Stress granules: Guardians of cellular health and triggers of disease

Stress granules are membraneless organelles that serve as a protective cellular response to external stressors by sequestering non-translating messenger RNAs (mRNAs) and regulating protein synthesis. Stress granules formation mechanism is conserved across species, from yeast to mammals, and they play a critical role in minimizing cellular damage during stress. Composed of heterogeneous ribonucleoprotein complexes, stress granules are enriched not only in mRNAs but also in noncoding RNAs and various proteins, including translation initiation factors and RNA-binding proteins. Genetic mutations affecting stress granule assembly and disassembly can lead to abnormal stress granule accumulation, contributing to the progression of several diseases. Recent research indicates that stress granule dynamics are pivotal in determining their physiological and pathological functions, with acute stress granule formation offering protection and chronic stress granule accumulation being detrimental. This review focuses on the multifaceted roles of stress granules under diverse physiological conditions, such as regulation of mRNA transport, mRNA translation, apoptosis, germ cell development, phase separation processes that govern stress granule formation, and their emerging implications in pathophysiological scenarios, such as viral infections, cancer, neurodevelopmental disorders, neurodegeneration, and neuronal trauma.

Recent advances in immunotherapy targeting amyloid-beta and tauopathies in Alzheimer's disease

Alzheimer's disease, a devastating neurodegenerative disorder, is characterized by progressive cognitive decline, primarily due to amyloid-beta protein deposition and tau protein phosphorylation. Effectively reducing the cytotoxicity of amyloid-beta42 aggregates and tau oligomers may help slow the progression of Alzheimer's disease. Conventional drugs, such as donepezil, can only alleviate symptoms and are not able to prevent the underlying pathological processes or cognitive decline. Currently, active and passive immunotherapies targeting amyloid-beta and tau have shown some efficacy in mice with asymptomatic Alzheimer's disease and other transgenic animal models, attracting considerable attention. However, the clinical application of these immunotherapies demonstrated only limited efficacy before the discovery of lecanemab and donanemab. This review first discusses the advancements in the pathogenesis of Alzheimer's disease and active and passive immunotherapies targeting amyloid-beta and tau proteins. Furthermore, it reviews the advantages and disadvantages of various immunotherapies and considers their future prospects. Although some antibodies have shown promise in patients with mild Alzheimer's disease, substantial clinical data are still lacking to validate their effectiveness in individuals with moderate Alzheimer's disease.

Biomaterial-based strategies: a new era in spinal cord injury treatment

Enhancing neurological recovery and improving the prognosis of spinal cord injury have gained research attention recently. Spinal cord injury is associated with a complex molecular and cellular microenvironment. This complexity has prompted researchers to elucidate the underlying pathophysiological mechanisms and changes and to identify effective treatment strategies. Traditional approaches for spinal cord injury repair include surgery, oral or intravenous medications, and administration of neurotrophic factors; however, the efficacy of these approaches remains inconclusive, and serious adverse reactions continue to be a concern. With advancements in tissue engineering and regenerative medicine, emerging strategies for spinal cord injury repair now involve nanoparticle-based nanodelivery systems, scaffolds, and functional recovery techniques that incorporate biomaterials, bioengineering, stem cell, and growth factors as well as three-dimensional bioprinting. Ideal biomaterial scaffolds should not only provide structural support for neuron migration, adhesion, proliferation, and differentiation but also mimic the mechanical properties of natural spinal cord tissue. Additionally, these scaffolds should facilitate axon growth and neurogenesis by offering adjustable topography and a range of physical and biochemical cues. The three-dimensionally interconnected porous structure and appropriate physicochemical properties enabled by three-dimensional biomimetic printing technology can maximize the potential of biomaterials used for treating spinal cord injury. Therefore, correct selection and application of scaffolds, coupled with successful clinical translation, represent promising clinical objectives to enhance the treatment efficacy for and prognosis of spinal cord injury. This review elucidates the key mechanisms underlying the occurrence of spinal cord injury and regeneration post-injury, including neuroinflammation, oxidative stress, axon regeneration, and angiogenesis. This review also briefly discusses the critical role of nanodelivery systems used for repair and regeneration of injured spinal cord, highlighting the influence of nanoparticles and the factors that affect delivery efficiency. Finally, this review highlights tissue engineering strategies and the application of biomaterial scaffolds for the treatment of spinal cord injury. It discusses various types of scaffolds, their integrations with stem cells or growth factors, and approaches for optimization of scaffold design.

