Raman Imaging: An Impending Approach Towards Cancer Diagnosis

In accordance with the recent studies, Raman spectroscopy is well experimented as a highly sensitive analytical and imaging technique in biomedical research, mainly for various disease diagnosis including cancer. In comparison with other imaging modalities, Raman spectroscopy facilitate numerous assistances owing to its low background signal, immense spatial resolution, high chemical specificity, multiplexing capability, excellent photo stability and non-invasive detection capability. In cancer diagnosis Raman imaging intervened as a promising investigative tool to provide molecular level information to differentiate the cancerous vs non-cancerous cells, tissues and even in body fluids. Anciently, spontaneous Raman scattering is very feeble due to its low signal intensity and long acquisition time but new advanced techniques like coherent Raman scattering (CRS) and surface enhanced Raman scattering (SERS) gradually superseded these issues. So, the present review focuses on the recent developments and applications of Raman spectroscopy-based imaging techniques for cancer diagnosis.     

Ultra sensitive trace gas detection for biomedical applications

We present an overview of our recent progress on spectroscopic trace gas detection for biomedical applications. The latest developments of cavity-enhanced spectroscopy as well as magnetic rotation spectroscopy lead to unprecedented sensitivity and specificity. The current detection limits of our laser spectroscopic approaches are in the picomolar to nanomolar range, depending on the molecular compound. The time resolution of the measurements is down to the sub-second range. This very high sensitivity and time resolution open up exciting perspectives for novel analytical tasks in biomedical research and clinical diagnosis.     

Recent developments in potentiometric biosensors for biomedical analysis

A large variety of potentiometric biosensors is developed using biocatalytic and bioaffinity-based biosensing schemes. However, only few of them could be applied for the biomedical analysis. The most promising are those for the detection of main products of protein metabolism, namely urea and creatinine. A novel group of potentiometric biosensors is constituted by bioaffinity-based devices that could be used for immunoassays or genoanalysis. This paper reviews the recent trends in these fields as well as discusses advantages, limitations and pitfalls of the developed biosensors. Some potentiometric biosensors useful for real biomedical analysis are reported in detail.     

Carbon Nanomaterials for Targeted Cancer Therapy Drugs: A Critical Review

Cancer represents one of the main causes of human death in developed countries. Most current therapies, unfortunately, carry a number of side effects, such as toxicity and damage to healthy cells, as well as the risk of resistance and recurrence. Therefore, cancer research is trying to develop therapeutic procedures with minimal negative consequences. The use of nanomaterial‐based systems appears to be one of them. In recent years, great progress has been made in the field using nanomaterials with high potential in biomedical applications. Carbon nanomaterials, thanks to their unique physicochemical properties, are gaining more and more popularity in cancer therapy. They are valued especially for their ability to deliver drugs or small therapeutic molecules to these cells. Through surface functionalization, they can specifically target tumor tissues, increasing the therapeutic potential and significantly reducing the adverse effects of therapy. Their potential future use could, therefore, be as vehicles for drug delivery. This review presents the latest findings of research studies using carbon nanomaterials in the treatment of various types of cancer. To carry out this study, different databases such as Web of Science, PubMed, MEDLINE and Google Scholar were employed. The findings of research studies chosen from more than 2000 viewed scientific publications from the last 15 years were compared.     

Molecular Assembly of Polysaccharide‐Based Microcapsules and Their Biomedical Applications

Advanced multifunctional microcapsules have revealed great potential in biomedical applications owing to their tunable size, shape, surface properties, and stimuli responsiveness. Polysaccharides are one of the most acceptable biomaterials for biomedical applications because of their outstanding virtues such as biocompatibility, biodegradability, and low toxicity. Many efforts have been devoted to investigating novel molecular design and efficient building blocks for polysaccharide‐based microcapsules. In this Personal Account, we first summarize the common features of polysaccharides and the main principles of the design and fabrication of polysaccharide‐based microcapsules, and further discuss their applications in biomedical areas and perspectives for future research.     

