Selective Detection Of Cancer Cells Research Articles

Protease-Responsive Potential-Tunable AIEgens for Cell Selective Imaging of TMPRSS2 and Accurate Inhibitor Screening.

Transmembrane protease serine 2 (TMPRSS2) is a plasma membrane protease that activates both spike protein of coronaviruses for cell entry and oncogenic signaling pathways for tumor progression. TMPRSS2 inhibition can reduce cancer invasion and metastasis and partially prevent the entry of SARS-CoV-2 into host cells. Thus, there is an urgent need for both TMPRSS2-selective imaging and precise screening of TMPRSS2 inhibitors. Here, we report a TMPRSS2-responsive surface-potential-tunable peptide-conjugated probe (EGTP) with aggregation-induced emission (AIE) features for TMPRSS2 selective imaging and accurate inhibitor screening. The amphiphilic EGTP was constructed with tunable surface potential and responsive efficiency with TMPRSS2 and its inhibitor. The rational construction of AIE luminogens (AIEgens) with modular peptides indicated that the cleavage of EGTP led to a gradual aggregation with bright fluorescence in high TMPRSS2-expressing cells. This strategy may have value for selective detection of cancer cells, SARS-CoV-2-target cells, and screening of protease inhibitors.

Water-soluble graphene quantum dot‐based polymer nanoparticles with internal donor/acceptor heterojunctions for efficient and selective detection of cancer cells

We present a new, insightful donor–acceptor (D-A) energy transfer-based strategy for the preparation and development of water-soluble multifunctional pH-responsive heterojunction nanoparticles. Hydrophilic tertiary amine-grafted polythiophene (WPT) as a donor and blue fluorescent graphene quantum dots (GQD) as an acceptor spontaneously form co-assembled nanoparticles that function as a highly pH-sensitive and efficient biosensor appropriate for the detection of cancer cells. These WPT/GQD nanoparticles exhibit a number of unique physical characteristics—such as broad-range, tunable GQD-loading contents and particle sizes, extremely low cytotoxicity in normal and cancer cells, and highly sensitive pH-responsiveness and rapid acid-triggered fluorescent behavior under aqueous acidic conditions. We show these features are conferred by self-aggregation of the GQD within the nanoparticles and subsequent aggregation-induced fluorescence of GQD after disassembly of the nanoparticles and dissociation of the D-A interactions under acidic conditions. Importantly, in vitro fluorescence imaging experiments clearly demonstrated the WPT/GQD nanoparticles were gradually taken up into normal and cancer cells in vitro. Selective formation of GQD aggregates subsequently occurred in the acidic microenvironment of the cancer cells and the interior of the cancer cells exhibited strong blue fluorescence; these phenomena did not occur in normal cells. In contrast, pristine WPT and GQD did not exhibit cellular microenvironment-triggered fluorescence transitions in cancer or normal cell lines. Therefore, this newly discovered water-soluble heterojunction system may represent a strongly fluorescent highly pH-sensitive bioprobe for rapid detection of cancer cells.

Folic‐Acid‐Functionalized Au Nanoclusters with Red Fluorescence Emission for Rapid and Selective Detection of Cancer Cells

AbstractMetal nanoclusters have low toxicity and excellent fluorescence properties, and play an important role in environmental and biological detection. Herein, we demonstrate a new approach for synthesis of fluorescent Au nanoclusters (Au NCs) with the function of cancer cells detection. Firstly, we design and synthesize the copolymers of Folic acid–bovine serum albumin (FA‐BSA). In addition, the FA‐BSA copolymer prepared can be used as both stabilizer and reducer of Au NCs, and Au NCs were synthesized by simple hydrothermal method. Therefore, we obtain the fluorescent Au NCs by a convenient, safety and environment‐friendly route. The as‐prepared FA‐functionalized Au NCs are water‐soluble, highly stable and good biological compatibility, and exhibit longwave emission with red light region. Significantly, the Au NCs show outstanding capacity to specifically target the cells overexpressing the folate receptor (FR). These properties indicate that the prepared Au NCs are a promising fluorescent probe for cancer diagnosis and treatment.

