| Summary: | 碩士 === 國立臺灣大學 === 醫學工程學研究所 === 94 === Molecular imaging is the technology that successfully combined molecular biology and clinical medicine, and it will be one of potential fields of medicine in the future. In this study, we successfully combined the biomolecular imaging and cellular specific imaging techniques to detect xenograft non-small cell lung cancer (NSCLC) murine model. And we used the aqueous Fe3O4-NH3+ nanoparticles conjugated with anti-epidermal growth factor receptor (EGFR) antibody as the biomedical probe to detect the NSCLC and animal disease model of lung cancer.
Herein, the experiments of this study included in vitro and in vivo assay. In in vitro studies, we used western blotting, immunofluorescence, and flowcytometry to quantify EGFR expression of NSCLC cell lines, such as CL1-0, CL1-5, and A549. Then, the Prussian blue staining and MR in vitro assay would be utilized to confirm the targeting efficiency of iron oxide biomedical probe. As the results, we found that the cell lines of CL1-5 and A549 exhibited more expression level of EGFR than CL1-0 about forty times. Based on the over expression level of EGFR of cell, the Fe3O4-NH3+ nanoparticles conjugated with EGFR antibody could play as specific biomedical probe in NSCLC detection.
Furthermore, we used immunohistochemistry and Prussian’s iron staining to ensure EGFR expression and the targeting efficiency of nanocontrast agent in tumor region and tissue section of animal model, respectively. And the molecular imaging of the biodistribution and targeting efficiency of iron oxide probe were observed under the 3T MR system.
In vivo assay showed when mice were administrated with Fe3O4- anti-EGFR, the signal intensity of tumor region would be decreased by the time, and reached to 10 % at 6h in MR T2- weighted imaging. On the other hand, the MR T2*-weighted imaging also exhibited the variety of signal intensity of tumor region and it would be decreased about 17% as the mouse was administrated with the same dosage and detection time. Furthermore, we provide the Prussian’s iron staining of tumor histology to show the targeting of Fe3O4- anti-EGFR nanocontrast agent. Herein, the mice were injected with 10 mg/Kg of Fe3O4- anti-EGFR biomedical probe and Fe3O4 nanoparticles, respectively. And the Prussian’s iron staining of tumor histology showed that more iron oxide targeting on tumor region when the Fe3O4 nanoparticles conjugated with anti-EGFR antibody. As the results of Prussian’s iron staining, the Fe3O4-EGFR nanocontrast agent could be as the biomedical probe to detect NSCLC.
Herein, we provided the platform and procedures of Fe3O4-anti-EGFR nanocontrast agen for in vitro and in vivo targeting, and we also used this strategy to detect NSCLC successfully. In the future, we will built up metastatic and primary murine animal model of NSCLC and develop novel Fe3O4-EGFR nanoparticles for dual-purposes for molecular diagnosis and therapy evaluation.
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