Advances in single-particle detection for DNA sensing

Rapid, accurate and sensitive detection of particular DNA sequence is critical in fundamental biomedical research and clinical diagnostics. However, conventional approaches for DNA assay often suffer from cumbersome procedures, long analysis time and insufficient sensitivity. Recently, single-particle detection technology has emerged as a powerful tool in the biosensing area due to its significant advantages of ultrahigh sensitivity, low sample-consumption and rapid analysis time. Especially, the introduction of novel nanomaterials has greatly promoted the development of single-particle detection and its applications for DNA sensing. In this review, we summarize the recent advance in single-particle detection strategies for DNA sensing, and focus mainly on metallic nanoparticle-and semiconductor quantum dot-based single-particle detection. We highlight the emerging trends in this field as well.     

A new class of silica cross-linked micellar core-shell nanoparticles

Micellar nanoparticles made of surfactants and polymers have attracted wide attention in the materials and biomedical community for controlled drug delivery, molecular imaging, and sensing; however, their long-term stability remains a topic of intense study. Here we report a new class of robust, ultrafine silica core-shell nanoparticles formed from silica cross-linked, individual block copolymer micelles. Compared with pure polymeric micelles, the main advantage of the new core-shell nanoparticles is that they have significantly improved stability and do not break down during dilution. We also studied the drug loading and release properties of the silica cross-linked micellar particles, and we found that the new core-shell nanoparticles have a slower release rate which allows the entrapped molecules to be slowly released over a much longer period of time under the same experimental conditions. A range of functional groups can be easily incorporated through co-condensation with the silica matrix. The potential to deliver hydrophobic agents into cancer cells has been demonstrated. Because of their unique structures and properties, these novel core-shell nanoparticles could potentially provide a new nanomedicine platform for imaging, detection, and treatment, as well as novel colloidal particles and building blocks for mutlifunctional materials.     

Prostatic Zn determination for prostate cancer diagnosis

We present our studies of prostatic Zn concentration measurements, carried out in the light of a novel prostate cancer (CAP) diagnosis method proposed by us. The method is based on in vivo prostatic Zn mapping by XRF trans-rectal probe.

We report on the extensive clinical studies, intended to assess the validity of the novel proposed diagnostic method. Zn content was measured in vitro in needle-biopsy samples from several hundreds of patients, and was correlated with histological findings and other patient parameters. For this purpose, a technique of absolute Zn content determination in 1 mm³ fresh tissue samples by XRF was developed. The experimental details and the main clinical-evaluation results are presented.

We further outline the suggested design of the XRF trans-rectal probe for an efficient in vivo detection and mapping of the Zn fluorescence radiation from the prostate through the rectal wall. Laboratory phantom studies, a preliminary design concept and its expected performance are also reported.     

Nanoprobes in biomedical detection

Environmental problems caused by the development of nanotechnology have threatened human health. Investigating the biomedical effects of nanomaterials can help to solve these environmental safety issues. In studies on the biomedical effects of nanomaterials, several types of novel nanoscale probes that allow reliable, sensitive, accurate and rapid biomedical detection have emerged. We summarize recent developments in three categories of these nanoprobes, including noble metal nanocluster probes, carbon-based nanostructured probes, and unnatural amino acid-based probes. Besides reviewing the utility of different nanoprobes in cell imaging and protein detection, we also discuss the molecular mechanism of nanoprobe detection. Perspectives of novel nanoprobe design based on molecular details of biomedical detection are presented.     

Volatile Organic Compound Based Probe for Induced Volatolomics of Cancers

The development of efficient protocols for cancer diagnosis remains highly challenging. An emerging approach relies on the detection in exhaled breath of volatile organic compounds (VOC) produced by tumours. In this context, described here is a novel strategy in which a VOC‐based probe is converted selectively in malignant tissues, by a tumour‐associated enzyme, for releasing the corresponding VOC. The latter is then detected in the exhaled breath as a tumour marker for cancer diagnosis. This approach allows the detection of several different tumours in mice, the monitoring of tumour growth and tumour response to chemotherapy. Thus, the concept of “induced volatolomics” provides a new way to explore biological processes using VOC‐based probes that could be adapted to many biomedical applications.     

