The Synthesis Of Fluorescent Nanoparticle And Its Application In Cancer Cell Detection

Fluorescence molecular imaging technology becomes a new means of cell imaging,own to the advantages,like high sensitivity,simple and convenient,and no radiation.Recently,it is widely used in such areas as biomarker and cellular imaging.Real-time,noninvasive,detection of cell level tumor could provide a useful tool to detect the occurrence and metastasis of tumor biology and the physiological or pathological changes in the tumor.Thus it provides an effective technology for early clinical diagnosis and intraoperative imaging.In the past few decades,people have developed different kinds of fluorescent probes,including quantum dots,metal cluster,and composite fluorescent nanoparticles.Responsive polymer based fluorescent nanoparticle has many binding sites,which could modify some functional groups on the surface of nanoparticle through chemistry or physics modifications to increase its stability and biocompatibility and expand its function.When external environment of polymers change,their physical or chemical property change.In the second chapter of the thesis,we design the preparation of the fluorescent and positive-charged nanoparticle Eu-Doped PS-co-PNIPAM/FITC,which is synthesized by the method of soap-free emulsion polymerization.The positively charged fluorescent nanoparticles could bind negatively charged fluorescent molecules FITC by the electrostatic force.We have synthesized the fluorescent nanoparticles with uniform size,good biocompatibility.The fluorescent nanoparticles have good p H responsive within physiological environment p H = 4-10.As the p H increases,the inner fluorescence keeps stable,outer fluorescent molecules FITC fluorescence enhances gradually.Due to the different p H of normal cells and tumor cells,and the nanoparticles could distinguish these two types.Because of the increased intake of the nanoparticles,nanoparticles improve monitoring sensitivity.The results show that the fluorescent materials could be used to distinguish between tumor cells and normal cells.In the third chapter of the paper,in order to expand the function of fluorescent nanoparticles and improve the target ability,we design to construct targeted fluorescent polymer carbon dots by hydrothermal method.We adopt folic acid molecules as raw materials,own to the effective target of the tumor cells.The surface of polymer dots contains negative charges,which reduces the vivo biological pollution.We prepare high quantum yield carbon dots,which have a resonance energy transfer,and result in the fluorescence enhancement.Polymer dots have good biocompatibility and low toxicity.This feature could be applied in biological imaging.Besides,folic acid on the surface could target tumor cells,and polymer dots could accumulate more and rapidly into tumor cells,and thus different fluorescence intensities could be used to distinguish between tumor cells and normal cells.