A stacking classifier for distinguishing stages of Alzheimer's disease from a subnetwork perspective

Accurately distinguishing stages of Alzheimer's disease (AD) is crucial for diagnosis and treatment. In this paper, we introduce a stacking classifier method that combines six single classifiers into a stacking classifier. Using brain network models and network metrics, we employ t-tests to identify abnormal brain regions, from which we construct a subnetwork and extract its features to form the training dataset. Our method is then applied to the ADNI (Alzheimer's Disease Neuroimaging Initiative) datasets, categorizing the stages into four categories: Alzheimer's disease, mild cognitive impairment (MCI), mixed Alzheimer's mild cognitive impairment (ADMCI), and healthy controls (HCs). We investigate four classification groups: AD-HCs, AD-MCI, HCs-ADMCI, and HCs-MCI. Finally, we compare the classification accuracy between a single classifier and our stacking classifier, demonstrating superior accuracy with our stacking classifier from a subnetwork-based viewpoint.

External stimuli-responsive drug delivery to the posterior segment of the eye

Posterior segment eye diseases represent the leading causes of vision impairment and blindness globally. Current therapies still have notable drawbacks, including the need for frequent invasive injections and the associated risks of severe ocular complications. Recently, the utility of external stimuli, such as light, ultrasound, magnetic field, and electric field, has been noted as a promising strategy to enhance drug delivery to the posterior segment of the eye. In this review, we briefly summarize the main physiological barriers against ocular drug delivery, focusing primarily on the recent advancements that utilize external stimuli to improve treatment outcomes for posterior segment eye diseases. The advantages of these external stimuli-responsive drug delivery strategies are discussed, with illustrative examples highlighting improved tissue penetration, enhanced control over drug release, and targeted drug delivery to ocular lesions through minimally invasive routes. Finally, we discuss the challenges and future perspectives in the translational research of external stimuli-responsive drug delivery platforms, aiming to bridge existing gaps toward clinical use.

R, Khoza. S, Dube A. Vitamin D3 loaded polycaprolactone nanoparticles enhance the expression of the antimicrobial peptide cathelicidin in macrophages

Tuberculosis (TB), primarily caused by Mycobacterium tuberculosis, remains a global health burden. Current antibiotic treatments are limited by adverse effects, poor adherence, and drug resistance, necessitating new therapeutic approaches. Recent studies highlight the role of vitamin D3 (VD3) in enhancing host immune responses against the mycobacterium via cathelicidin (an antimicrobial peptide) and autophagy activation. In this study, VD3-loaded poly-ƹ-caprolactone (PCL) nanoparticles (NPs) were synthesized to enhance cathelicidin expression in macrophages. NPs containing cholecalciferol, calcifediol, and calcitriol were synthesized using an emulsification solvent-evaporation technique. Average sizes of synthesized NPs ranged from 304.7 to 458.7 nm, with polydispersity index (PDI) and zeta potential (ZP) ranging from 0.103 to 0.257 and -17.3 to -7.47 mV, respectively. Encapsulation efficiencies were 9.68%, 10.99%, and 19.28% for cholecalciferol, calcifediol, and calcitriol, respectively. VD3-encapsulated NPs stimulated a dose-dependent increase in cathelicidin expression in THP-1 macrophages. Encapsulated calcifediol and calcitriol (100 ng/ml) induced the expression of 243.46 ng/ml ± 4.55 ng/ml and 396.67 ng/ml ± 25.24 ng/ml of cathelicidin, respectively, which was significantly higher than that induced by the free drugs. These findings suggest that NP encapsulation may offer a more efficient approach to using vitamin D3 for inducing cathelicidin expression as a host-directed treatment for TB.

Antimicrobial capping agents on silver nanoparticles made via green method using natural products from banana plant waste

