Diagnostic spectro-cytology revealing differential recognition of cervical cancer lesions by label-free surface enhanced Raman fingerprints and chemometrics

• Published in: Nanomedicine Vol. 29; p. 102276
• Main Authors: Karunakaran, Varsha, Saritha, Valliamma N., Joseph, Manu M., Nair, Jyothi B, Saranya, Giridharan, Raghu, Kozhiparambil G., Sujathan, Kunjuraman, Kumar, Krishnannair S., Maiti, Kaustabh K.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-10-2020
• Subjects: Cervix; Gold nanoparticle; Human papilloma virus; Label-free; Surface enhanced Raman spectroscopy; Human papilloma virus; Cervix; Label-free; Gold nanoparticle; Surface enhanced Raman spectroscopy
• ISSN: 1549-9634; 1549-9642
• DOI: 10.1016/j.nano.2020.102276

Herein we have stepped-up on a strategic spectroscopic modality by utilizing label free ultrasensitive surface enhanced Raman scattering (SERS) technique to generate a differential spectral fingerprint for the prediction of normal (NRML), high-grade intraepithelial lesion (HSIL) and cervical squamous cell carcinoma (CSCC) from exfoliated cell samples of cervix. Three different approaches i.e. single-cell, cell-pellet and extracted DNA from oncology clinic as confirmed by Pap test and HPV PCR were employed. Gold nanoparticles as the SERS substrate favored the increment of Raman intensity exhibited signature identity for Amide III/Nucleobases and carotenoid/glycogen respectively for establishing the empirical discrimination. Moreover, all the spectral invention was subjected to chemometrics including Support Vector Machine (SVM) which furnished an average diagnostic accuracy of 94%, 74% and 92% of the three grades. Combined SERS read-out and machine learning technique in field trial promises its potential to reduce the incidence in low resource countries.
Pap smear test is the existing diagnostic method used for the cervical cancer detection which mainly looks upon the abnormal morphological characteristics in exfoliated cells. The inter-observer variability and less sensitivity demands ancillary techniques to be introduced. We have established a label-free surface enhanced Raman spectroscopy based differential diagnosis for the healthy, pre-cancerous lesion and invasive stages of cervical cancer using exfoliated cell samples for the first time. The resultant spectra were evaluated empirically as well as chemometrically and identified an average diagnostic accuracy of 94%, 74% and 92% for single cell, cell pellet and extracted DNA respectively. This study is more advantageous than label free SERS of blood based analysis where early molecular changes will not be as prevalent as in the exfoliated cell samples collected from the cervix. [Display omitted]
•Label free surface enhanced Raman spectroscopy (SERS) was introduced for differential diagnosis of the healthy, pre-cancerous lesion and invasive stages of cervical cancer using exfoliated cell samples.•Gold nanoparticles as a SERS substrate, a strategy developed achieved for the first time to generate a differential spectral classification using single cell, cell pellet and extracted DNA•SERS analysis together with conventional cytopathological investigations, Pap test and HPV DNA based analysis, HPV PCR•The resultant spectra have been classified empirically as well chemometrically using PCA, LDA as well as SVM analysis and identified well-found an average diagnostic accuracy of 94%, 74% and 92% of the three clinical grades.