Xueliang Lin

Identification of different tumor states in nasopharyngeal cancer using surface-enhanced Raman spectroscopy combined with Lasso-PLS-DA algorithm

Identification of different states in cancer is of vital importance for cancer treatment and management. A powerful diagnostic algorithm based on Lasso-partial least squares-discriminant analysis (Lasso-PLS-DA) was developed here for improving blood surface-enhanced Raman spectroscopy (SERS) analysis, with the aim to classify different states in nasopharyngeal cancer (NPC). A total of 160 blood plasma samples were collected for this study, obtained from 60 normal volunteers, 25 T1 stage cancer and 75 T2–T4 stages cancer patients. Results show that a diagnostic sensitivity of 68% and a specificity of 84.0% can be achieved for separating T2–T4 stage from T1 stage cancer, which had a 20% improvement in diagnostic specificity compared with the previous work. This exploratory study demonstrates that the Lasso-PLS-DA can be integrated with blood SERS analysis as a promising clinical complement for different T stages detection in NPC.

Nasopharyngeal carcinoma detection by tissue smears using surface-enhanced Raman spectroscopy

ABSTRACT Nasopharyngeal carcinoma is one of the most common malignant neoplasms in head and neck. In this work, surface-enhanced Raman spectroscopy technique was used to study the molecular differences between cancerous and noncancerous smear samples which were obtained after clinical biopsy by smearing the tissue on the slides. Principal component analysis combined with linear discriminant analysis provided a sensitivity of 79.4% and a specificity of 81.8% for differentiation between cancerous and noncancerous nasopharyngeal tissue smears. This work provides a good basis for the methodology of nasopharyngeal tissue smear based on surface-enhanced Raman spectroscopy technique and is worth further studying.

Discrimination of Nasopharyngeal Carcinoma from Noncancerous Ex Vivo Tissue Using Reflectance Spectroscopy

Reflectance spectroscopy is a low-cost, nondestructive, and noninvasive method for detection of neoplastic lesions of mucosal tissue. This study aims to evaluate the capability of reflectance spectroscopy system under white light (400–700 nm) with a multivariate statistical analysis for distinguishing nasopharyngeal carcinoma (NPC) from nasopharyngeal benign ex vivo tissues. High quality reflectance spectra were acquired from nasopharyngeal ex vivo tissues belonging to 18 noncancerous and 19 cancerous subjects, and the combination of principal component analysis-linear discriminant analysis (PCA-LDA) along with leave-one-spectrum-out cross-validation (LOOCV) diagnostic algorithm was subsequently employed to classify different types of tissue group, achieving a diagnostic sensitivity of 73.7% and a specificity of 72.2%. Furthermore, in order to distinguish NPC from nasopharyngeal benign ex vivo tissues based on reflectance spectra simply, spectral intensity ratios of oxyhemoglobin (540/576) were used as an indicator of the carcinogenesis associated transformation in the hemoglobin oxygenation. This tentative work demonstrated the potential of reflectance spectroscopy for NPC detection using ex vivo tissue and has significant experimental and clinical value for further in vivo NPC detection in the future.

Feasibility of glucose monitoring based on Brownian dynamics in time-domain optical coherence tomography

Our purpose is to investigate the feasibility of Brownian motion in time-domain optical coherence tomography (OCT) incorporated with wavelet power spectrum to monitor glucose concentration in Intralipid solution. The results show that the standard deviation (SD) of frequency in the superficial layer of single scattering region, linearly proportional to Brownian diffusion coefficient, is independent of the depth. Our preliminary results demonstrate that average SD of frequency in the single scattering region is inversely proportional to the glucose concentration in Intralipid solution, since the Brownian diffusion coefficient is a function of concentration. Thus the average SD of frequency in OCT signal is capable of differentiating the glucose concentration.

Noninvasive detection of nasopharyngeal carcinoma based on saliva proteins using surface-enhanced Raman spectroscopy

Abstract. The present study evaluated the capability of saliva analysis combining membrane protein purification with surface-enhanced Raman spectroscopy (SERS) for noninvasive detection of nasopharyngeal carcinoma (NPC). A rapid and convenient protein purification method based on cellulose acetate membrane was developed. A total of 659 high-quality SERS spectra were acquired from purified proteins extracted from the saliva samples of 170 patients with pathologically confirmed NPC and 71 healthy volunteers. Spectral analysis of those saliva protein SERS spectra revealed specific changes in some biochemical compositions, which were possibly associated with NPC transformation. Furthermore, principal component analysis combined with linear discriminant analysis (PCA-LDA) was utilized to analyze and classify the saliva protein SERS spectra from NPC and healthy subjects. Diagnostic sensitivity of 70.7%, specificity of 70.3%, and diagnostic accuracy of 70.5% could be achieved by PCA-LDA for NPC identification. These results show that this assay based on saliva protein SERS analysis holds promising potential for developing a rapid, noninvasive, and convenient clinical tool for NPC screening.