A rapid nanobiosensing platform based on herceptin-conjugated graphene for ultrasensitive detection of circulating tumor cells in early breast cancer

AbstractIn this paper, we use a simple and cheap approach for the synthesis of herceptin-conjugated graphene biosensor to detect the HER2-positive breast cancer cells. The bifunctional graphene-herceptin nanosheets are prepared from graphite by a simple ultrasonic-mediated technique. The prepared protein-mediated graphene is fully characterized. The results show the exfoliation of graphene layers in herceptin solution. Moreover, herceptin is effectively conjugated into the surface of graphene nanosheets. The synthesized herceptin-conjugated graphene is applied for breast cancer detection. The linear range of this biosensor is 1–80 cells, which is significant. The biosensor shows an excellent selectivity performance for detection of HER2-positive cancer cells. Likewise, the stability and functionality of the biosensor is about 40 days. Based on the results, this device is a promising candidate for rapid and selective detection of cancer cells.

Realizing the Principles for Remote and Selective Detection of Cancer Cells Using Magnetic Nanowires.

The unmet demand for selective and remote detection of biological entities has urged nanobiotechnology to prioritize the innovation of biolabels that can be remotely detected. Magnetic nanowires (MNWs) have been deemed promising for remote detection as the magnetic fields can deeply and safely penetrate into tissue. However, the overlapping nature of the magnetic signatures has been a long-standing challenge for selective detection, which we resolve here. To do so, 13 types of MNWs with unique irreversible switching field (ISF) signatures were synthesized for labeling canine osteosarcoma (OSCA-8) cancer cells (one set) and polycarbonate biopolymers (12 sets). After characterizing the ISF signature of each MNW type, the MNW-labeled cancer cells were transferred onto MNW-labeled biopolymers to determine the most distinguishable ISF signatures and to discern the principles for reliable selective detection of biological entities. We show that tailoring the ISF of MNWs by tuning their coercivity is a highly effective approach for generating distinct magnetic biolabels for selective detection of cells. These findings smooth the path for the progression of nanobiotechnology by enabling the remote and selective detection of biological entities using MNWs.

Selective Detection of Cancer Cells Using Magnetic Nanowires.

The main bottleneck for implementing magnetic nanowires (MNWs) in cell-biology research for multimodal therapeutics is the inapplicability of the current state of the art for selective detection and stimulation of MNWs. Here, we introduce a methodology for selective detection of MNWs in platforms that have multiple magnetic signals, such as future multimodal therapeutics. After characterizing the signatures of MNWs, MNWs were surface-functionalized and internalized into canine osteosarcoma (OSCA-8) cancer cells for cell labeling, manipulation, and separation. We also prepared and characterized magnetic biopolymers as multimodal platforms for future use in controlling the movement, growth, and division of cancer cells. First, it is important to have methods for distinguishing the magnetic signature of the biopolymer from the magnetically labeled cells. For this purpose, we use the projection method to selectively detect and demultiplex the magnetic signatures of MNWs inside cells from those inside magnetic biopolymers. We show that tailoring the irreversible switching field of MNWs by tuning their coercivity is a highly effective approach for generating distinct magnetic biolabels for selective detection of cancer cells. These findings open up new possibilities for selective stimulation of MNWs in multimodal therapeutic platforms for drug delivery, hyperthermia cancer therapy, and mitigating cancer cell movement and proliferation.

DOTAM-Based, Targeted, Activatable Fluorescent Probes for the Highly Sensitive and Selective Detection of Cancer Cells.

The utilization of an activatable, substrate-based probe design in combination with a cellular targeting approach has been rarely explored for cancer imaging on a small-molecule basis, although such probes could benefit from advantages of both concepts. Cysteine proteases like cathepsin S are known to be involved in fundamental processes associated with tumor development and progression and thus are valuable cancer markers. We report the development of a combined dual functional DOTAM-based, RGD-targeted internally quenched fluorescent probe that is activated by cathepsin S. The probe exhibits excellent in vitro activation kinetics which can be fully translated to human cancer cell lines. We demonstrate that the targeted, activatable probe is superior to its nontargeted analog, exhibiting improved uptake into ανβ3-integrin expressing human sarcoma cells (HT1080) and significantly higher resultant fluorescence staining. However, profound activation was also found in cancer cells with a lower integrin expression level, whereas in healthy cells almost no probe activation could be observed, highlighting the high selectivity of our probe toward cancer cells. These auspicious results show the outstanding potential of the dual functionality concept combining a substrate-based probe design with a targeting approach, which could form the basis for highly sensitive and selective in vivo imaging probes.

