Recent progress in the early detection of cancer based on CD44 biomarker; nano-biosensing approaches

A self-catalytic UCNP-based nanomachine activated by duplex DNA for highly sensitive detection of CTCs

Detection of circulating tumor cells (CTCs) has proven to be a crucial approach for early diagnosis, prognosis, and monitoring of cancer treatment. However, due to the low abundance of CTCs in blood, achieving accurate detection in the presence of a large number of blood cells remains challenging. In this study, we present a novel self-catalytic nanomachine for quantitative detection of CTCs, which includes a dual aptamer-triggered Catalytic Hairpin Assembly (CHA) reaction and subsequent UCNP-DNA-based biosensing. The dual-aptamer recognition, the two-step CHA reaction and the UCNP ratiometric sensing luminescence provide the assay with high specificity and sensitivity. Using MDA-MB-231 cells as model targets, the proposed detection system affords a wide linear detection range and a detection limit as low as 3 cells. Our system offers sensitive detection of CTCs without the need for enzymatic involvement, indicating its substantial potential for early cancer diagnosis and treatment based on CTCs.

The role of green synthesis metal and metal oxide nanoparticles in oral cancer therapy: a review

There are 275,000 new cases of oral cancer (OC) per year, making it the sixth most common cancer in the world. Severe adverse effects, including loss of function, deformity, and systemic toxicity, are familiar with traditional therapies such as radiation, chemotherapy, and surgery; due to their unique properties, nanoparticles (NPs) have emerged as a superior alternative over chemo/radiotherapy and surgery due to their targeting capability, bioavailability, compatibility, and high solubility. Due to their unique properties, metallic NPs have garnered significant attention in OC control. In addition to the fact that metal NPs may be harmful to human cells, the reactive chemicals used to make them pose the same risk, which limits their use in medicine. Green synthesis (GS) is a novel strategy that uses biological materials like yeast, bacteria, fungi, and plant extracts. Compared to more traditional chemical synthesis processes, these are more environmentally benign and manageable for living organisms. This article summarises the GS of NPs made of metals and metal oxides and their anticancer effects on OC. The method's potential benefits and drawbacks in advancing metallic NPs' GS and shaping OC therapy's future were also discussed.

Cubosomes-based hydrogels; A promising advancement for drug delivery

Hydrogels have so far shown promising opportunities for possible drug delivery applications. Cubosomes (Cub), bicontinuous cubic phase liquid crystals, possess several characteristics that make them appealing as a versatile medium for drug administration. They have been regarded as prospective nanocarriers for drugs, offering a promising alternative to liposomes as a drug delivery method. Cub have the ability to encapsulate lipophilic, hydrophilic, and amphiphilic medicines. Hydrogels have recently shown significant interest in using Cub-based formulations. This paper examines the current advancements in biodegradable Cub-based hydrogels (Cubogel) for intelligent medication delivery to various organs. In conclusion, this paper briefly discusses the prospects and problems of hydrogels based on Cub.

Dual-Functionalized Glass Micropipette Sensor for Simultaneous High Sensitivity Detection of Cancer Biomarkers

Early cancer detection is crucial for improving patient survival rates. However, current single-biomarker detection methods often face challenges, such as insufficient sensitivity, poor accuracy, and false positives. To address these issues, we report a dual-functionalized glass micropipet sensor (DFMS) capable of simultaneously detecting two cancer biomarkers, nucleic acids and proteins. The inner surface of the sensor is functionalized with amino-modified silicon nanowires (SiNWs) to capture disease-related miRNAs, enabling ionic-current-based detection, while the outer surface is decorated with gold nanoparticles to anchor specific protein aptamers for Raman-based detection. This dual-functionalization significantly enhances the sensitivity and selectivity by combining ionic current amplification with plasmonic Raman signal enhancement. The sensor achieves detection limits of 1 aM for miRNAs and 0.001 ng/mL for proteins, with minimal mutual interference between the two detection modes, ensuring accurate and independent detection. Validation with prostate cancer biomarkers miRNA-1246 and PSA, as well as gastric cancer biomarkers miRNA-106a and CD44, demonstrates its outstanding sensitivity, selectivity, stability, and broad applicability, providing a novel approach for early cancer detection with significant clinical implications.

