Search Results (1,532)

Brain organoid technology has revolutionized in vitro modeling of human neurodevelopment and disease, providing unprecedented insights into cortical patterning, neural circuit assembly, and pathogenic mechanisms of neurological disorders. Critically, human brain organoids uniquely recapitulate human-specific developmental processes—such as the expansion of outer radial glia and neuromelanin—that are absent in rodent models, making them indispensable for studying human brain evolution and dysfunction. However, a major bottleneck persists: Extended culture periods (≥6 months) are empirically required to achieve late-stage maturation markers like synaptic refinement, functional network plasticity, and gliogenesis. Yet prolonged conventional 3D culture exacerbates metabolic stress, hypoxia-induced necrosis, and microenvironmental instability, leading to asynchronous tissue maturation—electrophysiologically active superficial layers juxtaposed with degenerating cores. This immaturity/heterogeneity severely limits their utility in modeling adult-onset disorders (e.g., Alzheimer’s disease) and high-fidelity drug screening, as organoids fail to recapitulate postnatal transcriptional signatures or neurovascular interactions without bioengineering interventions. We summarize emerging strategies to decouple maturation milestones from rigid temporal frameworks, emphasizing the synergistic integration of chronological optimization (e.g., vascularized co-cultures) and active bioengineering accelerators (e.g., electrical stimulation and microfluidics). By bridging biological timelines with scalable engineering, this review charts a roadmap to generate translationally relevant, functionally mature brain organoids. Full article

Fused and spiro nitrogen-containing heterocycles play an important role as structural motifs in numerous biologically active natural products and pharmaceuticals. The review summarizes various approaches to the synthesis of three-, four-, five-, and six-membered fused and spiro heterocycles with one or two nitrogen atoms. The assembling of the titled compounds via cycloaddition, oxidative cyclization, intramolecular ring closure, and insertion of sextet intermediates—carbenes and nitrenes—is examined on a vast number of examples. Many of the reactions proceed with high regio-, stereo-, or diastereoselectivity and in excellent, up to quantitative, yield, which is of principal importance for the synthesis of chiral drug-like compounds. For most unusual and hardly predictable transformations, the mechanisms are given or referred to. Full article

Madangamine alkaloids have attracted considerable interest in the scientific community due to their complex polycyclic structures and potent biological activities. The six members identified to date have exhibited diverse and significant cytotoxic activities against various cancer cell lines. Despite their structural complexity, seven total syntheses—covering five of the six members—have been reported to date. These syntheses, involving 28 to 36 steps and global yields ranging from 0.006% to 0.029%, highlight the formidable challenge these compounds present. This review summarizes the key synthetic strategies developed to access critical fragments, including the construction of the ABC diazatricyclic core and the ACE ring systems. Approaches to assembling the ABCD and ABCE tetracyclic frameworks are also discussed. Finally, we highlight the completed total syntheses of madangamines A–E, with a focus on pivotal transformations and strategic innovations that have enabled progress in this field. Full article

Recombinant protein hydrogels have emerged as transformative biomaterials that overcome the bioinertness and unpredictable degradation of traditional synthetic systems by leveraging genetically engineered backbones, such as elastin-like polypeptides, SF, and resilin-like polypeptides, to replicate extracellular matrix (ECM) dynamics and enable programmable functionality. Constructed through a hierarchical crosslinking strategy, these hydrogels integrate reversible physical interactions with covalent crosslinking approaches, collectively endowing the system with mechanical strength, environmental responsiveness, and controlled degradation behavior. Critically, molecular engineering strategies serve as the cornerstone for functional precision: domain-directed self-assembly exploits coiled-coil or β-sheet motifs to orchestrate hierarchical organization, while modular fusion of bioactive motifs through genetic encoding or site-specific conjugation enables dynamic control over cellular interactions and therapeutic release. Such engineered designs underpin advanced applications, including immunomodulatory scaffolds for diabetic wound regeneration, tumor-microenvironment-responsive drug depots, and shear-thinning bioinks for vascularized bioprinting, by synergizing material properties with biological cues. By uniting synthetic biology with materials science, recombinant hydrogels deliver unprecedented flexibility in tuning physical and biological properties. This review synthesizes emerging crosslinking paradigms and molecular strategies, offering a framework for engineering next-generation, adaptive biomaterials poised to address complex challenges in regenerative medicine and beyond. Full article