Application of sulfur-doped graphene quantum dots@gold-carbon nanosphere for electrical pulse-induced impedimetric detection of glioma cells

Glioma is the predominant brain tumor with high death rate. The successful development of biosensor to achieve an efficient detection of glioma cells at low concentration remains a great challenge for the personalized glioma therapy. Herein, an ultrasensitive pulse induced electrochemically impedimetric biosensor for glioma cells detection has been successfully fabricated. The 4–11 nm sulfur-doped graphene quantum dots (S-GQDs) are homogeneously deposited onto gold nanoparticles decorated carbon nanospheres (Au–CNS) by Au-thiol linkage to form S-GQDs@Au–CNS nanocomposite which acts as dual functional probe for enhancing the electrochemical activity as well as conjugating the angiopep-2 (Ang-2) for glioma cell detection. Moreover, the application of an externally electrical pulse at +0.6 V expend the surface of glioma cells to accelerate the attachment of glioma cells onto the Ang-2-conjugated S-GQDs@Au–CNS nanocomposite, resulting in the enhanced sensitivity toward glioma cell detection. An ultrasensitive impedimetric detection of glioma cells with a wide linear range of 100–100,000 cells mL−1 and a limit of detection of 40 cells mL−1 is observed. Moreover, the superior selectivity with long-term stability of the developed biosensor in human serum matrix corroborates the feasibility of using S-GQDs@Au–CNS based nanomaterials as the promising sensing probe for practical application to facilitate the ultrasensitive and highly selective detection of cancer cells.

Design of PEGylated Three Ligands Silica Nanoparticles for Multi-Receptor Targeting

The synthesis of silica nanoparticles (SiNPs) decorated on their surface with a range of various elements (e.g., ligands, drugs, fluorophores, vectors, etc.) in a controlled ratio remains a big challenge. We have previously developed an efficient strategy to obtain in one-step, well-defined multifunctional fluorescent SiNPs displaying fluorophores and two peptides ligands as targeting elements, allowing selective detection of cancer cells. In this paper, we demonstrate that additional level of controlled multifunctionality can be achieved, getting even closer to the original concept of “magic bullet”, using solely sol–gel chemistry to achieve conjugation of PEG chains for stealth, along with three different ligands. In addition, we have answered the recurrent question of the surface ungrafting by investigating the stability of different siloxane linkages with the ERETIC Method (Electronic Reference to Access In Vivo Concentrations) by 19F NMR quantification. We also compared the efficiency of the hybrid silylated fluorophore covalent linkage in the core of the SiNP to conventional methods. Finally, the tumor-cell-targeting efficiency of these multi-ligand NPs on human endothelial cells (HUVEC or HDMEC) and mixed spheroids of human melanoma cells and HUVEC displaying different types of receptors were evaluated in vitro.

Design and synthesis of a novel peptide for selective detection of cancer cells.

Using a minimalist approach, an 11-residue peptide (Peptide 1) tagged with rhodamine fluorophore was designed and synthesized for selective detection of cancer cells. Peptide 1 contains RGD and NGR motifs to bind, respectively, integrins and aminopeptidase CD13, which are over expressed in cancer cells. Surface tension measurements revealed that peptide 1 possess surface-active property owing to the overall hydrophobicity and cationic nature of the peptide. Peptide 1 displays cancer cell-selective binding at ≤5.0µM concentrations, while peptide 2 (randomized sequence of 1) shows non-selective binding to normal and cancer cells. Fluorescence microscopy and FACS analysis demonstrated the intracellular localization of peptide 1 in three different cancer cell lines, confirming the role of RGD and NGR motifs. Cytotoxicity assay exhibited the viability of normal and cancer cells up to 100µM concentrations of peptide 1. Steady-state fluorescence measurements disclosed the preferential interactions of the peptide 1 with anionic POPC/POPG bilayers rather than with zwitterionic POPC lipid bilayers. Circular dichroism studies showed minimal changes in the secondary structure of peptide 1 upon binding with the anionic lipid bilayers. Peptide 1 is largely unordered, non-toxic, and useful for identification of cancer cells. Peptide 1 provides a template for designing drug-loaded peptides for targeted delivery into cancer cells.

