Search Results (285)

Foodborne pathogenic bacteria critically threaten public health and food industry sustainability, serving as a predominant trigger of food contamination incidents. To mitigate these risks, the development of rapid, sensitive, and highly specific detection technologies is essential for early warning and effective control of foodborne diseases. In recent years, biosensors have gained prominence as a cutting-edge tool for detecting foodborne pathogens, owing to their operational simplicity, rapid response, high sensitivity, and suitability for on-site applications. This review provides a comprehensive evaluation of critical biorecognition elements, such as antibodies, aptamers, nucleic acids, enzymes, cell receptors, molecularly imprinted polymers (MIPs), and bacteriophages. We highlight their design strategies, recent advancements, and pivotal contributions to improving detection specificity and sensitivity. Additionally, we systematically examine mainstream biosensor-based detection technologies, with a focus on three dominant types: electrochemical biosensors, optical biosensors, and piezoelectric biosensors. For each category, we analyze its fundamental principles, structural features, and practical applications in food safety monitoring. Finally, this review identifies future research priorities, including multiplex target detection, enhanced processing of complex samples, commercialization, and scalable deployment of biosensors. These advancements are expected to bridge the gap between laboratory research and real-world food safety surveillance, fostering more robust and practical solutions. Full article

Tumor immunotherapy has revolutionized cancer treatment by harnessing the immune system to recognize and eliminate malignant cells, with immune checkpoint inhibitors targeting programmed death receptor 1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) demonstrating remarkable clinical success. However, challenges such as treatment resistance, immune-related adverse effects, and high costs highlight the need for novel therapeutic approaches. Aptamers, short, single-stranded oligonucleotides with high specificity and affinity for target molecules, have emerged as promising alternatives to conventional antibody-based therapies. This review provides a comprehensive analysis of aptamer-based strategies targeting immune checkpoints, with a particular focus on PD-1/PD-L1 and CTLA-4. We summarize recent advances in aptamer design, including bispecific and multifunctional aptamers, and explore their potential in overcoming immune resistance and improving therapeutic efficacy. Additionally, we discuss strategies to enhance aptamer stability, bioavailability, and tumor penetration through chemical modifications and nanoparticle conjugation. Preclinical and early clinical studies have demonstrated that aptamers can effectively block immune checkpoint pathways, restore T-cell activity, and synergize with other immunotherapeutic agents to achieve superior anti-tumor responses. By systematically reviewing the current research landscape and identifying key challenges, this review aims to provide valuable insights into the future directions of aptamer-based cancer immunotherapy, paving the way for more effective and personalized treatment strategies. Full article

Shaking off the forgetfulness towards the methodological power of inosine-mediated error-prone PCR (epPCR), this study reintroduces an often-underappreciated method as a considerably powerful approach for generating aptamer libraries from a single decameric ATCG-repeat-oligonucleotide. The aim was to demonstrate that this simple way of creating sequence diversity was suitable for delivering functional starting libraries for a set of ten whole-cell-SELEX (Systematic Evolution of Ligands by Exponential Enrichment) processes. This epPCR method uses inosine to introduce targeted mutations, avoiding the need for commercial oligo pools or large-scale synthesis. We applied this method to a “universal aptamer” and subjected the three resulting libraries to two rounds of selection against ten diverse targets including probiotic and pathogenic bacteria (Gram-negative and -positive) as well as human cell lines. The enriched aptamers exhibited new binding specificities, demonstrating that the approach supports functional selection. Much like dusting off an old tool and finding it perfectly suited for a modern task, this work shows that revisiting established techniques can address current challenges in aptamer development. Our main finding is that epPCR provides a robust, cost-effective strategy for generating starting libraries and lowers the barrier for initiating successful SELEX campaigns. Full article

