The Research On Inflammation-mediated For Brain Targeting Drug Delivery

The inflammatory response plays an important role in the pathogenesis of many degenerative diseases of the central nervous,including cerebral ischemia,Alzheimer's disease,Parkinson's disease and other brain tumors·Inflammation process,leukocytes including monocytes and neutrophils can cross the blood-brain barrier(BBB)by exudation and chemotaxis and further to reach the site of injury or infection in the brain.This topic was selected to cyclic cRGD peptide,which used as integrins ligand,and coupled to the end of DSPE-PEG-NHS obtaining an DSPE-PEG-cRGD,then were coupled with the phospholipid to obtain brain targeting liposomes.Edaravone(ER)and trefoil Factor(TFF3)as amodel drugs loaded into liposomes.By coupling with cRGD,liposomes can preferentially deliver drugs to ischemic brain to improve the model drug for depression by brain targeting drug delivery system treatment.Research contents and results are as follows:cRGD were connected apparently to phospholipid DSPE-PEG-NHS,MALDI-TOF/TPF mass spectrometer as the process detection method and calculated yield of 72%.cRGD blank liposome by film dispersion method using dichloromethane as the organic phase,PBS(PH7.4)as the aqueous phase.The size of liposome was 117.5nm and Zeta potential was-20.8mV,liposomes look as round or oval shape by TME.A simple and fast UPLC method of trefoil factor for in vitro samples was established.Encapsulation efficiency and particle size as an indicator,the formulation of TFF3-L was optimized.Final active drug prepared liposomes TFF3-L and TFF3-cRGD-L,the particle size was 129.6nm and 127.8nm,encapsulation efficiency was 45.23%and 44.47%,Zeta potential were-36.6mV and-37.8 mV.More than 90%of TFF3 were released within 8h and TFF3-L and TFF3-cRGD-L showed similar released profile.The rat monocytes and neutrophils were separated by density gradient centrifugation.The affinity capacity of the two liposomes and the two kinds of cells was investigated using flow cytometry.The results showed that affinity capacity of targeting preparations is stronger than that of non-targeting.Nude mice model of acute inflammation of the brain was set up,in vivo targeting effects of the two preparations were inspected by small animal imaging of encephalitis nude mice.The results show that,the fluorescence intensity in brain of cRGD-L was significantly higher than PL group.The release and stability of drug which after the liposomes were uptaked by leukocytes were Investigated using UPLC.The two liposomes show strong stability in the leukocytes,drugs almost were no released.The cerebral ischemia/reperfusion injury model(I/R)nudes were set up.The fluorescent liposome PL and cRGD-L loaded with DiR were administrated to the I/R nudes.The fluorescence imaging showed that cRGD-L has obvious brain targeting effect and was significantly higher than PL.The results of TTC staining and fluorescence imaging confirmed that cRGD-L mainly accumulated in the ischemic regions of the brain sustained release in the ischemic hemisphere.THP-1 labeled with the liposomes which entrapp cytoplasmic luciferase were administrated to the I/R rats.The immunofluorescence shows that that cRGD-L has strong brain targeting effect and can reach to the outer parts of the blood vessels in the brain ischemia,explained that cRGD-L can across the BBB through the leukocytes.The rat of differernt depression models were given ERL?ERS and TFF3-L?TFF3-S respectively.The data suggest that ER and TFF3 at a low dose produces no antidepressant-like actions by itself but exerts enhanced behavioral responses when loaded into cRGDL.Consistent antidepressant-like effects of cRGDL-TFF3 were observed in both the forced swim test and olfactory bulbectomized rats.The targeting preparations compared with the control group,no significant decrease in the immobility time of rats,increase the consumption of sugar,reduce exercise of OB rats and the rats of NSF shorten latency time,increase the expression levels of c-fos protein,reduce LPS induced by IL-1? and IL-6.Altogether,these data suggest that cRGDL may be a valuable drug delivery system for the treatment of depression by allowing BBB transport.Above results showed that the targeted liposomes had obvious multi-brain targeting effect and deliver the drugs to the lesion.Therefore,the targeted drug delivery system designed in this study achieve the drug delivery of targeted brain lesion site successfully.