Impedimetric biosensor for detection of cancer cells employing carbohydrate targeting ability of Concanavalin A

The successful development of selective detection of cancer cells from normal cells is a highly demanded but challenging task. Herein, we have developed a rapid and label-free impedimetric biosensor for quantitative determination of cancer cells with high glycoprotein expression. Homogenously distributed 2–9 nm graphene quantum dots (GQDs) was anchored on the surface Fe3O4 through covalent bonding. Concovalin A (ConA) was then adhered onto GQDs by physical mixing to fabricate ConA-GQD@Fe3O4 nanosensing probe. A good dynamic range in the cell concentration of 5 × 102–1 × 105 cells mL-1 with LOD values of 246 and 367 cells mL-1 for HeLa and MCF-7, respectively, is obtained. The impedimetric responses to the cancerous HeLa and MCF-7 cells are 16.7 and 13.1 times higher than those of their original sensor electrodes. However, the interaction between sensing probe and normal MCF-10 and bEnd.3 cells is negligible, confirming the specific selectivity toward cancer cells. Cellular uptake images as well as in-vitro cytotoxicity corroborates the electrochemical results. In addition, the successful detection of cancer cells in human serum and circulating tumor cells in blood sample envisions the feasibility of using ConA-GQD@Fe3O4 as the nanosensing probe for clinically early diagnosis of cancer cells with high glycoprotein expression.

Electrochemiluminescence detection of human breast cancer cells using aptamer modified bipolar electrode mounted into 3D printed microchannel

In the present manuscript, a closed bipolar electrode system integrated with electrochemiluminescence (ECL) detection has been introduced for sensitive diagnosis of human breast cancer cells (MCF-7). For sensitive and selective detection, the anodic pole of the bipolar electrode was modified with the AS1411 aptamer, a specific aptamer for the nucleolin, and treated by the secondary aptamer modified gold nanoparticles. The electrochemiluminescence of luminol was followed in the presence of hydrogen peroxide on the anode pole of bipolar electrode (BPE) as an analytical signal. Moreover, 3D printed microchannels were used for the fabrication of BPE systems to minimize the required amounts of sample. The present aptasensor offers low cost, sensitive and selective cancer cell detection with two acceptable linear ranges. The first linear section appears within 10–100 cells and the latter is found to be within 100–700 cells. The limit of detection was about 10 cells.

Nanoarchitectured Electrochemical Cytosensor for Selective Detection of Cancer Cells

Nanoarchitectured Electrochemical Cytosensor for Selective Detection of Cancer Cells

Smart Probe for Tracing Cancer Therapy: Selective Cancer Cell Detection, Image-Guided Ablation, and Prediction of Therapeutic Response In Situ.

Integrated diagnosis and therapy systems that can offer traceable cancer therapy are in high demand for personalized medicine. Herein, a pH-responsive polymeric probe containing tetraphenylsilole (TPS) with aggregation-induced emission characteristics and pheophorbide A (PheA) photosensitizer (PS) with aggregation-caused quenching property for tracing the whole process of cancer therapy is reported. At physiological conditions (pH 7.4), the probe self-assembles into nanoparticles (NPs), which show weak fluorescence of PheA with low phototoxicity, but strong green fluorescence from TPS for probe self-tracking. Upon uptake by cancer cells and entrapment in lysosomes (pH 5.0), the NPs disassemble to yield weak emission of TPS but strong red fluorescence of PheA with restored phototoxicity for PS activation monitoring. Upon light irradiation, the generated reactive oxygen species can cause lysosomal disruption to trigger cell apoptosis. Meanwhile, the probe leaks to the cytoplasm (pH 7.2), where the TPS fluorescence is restored for in situ visualization of the therapeutic response. The probe design thus represents a novel strategy for traceable cancer therapy.