Bacteriophages (phages), the most abundant biological entities on Earth, have long served as both model systems and therapeutic tools. Recent advances in synthetic biology and genetic engineering have revolutionized the capacity to tailor phages with enhanced functionality beyond their natural capabilities. This review outlines the current landscape of synthetic and functional engineering of phages, encompassing both in-vivo and in-vitro strategies. We describe in-vivo approaches such as phage recombineering systems, CRISPR-Cas-assisted editing, and bacterial retron-based methods, as well as synthetic assembly platforms including yeast-based artificial chromosomes, Gibson, Golden Gate, and iPac assemblies. In addition, we explore in-vitro rebooting using TXTL (transcription–translation) systems, which offer a flexible alternative to cell-based rebooting but are less effective for large genomes or structurally complex phages. Special focus is given to the design of customized phages for targeted applications, including host range expansion via receptor-binding protein modifications, delivery of antimicrobial proteins or CRISPR payloads, and the construction of biocontained, non-replicative capsid systems for safe clinical use. Through illustrative examples, we highlight how these technologies enable the transformation of phages into programmable bactericidal agents, precision diagnostic tools, and drug delivery vehicles. Together, these advances establish a powerful foundation for next-generation antimicrobial platforms and synthetic microbiology. Full article

Deoxyribonucleic acid (DNA) is not only a fundamental biological molecule but also a versatile material for constructing sensitive and specific biosensing platforms. Its ability to undergo sequence-specific hybridization via Watson–Crick base pairing enables both precise target recognition and the programmable construction of nanoscale structures. The demand for ultrasensitive detection increases in fields such as disease diagnostics, therapeutics, and other areas, and the inherent characteristics of DNA have driven the development of a wide range of signal amplification strategies. Among these, polymerase chain reaction (PCR), rolling circle amplification (RCA), and loop-mediated isothermal amplification (LAMP) represent powerful target-based methods that enzymatically increase the concentration of nucleic acid targets, thereby boosting detection sensitivity. In parallel, structure-based strategies leverage the nanoscale spatial programmability of DNA to construct functional architectures with high precision. DNA can be used as a scaffold, such as DNA nanostructures, to organize sensing elements and facilitate signal transduction. It can also function as a probe, like aptamers, to recognize targets with high affinity. These versatilities enable the creation of highly sophisticated sensing platforms that integrate molecular recognition and signal amplification. Driven by DNA nano-assembly capability, both target-based and structure-based approaches are driving the advancement of highly sensitive, selective, and adaptable diagnostic technologies. This review highlights recent developments in DNA nano-assembly-driven amplification strategies. Full article

Chrysomya megacephala, as one of the common blowflies, displays biological characteristics, such as ovoviviparity and carrion-feeding adaptation. Thus, this species is generally considered of significant ecological, medical, and forensic importance. However, without a high-quality pseudo-chromosome genome for C. megacephala, elucidating its evolutionary trajectory proved difficult. Herein, we assembled and analyzed a high-quality chromosome-level genome assembly of the C. megacephala, combined with PacBio HiFi long reads, Hi-C data, and Illumina reads. The pseudo-chromosomes assembly of C. megacephala spans 629.44 Mb, with 97.05% anchored to five chromosomes. Final assembly includes 1056 contigs (N50 = 1.68 Mb), and 97 scaffolds (N50 = 121.37 Mb), achieving 98.90% BUSCO completeness (n = 1367). Gene annotation predicted 17,071 protein-coding genes (95.60% BUSCO completeness), while repeat masking identified 244.26 Mb (38.82%) as repetitive elements. Additionally, 3740 non-coding RNAs were characterized. Gene family analyses resulted in 10,579 gene families, containing 151 gene families that experienced rapid evolution. Comparative genomic analyses showed that the expanded genes are related to reproduction and necrophagous habits. In addition, we annotated the gene family P450s, CCEs, IRs, GRs, and ORs, all of which represent remarkable expansion, playing a crucial role in the mechanism of locating the hosts for forensic insects. Our research establishes a high-quality genome sequence to facilitate subsequent molecular investigations into significant species within forensic entomology. Full article

Histopathological grading of oral squamous cell carcinoma is currently based on differentiation of cells, while additional histological parameters, such as the tumor–stroma ratio (TSR), tumor budding (TB), or the combined TSR/tumor budding model could better assess tumor biological behavior and monitoring of patients. Background/Objectives: To integrate risk factors associated with tumor progression: the TSR, TB and TSR/tumor budding model, whose prognostic significance in oral cancer has not yet been evaluated. Methods: An observational cohort retrospective study assembled according to STROBE guidelines on histological materials from 196 patients with invasive squamous cell carcinoma of the oral cavity. The goal of the analysis was to evaluate the association between the tumor stroma ratio, tumor budding, and the combined model of TSR/TB with the clinical and pathologic features of patients with squamous cell carcinoma of the oral cavity and to determine the prognostic value of this model in relation to disease-free survival (DFS) Results: The analysis did not show that the tumor stroma ratio (TSR), tumor budding, and the combined model of TSR/tumor budding were statistically significantly associated with the occurrence of metastatic disease at the start of treatment or during postoperative follow-up, but confirmed the value of depth-of-invasion (DOI) as a negative prognostic factor (HR 15.3, p < 0.001). Conclusions: The TSR, TB, and the combined TSR/TB model were not found to be statistically significant predictors for the disease progression in the Cox regression survival analysis but were found to have a significant correlation with known negative prognostic factors: DOI, neural invasion, and T category. Full article