Herein, we investigated the phytochemical composition and antibacterial activities of the organic layers from biosynthesized silver nanoparticles (AgNPs). AgNPs were synthesized using Musa paradisiaca and Musa sapientum extracts. UV-vis absorption in the 400-450 nm range indicated surface plasmonic resonance peak of AgNPs. Samples analyses using dynamic light scattering and transmission electron microscopy revealed the presence of particles within nanometric ranges, with sizes of 30-140 nm and 8-40 nm, respectively. Fourier transform infrared (FTIR) unveiled the presence of several organic functional groups on the surface of AgNPs, indicating the presence of phytochemicals from plant extracts. Thin layer chromatography (TLC) of the phytochemicals (capping agents) from AgNPs identified multiple groups of secondary metabolites. These phytochemical capping agents exhibited antibacterial activities against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, with minimum inhibitory concentrations ranging from 62.5 to 1000 µg/mL. Regardless of the bacterial species or plant parts (leaves or pseudo-stems), capping agents from M. sapientum nanoparticles displayed significantly enhanced antibacterial effectiveness compared to all other samples, including the raw plant extracts and biosynthesized capped and uncapped AgNPs. These results suggest the presence of antimicrobial phytochemicals on biosynthesized AgNPs, highlighting the promise of green nanoparticle synthesis as a valuable approach in bioprospecting antimicrobial agents.

Harnessing nanofibers for targeted delivery of phytoconstituents in age-related macular degeneration

Age-related macular degeneration is a degenerative eye condition that affects the macula and results in central vision loss. Phytoconstituents show great promise in the treatment of AMD. AMD therapy can benefit from the advantages of phytoconstituents loaded nanofibers. There are opportunities to improve the effectiveness of phytoconstituents in the treatment of age-related macular degeneration (AMD) through the use of nanofiber-based delivery methods. These novel platforms encapsulate and distribute plant-derived bioactives by making use of the special qualities of nanofibers. These qualities include their high surface area-to-volume ratio, variable porosity, and biocompatibility. Exploring the use of nanofiber-based delivery methods to provide phytoconstituents in AMD treatment is a great choice for enhancing patient adherence, safety, and efficacy in managing this condition. This article explores the potential of nanofiber-based delivery methods to revolutionize AMD treatment, providing an innovative and effective approach to treat this condition.

Staphylococcus warneri dampens SUMOylation and promotes intestinal inflammation

Gut bacteria play key roles in intestinal physiology, via the secretion of diversified bacterial effectors. Many of these effectors remodel the host proteome, either by altering transcription or by regulating protein post-translational modifications. SUMOylation, a ubiquitin-like post-translational modification playing key roles in intestinal physiology, is a target of gut bacteria. Mutualistic gut bacteria can promote SUMOylation, via the production of short- or branched-chain fatty acids (SCFA/BCFA). In contrast, several pathogenic bacteria were shown to dampen SUMOylation in order to promote infection. Here, we demonstrate that Staphylococcus warneri, a natural member of the human gut microbiota, decreases SUMOylation in intestinal cells. We identify that Warnericin RK, a hemolytic toxin secreted by S. warneri, targets key components of the host SUMOylation machinery, leading to the loss of SUMO-conjugated proteins. We further demonstrate that Warnericin RK promotes inflammation in intestinal and immune cells using both SUMO-dependent and SUMO-independent mechanisms. We finally show that Warnericin RK regulates the expression of genes involved in intestinal tight junctions. Together, these results highlight the diversity of mechanisms used by bacteria from the gut microbiota to manipulate host SUMOylation. They further highlight that changes in gut microbiota composition may impact intestinal inflammation, by altering the equilibrium between bacterial effectors promoting or dampening SUMOylation.

Proteins of the SubB family provide multiple mechanisms of serum resistance in Yersinia pestis

The serum complement system is a cornerstone element of the innate immune response. Bacterial resistance to this system is a multifaceted process involving various proteins and molecular mechanisms. Here, we report several genes required for the growth of Yersinia pestis in serum. Among them, we found that ypo0337 encodes an outer-membrane-associated lectin that recruits factor H, C4BP and hemopexin, conferring resistance to the serum complement system. YPO0337 displays high sequence similarity with the SubB subunit of the AB5 toxin from Escherichia coli, as well as other SubB-like proteins, and subB from E. coli restores the ability of Y. pestis Δypo0337 mutant to resist to serum complement. Altogether, the data suggest that at least two members of the SubB protein family function as virulence factors, conferring resistance to serum complement through a unique mode of action.

