Search Results (150)

In the last half-century, capillary gel electrophoresis (CGE) became a versatile and high-performance analytical platform for the separation of complex biomolecular mixtures featuring rapid separations, high efficiency, and small sample consumption. Integrating a pore-size gradient mechanism in CGE makes it possible to achieve enhanced selectivity of polyionic macromolecules such as SDS-proteins and nucleic acids. This review provides a comprehensive overview of the theoretical foundations and operational principles of capillary pore-size gradient gel electrophoresis (CGGE), including the physicochemical basis of gradient formation, the influence of pore-size distributions on analyte mobility, and the challenges of generating stable, reproducible gradients in narrow-bore capillaries. Instrumental considerations such as capillary surface treatment, gradient filling and polymerization strategies, temperature and voltage control, detection modalities, and method-development frameworks are discussed in detail, emphasizing their critical impact on analytical performance and reproducibility. Key application areas in bioanalytical chemistry are highlighted, covering nucleic acid analysis and peptide/protein characterization. CGGE offers unique analytical advantages where fine molecular discrimination, tunable selectivity, and high resolution in a broad molecular weight range are required. Full article

Background/Objectives: Cell-mediated and peptide-assisted delivery systems have emerged as powerful platforms at the intersection of chemistry, nanotechnology, and molecular medicine. By leveraging the intrinsic targeting, transport, and signaling capacities of living cells and bioinspired peptides, these systems facilitate the delivery of therapeutic agents across otherwise restrictive biological barriers such as the blood–brain barrier (BBB) and the tumor microenvironment. This review aims to summarize recent advances in engineered cell carriers, peptide vectors, and hybrid nanostructures designed for enhanced intracellular and tissue-specific delivery. Methods: We surveyed recent literature covering molecular design principles, mechanistic studies, and in vitro/in vivo evaluations of cell-mediated and peptide-enabled delivery platforms. Emphasis was placed on neuro-oncology, immunotherapy, and regenerative medicine, with particular focus on uptake pathways, endosomal escape mechanisms, and structure–function relationships. Results: Analysis of current strategies reveals significant progress in optimizing cell-based transport systems, peptide conjugates, and multifunctional nanostructures for the targeted delivery of drugs, nucleic acids, and immunomodulatory agents. Key innovations include improved BBB penetration, enhanced tumor homing, and more efficient cytosolic delivery enabled by advanced peptide designs and engineered cellular carriers. Several platforms have progressed toward clinical translation, underscoring their therapeutic potential. Conclusions: Cell-mediated and peptide-assisted delivery technologies represent a rapidly evolving frontier with broad relevance to next-generation therapeutics. Despite notable advances, challenges remain in scalability, manufacturing, safety, and regulatory approval. Continued integration of chemical design, molecular engineering, and translational research will be essential to fully realize the clinical impact of these delivery systems. Full article

Background: High expression of nucleolin (NCL) on the surface of tumor cells is closely associated with disease progression and poor prognosis. The aptamer–PROTAC conjugate (APC) technology provides a novel molecular design strategy for the targeted degradation of NCL. Methods: Based on the principles of PROTAC technology and chemical modification techniques, in this study, a series of AS1411-lenalidomide chimeras featuring different linker structures were designed and synthesized for the specific purpose of targeted degradation of NCL. Four AS1411-PROTACs (C1–C4) were successfully constructed via a click chemistry strategy, and their structures were validated. Results: In vitro experimental results showed that C4 exhibited the most optimal activity, significantly downregulating NCL expression and inhibiting the proliferation of breast cancer cells (MCF-7). Notably, the activity of C4 remained unaltered regardless of the annealing process. Mechanistic studies demonstrated that C4 induced NCL degradation through the ubiquitin–proteasome pathway while also promoting apoptosis and cell cycle arrest. In a nude mouse tumor model, C4 displayed potent antitumor efficacy, with no discernible signs of obvious systemic toxicity. Conclusions: This study provides compelling evidence demonstrating that C4 is a highly promising anticancer compound. It also provides important evidence for the development of novel nucleic acid aptamer–PROTAC conjugate drugs for more clinical applications. Full article

Background/Objectives: Natural metabolites, due to their abundance, structural diversity, and availability in enantiomerically pure form, are broadly utilized in the synthesis of reagents, catalysts, building blocks, and potential therapeutics. To date, various organoselenium compounds, including selenides, diselenides, selenols, selenonium salts, and ylides, have been created based on the scaffold of primary and secondary metabolites like amino acids, sugars, nucleic bases, terpenes, and steroids. Their synthesis and application routes as reagents and catalysts in organic synthesis and biological systems are summarized in the presented review. Methods: The gathered material has been divided into two sections—naturally derived organoselenium compounds, such as antioxidants and GPx-mimetics, and reagents utilized in modern organic transformations. Results: The review summarizes the utility of natural scaffolds in the construction of organoselenium compounds with promising applications as antioxidant-type catalysts in biological systems (GPx-mimetics) and potent reagents for organic transformations, including asymmetric reactions. Conclusions: This review provides a comprehensive overview of known organoselenium reagents derived from natural compounds, discusses the advantages of their use in medicinal chemistry and modern organic synthesis, and outlines prospective directions for future development in this area. Full article

