Rapid SERS-based recognition of cell secretome on the folic acid-functionalized gold gratings

Nowadays, functionalization of the plasmon-supported nanostructured surface is considered as a powerful tool for tumour cell recognition. In this study, the SERS on a surface plasmon polariton-supported gold grating functionalized with folic acid was used to demonstrate an unpretentious recognition of melanoma-associated fibroblasts. Using cultivation media conditioned by different cells, we were able to detect reproducible differences in the secretome of melanoma-associated and normal control fibroblasts. The homogeneous distribution of plasmon energy along the grating surface was proved to provide excellent SERS signal reproducibility, while, to increase the affinity of (bio)molecules to SERS substrate, folic acid molecules were covalently grafted to the gold gratings. As proof of concept, fibroblasts were cultured in vitro, and culture media from the normal and tumour-associated lines were collected and analysed with our proposed SERS substrates. Identifying individual peaks of the Raman spectra as well as comparing their relative intensities, we showed that the proposed functional SERS platform can recognise the melanoma-associated cells without the need for further statistical spectral evaluation directly. We also demonstrated that the SERS chip created provided a stable SERS signal over a period of 90 days without loss of sensitivity. Graphical abstract.

In Vitro and In Vivo SERS Biosensing for Disease Diagnosis

For many disease states, positive outcomes are directly linked to early diagnosis, where therapeutic intervention would be most effective. Recently, trends in disease diagnosis have focused on the development of label-free sensing techniques that are sensitive to low analyte concentrations found in the physiological environment. Surface-enhanced Raman spectroscopy (SERS) is a powerful vibrational spectroscopy that allows for label-free, highly sensitive, and selective detection of analytes through the amplification of localized electric fields on the surface of a plasmonic material when excited with monochromatic light. This results in enhancement of the Raman scattering signal, which allows for the detection of low concentration analytes, giving rise to the use of SERS as a diagnostic tool for disease. Here, we present a review of recent developments in the field of in vivo and in vitro SERS biosensing for a range of disease states including neurological disease, diabetes, cardiovascular disease, cancer, and viral disease.

Multifunctional hybrid graphene oxide for circulating tumor cell isolation and analysis

Even in 21st century, >90% cancer-associated deaths are caused by metastatic disease. Circulating tumor cells (CTCs), which circulate in the blood stream after release from primary tumors, extravasate and form fatal metastases in different organs. Several clinical trials indicate that CTCs can be used as a liquid biopsy of tumors for early diagnosis of cancers. Since CTCs are extremely rare and exhibit heterogeneous biology due to epithelial-mesenchymal transition (EMT), oncologists continue to face enormous challenges in using CTCs as a true "liquid biopsy" for cancer patients. Recent advancements in nanoscience allow us to design nano-architectures with the capability of targeted CTCs isolation and identification. In the current review, we discuss contribution from different groups on the development of graphene oxide based nanoarchitecture for effective isolation and accurate identification of CTCs from whole blood. In the last few years, using zero-dimensional (0D), two dimensional (2D) and three dimensional (3D) multifunctional hybrid graphene oxide (GO), different types of nanoarchitectures have been designed. These nanoarchitectures represent a highly powerful platform for CTC diagnosis. We discuss the major design criteria that have been used to develop hybrid GO nanoarchitectures for selective capture and accurate identification of heterogeneous CTCs from whole blood. At the end, we conclude with the promises, major challenges, and prospect to clinically translate the identification of CTCs using GO based nanotechnology.

Hybrid Theranostic Platform for Second Near-IR Window Light Triggered Selective Two-Photon Imaging and Photothermal Killing of Targeted Melanoma Cells

Despite advances in the medical field, even in the 21st century cancer is one of the leading causes of death for men and women in the world. Since the second near-infrared (NIR) biological window light between 950 and 1350 nm offers highly efficient tissue penetration, the current article reports the development of hybrid theranostic platform using anti-GD2 antibody attached gold nanoparticle (GNP) conjugated, single-wall carbon nanotube (SWCNT) for second near-IR light triggered selective imaging and efficient photothermal therapy of human melanoma cancer cell. Reported results demonstrate that due to strong plasmon-coupling, two-photon luminescence (TPL) intensity from theranostic GNP attached SWCNT materials is 6 orders of magnitude higher than GNP or SWCNT alone. Experimental and FDTD simulation data indicate that the huge enhancement of TPL intensity is mainly due to strong resonance enhancement coupled with the stronger electric field enhancement. Due to plasmon coupling, the theranostic material serves as a local nanoantennae to enhance the photothermal capability via strong optical energy absorption. Reported data show that theranostic SWCNT can be used for selective two-photon imaging of melanoma UACC903 cell using 1100 nm light. Photothermal killing experiment with 1.0 W/cm(2) 980 nm laser light demonstrates that 100% of melanoma UACC903 cells can be killed using theranostic SWCNT bind melanoma cells after just 8 min of exposure. These results demonstrate that due to plasmon coupling, the theranostic GNP attached SWCNT material serves as a two-photon imaging and photothermal source for cancer cells in biological window II.

Multifunctional carbon nanomaterial hybrids for magnetic manipulation and targeting

Nanosized materials and multifunctional nanoscale platforms have attracted in the last years considerable interest in a variety of different fields including biomedicine. Carbon nanotubes and graphene are some of the most widely used carbon nanomaterials (CNMs) due to their unique morphology and structure and their characteristic physicochemical properties. Their high surface area allows efficient drug loading and bioconjugation and makes them the ideal platforms for decoration with magnetic nanoparticles (MNPs). In the biomedical area, MNPs are of particular importance due to their broad range of potential applications in drug delivery, non-invasive tumor imaging and early detection based on their optical and magnetic properties. The remarkable characteristics of CNMs and MNPs can be combined leading to CNM/MNP hybrids which offer numerous promising, desirable and strikingly advantageous properties for improved performance in comparison to the use of either material alone. In this minireview, we attempt to comprehensively report the most recent advances made with CNMs conjugated to different types of MNPs for magnetic targeting, magnetic manipulation, capture and separation of cells towards development of magnetic carbon-based devices.

Aptamer-conjugated theranostic hybrid graphene oxide with highly selective biosensing and combined therapy capability

Cancer is a life-threatening disease, which is rapidly becoming a global pandemic. Driven by this need, here we report for the first time an aptamer-conjugated theranostic magnetic hybrid graphene oxide-based assay for highly sensitive tumor cell detection from blood samples with combined therapy capability. AGE-aptamer-conjugated theranostic magnetic nanoparticle-attached hybrid graphene oxide was developed for highly selective detection of tumor cells from infected blood samples. Experimental data indicate that hybrid graphene can be used as a multicolor luminescence platform for selective imaging of G361 human malignant melanoma cancer cells. The reported results have also shown that indocyanine green (ICG)-bound AGE-aptamer-attached hybrid graphene oxide is capable of combined synergistic photothermal and photodynamic treatment of cancer. Targeted combined therapeutic treatment using 785 nm near-infrared (NIR) light indicates that the multimodal therapeutic treatment is highly effective for malignant melanoma cancer therapy. The reported data show that this aptamer-conjugated theranostic graphene oxide-based assay has exciting potential for improving cancer diagnosis and treatment.