Interkingdom signaling between gastrointestinal hormones and the gut microbiome

The interplay between the gut microbiota and gastrointestinal hormones plays a pivotal role in the health of the host and the development of diseases. As a vital component of the intestinal microecosystem, the gut microbiota influences the synthesis and release of many gastrointestinal hormones through mechanisms such as modulating the intestinal environment, producing metabolites, impacting mucosal barriers, generating immune and inflammatory responses, and releasing neurotransmitters. Conversely, gastrointestinal hormones exert feedback regulation on the gut microbiota by modulating the intestinal environment, nutrient absorption and utilization, and the bacterial biological behavior and composition. The distributions of the gut microbiota and gastrointestinal hormones are anatomically intertwined, and close interactions between the gut microbiota and gastrointestinal hormones are crucial for maintaining gastrointestinal homeostasis. Interventions leveraging the interplay between the gut microbiota and gastrointestinal hormones have been employed in the clinical management of metabolic diseases and inflammatory bowel diseases, such as bariatric surgery and fecal microbiota transplantation, offering promising targets for the treatment of dysbiosis-related diseases.

Human tendon stem/progenitor cell-derived extracellular vesicle production promoted by dynamic culture

Tendon injuries significantly impact quality of life, prompting the exploration of innovative solutions beyond conventional surgery. Extracellular Vesicles (EVs) have emerged as a promising strategy to enhance tendon regeneration. In this study, human Tendon Stem/Progenitor Cells (TSPCs) were isolated from surgical biopsies and cultured in a Growth-Differentiation Factor-5-supplemented medium to promote tenogenic differentiation under static and dynamic conditions using a custom-made perfusion bioreactor. Once at 80% confluence, cells were transitioned to a serum-free medium for conditioned media collection. Ultracentrifugation revealed the presence of vesicles with a 106 particles/mL concentration and sub-200nm diameter size. Dynamic culture yielded a 3-fold increase in EV protein content compared to static culture, as confirmed by Western-blot analysis. Differences in surface marker expression were also shown by flow cytometric analysis. Data suggest that we efficiently developed a protocol for extracting EVs from human TSPCs, particularly under dynamic conditions. This approach enhances EV protein content, offering potential therapeutic benefits for tendon regeneration. However, further research is needed to fully understand the role of EVs in tendon regeneration.

Deciphering the role of APOE in cerebral amyloid angiopathy: from genetic insights to therapeutic horizons

Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid-β (Aβ) peptides in the walls of medium and small vessels of the brain and leptomeninges, is a major cause of lobar hemorrhage in elderly individuals. Among the genetic risk factors for CAA that continue to be recognized, the apolipoprotein E (APOE) gene is the most significant and prevalent, as its variants have been implicated in more than half of all patients with CAA. While the presence of the APOE ε4 allele markedly increases the risk of CAA, the ε2 allele confers a protective effect relative to the common ε3 allele. These allelic variants encode three APOE isoforms that differ at two amino acid positions. The primary physiological role of APOE is to mediate lipid transport in the brain and periphery; however, it has also been shown to be involved in a wide array of biological functions, particularly those involving Aβ, in which it plays a known role in processing, production, aggregation, and clearance. The challenges posed by the reliance on postmortem histological analyses and the current absence of an effective intervention underscore the urgency for innovative APOE-targeted strategies for diagnosing CAA. This review not only deepens our understanding of the impact of APOE on the pathogenesis of CAA but can also help guide the exploration of targeted therapies, inspiring further research into the therapeutic potential of APOE.

Small molecules targeting the eubacterial β-sliding clamp discovered by combined in silico and in vitro screening approaches

Antibiotic resistance stands as the foremost post-pandemic threat to public health. The urgent need for new, effective antibacterial treatments is evident. Protein-protein interactions (PPIs), owing to their pivotal role in microbial physiology, emerge as novel and attractive targets. Particularly promising is the α-subunit/β-sliding clamp interaction, crucial for the replicative competence of bacterial DNA polymerase III holoenzyme. Through pharmacophore-based virtual screening, we identified 4,000 candidate small molecule inhibitors targeting the β-clamp binding pocket. Subsequently, these candidates underwent evaluation using the BRET assay in yeast cells. Following this, three hits and 28 analogues were validated via Protein Thermal Shift and competitive ELISA assays. Among them, thiazolo[4,5-d]-pyrimidinedione and benzanilide derivatives exhibited micromolar potency in displacing the β-clamp protein partner and inhibiting DNA replication. This screening campaign unveiled new chemical classes of α/β-clamp PPI disruptors capable of inhibiting DNA polymerase III activity, which lend themselves for further optimisation to improve their antibacterial efficacy.

