Direct profiling of cancer biomarkers in tumor tissue using a multiplexed nanostructured microelectrode integrated circuit

Predictive and prognostic molecular markers for cancer medicine

Over the last 10 years there has been an explosion of information about the molecular biology of cancer. A challenge in oncology is to translate this information into advances in patient care. While there are well-formed routes for translating new molecular information into drug therapy, the routes for translating new information into sensitive and specific diagnostic, prognostic and predictive tests are still being developed. Similarly, the science of using tumor molecular profiles to select clinical trial participants or to optimize therapy for individual patients is still in its infancy. This review will summarize the current technologies for predicting treatment response and prognosis in cancer medicine, and outline what the future may hold. It will also highlight the potential importance of methods that can integrate molecular, histopathological and clinical information into a synergistic understanding of tumor progression. While these possibilities are without doubt exciting, significant challenges remain if we are to implement them with a strong evidence base in a widely available and cost-effective manner.

Graphene as cellular interface: electromechanical coupling with cells

Interfacing cells with nanomaterials such as graphene, nanowires, and carbon nanotubes is useful for the integration of cellular physiology with electrical read outs. Here we show the interfacing of graphene sheets on the surface of yeast cells, leading to electromechanical coupling between the sheets and the cells. The cells are viable after the interfacing. The response caused by physiologically stressing the cells by exposure to alcohols, which causes a change in cell volume, can be observed in the electrical signal through graphene. The change in the cell volume leads to straining of the sheets, forming wrinkles which reduce the electrical conductivity. As the dynamic response of the cell can be observed, it is possible to differentiate between ethanol, 2-propanol, and water. We believe this will lead to further development of cell-based electrical devices and sensors.

Hierarchical nanotextured microelectrodes overcome the molecular transport barrier to achieve rapid, direct bacterial detection

Detection of biomolecules at low abundances is crucial to the rapid diagnosis of disease. Impressive sensitivities, typically measured with small model analytes, have been obtained with a variety of nano- and microscale sensors. A remaining challenge, however, is the rapid detection of large native biomolecules in real biological samples. Here we develop and investigate a sensor system that directly addresses the source of this challenge: the slow diffusion of large biomolecules traveling through solution to fixed sensors, and inefficient complexation of target molecules with immobilized probes. We engineer arrayed sensors on two distinct length scales: a ∼100 μm length scale commensurable with the distance bacterial mRNA can travel in the 30 min sample-to-answer duration urgently required in point-of-need diagnostic applications; and the nanometer length scale we prove necessary for efficient target capture. We challenge the specificity of our hierarchical nanotextured microsensors using crude bacterial lysates and document the first electronic chip to sense trace levels of bacteria in under 30 min.

Gold nanoparticle layer: a promising platform for ultra-sensitive cancer detection

Developing new technologies applicable to the sensitive detection of cancer in its early stages has always been attractive in diagnosis. A stable gold nanoparticle layer (GNPL)-modified high-binding ELISA plate was obtained via chemical plating and was proven to be more efficient in binding proteins while maintaining their activity. GNPL-based ELISA for the representative biomarker carcinoembryonic antigen (CEA) demonstrated that GNPL markedly amplified the ELISA signal and significantly improved the limit of detection (LOD). Antithrombin detection further confirms the effectiveness and universality of this GNPL-based platform. The entire assay procedure is simple and low in cost and does not require special facilities. All these virtues indicate that this GNPL platform holds great promise in clinical applications for the early diagnosis of cancer.

Multiplexed DNA-modified electrodes

We report the use of silicon chips with 16 DNA-modified electrodes (DME chips) utilizing DNA-mediated charge transport for multiplexed detection of DNA and DNA-binding protein targets. Four DNA sequences were simultaneously distinguished on a single DME chip with 4-fold redundancy, including one incorporating a single base mismatch. These chips also enabled investigation of the sequence-specific activity of the restriction enzyme Alu1. DME chips supported dense DNA monolayer formation with high reproducibility, as confirmed by statistical comparison to commercially available rod electrodes. The working electrode areas on the chips were reduced to 10 microm in diameter, revealing microelectrode behavior that is beneficial for high sensitivity and rapid kinetic analysis. These results illustrate how DME chips facilitate sensitive and selective detection of DNA and DNA-binding protein targets in a robust and internally standardized multiplexed format.

Multifunctional oval-shaped gold-nanoparticle-based selective detection of breast cancer cells using simple colorimetric and highly sensitive two-photon scattering assay

Breast cancer is the most common cancer among women, and it is the second leading cause of cancer deaths in women today. The key to the effective and ultimately successful treatment of diseases such as cancer is early and accurate diagnosis. Driven by the need, in this article, we report for the first time a simple colorimetric and highly sensitive two-photon scattering assay for highly selective and sensitive detection of breast cancer SK-BR-3 cell lines at a 100 cells/mL level using a multifunctional (monoclonal anti-HER2/c-erb-2 antibody and S6 RNA aptamer-conjugated) oval-shaped gold-nanoparticle-based nanoconjugate. When multifunctional oval-shaped gold nanoparticles are mixed with the breast cancer SK-BR-3 cell line, a distinct color change occurs and two-photon scattering intensity increases by about 13 times. Experimental data with the HaCaT noncancerous cell line, as well as with MDA-MB-231 breast cancer cell line, clearly demonstrated that our assay was highly sensitive to SK-BR-3 and it was able to distinguish from other breast cancer cell lines that express low levels of HER2. The mechanism of selectivity and the assay's response change have been discussed. Our experimental results reported here open up a new possibility of rapid, easy, and reliable diagnosis of cancer cell lines by monitoring the colorimetric change and measuring TPS intensity from multifunctional gold nanosystems.

Nanotechnology for early cancer detection

Vast numbers of studies and developments in the nanotechnology area have been conducted and many nanomaterials have been utilized to detect cancers at early stages. Nanomaterials have unique physical, optical and electrical properties that have proven to be very useful in sensing. Quantum dots, gold nanoparticles, magnetic nanoparticles, carbon nanotubes, gold nanowires and many other materials have been developed over the years, alongside the discovery of a wide range of biomarkers to lower the detection limit of cancer biomarkers. Proteins, antibody fragments, DNA fragments, and RNA fragments are the base of cancer biomarkers and have been used as targets in cancer detection and monitoring. It is highly anticipated that in the near future, we might be able to detect cancer at a very early stage, providing a much higher chance of treatment.