Label-free electrochemical aptasensor constructed by layer-by-layer technology for sensitive and selective detection of cancer cells

Here, a cytosensor was constructed with ferrocene-appended poly(allylamine hydrochloride) (Fc-PAH) functionalized graphene (Fc-PAH-G), poly(sodium-p-styrenesulfonate) (PSS) and aptamer (AS1411) by layer-by-layer assembly technology. The hybrid nanocomposite Fc-PAH-G not only brings probes on the electrode and also promotes electron transfer between the probes and the substrate electrode. Meanwhile, LBL technology provides more effective probes to enhance amplified signal for improving the sensitivity of the detection. While AS1411 forming G-quardruplex structure and binding cancer cells, the current response of the sensing electrode decreased due to the insulating properties of cellular membrane. Differential pulse voltammetry (DPV) was performed to investigate the electrochemical detection of HeLa cells attributing to its sensitivity of the current signal change. The as-prepared aptasensor showed a high sensitivity and good stability, a widely detection range from 10 to 106cells/mL with a detection limit as low as 10cells/mL for the detection of cancer cells.

N-Pyridineium-2-yl Darrow Red analogue: unique near-infrared lysosome-biomarker for the detection of cancer cells.

The lysosome-targetable OFF-ON type pH sensor that does not emit at pH = 4.0 is adopted for the selective detection of cancer cells, and the acidity difference of lysosomes in cancer and normal cells is verified. Three pH probes based on Darrow Red derivatives were designed and prepared that were demonstrated to be lysosome-specific biomarkers with inducible emission at 580-850 nm by the comparable in cellular imaging assays using HeLa, KB, and V79 cells. Of these, a pyridineium-2-yl Darrow Red analogue with a pKa of 2.4 was found to be a lysosome tracker for cancer cells, it is a unique pH sensor for the optical identification and distinction of cancer cells from normal cells and has potential application as a fluorescent biomaker of cancer cells in in vitro assays.

Tunable and selective detection of cancer cells using a betainized zwitterionic polymer with BODIPY and graphene oxide

Novel fluorescence probes, reduced graphene oxide (rGO) containing zwitterionic fluorescent nanoparticles, for effective diagnosis of cancer cells.

Folic Acid Functionalized Nanoprobes for Fluorescence‐, Dark‐Field‐, and Dual‐Imaging‐Based Selective Detection of Cancer Cells and Tissue

AbstractFolate‐functionalized quantum dots, gold/silver nanoparticles, and magnetic quantum dots have been synthesized and used as fluorescence, dark‐field, and dual‐imaging probes for the detection of cancer cells and tissues. A very efficient and generalized folate‐functionalization method has been developed for various amine‐terminated nanoparticles. The advantages of the presented approach are that it can be used to synthesize a wide range of folate‐functionalized nanoparticles and the number of folate molecules per nanoparticle can be controlled easily to tune their interaction with folate receptors present at the cell surface. These folate‐functionalized nanoparticles have been used as cellular and tissue‐imaging bioprobes. Results show that folate‐functionalized nanoparticles act as efficient and selective imaging probes in targeting cancer cells and tissues and labeled cells/tissues can be detected by using different imaging modalities.

Highly fluorescent dye-doped silica nanoparticles increase flow cytometry sensitivity for cancer cell monitoring

Early and accurate diagnosis and treatment of cancer depend on rapid, sensitive, and selective detection of tumor cells. Current diagnosis of cancers, especially leukemia, relies on histology and flow cytometry using single dye-labeled antibodies. However, this combination may not lead to high signal output, which can hinder detection, especially when the probes have relatively weak affinities or when the receptor is expressed in a low concentration on the target cell surface. To solve these problems, we have developed a novel method for sensitive and rapid detection of cancer cells using dye-doped silica nanoparticles (NPs) which increases detection sensitivity in flow cytometry analyses between 10- and 100-fold compared to standard methods. Our NPs are ∼60 nm in size and can encapsulate thousands of individual dye molecules within their matrix. We have extensively investigated surface modification strategies in order to make the NPs suitable for selective detection of cancer cells using flow cytometry. The NPs are functionalized with polyethylene glycol (PEG) to prevent nonspecific interactions and with neutravidin to allow universal binding with biotinylated molecules. By virtue of their reliable and selective detection of target cancer cells, these NPs have demonstrated their promising usefulness in conventional flow cytometry. Moreover, they have shown low background signal, high signal enhancement, and efficient functionalization, either with antibody- or aptamer-targeting moieties.