Klebsiella pneumoniae derived outer membrane vesicles mediated bacterial virulence, antibiotic resistance, host immune responses and clinical applications

Klebsiella pneumoniae is a gram-negative pathogen that can cause multiple diseases including sepsis, urinary tract infections, and pneumonia. The escalating detections of hypervirulent and antibiotic-resistant isolates are giving rise to growing public concerns. Outer membrane vesicles (OMVs) are spherical vesicles containing bioactive substances including lipopolysaccharides, peptidoglycans, periplasmic and cytoplasmic proteins, and nucleic acids. Emerging studies have reported various roles of OMVs in bacterial virulence, antibiotic resistance, stress adaptation, and host interactions, whereas knowledge on their roles in K. pneumoniae is currently unclear. In this review, we summarized recent progress on the biogenesis, components, and biological function of K. pneumoniae OMVs, the impact and action mechanism in virulence, antibiotic resistance, and host immune response. We also deliberated on the potential of K. pneumoniae OMVs in vaccine development, as diagnostic biomarkers, and as drug nanocarriers. In conclusion, K. pneumoniae OMVs hold great promise in the prevention and control of infectious diseases, which merits further investigation.

Cross-feeding-based rational design of a probiotic combination of Bacterides xylanisolvens and Clostridium butyricum therapy for metabolic diseases

The human gut microbiota has gained interest as an environmental factor that contributes to health or disease. The development of next-generation live biotherapeutic products (LBPs) is a promising strategy to modulate the gut microbiota and improve human health. In this study, we identified a novel cross-feeding interaction between Bacteroides xylanisolvens and Clostridium butyricum and developed their combination into a novel LBP for treating metabolic syndrome. Using in-silico analysis and in vitro experiments, we demonstrated that B. xylanisolvens supported the growth and butyrate production of C. butyricum by supplying folate, while C. butyricum reciprocated by providing pABA for folate biosynthesis. Animal gavage experiments showed that the two-strain combination LBP exhibited superior therapeutic efficacy against metabolic disorders in high-fat diet-induced obese (DIO) mice compared to either single-strain treatment. Further omics-based analyses revealed that the single-strain treatments exhibited distinct taxonomic preferences in modulating the gut microbiota, whereas the combination LBP achieved more balanced modulation to preserve taxonomic diversity to a greater extent, thereby enhancing the stability and resilience of the gut microbiome. Moreover, the two-strain combinations more effectively restored gut microbial functions by reducing disease-associated pathways and opportunistic pathogen abundance. This work demonstrates the development of new LBP therapy for metabolic diseases from cross-feeding microbial pairs which exerted better self-stability and robust efficacy in complex intestinal environments compared to conventional single-strain LBPs.

The role of cisplatin in modulating the tumor immune microenvironment and its combination therapy strategies: a new approach to enhance anti-tumor efficacy

Cisplatin is a platinum-based drug that is frequently used to treat multiple tumors. The anti-tumor effect of cisplatin is closely related to the tumor immune microenvironment (TIME), which includes several immune cell types, such as the tumor-associated macrophages (TAMs), cytotoxic T-lymphocytes (CTLs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), and natural killer (NK) cells. The interaction between these immune cells can promote tumor survival and chemoresistance, and decrease the efficacy of cisplatin monotherapy. Therefore, various combination treatment strategies have been devised to enhance patient responsiveness to cisplatin therapy. Cisplatin can augment anti-tumor immune responses in combination with immune checkpoint blockers (such as PD-1/PD-L1 or CTLA4 inhibitors), lipid metabolism disruptors (like FASN inhibitors and SCD inhibitors) and nanoparticles (NPs), resulting in better outcomes. Exploring the interaction between cisplatin and the TIME will help identify potential therapeutic targets for improving the treatment outcomes in cancer patients.

In vivo toxicity of chitosan-based nanoparticles: a systematic review

Chitosan nanoparticles have been extensively utilised as polymeric drug carriers in nanoparticles formulations due to their potential to enhance drug delivery, efficacy, and safety. Numerous toxicity studies have been previously conducted to assess the safety profile of chitosan-based nanoparticles. These toxicity studies employed various methodologies, including test animals, interventions, and different routes of administration. This review aims to summarise research on the safety profile of chitosan-based nanoparticles in drug delivery, with a focus on general toxicity tests to determine LD50 and NOAEL values. It can serve as a repository and reference for chitosan-based nanoparticles, facilitating future research and further development of drugs delivery system using chitosan nanoparticles. Publications from 2014 to 2024 were obtained from PubMed, Scopus, Google Scholar, and ScienceDirect, in accordance with the inclusion and exclusion criteria.The ARRIVE 2.0 guidelines were employed to evaluate the quality and risk-of-bias in the in vivo toxicity studies. The results demonstrated favourable toxicity profiles, often exhibiting reduced toxicity compared to free drugs or substances. Acute toxicity studies consistently reported high LD50 values, frequently exceeding 5000 mg/kg body weight, while subacute studies typically revealed no significant adverse effects. Various routes of administration varied, including oral, intravenous, intraperitoneal, inhalation, and topical, each demonstrating promising safety profiles.