RNAs have recently emerged as versatile therapeutic targets, broadening the scope of drug discovery beyond the conventional protein-centered paradigm. Small-molecule-induced RNA degradation has been established as a promising approach, with novel modalities such as Ribonuclease-Targeting Chimeras (RIBOTACs), bleomycin-conjugated degraders, and imidazole-based RNA degrader demonstrating strong potential. These strategies selectively eliminate disease-associated RNAs by harnessing endogenous ribonucleases, redirecting the nucleic acid-cleaving activity of natural products, or incorporating catalytic warheads. Recent studies have validated therapeutic applications across cancer, neurodegenerative disorders, and viral infections, underscoring the wide-ranging impact of this strategy. Nevertheless, key challenges remain, including the development of more potent recruiters, diversification of degradation mechanisms, optimization of linker chemistry, and overcoming pharmacokinetic limitations. With continued innovation, RNA degraders are expected to evolve into a robust therapeutic platform that expands the druggable space and enables new treatment opportunities for diseases once considered untreatable. Full article

Real-Time PCR (qPCR) is an extensively used biomolecular tool for the detection and quantification of nucleic acids for a variety of applications, spanning from clinical to environmental settings. However, qPCR relies on an external calibration curve and can be susceptible to inhibition caused by pollutants that are commonly found in environmental samples. More recently, droplet digital PCR (ddPCR) was proven to be the method of choice for detection and quantification when a target is present at a low abundance. While it has been extensively utilized in clinical studies, only a small amount of data is available for complex samples, which are often characterized by a low target concentration and high abundances of non-target and PCR inhibitors. In this study, ddPCR and qPCR assays were performed on the same DNA serial dilutions with both Eva/SYBR Green and TaqMan chemistry. The comparative analysis was conducted on seven different samples taken from environmental and engineered settings. Ammonia-oxidizing bacteria (AOB) were chosen as the target, as they are ubiquitous and widespread and responsible for a fundamental environmental process in the global biogeochemical nitrogen cycle and in engineered settings such as wastewater treatment plants (WWPTs). ddPCR produced precise, reproducible, and statistically significant results in all samples, also showing an increased sensitivity to detecting AOB in complex samples characterized by low levels of the target and low target/non-target ratios. Full article

Comets are chemically rich and thermally extreme, spanning surface temperatures from ~50 K in the Oort Cloud to >1000 K for sungrazing bodies. These conditions may support key steps of prebiotic chemistry, including the synthesis of nucleic acid precursors. This study present a thermodynamic evaluation of seven candidate reactions, producing nitrogenous bases, sugars, nucleosides, and nucleotides, across the cometary temperature spectrum, 50–1000 K. Purine nucleobase synthesis, including adenine formation via aminoacetonitrile polymerization and HCN polymerization, is strongly exergonic at all temperatures. Sugar formation from formaldehyde is also exergonic, while intermediate pathways, e.g., 2-aminooxazole synthesis, become thermodynamically viable only above ~700 K. Nucleoside formation is thermodynamically neutral at low T but becomes favorable at elevated temperatures, whereas phosphorylation to AMP, i.e., adenosine-monophosphate, a nucleotide serving as a critical regulator of cellular energy status, remains highly endergonic under the entire T range studied. My analysis suggests that, under standard-state assumptions, comets can thermodynamically support formation routes of nitrogenous bases and simple sugars but not a complete nucleotide assembly. This supports a dual-phase origin scenario, where comets act as molecular reservoirs, with further polymerization and biological activation occurring post-delivery on planetary surfaces. Importantly, these findings represent purely thermodynamic assessments under standard-state assumptions and do not address kinetic barriers, catalytic influences, or adsorption effects on ice or mineral surfaces. The results should therefore be viewed as a baseline map of feasibility, subject to modifications in more complex chemical environments. Full article

