Construction Of Functionalized Nano-materials And Its Application In Early Diagnosis Of Liver Cancer

ObjectiveHepatocellular carcinoma (HCC) is the sixth most common cancer worldwide. HCC isone of the most common malignant tumors in China, having the mortality ranking the first inthe city and the second in rural areas. Surgical treatments, which can prolong survival, mustdepend on the rapid effective early-detection. Now Alpha-fetoprotein (AFP) has been used inclinical diagnosis for HCC, however, lacking enough sensitivity and specificity. Thus, novelcheap, rapid, more sensitive detection methods are urgent to figure out.Recently, quantum dots (QDs) have been investigated for their uses as biologicalfluorescent probes instead of common organic dyes for their unique optical feature and otheradvantages. QDs have exhibited significant advantages over traditional organic fluorophoresas special probes in biological staining, detection and diagnosis. QDs have not only wideabsorbed spectrum, but also narrow symmetrical emission spectrum. In addition, differentfluorescent QDs can be obtained by adjusting the dimension and composition of it. It alsoshows good characteristics, such as the higher intensity of fluorescence and mere stability,overcoming a great deal of weak points of the organic fluorescence dyes. It is hopeful tosubstitute those dyes. People have got successful exploration and tried in the immunoassays,DNA hybridization, cell image formation, biology, resonance energy transfer, etc. In thisstudy, we synthesized glutathione capped CdTe QDs and then conjugated withAlpha-fetoprotein (AFP), with which to be used as fluorescent probe for HCC earlydetection.Methods(1) We synthesized GSH-modified QDs-CdTe.(2) We finished the physicochemical characterization of QDs-CdTe, including TEM,IR-spectrum, fluorescent spectrum and UV-vis spectrum.(3) Understood the cytotoxicity of QDs-CdTe through MTT, RTCA, cell cycle andAO staining.(4) Detected the effect of cell labeling.(5) Coupled the QDs-CdTe with AFP antibody and BSA-v separately, got thefluorescent probes which were detected by fluorescent spectrum and SDS-PAGEelectrophoresis.(6) Liver cells imaged with the fluorescent probes.(7) Detected the AFP levels in the serum and cell-culture medium, and compared withthe the method of chemiluminescence analysis.Results (1) We got kinds of soluble QDs-CdTe with different fluoresce.(2) We fabricated QDs-CdTe-AFP and QDs-CdTe-BSA-v nano-probes.(3) The cell growth effect of QDs-CdTe (<5μmol/L) was lightly.(4) The probes could be used for liver cells imaging.(5) The probes was more sensitivity than the method of chemiluminescence analysis.ConclutionThe main work of this thesis is to synthesize high-quality water-soluble CdTe QDsthrough water-phase methods, conjugated QDs with AFP and BSA-v to make stable probes,and make use of these probes in the early detection of HCC. The as-prepared probes wereused in the detection of AFP antigen in vitro which is more sensitivity than thechemiluminescence analysis. The study shows that QDs-AFP fluorescent probes are potentialcandidates for liver cancer early diagnosis, and worth investigating further.