RNase P cleavage of pseudoknot substrates reveals differences in active site architecture that depend on residue N-1 in the 5' leader

We show that a small biotin-binding RNA aptamer that folds into a pseudoknot structure acts as a substrate for bacterial RNase P RNA (RPR) with and without the RNase P C5 protein. Cleavage in the single-stranded region in loop 1 was shown to depend on the presence of a RCCA-motif at the 3' end of the substrate. The nucleobase and the 2'hydroxyl at the position immediately 5' of the cleavage site contribute to both cleavage efficiency and site selection, where C at this position induces significant cleavage at an alternative site, one base upstream of the main cleavage site. The frequencies of cleavage at these two sites and Mg2+ binding change upon altering the structural topology in the vicinity of the cleavage site as well as by replacing Mg2+ with other divalent metal ions. Modelling studies of RPR in complex with the pseudoknot substrates suggest alternative structural topologies for cleavage at the main and the alternative site and a shift in positioning of Mg2+ that activates the H2O nucleophile. Together, our data are consistent with a model where the organization of the active site structure and positioning of Mg2+ is influenced by the identities of residues at and in the vicinity of the site of cleavage.

Exploring the efficacy and constraints of platinum nanoparticles as adjuvant therapy in silicosis management

Silicosis represents a formidable occupational lung pathology precipitated by the pulmonary assimilation of respirable crystalline silica particulates. This condition engenders a cascade of cellular oxidative stress via the activation of bioavailable silica, culminating in the generation of reactive oxygen species (ROS). Such oxidative mechanisms lead to irrevocable pulmonary impairment. Contemporary scholarly examinations have underscored the substantial antioxidative efficacy of platinum nanoparticles (PtNPs), postulating their utility as an adjunct therapeutic modality in silicosis management. The physicochemical interaction between PtNPs and silica demonstrates a propensity for adsorption, thereby facilitating the amelioration and subsequent pulmonary clearance of silica aggregates. In addition to their detoxifying attributes, PtNPs exhibit pronounced anti-inflammatory and antioxidative activities, which can neutralize ROS and inhibit macrophage-mediated inflammatory processes. Such attributes are instrumental in attenuating inflammatory responses and forestalling subsequent lung tissue damage. This discourse delineates the interplay between ROS and PtNPs, the pathogenesis of silicosis and its progression to pulmonary fibrosis, and critically evaluates the potential adjunct role of PtNPs in the therapeutic landscape of silicosis, alongside a contemplation of the inherent limitations associated with PtNPs application in this context.

A surrogate BSL2-compliant infection model recapitulating key aspects of human Marburg virus disease

Marburg virus disease (MVD) is a severe infectious disease caused by the Marburg virus (MARV), posing a significant threat to humans. MARV needs to be operated under strict biosafety Level 4 (BSL-4) laboratory conditions. Therefore, accessible and practical animal models are urgently needed to advance prophylactic and therapeutic strategies for MARV. In this study, we constructed a recombinant vesicular stomatitis virus (VSV) expressing the Marburg virus glycoprotein (VSV-MARV/GP). Syrian hamsters infected with VSV-MARV/GP presented symptoms such as thrombocytopenia, lymphopenia, haemophilia, and multiorgan failure, developing a severe systemic disease akin to that observed in human MARV patients. Notably, the pathogenicity was found to be species-specific, age-related, sex-associated, and challenge route-dependent. Subsequently, the therapeutic efficacy of the MR191 monoclonal antibody was validated in this model. In summary, this alternative model is an effective tool for rapidly screening medical countermeasures against MARV GP in vivo under BSL-2 conditions.