Positron emission tomography (PET) imaging targeting glypican-3 (GPC3) holds promise for improving the detection and characterization of hepatocellular carcinoma (HCC). Preclinical and early clinical studies have largely utilized high-molecular-weight antibodies radiolabeled with isotopes such as ⁸⁹Zr and ¹²⁴I, demonstrating high affinity and tumor uptake but suffering from prolonged circulation times and suboptimal signal-to-background ratios. To address these limitations, interest has shifted toward low-molecular-weight vectors—synthetic peptides and small antibody fragments—labeled with shorter-lived radionuclides (e.g., ⁶⁸Ga and ¹⁸F) to enable rapid pharmacokinetics and same-day imaging protocols. Emerging platforms such as affibodies and aptamers offer further advantages in target affinity and reduced immunogenicity. However, clinical translation requires rigorous validation: larger, histologically confirmed cohorts, head-to-head comparison with CT/MRI, and correlation with hard clinical endpoints. Moreover, leveraging GPC3 expression as a biomarker could guarantee a deeper knowledge of tumor biology—differentiation grade and vascular invasion risk—and guide theranostic strategies. While β-emitters (⁹⁰Y, ¹⁷⁷Lu) have been explored for GPC3-directed therapy, their efficacy is influenced by oxygenation and cell-cycle status, whereas α-emitters (²²⁵Ac) may overcome these constraints, albeit with challenges in radionuclide selection and daughter nuclide management. Finally, dual-targeting probes combining GPC3 and prostate-specific membrane antigen (PSMA) have demonstrated superior uptake and retention in murine models, suggesting a versatile approach for future clinical diagnostics and therapy planning. Full article

Background: Cell membrane proteins play crucial roles in signal transduction and nutrient transport. Many membrane proteins are reportedly overexpressed in cancer cells, which is closely related to cancer progression. The targeted degradation of these membrane proteins has been demonstrated to be a promising strategy for tumor treatment. Several strategies using aptamers to mediate membrane protein lysis, such as lysosomal-mediated lysis and proteasome-mediated lysis, have been reported, but their efficiency is limited by the binding affinity of the aptamer to a single target. Methods: We constructed DNA tweezers with replaceable clamps, which can lyse different proteins upon clamp replacement. Moreover, the clamp improved the degradation efficiency of the target proteins by enhancing the specificity and improving the binding affinity. Results: Lysis was verified in different tumor cell lines and the antitumor activity was confirmed in zebrafish. Conclusions: Overall, these DNA tweezers improve the efficiency of the targeted delivery of functional nucleic acids, provide an efficient and versatile strategy for the degradation of disease-causing proteins, and expand the approach to antitumor therapy. Full article

Nucleic acid aptamers, selected through the Systematic Evolution of Ligands by Exponential Enrichment (SELEX), are short nucleic acid sequences that exhibit high affinity and specificity towards diverse targets. Over the past three decades, substantial advancements have been made in both the technology and applications of nucleic acid aptamers. This review provides an in-depth analysis of the historical development and defining characteristics of aptamers, highlighting recent technological innovations in SELEX, including Capillary Electrophoresis SELEX, Microfluidic SELEX, Cell-SELEX, and others. We explore the applications of aptamers in therapeutic and targeted drug delivery, emphasizing their advantages over traditional antibodies such as cost-effectiveness, ease of synthesis, and lower immunogenicity. Key challenges such as stability, specificity, and efficient delivery are discussed, with proposed strategies for improvement including advanced chemical modifications and integration with nanotechnology. By integrating advanced technologies, aptamers hold significant promise for enhancing precision medicine and personalized therapeutic interventions, offering new avenues for the treatment of complex diseases. Full article

Aptamers are synthetic nucleic acids or peptides that exhibit high specificity and affinity for target molecules such as small molecules, proteins, or cells. Due to their ability to bind precisely to these targets, aptamers have found widespread use in bioanalytical and diagnostic applications. Rolling circle amplification (RCA) is an amplification technique that utilizes DNA or RNA templates, where circular primers are extended by polymerases to generate multiple repeated sequences, enabling highly sensitive detection of target molecules. The integration of aptamers with RCA offers significant advantages, enhancing both the specificity and sensitivity of detection while ensuring a fast and straightforward process. This synergy has already been widely applied across various fields, including fluorescence, microfluidics, visualization, and electrochemical technologies. Examples include molecular probe development, rapid detection of disease biomarkers, and environmental monitoring. Looking ahead, the aptamer-RCA platform holds great promise for advancing early disease diagnosis, precision medicine, and the development of nanosensors, driving innovation and new applications in these fields. Full article

Glioblastoma (GBM) is the most aggressive and challenging brain cancer, in terms of diagnosis and therapy. The highly infiltrative glioblastoma stem cells (GSCs) are difficult to visualize and surgically remove with the current diagnostic tools, which often lead to misdiagnosis and false-positive results. In this study, we focused on a groundbreaking tool for specifically visualizing and removing GSCs. We exploited the specific binding of A40s aptamer to EphA2 for the selective delivery of Near-Infrared Dyes (NIR-Dyes), like IR700DX and ICG, both in vitro and in vivo. The A40s aptamer, engineered through the NIR-Dye conjugation, did not affect aptamer binding ability; indeed, A40s-NIR-Dye conjugates bound GLI261 stem-like cells and patient-derived GSCs in vitro; moreover, they induced cell death upon photodynamic therapy treatment (PDT). Additionally, when systemically administrated, the A40s-NIR-Dye conjugates allowed GSC visualization and accumulated in tumor mass. This allows GSCs detection and treatment. Our findings demonstrate the potential use of A40s aptamer as a targeted therapeutic approach and imaging tool in vivo for GSCs, paving the way for improved, more effective, and less invasive GBM management. Full article