The development of efficient and sustainable water recycling systems is essential for long-term human missions and the establishment of space habitats on the Moon, Mars, and beyond. Humidity condensate (HC) is a low-strength wastewater that is currently recycled on the International Space Station (ISS). The main contaminants in HC are primarily low-molecular-weight organics and ammonia. This has caused operational issues due to microbial growth in the Water Process Assembly (WPA) storage tank as well as failure of downstream systems. In addition, treatment of this wastewater primarily uses adsorptive and exchange media, which must be continually resupplied and represent a significant life-cycle cost. This study demonstrates the integration of a membrane-aerated biological reactor (MABR) for pretreatment and storage of HC, followed by brackish water reverse osmosis (BWRO). Two system configurations were tested: (1) periodic MABR fluid was sent to batch RO operating at 90% water recovery with the RO concentrate sent to a separate waste tank; and (2) periodic MABR fluid was sent to batch RO operating at 90% recovery with the RO concentrate returned to the MABR (accumulating salinity in the MABR). With an external recycle tank (configuration 2), the system produced 2160 L (i.e., 1080 crew-days) of near potable water (dissolved organic carbon (DOC) < 10 mg/L, total nitrogen (TN) < 12 mg/L, total dissolved solids (TDS) < 30 mg/L) with a single membrane (weight of 260 g). When the MABR was used as the RO recycle tank (configuration 1), 1100 L of permeate could be produced on a single membrane; RO permeate quality was slightly better but generally similar to the first configuration even though no brine was wasted during the run. The results suggest that this hybrid system has the potential to significantly enhance the self-sufficiency of space habitats, supporting sustainable extraterrestrial human habitation, as well as reducing current operational problems on the ISS. These systems may also apply to extreme locations such as remote/isolated terrestrial locations, especially in arid and semi-arid regions. Full article

Background: The overwhelming majority of the antimicrobial peptides (AMPs) studied in mussels (Mytilus spp.) so far are specifically expressed by hemocytes and display compact disulfide-stabilized structures. However, gill-specific myticalins play a role in mucosal immunity and are one of the very few examples of known molluscan AMPs lacking cysteine residues. Methods: We investigate the molecular evolution of myticalins, compiling a collection of sequences obtained by carefully annotating 169 genome assemblies of different Mytilus species. We determine the gene presence/absence patterns and gene expression profiles for the five myticalin subfamilies, including the newly reported myticalin E. Results: All sequences are deposited in MyticalinDB, a novel database that includes a total of 100 unique mature myticalin peptides encoded by 215 protein precursors, greatly enriching the compendium of these molecules from previous reports. Among the five subfamilies, myticalin A and C are the most widespread and highly expressed across all Mytilus species. Interestingly, structural prediction reveals a previously unreported strong amphipathic nature for some myticalins, which may be highly relevant for their biological activity. Conclusions: The results reported in this work support the role of myticalins in gill-associated mucosal immunity and highlight the importance of inter-individual molecular diversity in establishing an efficient response to microbial infections. The newly established MyticalinDB provides a valuable resource for investigating the evolution and extraordinary molecular diversity of this AMP family. Full article

Calcium plays a major role in all cellular functions, and its regulation is important in all aspects of human health. This key role calcium plays in cell function can be traced to its unique molecular coordination geometry, which is often overlooked in understanding calcium function. In this review, we integrate calcium’s ability to form various complexes with proteins and small molecules with its role as a key signaling atom. We argue that calcium’s ability to vary its coordination structures, compared to magnesium’s rigid geometry, explains its importance in biological functions. By examining calcium-mediated proteins, such as those containing EF-hand domains and those that assemble and stabilize the extracellular matrix in tissue organization, we demonstrate how calcium’s varied geometric coordination serves as both a signaling molecule and a regulator of physiological homeostasis. Full article