Influences of physical stimulations on the migration and differentiation of Schwann cells involved in peripheral nerve repair

Peripheral nerve injury repair has always been a research concern of scientists. At the tissue level, axonal regeneration has become a research spotlight in peripheral nerve repair. Through transplantation of autologous nerve grafts or other emerging biomaterials functional recovery after facial nerve injury is not ideal in clinical scenarios. Great strides have been made to improve facial nerve repair at the micro-cellular level. Physical stimulation techniques can trigger Schwann cells (SCs) to migrate and differentiate into cells required for peripheral nerve repair. Classified by the sources of physical stimulations, SCs repair peripheral nerves through galvanotaxis, magnetotaxis and durotaxis. This article summarized the activation, directional migration and differentiation of SCs induced by physical stimulations, thus providing new ideas for the research of peripheral nerve repair.

Precursor of H-type II histo-blood group antigen and subterminal sialic acids on gangliosides are significantly implicated in cell entry and infection by a porcine P[11] rotavirus

Rotaviruses, non-enveloped viruses with a double-stranded RNA genome, are the leading etiological pathogen of acute gastroenteritis in young children and animals. The P[11] genotype of rotaviruses exhibits a tropism for neonates. In the present study, a binding assay using synthetic oligosaccharides demonstrated that the VP8* protein of P[11] porcine rotavirus (PRV) strain 4555 binds to lacto-N-neotetraose (LNnT) with the sequence Galβ1,4-GlcNAcβ1,3-Galβ1,4-Glc, one of the core parts of histo-blood group antigen (HBGA) and milk glycans. However, infections were significantly inhibited by blocking of endogenous monosialoganglioside (GM) GM1a with cholera toxin B subunit and preincubation of the virus with exogenous GM1a, suggesting that GM1a is involved in the infection of P[11] PRV 4555. In addition to GM1a, preincubation of the virus with exogenous disialogangliosides (GD) GD1a, GD1b, and trisialoganglioside (GT) GT1b also prevented infection. In contrast, exogenous ganglioside GM3 only inhibited infections at an early time point, and exogenous asyalosphingolipids GA1 and LacCer did not show any inhibitory effect on infections. This indicates that P[11] PRV 4555 preferentially utilizes gangliosides containing subterminal sialic acids. Further experiments revealed that P[11] PRV 4555 infections were prevented by preincubation of the virus with Neu5Ac and Neu5Gc. These results confirmed that sialic acids are essential for P[11] PRV 4555 cell entry, despite the classification as NA-resistant strain. Overall, our results proved that P[11] rotavirus not only binds to the Gal-GlcNAc motif but also utilizes gangliosides containing subterminal sialic acids.

Identifying sex-based disparities in porcine mitochondrial function

In pigs, the effect of sex on production and reproductive traits has been largely reported, however, whether sex exerts its influence through regulating mitochondrial function is still unclear. In this study, we constructed 15 male cells and 15 female fibroblasts derived from 35-day and 50-day fetuses, newborn piglets and 1-year-old pigs to identify the sex effect on mitochondrial functions. Results indicated significant differences on cellular and molecular characteristics between male and female cells, including energy metabolic trait, mitochondrial DNA (mtDNA) replication and transcription, and mRNA expressions of mitochondrial biogenesis genes and mitoprotease genes. Referring to sex, males exhibited significantly higher oxygen consumption rate productions, levels of reactive oxygen species (ROS) and mtDNA copy numbers than those with females in muscle and ear fibroblasts. And the expressions of mtDNA, mitochondrial biogenesis genes (POLG, PPARGC1A, TFAM and TWNK) and XPNPEP3 were higher in males than females in ear fibroblasts derived from 1-year-old adult pigs (EFA cells). While, the cell proliferation and expressions of genes related to ROS metabolism were not influenced by sex. The results highlight the effect of sex on mitochondrial function and gene expression, and provide important data for a comprehensive understanding of the mechanisms underlying sex regulation of energy metabolism-related traits in pigs.

Caspase 3-specific cleavage of ubiquitin-specific peptidase 48 enhances drug-induced apoptosis in AML

Dysfunction or dysregulation of deubiquitination is closely related to the initiation and development of multiple cancers. Targeted regulation of deubiquitination has been recognized as an important strategy in tumor therapy. However, the mechanism by which drugs regulate deubiquitinase is not clear. Here, we identified ubiquitin-specific peptidase 48 (USP48), a member of the ubiquitin-specific protease family highly expressed in various tumors, as a specific substrate for the activated caspase-3. During drug induced apoptosis of AML cells, activated caspase-3 cleaves USP48 through recognizing the conservative motif DEQD located at 611-614 sites of human USP48. Subsequent analysis showed that the cleavage USP48 N-terminal fragment which contains catalytic active domain is easily degraded by ubiquitination. Meanwhile knockdown experiment showed that inhibiting the expression of USP48 could also promotes apoptosis and enhance the efficacy of chemotherapy drugs. Altogether, these results suggest that targeting USP48 may represent a novel therapeutic strategy in AML.

