Use Of The Highly Biocompatible Au Nanocages@PEG Nanoparticles As A New Contrast Agent For In Vivo Computed Tomography Scan Imaging

Objective In this study explored that the AuNC@PEGs as a new CT contrast agent had good biocompatibility and had stronger X absorption coefficient and longer blood retention time,which provide experimental basis for appliacation in human imaging.Methods Au nanocages were prepared using a simple galvanic replacement reaction between Ag nanocubes and HAu Cl4 solution.25 nm Ag nanocubes were prepared in diethylene glycol and were used as templates for the synthesis of 30 nm Au nanocages.Then,SH-PEG(MW ≈ 2000,10 mg dissolved in 5m L of phosphate-buffered saline(PBS))was added to the AuNCs solution(p H 8.0,6.55 nm,6mL).Finally,AuNanocages@PEG solution was prepared.The structure and characters of AuNC@PEGs were determined by TEM and DLS.Then,the in vitro biocompatibility of AuNC@PEGs was evaluated by MTT colorimetry,lactate dehydrogenase(LDH)leakage method,intracellular reactive oxygen species(ROS)concentration assay,Calcein-AM/PI,and other experimental techniques.Through CT scanning imaging,The in vitro imaging ability of AuNC@PEGs solution and clinical iodine-based contrast agent were compared and in vivo imaging ability in animal model were compared.The impact on organs of AuNC@PEGs was detected by HE staining and Hematology analysis.Results Characterization of the AuNC@PEGs: the size of AuNC@PEGs was around 40 nm and the hydration radius of AuNC@PEGs was about 50 nm.AuNC@PEGs have a smaller size and relatively good biological inertia,which are better for nanomedicine applications.With its obvious core-shell structure,the outside was covered with PEG of biological applicability,which can effectively enhance biocompatibility and escape macrophage capture.The results of cellular experiments validated that AuNC@PEGs at a concentration of 200 μg/m L are stable and have good cell compatibility.In vitro and in vivo CT scan imaging results validated that the absorption coefficient of AuNC@PEGs was better than that of iodine-based contrast agents,indicating that the use of AuNC@PEGs for CT scan imaging is better.The longer blood circulation time of AuNC@PEGs can provide a better diagnosis.The histological analysis and Hematology analysis exhibited that there were no significant histological injuries observed in the major organs of the nanocages injected rats.Conclusions The AuNC@PEGs had good aqueous dispensation,low cytotoxicity,and strong X-ray absorption ability.Furthermore,the synthesized AuNC@PEGs have an evident contrast enhancement,long circulation time in the blood,and negligible toxicity in vivo.Therefore,the synthesized functionalized AuNC@PEGs in this study have great potential for clinical application in CT scan imaging.