Mesoporous Silicon Nanocarriers Loaded With COSM For The Treatment Of Acute Liver Injury

Drug-Induced Liver Injury（DILI）is a necroinflammatory liver disease,and drug-induced liver injury caused by acetaminophen（APAP）is the second leading cause of human liver transplantation.50%of acute liver failure in European and American countries is drug-induced liver injury caused by APAP;among the drugs that cause liver injury in my country,liver injury caused by APAP accounts for 50.8%of DILI caused by all analgesics and anti-inflammatory drugs.Liver injury caused by APAP is the main problem faced by the domestic application of painkillers and anti-inflammatory drugs,and the situation is very serious.Therefore,to develop more effective and safer drugs for the treatment of APAP-induced liver injury is urgent need.Chitosan oligosaccharide（COS）is a marine oligosaccharide obtained by hydrolysis of chitosan（Chitosan,CTS）.It has good antioxidant,anti-inflammatory and antibacterial activities.Studies have shown that chitosan oligosaccharide can be used for treatment of acute liver injury caused by APAP.Mesoporous silicon nanocarriers have the advantages of good biocompatibility,easy modification of surface active groups,high specific surface area,and rapid targeted drug delivery can be achieved through targeted modification.In this topic,the preparation of synthetic liver-targeted mesoporous silicon nanocarriers loaded with chitosan oligosaccharide drug COSM（average molecular weight≤3000 Da）was used to study the therapeutic activity of acetaminophen-induced acute liver injury.The optimal preparation process conditions of MSN are as follows:24 ml（25wt%）CTAC solution,0.18 g TEA,20 ml TEOS（10v/v%）1-octadecene solution,70°C,150 rpm,react for 24hours.The nanoparticles prepared according to the process conditions are spherical,with uniform mesoporous channels on the surface and uniform particle size;MSN-NH₂-GA nanoparticles are obtained by modificated with glycyrrhetic acid,it’s with uniform particle size and complete morphology.The results of laser particle size analyzer showed that the particle sizes of MSN,MSN-NH₂ and MSN-NH₂-GA nanoparticles were（156.7±61.7）nm,（168.1±45.8）nm and（190.7±78.1）nm,and the Zeta potentials of each nanoparticles were（-40.42±22.11）m V,（58.62±4.48）m V and（7.013±4.13）m V;BET shows that MSN has a specific surface area of（565.27m²/g）,a pore diameter of（6.15 nm）,and a pore volume of（1.18 cm³/g）,MSN-NH₂-GA specific surface area of（245.83 m³/g）,a pore diameter of（6.04 nm）pore volume is（0.69 cm³/g）.The infrared spectrometer detected C=C stretching vibrations representing amino groups,amide II bands,and GA,indicating that the surface coupling of mesoporous silicon was successful.The preparation method of COSM-loaded nanoparticles COSM@MSN-NH₂-GA is as follows:After the standard solution group was treated by DNS method,540 nm was selected as the optimum wavelength for measurement.Good linear relationship is（R²=0.9991）,the standard curve is:Y=0.0006x+0.0197,and the results of precision,repeatability,stability and recovery rate are good（RSD<2%）,which meets the detection requirements.The drug loading experiment finally used PBS as the medium,drug:carrier=1:2,drug loading time of 12 h was the optimal drug loading condition,the drug loading of COSM@MSN-NH₂-GA was 28.36%±1.00%,and the encapsulation efficiency it was 56.72%±1.99%,all of which met the preparation requirements.Cell pharmacodynamics evaluation,cytotoxicity test results show that when the dose of nanoparticles is less than 3200μg/ml,there is no significant toxicity to cells,and hemolysis test shows that the nanoparticles have no hemolysis and have good biocompatibility.According to the CCK-8 method and the IC₅₀ principle,the modeling time of APAP was selected as 12h,and the modeling concentration was 10mmol/L.At this time,the cell inhibition rate was 41.56%±3.04%.According to the cytotoxicity results,the dosage of COSM@MSN-NH₂-GA group was determined:low dose（200μg/ml）,medium dose（400μg/ml）,high dose（800μg/ml）;by equivalent conversion,free drug COSM Dosages:low dose（56μg/ml）,medium dose（113μg/ml）,high dose（226μg/ml）.The AST and ALT indicators demonstrated that COSM@MSN-NH₂-GA at medium and high doses had a good therapeutic effect on APAP-induced acute liver injury,and could effectively improve the efficacy of free drugs.Cell uptake experiment:Observed by fluorescence microscope,weak fluorescence could be observed in the cytoplasm of C6group after 1h,and the fluorescence in C6-NPs group showed obvious fluorescence.At 2h,the fluorescence intensity in C6 group and C6-NPs group showed an increasing trend.This indicates that the targeted nanoparticles have higher cellular uptake ability;flow cytometry results show that there is a significant difference in the fluorescence intensity between the C6 group and the C6-NPs group at 1h and 2h,indicating that the targeted nanoparticles have stronger targeting delivery capacity.