| Nasopharyngeal cancer(NPC)arising from the nasopharyngeal epithelial lining is one of otorhinolaryngological malignant tumors in China.Due to its insidious anatomical location,highly invasive and metastatic features,it is still challenging to detect NPC at early stage.Excisional nasopharyngeal suspicious lesions for histopathological examinations currently remains the diagnostic standard,though it suffers from invasive procedure and subjective methodology,making it hard for detecting subtle local lesion.In this thesis,Raman spectroscopy technology capable of optically probing the biomolecular changes was employed for NPC biological samples detection,with aim of exploring specific biomolecular changes associated with NPC transformation.The main research contents are as follows.1)Lable free surface-enhanced Raman spectroscopy(SERS)technology was used to detect blood samples from different tumor(T)stages of patients with NPC,with the aim of exploring the specific variability at different T stages.And good classification between early stage(T1)cancer and normal can be achieved.Furthermore,a powerful diagnostic algorithm based on Lasso-partial least squares-discriminant analysis(Lasso-PLS-DA)was developed here to avoid interferences to the variables from the noise,which is better for classifying different T stage samples.2)A rapid macro-Raman spectroscopy system was developed for NPC blood analysis.In comparison to commercial Raman system,the developed system held advantage in short detection time,making it more suitable for clinical real-time measurement.This work would be a valuable exploration in medical translation of Raman spectroscopy technology.3)A novel SERS substrate with interior label was combined with SERS lable for quantitatively detecting circulating tumor DNA in blood.The Raman signals of the proposed interior lable and SERS lable molecules lay in the silent region,so their signals would not be interfered by target DNA and other biomolecules.This novel SERS strategy would significantly improve the reliability and accuracy of quantitative detection.4)We evaluated the capability of saliva analysis combining membrane protein purification with SERS for noninvasive detection of NPC.A rapid and convenient protein purification method based on cellulose acetate membrane was developed to avoid the interferences from exogenous substances,and better reproducibility of saliva SERS spectra could be achieved.5)A home-made laser tweezers Raman spectroscopy(LTRS)system was applied to detect nasopharyngeal normal cells and tumor cells.Live cell analysis under physiological environment was achieved by this system,and results could reflect real status of cells.This work would provide a novel methodology for tumor cell study.6)An integrated 4-modality endoscopy system combining white light imaging,autofluorescence imaging,diffuse reflectance spectroscopy and Raman spectroscopy technologies was developed for in vivo endoscopic NPC detection.A combination of autofluorescence imaging technology with high sensitivity and spectroscopic technology with high specificity made this system capable for comprehensively capturing diagnostic information from morphological changes and biomolecular changes in NPC tissue.The preliminary results demonstrated great potential of this endoscopy system to be a rapid,objective and accurate optical biopsy for NPC screening.This thesis focuses on international biomedical research hotspot and clinical urgent need for NPC diagnosis,and developed novel method and system based on Raman spectroscopy for blood,saliva,cell and tissue detection,with the aim of exploring a non-invasive,rapid,objective and accurate detection method for NPC. |
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