Lipid nanoparticles are a clinically validated platform for delivering nucleic acids, but performance is constrained by multiscale physiological barriers spanning circulation, vascular interfaces, extracellular matrices, cellular uptake, and intracellular trafficking. This review links composition–structure–function relationships for ionizable lipids, helper phospholipids, cholesterol, and PEG-lipids to systemic fate, endothelial access, endosomal escape, cytoplasmic stability, and nuclear transport. We outline strategies for tissue and cell targeting, including hepatocyte ligands, immune and tumor selectivity, and selective organ targeting through compositional tuning, together with approaches that modulate escape using pH-responsive chemistries or fusion-active peptides and polymers. We further examine immunomodulatory co-formulation, route and schedule effects on biodistribution and immune programming, and manufacturing and stability levers from microfluidic mixing to lyophilization. Across these themes, we weigh trade-offs between stealth and engagement, potency and tolerability, and potency and manufacturability, noting that only a small fraction of endosomes supports productive release and that protein corona variability and repeat dosing can reshape tropism and clearance. Convergence of standardized assays for true cytosolic delivery, biomarker-guided patient selection, and robust process controls will be required to extend LNP therapeutics beyond the liver while sustaining safety, access, and scale. Full article

Cytosine and its derivatives are an important research topic in the fields of bioorganic chemistry, molecular biology and medicine due to their key role in the structure and function of nucleic acids. The article provides a detailed overview of the natural occurrence of cytosine, its biosynthetic and degradation pathways in living organisms, as well as its physicochemical and chemical properties. Particular attention was paid to the biological activity and therapeutic applications of cytosine derivatives, including their use in cancer, antiviral and epigenetic therapy. The analytical section describes high-performance liquid chromatography techniques as a major tool for identifying and determining cytosine and its derivatives in biological samples. Examples of separation conditions, column selection, mobile phases and detection parameters for these compounds are presented. The article also provides chemical structures, graphs, comparative tables and an up-to-date review of the scientific literature, presenting a comprehensive overview of the topic, including biological, chemical and analytical aspects. Full article

Hydrogels have emerged as multifunctional biomaterials in cardiac surgery, offering promising solutions for myocardial regeneration, adhesion prevention, valve engineering, and localized drug and gene delivery. Their high water content, biocompatibility, and mechanical tunability enable close emulation of the cardiac extracellular matrix, supporting cellular viability and integration under dynamic physiological conditions. In myocardial repair, injectable and patch-forming hydrogels have been shown to be effective in reducing infarct size, promoting angiogenesis, and preserving contractile function. Hydrogel coatings and films have been designed as adhesion barriers to minimize pericardial adhesions after cardiotomy and improve reoperative safety. In heart valve and patch engineering, hydrogels contribute to scaffold design by providing bio-instructive, mechanically resilient, and printable matrices that are compatible with 3D fabrication. Furthermore, hydrogels serve as localized delivery platforms for small molecules, proteins, and nucleic acids, enabling sustained or stimuli-responsive release while minimizing systemic toxicity. Despite these advances, challenges such as mechanical durability, immune compatibility, and translational scalability persist. Ongoing innovations in smart polymer chemistry, hybrid composite design, and patient-specific manufacturing are addressing these limitations. This review aims to provide an integrated perspective on the application of hydrogels in cardiac surgery. The relevant literature was identified through a narrative search of PubMed, Scopus, Web of Science, Embase, and Google Scholar. Taken together, hydrogels offer a uniquely versatile and clinically translatable platform for addressing the multifaceted challenges of cardiac surgery. Hydrogels are poised to redefine clinical strategies in cardiac surgery by enabling tailored, bioresponsive, and functionally integrated therapies. Full article

Background: Hydrogels are 3D networks of hydrophilic polymers with various biomedical applications, including tissue regeneration, wound healing, and localized drug delivery. Hydrogel conjugation links therapeutic agents to a hydrogel network, creating a delivery system with adjustable and flexible hydrogel properties and drug activity, allowing for controlled release and enhanced drug stability. Conjugating therapeutic agents to hydrogels provides innovative delivery formats, including injectable and sprayable dosage forms, which facilitate localized and long-lasting delivery. This approach enables non-viral therapeutic methods, such as insertional mutagenesis, and minimally invasive drug administration. Scope and Objectives: While numerous reviews have analyzed advancements in hydrogel synthesis, characterization, properties, and hydrogels as a drug delivery vehicle, this review focuses on hydrogel conjugation, which enables the precise functionalization of hydrogels with small molecules and macromolecules. Subsequently, a description and discussion of several bio-conjugated hydrogel systems, as well as binding motifs (e.g., “click” chemistry, functional group coupling, enzymatic ligation, etc.) and their potential for clinical translation, are provided. In addition, the integration of therapeutic agents with nucleic acid-based hydrogels can be leveraged for sequence-specific binding, representing a leap forward in biomaterials. Key findings: Special attention was given to the latest conjugation approaches and binding motifs that are useful for designing hydrogel-based drug delivery systems. The review systematically categorizes hydrogel conjugates for drug delivery, focusing on conjugating hydrogels with major classes of therapeutic agents, including small-molecule drugs, nucleic acids, proteins, etc., each with distinct conjugation challenges. The design principles were discussed along with their properties and drug release profiles. Finally, future opportunities and current limitations of conjugated hydrogel systems are addressed. Full article