Assays for human telomerase activity: progress and prospects

Human telomerase is a ribonucleoprotein complex that functions as a telomere terminal transferase by adding multiple TTAGGG hexamer repeats using its integral RNA as the template. There is a very strong association between telomerase activity and malignancy in nearly all types of cancer, suggesting that telomerase could be used not only as a diagnostic and prognostic marker but also as a therapeutic target for managing cancer. The significant progress in biomedical telomerase research has necessitated the development of new bioanalytical methods for the rapid, sensitive, and reliable detection of telomerase activity in a particular cell or clinical tissue and body fluids. In this review, we highlight some of the latest methods for identifying telomerase activity and inhibition and discuss some of the challenges for designing innovative telomerase assays. We also summarise the current technologies and speculate on future directions for telomerase testing.     

A bibliometric analysis: Research progress and prospects on transition metal dichalcogenides in the biomedical field

Recent years have witnessed the wide contributions made by transition metal dichalcogenides (TMDCs) to various fields, including the biomedical field. Here, to identify and further promote the development of biomedical TMDCs, we provide a bibliometric analysis of literature regarding TMDCs for biomedical applications. Firstly, general bibliometric distributions of the dataset by year, country, institute, Web of Science category and referenced source are recognized. Following, we carefully explore the research hotspots of the TMDC-related biomedical field, among which biosensing, bioelectronics, cancer theranostics, antibacterial and tissue engineering are identified. The functions of TMDCs in each biomedical scenario, the related properties and research challenges are highlighted. Finally, future prospects are proposed to shed light on the design of novel TMDC-related biomaterials, potential new biomedical applications, as well as their clinical translation.     

A novel sensing platform using aptamer and RNA polymerase-based amplification for detection of cancer cells

Cancer is one of the most serious and lethal diseases around the world. Its early detection has become a challenging goal. To address this challenge, we developed a novel sensing platform using aptamer and RNA polymerase-based amplification for the detection of cancer cells. The assay uses the aptamer as a capture probe to recognize and bind the tumor marker on the surface of the cancer cells, forming an aptamer-based sandwich structure for collection of the cells in the microplate wells, and uses SYBR Green II dye as a tracer to produce strong fluorescence signal. The tumor marker interacts first with the recognition probes which were composed of the aptamer and single-stranded T7 RNA polymerase promoter. Then, the recognition probe hybridized with template probes to form a double-stranded T7 RNA polymerase promoter. This dsDNA region is extensively transcribed by T7 RNA polymerase to produce large amounts of RNAs, which are easily monitored using the SYBR Green II dye and a standard fluorometer, resulting in the amplification of the fluorescence signal. Using MCF-7 breast cancer cell as the model cell, the present sensing platform showed a linear range from 5.0 × 10² to 5.0 × 10⁶ cells mL⁻¹ with a detection limit of 5.0 × 10² cells mL⁻¹. This work suggested a strategy to use RNA signal amplification combining aptamer recognition to develop a highly sensitive and selective method for cancer cells detection.     

Recent advances in miniaturized microfluidic flow cytometry for clinical use

This article provides an overview of recent research achievements in miniaturized flow cytometry. The review focuses on chip-based microfluidic flow cytometers, classified by cell transport method, detection technology, and biomedical application. By harnessing numerous ideas and cutting-edge microfabrication technologies, microfluidic flow cytometry benefits from ever-increasing functionalities and the performance levels achieved make it an attractive biomedical research and clinical tool. In this article, we briefly describe an update of recent developments that combine novel microfluidic characteristics and flow cytometry on chips that meet biomedical needs.     

基于Cy7类菁染料分子探针的设计策略

菁染料是一类经典的荧光染料母核, 具有摩尔消光系数大、 吸收波长可调、 溶解性良好及生物兼容性好等优点, 被广泛用于蛋白标记、 痕量金属离子检测、 生物活性物质检测、 细胞和活体成像及肿瘤靶向治疗等领域. 近年来, 生物医学领域对活体结构及功能成像深度提出更高的需求, 基于优异的长波长染料母核开发近红外荧光分子探针逐渐成为领域的研究重点. 吲哚七甲川菁染料(Cy7)是一类最具代表性的菁染料, 本文重点综合评述了自1992年以来基于Cy7结构开发的分子探针, 并介绍了该类荧光探针的设计策略. 最后, 讨论了该领域研究面临的挑战, 并对未来的发展方向进行了总结和展望.     

