Preparation And Antioxidation Of Myocardial Targeted Nano-drug Delivery System

Objective:To prepare a new nano-drug delivery system?myocardial targeting peptide@quercetin@mesoporous hydroxyapatite,PCM@QUE@MHAs?and study its anti-oxidation effect on cardiomyocytes.Methods:MHAs were prepared by synthetic method.MHAs adsorbed QUE through hydrogen bonds in mesoporous,and then combined with hydroxyl groups on the surface and targeting peptide?PCM?to prepare PCM@QUE@MHAs.Transmission electron microscopy,dynamic light scattering instrument and Zeta potential analyzer characterized the nano-drug delivery system.The QUE in vitro high performance liquid chromatography?HPLC?analysis method was established.The drug release behavior of nanoparticles was investigated by HPLC.H9c2 cardiomyocytes were used as model cells to establish the myocardial injury model of H₂O₂.The cytotoxicity of the nano-drug delivery system was determined by MTT assay,and the intracellular ROS probe?DCFH-DA?was used to detect the intracellular ROS content.Results:The average TEM particle size of PCM@QUE@MHAs was 185.2±5.9 nm,the Zeta potential was-16.5±2.9 mV,and the drug load was 25.2%.The stability experiments showed that the size of nanoparticles did not change.QUE was determined by HPLC,the peak shape of chromatographic peak was good,and the linear relationship and precision were good.Within 2 hours,the cumulative release amount of QUE in QUE@MHAs and PCM@QUE@MHAs was 59.7%and 50.3%respectively.Cell experiments showed that MHAs co-cultured with H9c2 cells for 24 h and 48 h at a concentration of 5?g/mL,and the cell viability reached 95.1%.When the concentration of MHAs was 100?g/mL,the survival rate of H9c2 cells reached 79.0%.In addition,the prepared QUE@MHAs and PCM@QUE@MHAs were co-cultured with H9c2 cells for 24h and 48 h,and their cell viability was higher than 90.0%.Cells were treated with H₂O₂?500?mol/L?to establish a cell injury model.PCM@QUE@MHAs increased cell viability from 42.3%to 85.8%.The intracellular reactive oxygen species probe?DCFH-DA?was used to detect the intracellular ROS content.PCM@QUE@MHAs reduced the average fluorescence intensity of DCF in cells from 3557 to 390.Conclusion:The nanoparticles?PCM@QUE@MHAs?have uniform particle size,high loading and good stability.At the same time,the HPLC peak of QUE is good,the sensitivity meets the requirements,the linear relationship and precision are good,and meet the requirements.PCM@QUE@MHAs can slow the release of the drug.MHAs have good biocompatibility and can be used for drug delivery with high safety.At the same time,PCM@QUE@MHAs has no toxic side effects on normal cells.PCM@QUE@MHAs can significantly improve cell viability and improve cellular oxidative stress damage.PCM@QUE@MHAs significantly reduces the amount of ROS in damaged cardiomyocytes?H₂O₂ treatment?,thereby protecting damaged cardiomyocytes.This study will provide a theoretical basis for the inhibition of myocardial injury by nano-drug delivery systems and provide experimental evidence for its clinical application.