrasound to stimulate the nanoparticles to characterize the ultrasound response,and obtained that the amphiphilic poly(N,N-dimethylacrylamide-b-tetrahydropyranyl methacrylate)self-assembled nanoparticles have a particle size ranging from 100 nm When it becomes 150 nm,the morphology changes obviously;poly(N,Ndimethylacrylamide-co-fluorescein acrylate-b-tetrahydropyranyl methacrylate)selfassembled nanoparticles and their particles The size of the self-assembled nanoparticles of amphiphilic poly(N,N-dimethylacrylamide-b-tetrahydropyranyl methacrylate)changed from 160 nm to 220 nm,and the self-assembled nanoparticles of amphiphilic poly(N,N-dimethylacrylamide-b-tetrahydropyranyl methacrylate)encapsulate rhodamine B as a drug After the model was subjected to the same ultrasonic treatment,the size of the nanoparticles changed from 160 nm to 210 nm.At the same time,we conducted ultrasound response experiments of nanoparticles in glioma U87 MG cells,and concluded that nanoparticles can respond to ultrasound in cells to achieve controlled release of rhodamine B drug model molecules.This study designed and successfully constructed ultrasound-responsive nanoparticles for controlled drug delivery,and used medical therapeutic ultrasound to successfully release drug model molecules,providing a new theoretical basis for the treatment of glioma.