Facile preparation of iridium-based AIE polymer dots for sensitive electrochemiluminescence immunoassay of CD44 protein

The development of aggregation-induced emission (AIE) luminophores is a fascinating and promising topic in electrochemiluminescence (ECL) bioanalysis. Herein, the AIE-active but water-insoluble [Ir(bt)₂(acac)] (bt = 2-phenylbenzothiazole, acac = acetylacetonate) was encapsulated within poly(styrene-maleic anhydride) (PSMA) using a simple nanoprecipitation method. This encapsulation strategy could effectively limit the free motion of Ir(bt)₂(acac) and trigger the aggregation-induced electrochemiluminescence (AIECL) effect. The water dispersibility and ECL intensity of Ir(bt)₂(acac)-polymer dots (IrPdots) were greatly improved compared to equivalent amounts of Ir(bt)₂(acac) alone. More importantly, unlike Ir(bt)₂(acac), the IrPdots possess carboxyl groups, allowing them to be conjugated with biomolecules for bioanalytical applications. Consequently, a sandwich ECL immunosensor for the sensitive detection of CD44 was constructed using the prepared IrPdots-labeled detection antibody (Ab2) as the ECL probe and polyaniline nanorods (PANI NRs) as the substrate that provided a large electroactive surface for immobilizing capture antibody (Ab1). Under optimized experimental conditions, a good linear relationship was observed between the logarithm of ECL intensity and the CD44 concentration, ranging from 0.1 pg/mL to 50 ng/mL, with a detection limit as low as 77 fg/mL. This work introduces a method for the preparation of Pdots containing AIE-active cyclometallated iridium complexes, potentially broadening the application of these water-insoluble but highly AIE-active iridium complexes in aqueous bioassays.

Visualizing cancer resistance via nano-quenching and recovery detector of CD44

Drug resistance to chemotherapy in cancers remains significant clinical challenges. CD44 modulates cellular adhesion, migration and growth, which plays a pivotal role in driving cancer resistance and even recurrence. Despite ongoing efforts, accurate, safe, and real-time dynamic monitoring techniques for CD44 expression remain inadequate in guiding the management of drug-resistant cancer treatment. In this study, we developed a nano-quenching and recovery detector of CD44 (Cy3-AptCD44@BPNSs) for visualizing cancer drug resistance. The fluorescence recovery of the detector is directly related to the CD44 expression level on cancer cells, which can be used to indicate the degree of drug resistance. It's confirmed that downregulating CD44 expression on cancer cells results in a corresponding decrease in the fluorescence intensity of the detector, which enables precise and dynamic monitoring of CD44. In addition, the Cy3-AptCD44@BPNSs also exhibited specificity in detecting CD44. This visualizing strategy may open up a wide range of possibilities for rapid recognition to cancer drug resistance, which is more efficient and flexible.

Ultrasensitive Electrochemiluminescence Biosensor Based on Efficient Signal Amplification of Copper Nanoclusters Induced by CaMnO3 for CD44 Trace Detection

Metal nanoclusters (Me NCs) have become a research hotspot in the field of electrochemiluminescence (ECL) sensing analysis. This is primarily attributed to their excellent luminescent properties and biocompatibility along with their easy synthesis and labeling characteristics. At present, the application of Me NCs in ECL mainly focuses on precious metals, whose high cost, to some extent, limits their widespread application. In this work, Cu NCs with cathode ECL emissions in persulfate (S2O82-) were prepared as signal probes using glutathione as ligands, which exhibited stable luminescence signals and high ECL efficiency. At the same time, CaMnO3 was introduced as a co-reaction promoter to increase the ECL responses of Cu NCs, thereby further expanding their application potential in biochemical analysis. Specifically, the reversible conversion of Mn3+/Mn4+ greatly promoted the generation of sulfate radicals (SO4•-), providing a guarantee for improving the luminescence signals of Cu NCs. Furthermore, a short peptide (NARKFYKGC) was introduced to enable the fixation of antibodies to specific targets, preventing the occupancy of antigen-binding sites (Fab fragments). Therefore, the sensitivity of the biosensor could be significantly enhanced by releasing additional Fab fragments. Considering the approaches discussed above, the constructed biosensor could achieve sensitive detection of CD44 over a broad range (10 fg/mL-100 ng/mL), with an ultralow detection limit of 3.55 fg/mL (S/N = 3), which had valuable implications for the application of nonprecious Me NCs in biosensing analysis.

Tumor diagnosis using carbon-based quantum dots: Detection based on the hallmarks of cancer

Carbon-based quantum dots (CQDs) have been shown to have promising application value in tumor diagnosis. Their use, however, is severely hindered by the complicated nature of the nanostructures in the CQDs. Furthermore, it seems impossible to formulate the mechanisms involved using the inadequate theoretical frameworks that are currently available for CQDs. In this review, we re-consider the structure-property relationships of CQDs and summarize the current state of development of CQDs-based tumor diagnosis based on biological theories that are fully developed. The advantages and deficiencies of recent research on CQDs-based tumor diagnosis are thus explained in terms of the manifestation of nine essential changes in cell physiology. This review makes significant progress in addressing related problems encountered with other nanomaterials.