Oligonucleotides (ODNs) such as siRNA, saRNA, and miRNA regulate gene expression through a variety of molecular mechanisms and show unique potential in the treatment of genetic diseases and rare diseases, but their clinical application is still limited by the efficiency of the delivery system, especially the problem of the insufficient targeting of extrahepatic tissues. As homologous nucleic acid molecules, aptamers have become a key tool to improve the targeted delivery of ODNs. Aptamer–ODN chimeras can not only bind to multiple proteins on the cell surface with high specificity and selectivity, but they can also internalize into cells. Furthermore, they outperform traditional delivery systems in terms of cost-effectiveness and chemical modification flexibility. This review systematically summarizes the origin and progress of aptamer–ODN chimera therapy, discusses some innovative design strategies, and proposes views on the future direction of aptamer-ODN chimeras. Full article

Nano-luciferase binary technology (NanoBiT)-based pseudoviral sensors are innovative tools for monitoring viral infection dynamics. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells via its trimeric surface spike protein, which binds to the human angiotensin-converting enzyme II (hACE2) receptor. This interaction is crucial for viral entry and serves as a key target for therapeutic interventions against coronavirus disease 2019 (COVID-19). Aptamers, short single-stranded DNA (ssDNA) or RNA molecules, are highly specific, high-affinity biorecognition elements for detecting infective pathogens. Despite their potential, optimizing viral infection assays using traditional protein–protein interaction (PPI) methods often face challenges in optimizing viral infection assays. In this study, we selected and evaluated aptamers for their ability to interact with viral proteins, enabling the dynamic visualization of infection progression. The NanoBiT-based pseudoviral sensor demonstrated a rapid increase in luminescence within 3 h, offering a real-time measure of viral infection. A comparison of detection technologies, including green fluorescent protein (GFP), luciferase, and NanoBiT technologies for detecting PPI between the pseudoviral spike protein and hACE2, highlighted NanoBiT’s superior sensitivity and performance, particularly in aptamer selection. This bioluminescent system provides a robust, sensitive, and early-stage quantitative approach to studying viral infection dynamics. Full article

Efficient bacterial lysis and RNA purification are essential for molecular diagnostics and biosensing applications. This study presents a piezoelectric platform integrated with gold-plated RNA capture pins (RCPs) functionalized with synthetic oligonucleotides to extract and enrich E. coli 16S ribosomal RNA (rRNA). The 3D-printed device enables selective bacterial capture using E. coli-specific aptamers and incorporates a piezoelectric transducer operating at 60 kHz to facilitate bacterial cell wall disruption. The platform demonstrated high specificity for E. coli over B. cereus, confirming aptamer selectivity. E. coli viability assessment demonstrated that positioning the piezoelectric plate in contact with the bacterial suspension significantly improved the bacterial lysis, reducing viability to 33.68% after 15 min. RNA quantification confirmed an increase in total RNA released by lysed E. coli, resulting in 10,913 ng after 15 min, compared to 4310 ng obtained via conventional sonication. RCP-extracted RNA has a threefold enrichment of 16S rRNA relative to 23S rRNA. RT-qPCR analysis indicated that the RCPs recovered, on average, 2.3 ng of 16S RNA per RCP from bacterial suspensions and 0.1 ng from aptamer-functionalized surfaces. This integrated system offers a rapid, selective, and label-free approach for bacterial lysis, RNA extraction, and enrichment for specific types of RNA with potential applications in clinical diagnostics and microbial biosensing. Full article

Tumor metastasis, the spread of cancer cells from the primary site to distant organs, remains a formidable challenge in oncology. Central to this process is the involvement of subcellular organelles, which undergo significant functional and structural changes during metastasis. Targeting these specific organelles offers a promising avenue for enhanced drug delivery and metastasis therapeutic efficacy. This precision increases the potency and reduces potential off-target effects. Moreover, by understanding the role of each organelle in metastasis, treatments can be designed to disrupt the metastatic process at multiple stages, from cell migration to the establishment of secondary tumors. This review delves deeply into tumor metastasis processes and their connection with subcellular organelles. In order to target these organelles, biomembranes, cell-penetrating peptides, localization signal peptides, aptamers, specific small molecules, and various other strategies have been developed. In this review, we will elucidate targeting delivery strategies for each subcellular organelle and look forward to prospects in this domain. Full article

