Detection of circulating tumor cells in blood by shell-isolated nanoparticle – enhanced Raman spectroscopy (SHINERS) in microfluidic device

Abstract

Isolation and detection of circulating tumor cells (CTCs) from human blood plays an important role in non- invasive screening of cancer evolution and in predictive therapeutic treatment. Here, we present the novel tool utilizing: (i) the microfluidic device with (ii) incorporated photovoltaic (PV) based SERS-active platform, and (iii) shell-isolated nanoparticles (SHINs) for simultaneous separation and label-free analysis of circulating tumour cells CTCs in the blood specimens with high specificity and sensitivity. The proposed microfluidic chip enables the efficient size – based inertial separation of circulating cancer cells from the whole blood samples. The SERS-active platform incorporated into the microfluidic device permits the label-free detection and identification of isolated cells through the insight into their molecular and biochemical structure. Additionally, the silver nanoparticles coated with an ultrathin shell of silica (Ag@SiO 2 ) was used to improve the detection accuracy and sensitivity of analysed tumor cells via taking advantages of shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). The empirical analysis of SHINERS spectra revealed that there are some differences among studied (HeLa), renal cell carcinoma (Caki-1), and blood cells. Unique SHINERS features and differences in bands intensities between healthy and cancer cells might be associated with the variations in the quantity and quality of molecules such as lipid, protein, and DNA or their structure during the metastasis cancer formation. To demonstrate the statistical efficiency of the developed method and improve the differentiation for circulating tumors cells detection the principal component analysis (PCA) has been performed for all SHINERS data. PCA method has been applied to recognize the most significant differences in SHINERS data among the three analyzed cells: Caki-1, HeLa, and blood cells. The proposed approach challenges the current multi-steps CTCs detection methods in the terms of simplicity, sensitivity, invasiveness, destructivity, time and cost of analysis, and also prevents the defragmentation/damage of tumor cells and thus leads to improving the accuracy of analysis. The results of this research work show the potential of developed SERS based tool for the separation of tumor cells from whole blood samples in a simple and minimally invasive manner, their detection and molecular characterization using one single technology.

Microfluidics and surface-enhanced Raman spectroscopy, a win–win combination?

“…The limitations of PDMS have fueled researchers to pay attention to other polymer materials such as poly(methyl methacrylate) (PMMA), 125 polycarbonates (PC), 126,127 polystyrenes (PS), 111 polyurethanes (PU), 128 and Teflon 129 for microfluidic devices. For microfluidic SERS measurements, it is preferable to use optically transparent building blocks such as PDMS, polystyrene and PMMA.…”

“…Recently, Niciński et al employed SHINs in a microfluidic device with a photovoltaic-based SERS-active platform for simultaneous separation and label-free analysis of circulating tumor cells. 127 Particularly, SHINs can also be used for photochemical or chemical reaction monitoring in microfluidic chips if bare nanoparticles interfere with target molecules. 197…”

Multiplexing Liquid Biopsy with Surface‐Enhanced Raman Scattering Spectroscopy

“…Different reports have also been published during the last year that combine different approaches regarding the SERS sensing strategy, for different types of cancer and using blood either spiked, or from patients (Table 2). [ 168–171 ]…”

MiRNA-Based Inspired Approach in Diagnosis of Prostate Cancer

“…SERS technique is increasingly employed for prostate cancer detection from body fluids. The most preferred SERS substrates are silver nanoparticles [114], gold nanoparticles targeting different circulating molecules (non-coding RNA, PSA, MUC4, IgG) [115], polymeric membranes [112] and microfluidic devices [116,117].…”