In-tip nanoreactors for cancer cells proteome profiling

Mass spectrometry (MS)-based proteome profiling is essential for molecular diagnostics in modern biomedical study. To date, sample preparation including protein extraction and proteolysis is still very challenging and lack of efficiency. Recently tips-based sample preparation protocols exhibit strong potentials to achieve the goal of “a proteome in an hour”. However, in-tip proteolysis is still rarely reported and far from ideal for dealing with complex bio-samples. In this work, nanoreactors encapsulated micropipette tips were demonstrated as high performance devices for fast (∼minutes) and multiplexing proteolysis to assist the profiling of cancer cells proteome. Nanoporous silica materials with controlled pore size and surface chemistry were prepared as nanoreactors and encapsulated in micropipette tips for efficient in situ proteolysis. The as-constructed device showed desirable sensitivity (LOD of 0.204 ± 0.008 ng/μL and LOQ of 0.937 ± 0.055 ng/μL), selectivity, stability (two months under −20 °C), reusability (at least 10 times), and little memory effect in MS based bottom-up proteomic analysis. It was used for comprehensive protein mapping from cancer cell lines. The number of identified proteins was increased by 18%, 22%, 52%, and 52% dealing with HepG2, F56, MCF7, and HCCLM3 cancer cells, compared to traditional in-solution proteolysis based bottom-up proteomic strategy. With the enhanced performance, our work built a novel, efficient and miniaturized platform for facile proteomic sample preparation, which is promising for advanced biomarkers discovery in biomedical study.     

Electrochemical aptamer-based assays coupled to isothermal nucleic acid amplification techniques: New tools for cancer diagnosis

Highly sensitive detection of cancer biomarkers in blood is key not only to find cancer at an early stage but also to help clinicians to decide the best treatment plan and to find how well treatment is working. To quantify the small changes in clinically validated biomarkers associated with carcinogenesis both selective receptors and signal amplification strategies of the recognition event between the receptor and the biomarker are highly in demand. This report covers the most recent developments in the integration of aptamer-based recognition of blood-circulating cancer biomarkers and isothermal nucleic acid amplification platforms with electrochemical readout, highlighting the potential of these novel tools, and the challenges to translate these assays to the clinical practice.     

Detection of DNA hybridization on chemically modified graphene platforms

The increasing demand for simple, low-cost, rapid, sensitive and label-free methods for the detection of DNA sequences and the presence of single nucleotide polymorphisms (SNPs) has become an important issue in biomedical research. In this work, we studied the performances of several chemically modified graphene nanomaterials as sensing platforms by using the electrochemical impedance spectroscopy technique for the detection. We employed a hairpin DNA as a highly selective probe for the detection of SNP correlated to Alzheimer's disease. We believe that our findings may present a foundation for further research and development in graphene-based impedimetric biosensing.     

Electrochemical Biosensors for Cancer Biomarker Detection

Cancer is still one of the leading causes of death in the world. There are over 200 types of cancers currently known according to the National Cancer Institute. However, early diagnosis continues to be an important integral part of cancer treatment even though many advances in therapeutics have been made in the past decade. Quick diagnosis and early prevention are critical for the control of the disease status. Biomarkers are commonly indicative of a particular disease process and the cancer biomarkers are also widely used in oncology to help detecting the presence of various carcinomas. The detection of cancer biomarkers plays an important role in clinical diagnoses and evaluation of treatment for patients. Many immunoassay methods are developed for detection of cancer biomarkers. As the detection devices are normally viewed with high sensitivity, simple preparation and rapid response, electrochemical biosensors are increasingly used for the detection of cancer markers. This review describes the status, the latest research and trends of electrochemical sensors in the quantitation of cancer markers in recent years. In particular, the strategy to improve the sensitivities of the electrochemical biosensors by the aid of enzymatic amplification, nanoparticle amplification, ultilization of magnetic microspheres etc. is described herein. At last, we discuss some special features and limitations associated with the described systems that summarize the application and the development prospects of electrochemical immunoassay technology.