DVDMS Multi-level Targeted Liposome-mediated Sonodynomic Therapy Application On Glioma

Objective:Sonodynomic therapy,a novel tumor treatment approach,is attracting more and more researchers’ attention.However,it is difficult for sonosensitizer to cross the blood-brain barrier,to be imaged in the deep brain and to be excited by ultrasound,which limits its aLPPiacation to glimoa treatment.Evidences have demonstrated that iRGD peptides can help drugs to penetrate the blood-brain burrier and to deliver into the cancer cells.Also,many kinds of metalloporphyrins have been obtained through chelating some metal ions into porphyrins or their derivatives,giving them the abilitity to be imaged.In this project,we propose a novel approach to realize imaging-guided sonodynomic therapy of glioma through metallosinoporphyrin-encapsulated targeted liposomes.In brief,mangenese ions will be chelated into iRGD-targeted lipsomes.With the help of iRGD peptides,the resulting sonosensitizer would be deliverd into the glioma and be imaged by magnetic resonance imaging.Based on the position information detected by MRI,ultrasound beam would be posotioned on the sonosensitizer.the sensibilizer will be excited by focused ultrasound,resulting in oxygen free radicals to kill the cancer cells.Obtained conclusions can provide proof for the reseach that iRGD targeted liposome can guide ultrasoud for the treatment of intracranial tumor,and it is biological safety.And the result can provide new ideas and methods for the sonodymic therapy on cancer and other diseases.Methods and Results:Part Ⅰ The preparation and characterization of DVDMS-Mn liposomesIn this study,DVDMS was chemically synthesized using the characteristic that H ions can be reLPaced by Mn ions to form porphyrin-based metal compounds and synthesized into DVDMS-Mn nanoparticles.The standard PEGylated liposomes and iRGD liposomes were selected as drug loading LPatforms for DVDMS-Mn nanoparticles.The LP-DVDMS liposome with a particle size of 96±2.26 nm,the LP-DVDMS-Mn(Lp)liposome with a particle size of approximately 106±2.32 nm and a particle size of approximately 110±2.6 of iRGD-Lp-DVDMS-Mn(iRGDLP)liposomes were prepared by a nitrogen blown film hydration method.The three liposomes were characterized by TEM,Malvern Nano-ZS90 dynamic light scattering particle size analyzer and MRI.Finally,a nanoliposome with iRGD’s tumor targeting,the acoustic characteristics of DVDMS,and MRI imaging was obtained.Part Ⅱ The establishment methods of DVDMS and Mn2+ encapsulation efficiencyUV-spectrophotometry was used to determine the drug concentration of various liposomes sodium porphyrins.The concentration of Mn2+ in liposomes was determined by inductively couLPed LPasma spectrometer ICP.The ratios were evaluated and the true ratio of DVDMS:Mn in the liposomes was determined.The results showed that the iRGD-targeting peptide on the outer surface of the liposome had no effect on the encapsulation efficiency of the DVDMS-Mn core.The ratio of DVDMS and Mn in Lp,iRGDLP liposome was nearly 1:2.Part Ⅲ Anti-tumor effects of DVDMS targeted liposomes on glioma cellsThe experiments were divided into six groups:Control group,US only group,LP group,iRGDLP group,LP+US group,iRGDLP+US group.Control group did not do treatment;US only group did not do drug incubation,only 1W,10%duty ratio of the focus probe ultrasound 1 min;LP group only 2 μm of LP liposomes incubated with cells for 8 hours,do not take ultrasound Treatments;iRGDLP groups were incubated with cells for 2 hours with 2μm iRGDLP liposomes without sonicating.The LP+US group was incubated with cells for 8 hours with 2μm of LP liposomes and then sonicated for 1 min with a 1 W,10%duty-focusing probe;the iRGDLP + US group was incubated with cells for 8 hours with 2 μm of iRGDLP liposomes.Then use a 1 W,10%duty focus probe for 1 min of ultrasound;then we conclude that:The depth of Group LP and Group iRGDLP is 53 nm and 102 nm,respectively.At the same time,the penetration depth of Group iRGDLP was 1.84 times that of Group LP.In the presence of ultrasound,LP and IRGDLP could generate ROS,and the target peptide iRGDLP group produced more fluorescence intensity than the normal liposome LP group,and the ability to kill cells was stronger.Part Ⅳ Antitumor Effects of DVDMS-Mn Targeting Liposome in VivoFirstly,mice intracranial orthotopic tumor models were successfully established.Then tumor-bearing mice were equally divided into six groups of 5 in each group according to tumor size:Control group,US only group,LP group,iRGDLP group,LP+US group,iRGDLP+US group.Group control:Each mouse received only 200 μl normal saline injections.In the LP group,each mouse was injected with 0.02 μmol LP liposome via the tail vein without ultrasound;Group iRGDLP:Each mouse was injected with 0.02 μmol iRGDLP liposome via the tail vein.Ultrasound therapy was not performed;Group US only:Each mouse received only 200 μl normal saline injections,ultrasound irradiation only at 2h and 8h,frequency 1 MHz,10%duty,1 min each time;LP+US group:each rat was injected via tail vein 0.02 μmol LP liposome was irradiated with ultrasound at 2 h and 8 h after drug injection at a frequency of 1 MHz,10%duty,1min each time;iRGDLP+US group:each mouse was injected with 0.02 μmol iRGDLP liposome via tail vein and then irradiated with ultrasound at 2 h and 8 h after drug injection at a frequency of 1 MHz,10%duty,1 min each time.The results showed that:(1)LP,iRGDLP two groups of tumor growth inhibition effect is not very obvious,which also shows that the sonosensor itself has no strong side effects,only in conjunction with ultrasound The effect of time on tumor apoptosis is more pronounced.(2)Ultrasound has an effect on tumor growth,and ultrasound can slightly slow the rate of tumor growth.Compared with iRGDLP+US and LP+US,the growth of iRGDLP+US tumors was slower than that of iRGDLP+US,iRGDLP+US had a stronger inhibition on tumor growth.