CD44, a pivotal cell surface molecule, plays a crucial role in many cellular functions, including cell-cell interactions, adhesion, and migration. It serves as a receptor for hyaluronic acid and is involved in lymphocyte activation, recirculation, homing, and hematopoiesis. Moreover, CD44 is a commonly used cancer stem cell marker associated with tumor progression and metastasis. The development of CD44 aptamers that specifically target CD44 can be utilized to target CD44-positive cells, including cancer stem cells, and for drug delivery. Building on the primary sequences of our previously selected thioaptamers (TAs) and observed variations, we developed a bead-based X-aptamer (XA) library by conjugating drug-like ligands (X) to the 5-positions of certain uridines on a complete monothioate backbone. From this, we selected an XA with high affinity to the CD44 hyaluronic acid binding domain (HABD) from a large combinatorial X-aptamer library modified with N-acetyl-2,3-dehydro-2-deoxyneuraminic acid (ADDA). This XA demonstrated an enhanced binding affinity for the CD44 protein up to 23-fold. The selected CD44 X-aptamers (both amine form and ADDA form) also showed enhanced binding affinity to CD44-overexpressing human ovarian cancer IGROV cells. Secondary structure predictions of CD44 using MFold identified several binding motifs and smaller constructs of various stem-loop regions. Among our identified binding motifs, X-aptamer motif 3 and motif 5 showed enhanced binding affinity to CD44-overexpressing human ovarian cancer IGROV cells with ADDA form, compared to the binding affinities with amine form and scrambled sequence. The effect of ADDA as a binding affinity enhancer was not uniform within the aptamer, highlighting the importance of optimal ligand positioning. The incorporation of ADDA not only broadened the XA’s chemical diversity but also increased the binding surface area, offering enhanced specificity. Therefore, the strategic use of site-directed modifications allows for fine-tuning aptamer properties and offers a flexible, generalizable framework for developing high-performance aptamers that target a wide range of molecules. Full article

The notion of RNA-based therapeutics has gained wide attractions in both academic and commercial institutions. RNA is a polymer of nucleic acids that has been proven to be impressively versatile, dating to its hypothesized RNA World origins, evidenced by its enzymatic roles in facilitating DNA replication, mRNA decay, and protein synthesis. This is underscored through the activities of riboswitches, spliceosomes, ribosomes, and telomerases. Given its broad range of interactions within the cell, RNA can be targeted by a therapeutic or modified as a pharmacologic scaffold for diseases such as nucleotide repeat disorders, infectious diseases, and cancer. RNA therapeutic techniques that have been researched include, but are not limited to, CRISPR/Cas gene editing, anti-sense oligonucleotides (ASOs), siRNA, small molecule treatments, and RNA aptamers. The knowledge gleaned from studying RNA-centric mechanisms will inevitably improve the design of RNA-based therapeutics. Building on this understanding, we explore the physiological diversity of RNA functions, examine specific dysfunctions, such as splicing errors and viral interactions, and discuss their therapeutic implications. Full article

Background/Objectives: Traditional paclitaxel therapy often results in significant side effects due to its non-specific targeting of cancer cells. Peptide aptamer–paclitaxel conjugates present a promising alternative by covalently attaching paclitaxel to a versatile peptide aptamer via a linker. Compared to antibody–paclitaxel conjugates, peptide aptamer–paclitaxel conjugates offer several advantages, including a smaller size, lower immunogenicity, improved tissue penetration, and easier engineering. Methods: This review provides an in-depth analysis of the multifunctional peptide aptamers in these conjugates, emphasizing their structural features, therapeutic efficacy, and challenges in clinical applications. Results: This analysis highlights the potential of peptide aptamer–paclitaxel conjugates as a novel and effective approach for targeted cancer therapy. By harnessing the unique properties of peptide aptamers, these conjugates demonstrate significant promise in improving drug delivery efficiency while reducing the adverse effects associated with traditional paclitaxel therapy. Conclusions: The incorporation of peptide aptamers into paclitaxel conjugates offers a promising pathway for developing more efficient and targeted cancer therapies. However, further research and clinical studies are essential to fully unlock the therapeutic potential of these innovative conjugates and enhance patient outcomes. Full article