Understanding the mechanistic pathways and clinical aspects associated with protein and gene based biomarkers in breast cancer

Cancer is one of the most widespread and severe diseases with a huge mortality rate. In recent years, the second-leading mortality rate of any cancer globally has been breast cancer, which is one of the most common and deadly cancers found in women. Detecting breast cancer in its initial stages simplifies treatment, decreases death risk, and recovers survival rates for patients. The death rate for breast cancer has risen to 0.024 % in some regions. Sensitive and accurate technologies are required for the preclinical detection of BC at an initial stage. Biomarkers play a very crucial role in the early identification as well as diagnosis of women with breast cancer. Currently, a wide variety of cancer biomarkers have been discovered for the diagnosis of cancer. For the identification of these biomarkers from serum or other body fluids at physiological amounts, many detection methods have been developed. In the case of breast cancer, biomarkers are especially helpful in discovering those who are more likely to develop the disease, determining prognosis at the time of initial diagnosis and choosing the best systemic therapy. In this study we have compiled various clinical aspects and signaling pathways associated with protein-based biomarkers and gene-based biomarkers.

Circulating Tumor Cells Adhesion: Application in Biosensors

The early and non-invasive diagnosis of tumor diseases has been widely investigated by the scientific community focusing on the development of sensors/biomarkers that act as a way of recognizing the adhesion of circulating tumor cells (CTCs). As a challenge in this area, strategies for CTCs capture and enrichment currently require improvements in the sensors/biomarker's selectivity. This can be achieved by understanding the biological recognition factors for different cancer cell lines and also by understanding the interaction between surface parameters and the affinity between macromolecules and the cell surface. To overcome some of these concerns, electrochemical sensors have been used as precise, fast-response, and low-cost transduction platforms for application in cytosensors. Additionally, distinct materials, geometries, and technologies have been investigated to improve the sensitivity and specificity properties of the support electrode that will transform biochemical events into electrical signals. This review identifies novel approaches regarding the application of different specific biomarkers (CD44, Integrins, and EpCAm) for capturing CTCs. These biomarkers can be applied in electrochemical biosensors as a cytodetection strategy for diagnosis of cancerous diseases.

Imidazolium-based mass tags for protein biomarker detection using laser desorption ionization mass spectrometry

Novel imidazolium-based mass tags (IMTs) were designed, synthesized and applied to simultaneous in situ analysis of multiple biomarkers on less than 10 cells. The high sensitivity, flexible extensibility and excellent distinguishability of IMTs open new avenues for designing common mass tag templates suitable for mass spectrometric immunoassay and provide an ideal option for multiplex-sensitive detection at the cellular scale.

DNA-Based Nanomaterials as Drug Delivery Platforms for Increasing the Effect of Drugs in Tumors

DNA nanotechnology has significantly advanced and might be used in biomedical applications, drug delivery, and cancer treatment during the past few decades. DNA nanomaterials are widely used in biomedical research involving biosensing, bioimaging, and drug delivery since they are remarkably addressable and biocompatible. Gradually, modified nucleic acids have begun to be employed to construct multifunctional DNA nanostructures with a variety of architectural designs. Aptamers are single-stranded nucleic acids (both DNAs and RNAs) capable of self-pairing to acquire secondary structure and of specifically binding with the target. Diagnosis and tumor therapy are prospective fields in which aptamers can be applied. Many DNA nanomaterials with three-dimensional structures have been studied as drug delivery systems for different anticancer medications or gene therapy agents. Different chemical alterations can be employed to construct a wide range of modified DNA nanostructures. Chemically altered DNA-based nanomaterials are useful for drug delivery because of their improved stability and inclusion of functional groups. In this work, the most common oligonucleotide nanomaterials were reviewed as modern drug delivery systems in tumor cells.

The recent advancement in the PLGA-based thermo-sensitive hydrogel for smart drug delivery

To date, hydrogels have opened new prospects for potential applications for drug delivery. The thermo-sensitive hydrogels have the great potential to provide more effective and controllable release of therapeutic/bioactive agents in response to changes in temperature. PLGA is a safe FDA-approved copolymer with good biocompatibility and biodegradability. Recently, PLGA-based formulation have attracted a lot of interest for thermo-sensitive hydrogels. Thermo-sensitive PLGA-based hydrogels provide the delivery system with good spatial and temporal control, and have been widely applied in drug delivery. This review is focused on the recent progression of the thermo-sensitive and biodegradable PLGA-based hydrogels that have been reported for smart drug delivery to the different organs. Eventually, future perspectives and challenges of thermo-sensitive PLGA-based hydrogels are discussed briefly.