Cancer is a leading cause of death globally, claiming millions of lives each year. Despite the availability of numerous anticancer drugs, the need for new treatment options remains essential. Many current therapies come with significant toxicity, lead to various side effects, or do not consistently deliver the expected therapeutic results. Purines and pyrimidines are fundamental building blocks of nucleic acids and play crucial roles in cellular metabolism and signaling. Recent advances in medicinal chemistry have led to the development and synthesis of various derivatives that exhibit selective cytotoxic effects against cancer cells while minimizing toxicity to healthy tissues. Purine and pyrimidine scaffolds, due to their well-established biological roles and structural versatility, have emerged as key pharmacophoric fragments in anticancer drug discovery. In recent years, the rational design of hybrid molecules incorporating these heterocycles has shown promise in overcoming drug resistance, improving target selectivity, and enhancing pharmacological profiles. Purine and pyrimidines scaffolds hold significant potential as foundations for novel antitumor drugs, with established representatives in cancer treatment, including 5-fluorouracil, cladribine, capecitabine, and several others. In addition, the article discusses the challenges and future developments of purine and pyrimidine derivatives and hybrid molecules as antitumor drugs and emphasizes the need for continued research to optimize their effectiveness and reduce side effects. Overall, the innovative use of these compounds represents a major advance in targeted cancer therapy and holds promise for improving the therapeutic efficacy of malignant diseases. Full article

Nitroxides are stable organic free radicals with a wide range of applications. They have found applications in chemistry, biochemistry, biophysics, molecular biology, and biomedicine as EPR/NMR imaging techniques. As spin labels and probes, they are used in electron paramagnetic resonance (EPR) spectroscopy in the study of proteins, lipids, nucleic acids, and enzymes, as well as for measuring oxygen concentration in cells and cellular organelles, as well as tissues and intracellular pH. Their unique redox properties have allowed them to be used as exogenous antioxidants. In this review, we have discussed the chemical properties of nitroxides and their antioxidant properties. Furthermore, we have considered their use as radioprotectors and protective agents in ischemia/reperfusion in vivo and in vitro. We also presented other applications of nitroxides in protecting cells and tissues from oxidative stress and in protein studies and discussed their use in EPR/MRI. Full article

The United States is facing outbreaks of highly pathogenic avian influenza H5N1 in birds and dairy cattle, along with threats of African swine fever, classical swine fever, and foot-and-mouth disease. While the National Animal Health Laboratory Network (NAHLN) depends on high-throughput testing, the KingFisher Duo Prime, IndiMag 48s, and IndiMag 2 are viable alternatives to aid in outbreak assessments. This study evaluates extraction platforms and the IndiMag Pathogen Kit for detecting the previous listed pathogens. Samples and reference materials were extracted using the MagMAX Viral RNA Isolation Kit, MagMAX CORE Nucleic Acid Purification Kit, and IndiMag Pathogen Kit. Real-time RT-PCR was performed following NAHLN protocols to assess analytical and diagnostic performance. Comparable limits of detection across extraction chemistries, instrumentation, and pathogens were demonstrated, with PCR efficiency ranging between 82.5% and 107.6%. The precision variability was low, with the coefficient of variation ranging from 0.16% to 1.76%. Diagnostic sensitivity and specificity were 100%, with a kappa coefficient of 1.0, indicating strong agreement between methods. These findings support the KingFisher Duo Prime, IndiMag 48s, IndiMag 2, and IndiMag Pathogen Kits as reliable options for NAHLN-approved testing, increasing equipment and reagent alternatives to enhance diagnostic resilience and improve response capabilities to emerging animal health threats. Full article

Homochirality, the ubiquitous preference of biological molecules, such as amino acids, sugars, and phospholipids, for a single enantiomeric form, is a fundamental characteristic of life. This consistent bias across the biosphere, where proteins predominantly utilize L-amino acids and nucleic acids predominantly utilize D-sugars, is not merely a biochemical peculiarity but a crucial aspect of life’s molecular architecture. However, the origin of this homochirality remains one of the most compelling and unresolved mysteries in the study of life’s origins, drawing inquiry from fields as diverse as cosmology, physics, chemistry, and biology. This article provides an overview of chirality’s pervasive influence across these domains, tracing its potential origins from early Earth’s conditions to its pivotal role in shaping both natural phenomena and the technological advancements that define our future. Full article