Saliva surface-enhanced Raman spectroscopy for noninvasive optical detection of nasopharyngeal cancer

The early cancer detection is of great significance to increase the patient’s survival rate and reduce the risk of cancer development. Surface enhanced Raman spectroscopy (SERS) technique, a rapid, convenient, nondestructive optical detection method, can provide a characteristic “fingerprint” information of target substances, even achieving single molecule detection. Its ultra-high detection sensitivity has made it become one of the most potential biochemical detection methods. Saliva, a multi-constituent oral fluid, contains the bio-markers which is capable of reflecting the systemic health condition of human, showing promising potential as an effect medium for disease monitoring. Compared with the serum samples, the collection and processing of saliva is safer, more convenient and noninvasive. Thus, saliva test is becoming the hotspot issues of the noninvasive cancer research field. This review highlights and analyzes current application progress within the field of SERS saliva test in cancer detection. Meanwhile, the primary research results of SERS saliva for the noninvasive differentiation of nasopharyngeal cancer, normal and rhinitis obtained by our group are shown.

Study on nasopharyngeal cancer tissue using surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS) can provide detailed molecular structure and composition information, and has demonstrated great potential in biomedical filed. This spectroscopy technology has become one of the most important optical techniques in the early diagnosis of cancer. Nasopharyngeal cancer (NPC) is a malignant neoplasm arising in the nasopharyngeal epithelial lining, which has relatively high incidence and death rate in Southeast Asia and southern China. This paper reviews the current progress of SERS in the field of cancer diagnostics, including gastric cancer, colorectal cancer, cervical cancer and nasopharyngeal cancer. In addition to above researches, we recently develop a novel NPC detection method based on tissue section using SERS, and obtain primary results. The proposed method has promising potential for the detection of nasopharyngeal carcinoma.

Diffuse reflectance spectroscopy study of in vitro tissue for nasopharyngeal carcinoma diagnosis

Diffuse reflectance spectroscopy is a non-contact, non-invasive, and low-cost optical technique that provides real-time feedback about the absorptive characteristics and the microstructure properties of biological tissue. This optical technique shows the potential for monitoring metabolic status associated with malignancy transformation. Nasopharyngeal carcinoma (NPC) is the third most frequently diagnosed cancer associated with virus and is the most common male malignancy with a characteristic regional and racial distribution worldwide. This paper investigates the current screening state of nasopharyngeal malignancies and also provides an overview on the applications of diffuse reflectance spectroscopy in the cancer detection. Furthermore, the latest research relevant to the diagnosis of NPC in vitro tissue using diffuse reflectance spectroscopy is introduced. The results of diffuse reflectance spectroscopy are summarized, showing a significant experimental and clinical value for further NPC detection in vivo in the future.

Non-invasive optical detection of HBV based on serum surface-enhanced Raman spectroscopy

An optical method of surface-enhanced Raman spectroscopy (SERS) was developed for non-invasive detection of hepatitis B surface virus (HBV). Hepatitis B virus surface antigen (HBsAg) is an established serological marker that is routinely used for the diagnosis of acute or chronic hepatitis B virus(HBV) infection. Utilizing SERS to analyze blood serum for detecting HBV has not been reported in previous literature. SERS measurements were performed on two groups of serum samples: one group for 50 HBV patients and the other group for 50 healthy volunteers. Blood serum samples are collected from healthy control subjects and patients diagnosed with HBV. Furthermore, principal components analysis (PCA) combined with linear discriminant analysis (LDA) were employed to differentiate HBV patients from healthy volunteer and achieved sensitivity of 80.0% and specificity of 74.0%. This exploratory work demonstrates that SERS serum analysis combined with PCA-LDA has tremendous potential for the non-invasive detection of HBV.

Blood surface-enhanced Raman spectroscopy based on Ag and Au nanoparticles for nasopharyngeal cancer detection

This study aims to evaluate and compare the utility of blood surface-enhanced Raman spectroscopy (SERS) based on Au or Ag nanoparticles (NPs), respectively, for detection of nasopharyngeal cancer (NPC). A rapid home-made Raman system was employed for SERS measurement, and high quality SERS spectra can be recorded from blood plasma samples belonging to 60 healthy volunteers and 100 NPC patients, using both metallic NPs. The spectral differences under Ag-SERS measurement between the normal and cancer groups are more significant than Au-SERS. Principal component analysis combined with linear discriminant analysis (PCA-LDA) was used for differentiating the two blood groups with a diagnostic sensitivity and specificity of 90% and 95%, respectively, using Ag-SERS method, which has almost a 20% improvement in diagnostic specificity in comparison to Au-SERS. This exploratory study demonstrates that blood SERS based on Ag NPs is capable of achieving a better diagnostic performance for NPC detection, and has promising potential for improving NPC screening.