Ce Doped Polyanliline Nanoparticles For Absorption And Photoacoustic Imaging Response To GSH In Vitro And In Vivo

Photoacoustic Imaging(PAI)refers to irradiating endogenous or exogenous contrast agents with nanosecond pulsed lasers,so that the photons of the contrast agents undergo a series of electronic energy level transitions,and then local temperature increases and transients are generated.Thermoelastic expansion,thereby generating ultrasonic waves,and then using ultrasonic transducers to receive and detect ultrasonic waves,i.e.,photoacoustic signals,and then reconstruct them into visual images.PAI is a combination of optical imaging and acoustic imaging,which has the advantages of non-invasiveness,high resolution,high contrast,high penetration and high sensitivity,and is widely used in the field of biomedical imaging.In this paper,a near-infrared absorbing cerium-doped polyaniline nanoparticle was designed and constructed,its structure was characterized,the effect of glutathione(GSH)on near-infrared absorption and photoacoustic imaging performance was investigated,and its in vivo GSH photoacoustic imaging ability was explored.To guide the diagnosis and treatment of tumors.The work of the thesis is mainly divided into three parts:Part One:Ce-doped polyaniline nanoparticles(Ce-Fe@PANI NPs)were prepared by chemical oxidative polymerization using FeCl3·6H2O,CeCl3 and aniline as raw materials and BSA as dispersant.It was characterized by UV-Vis spectroscopy,infrared spectroscopy(IR),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and inductively coupled plasma atomic emission spectroscopy(ICP-MS).Structure and optical properties of Ce-Fe@PANI NPs,Ce-Fe@PANI NPs with UV absorption of 620 nm,average diameter of about 180±10 nm,Zeta potential of+25 mV,uniform particle size distribution and good morphology were obtained.Part Two:The effects of in vitro GSH on the UV absorption and photoacoustic imaging properties of Ce-Fe@PANI NPs were investigated.By adding different concentrations of GSH to Ce-Fe@PANI NPs in test tubes,their UV-Vis spectra and PA imaging were detected;their cytotoxicity to normal and tumor cells was detected by the CCK-8 method;their in vitro Photoacoustic imaging capabilities.The results demonstrate that Ce-Fe@PANI NPs have low cytotoxicity,good biocompatibility,and excellent photoacoustic imaging performance.It was found that the UV-Vis absorption spectrum of Ce-Fe@PANI NPs red-shifted from 620 nm to 820 nm with the increase of GSH concentration.At the same time,when the concentration of GSH is increased,the peak of PA intensity is red-shifted,showing good UV absorption and photoacoustic imaging response performance to GSH.Part Three:To investigate the in vivo photoacoustic imaging performance of CeFe@PANI NPs for GSH.A subcutaneous 4T1-bearing tumor model was constructed,and the tumor was subjected to PA imaging after intratumoral injection of CeFe@PANI NPs.The study found that the peak of PA intensity in tumor tissue was red-shifted from 680 nm to 820 nm,thus guiding the diagnosis of tumor.In addition,the experiments proved that Ce-Fe@PANI NPs had weak effects on the growth of mice,the damage of major organs and hematology,and had good biological safety.