Anthocyanins (ACNs), characterized by their polyhydroxy structures, exhibit high susceptibility to external environmental factors, which significantly limits their application in the food and industrial sectors. To enhance the stability of anthocyanins, anthocyanin nanoliposomes (ACN-NLs) were developed, with encapsulation efficiency, particle size and zeta potential serving as key evaluation parameters. Furthermore, through layer-by-layer self-assembly and electrostatic interactions, ACN-NLs were modified using synanthrin (SY) and pea protein isolate (PPI). Consequently, PPI-modified ACN-NLs (PPI-ACN-NLs) and SY-PPI-modified ACN-NLs (SY-PPI-ACN-NLs) were successfully synthesized. In this study, the structural characteristics of liposomes were investigated using X-ray diffraction (XRD), their in vitro digestibility was evaluated, and their stability under different temperatures, light conditions, and simulated food system conditions was assessed. The results demonstrated that when the mass ratio of soybean lecithin to cholesterol, soybean lecithin to anhydrous ethanol, and drug-to-lipid ratio were set at 5:1, 3:100, and 3:10, respectively, with an ACN concentration of 4 mg/mL, a pea protein solution with pH 3.0, a PPI concentration of 10 mg/mL, and an SY concentration of 8 mg/mL, the prepared ACN-NLs, PPI-ACN-NLs, and SY-PPI-ACN-NLs exhibited optimal performance. Their respective encapsulation efficiencies were 52.59 ± 0.24%, 83.80 ± 0.43%, and 90.38 ± 0.24%; average particle sizes were 134.60 ± 0.76 nm, 213.20 ± 0.41 nm, and 246.60 ± 0.24 nm zeta potentials were −32.4 ± 0.75 mV, −27.46 ± 0.69 mV, and −16.93 ± 0.31 mV. The changes in peak shape observed via X-ray diffraction (XRD), in vitro digestion profiles, and alterations in anthocyanin release rates under different conditions collectively indicated that the modification of ACN-NLs using SY and PPI enhanced the protective effect on the ACNs, improving their biological activity, and providing a robust foundation for the practical application of ACNs. Full article

The virus-first theory presents a model in which viral lineages emerged before cells. This proposal aims to give the theory greater relevance by offering a plausible evolutionary framework that explains both (i) the origin of viruses from prebiotic chemistry and (ii) how viruses contributed to the emergence of cells. Here, we propose that viruses should be understood as a distinct class of ribonucleoprotein (RNP) systems, some of which evolved directly from the RNP-world. In our model, simple progenotes produced capsid-like particles through the evolution of a single gene encoding a self-assembling peptide. This allowed the formation of icosahedral shells around RNA genomes, as observed today in certain viral families whose capsids consist of ~60 identical subunits derived from a single gene product. These early capsids enabled mobility and protection, representing key intermediates toward biological complexity. Over time, some of those populations acquired additional peptides and evolved more elaborate architectures. Finally, the incorporation of lipid-binding domains in those capsid-like peptides allowed the formation of proteolipidic membranes akin to those found in modern cells. This model provides a gradualistic and logically coherent evolutionary path from the RNP-world to the emergence of cellular life, emphasizing the foundational role of viruses in early evolution. Full article

DNA methylation, as a critical epigenetic modification, plays a central role in gene regulation and has emerged as a powerful biomarker for early disease diagnostics, particularly in cancer. Owing to the limitations of traditional bisulfite sequencing—such as high cost, complexity, and chemical degradation—electrochemical biosensors have gained substantial attention as promising alternatives. This review summarizes recent advancements in electrochemical platforms for bisulfite-free detection of DNA methylation, encompassing direct oxidation strategies, enzyme-assisted recognition (e.g., restriction endonucleases and methyltransferases), immunoaffinity-based methods, and a variety of signal amplification techniques such as rolling circle amplification and catalytic hairpin assembly. Additional approaches, including strand displacement, magnetic enrichment, and adsorption-based detection, are also discussed. These systems demonstrate exceptional sensitivity, often down to the attomolar or femtomolar level, as well as high selectivity, reproducibility, and suitability for real biological matrices. The integration of nanomaterials and redox-active probes further enhances analytical performance. Importantly, many of these biosensing platforms have been validated using clinical samples, reinforcing their translational relevance. The review concludes by outlining current challenges and future directions, emphasizing the potential of electrochemical biosensors as scalable, cost-effective, and minimally invasive tools for real-time epigenetic monitoring and early-stage disease diagnostics. Full article

Multicomponent reactions (MCRs) enable the efficient assembly of complex small molecules via multiple bond-forming events in a single step. However, individual MCRs typically yield products with similar core structures, limiting access to larger, more intricate scaffolds. Strategic selection of reactants allows the combination of distinct MCRs, thus facilitating the synthesis of advanced molecular architectures with potential biological significance. Using our previously reported method for performing the aza-Friedel Crafts multicomponent reaction under green heterogeneous conditions, we have incorporated some of the obtained products into diverse multicomponent reactions to generate, in an unprecedent approach, eight novel products, some of which were also characterized by two-dimensional NMR techniques. The biological properties of such products are under investigation. Full article