Neuroprotective Effect Of Ultrasound Triggered Astaxanthin Release Nanoparticles On Early Brain Injury After Subarachnoid Hemorrhage

Background:Subarachnoid hemorrhage is an acute condition that can be life-threatening.Within 72 hours of its occurrence,the blood-brain barrier is destroyed,and a series of changes such as autophagy,apoptosis and oxidative stress occur in neurons,while antioxidant stress is an important treatment method.Astaxanthin(ATX)is a strong oxidant,which can produce antioxidant behavior by regulating related signaling pathways to alleviate brain injury.However,ATX is insoluble in water and easy to photolysis.At present,intraventricular administration has great trauma and low bioavailability.Objective:To construct astaxanthin nano drug delivery system to improve the decomposition of astaxanthin.Methods:(1)Combined with the ultrasonic cavitant perfluorocarbon(PFH),ATX,and tracer IR780,the trigger release nanoparticles(AUT NPs)were obtained by means of Polydopamine(PDA),and the cokernel/shell nanostructures formed the physical barrier.To improve the bioavailability of ATX.(2)The characterization,stability and ultrasonic responsiveness of AUT NPs were tested by transmission electron microscopy and Malvern particle size analyzer.(3)The toxicity and uptake capacity of AUT NPs were evaluated at the cellular and animal levels by CCK8,colony formation assay,acute hemolysis assay,immunohistochemistry,etc.(4)In vivo imaging system was used to detect the distribution of AUT NPs in mouse organs;(5)A subarachnoid hemorrhage model was constructed to evaluate the effect of AUT NPs on early brain injury caused by subarachnoid hemorrhage.Results:(1)the average particle size of AUTNPs was 308.4±51.9 nm,and the surface potential was-11.2±2.1 mV.(2)AUT NPs have high stability in physiological environment and can release ultrasonic and pH responses.(3)The toxicity test showed that AUT NPs had low toxicity to normal cells and mice,did not cause inflammatory reaction,and the nanoparticles could be ingested by neurogenic cells.(4)In vivo imaging of mice showed that the fluorescence signal ofA UT NPs group was much higher than other groups.With the extension of ultrasonic trigger time,the fluorescence signal of the trigger group gradually increased,while the fluorescence signal of the other groups remained unchanged.In vivo experiments showed that AUT NPs could achieve responsive release in the brain region.(5)After constructing the subarachnoid hemorrhage model,in vivo treatment results also showed that AUT NPs had better effect than other groups.Conclusion:AUT NPs has been constructed for brain directional delivery ofA TX.In vitro characterization and release tests proved that AUT NPs had good stability and could release ATX under ultrasonic and pH stimulation.In vivo trigger experiments showed that AUT NPs could achieve stable long-term release in intracranial cells.Treatment tests showed that AUTNPs was superior to ATX.Through the above series of experiments,the constructed AUT NPs conforms to the initial experimental design concept and shows great potential in the treatment of central nervous diseases.