Colloidal Polyelectrolyte Complexes from Hyaluronic Acid: Preparation and Biomedical Applications

Hyaluronic acid (HA) is a naturally occurring polysaccharide which has been extensively exploited in biomedical fields owing to its outstanding biocompatibility. Self-assembly of HA and polycations through electrostatic interactions can generate colloidal polyelectrolyte complexes (PECs), which can offer a wide range of applications while being relatively simple to prepare with rapid and "green" processes. The advantages of colloidal HA-based PECs stem from the combined benefits of nanomedicine, green chemistry, and the inherent properties of HA, namely high biocompatibility, biodegradability, and biological targeting capability. Accordingly, colloidal PECs from HA have received increasing attention in the recent years as high-performance materials for biomedical applications. Considering their potential, this review is aimed to provide a comprehensive understanding of colloidal PECs from HA in complex with polycations, from the most fundamental aspects of the preparation process to their various biomedical applications, notably as nanocarriers for delivering small molecule drugs, nucleic acids, peptides, proteins, and bioimaging agents or the construction of multifunctional platforms.

Electrochemically Exfoliated Graphene Quantum Dots Based Biosensor for CD44 Breast Cancer Biomarker

An innovative electrochemical biosensor based on graphene quantum dots (GQDs) is developed for a simple, rapid, and highly sensitive primary diagnosis of the breast cancer biomarker cluster of differentiation-44 (CD44) antigen. Herein, electrochemical exfoliation of waste dry batteries provides facile, eco-friendly, and cost-effective synthesis of GQDs. Transmission electron microscopy (TEM) analysis reveals that GQDs exhibit spherical shapes with an average diameter of 4.75 nm. Further, electrochemical analysis through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) reveals that the electrochemical properties of GQDs are suitable for biosensing applications. Subsequently, GQDs have a large electroactive surface area that has been utilized for the immobilization of CD44 antibodies to fabricate the electrochemical biosensor. The electroanalytical performance of GQDs for CD44 biosensing capabilities is studied by differential pulse voltammetry (DPV). The developed electrochemical biosensor has high sensitivity with the lowest detection limit (LOD) of 2.11 fg/mL in the linear range of 0.1 pg/mL to 100.0 ng/mL in phosphate buffer saline (PBS). Further, the linear response of the electrochemical biosensor for CD44 antigen concentration is in the range of 1.0 pg/mL to 100.0 ng/mL with a LOD of 2.71 fg/mL in spiked serum samples. The outcomes suggest that the synthesized GQDs demonstrate promising attributes to be utilized as a viable nanomaterial in biosensing applications.

PNA-ATP aptamer-capped doxorubicin-loaded silica nanoparticles for targeted cancer therapy

Nanomaterial-based drug delivery has opened new horizons in cancer therapy. This study aimed to investigate the in vitro and in vivo anti-cancer effects of a hyaluronic acid (HA)-targeted nanocarrier based on hollow silica nanoparticles (HSNPs), gated with peptide nucleic acid (PNA) and ATP aptamer (ATP_Apt) and loaded with doxorubicin (DOX). After formulation of a smart drug delivery nanosystem (HSNPs/DOX/ATP_Apt/PNA/HA), drug release, cytotoxicity, uptake, and in vivo anti-tumor properties were studied. Drug release test showed the controlled release of encapsulated DOX in response to ATP content. MTT and flow cytometry indicated that HA could improve both cytotoxicity and cellular uptake of the formulation. Moreover, HA-targeted formulation enhanced both the survival rate and tumor inhibition in the tumor-bearing mice compared with free DOX (P < 0.05). Our findings confirmed that HA-targeted nanoformulation, gated with PNA/aptamer and loaded with DOX can provide a novel therapeutic platform with great potential for cancer therapy.

Hyaluronic Acid within Self-Assembling Nanoparticles: Endless Possibilities for Targeted Cancer Therapy

Self-assembling nanoparticles (SANPs) based on hyaluronic acid (HA) represent unique tools in cancer therapy because they combine the HA targeting activity towards cancer cells with the advantageous features of the self-assembling nanosystems, i.e., chemical versatility and ease of preparation and scalability. This review describes the key outcomes arising from the combination of HA and SANPs, focusing on nanomaterials where HA and/or HA-derivatives are inserted within the self-assembling nanostructure. We elucidate the different HA derivatization strategies proposed for this scope, as well as the preparation methods used for the fabrication of the delivery device. After showing the biological results in the employed in vivo and in vitro models, we discussed the pros and cons of each nanosystem, opening a discussion on which approach represents the most promising strategy for further investigation and effective therapeutic protocol development.