Rational design of an acid-sensitive fluorophore from 8-hydroxy quinoline derivative exhibiting proton activated charge transfer characteristics

A pH-responsive small organic molecule 8OMeQBI has been synthesized by functionalizing 8-hydroxy quinoline and benzimidazole derivatives in an organo-aqueous medium. The pH-responsive fluorescence behavior in a semi-aqueous environment was studied using UV-visible and fluorescence spectral analysis. The newly prepared fluorophores show a protonation-activated fluorescence enhancement in an acidic environment. An increase in pH in an alkaline environment has caused deprotonation, resulting in diminished fluorescence intensity. Additionally, the protonation-induced fluorescence was confirmed through the proton-nuclear magnetic resonance titration analysis. Further, the photophysical studies reveal an enhancement in the relative quantum yield (ɸ = 0.3) and fluorescence lifetime (increases to 3 ns at pH 3) in an acidic environment. Also, the fluorophore shows fluorescence "On" with acids such as hydrochloric acid and fluorescence "Off" with bases such as triethylamine (TEA). This fluorescence "on-off" behavior is reversible and repeatable, which helps to develop a molecular-level logic gate and sequential memory unit with "Writing-Reading-Erasing-Reading" behavior. Furthermore, solid supportive experiments were carried out by preparing fluorophore-based films and paper strips. Also, the fluorophore demonstrates the practical applicability of potable water samples.

Tryptanthrin incorporated spiropiperidine derivative as a fluorescent chemosensor for picric acid detection

The photophysical properties of a previously synthesized tryptanthrin incorporated spiropiperidine molecule (CTSP) is described. Studies revealed that the fluorescence of the compound gets significantly quenched by addition of picric acid (PA). The selectivity, anti-interference and quenching mechanistic studies are also described. The quenching mechanism was largely attributed to photo-induced electron transfer (PET) process facilitated by a strong electrostatic interaction between the protonated NH2 group of CTSP and PA. Additionally, pH variations significantly influenced the quenching efficiency, with the highest response observed at neutral pH. These findings demonstrate that CTSP is a promising candidate for PA detection, with potential applications in environmental monitoring and security fields.

Antenna effect-modulated luminescent lanthanide complexes for biological sensing

With the discovery and further exploitation of the antenna effect, the optical properties of luminescent lanthanide complexes (LLCs) have been greatly improved. Antenna effect-modulated LLCs exhibit long luminescence lifetimes, large Stokes shifts, narrow emission spectra, pure chromaticity, and high photostability. Meanwhile, LLCs have garnered considerable attention in recent years and are widely used as biosensors in the fields of food safety, environmental monitoring, clinical diagnosis, and drug analysis. In this review, we first systematically review the design of antenna effect-modulated LLC sensors, including the construction principle of antenna effect in LLCs and the selection of antenna ligands. Secondly, the classification of antenna ligands was discussed in detail. Thirdly, biological sensing applications of antenna effect-modulated LLCs in the past three years are described in terms of the role of LLCs in fluorescence sensors and electrochemiluminescence sensors. Finally, we also discussed the challenges and emerging opportunities of antenna effect-modulated LLCs in future sensing applications.

Mueller matrix polarimetry reveals chiroptical properties of metal chelates in solutions

Proper characterization of molecular chiroptical properties is vital for organic chemistry and drug development. Nonetheless, narrow spectral ranges and the necessity for specialized equipment often limit traditional methods such as optical rotatory dispersion and electronic circular dichroism. Here, we introduce Mueller matrix polarimetry (MMP) as a more versatile tool for chiroptical analysis, capable of simultaneously capturing circular dichroism and optical rotatory dispersion spectra across ultraviolet to near-infrared wavelengths in a single measurement. We applied MMP to chiral metal complexes of Al, Mn, and Co, commonly used as catalysts in asymmetric syntheses. Using a robust experimental methodology, MMP distinguished enantiomeric forms and provided reliable chiroptical information by leveraging the inherent relationship between circular dichroism and optical rotatory dispersion. We interpreted our findings on the basis of density functional theory simulations, compared them to traditional electronic circular dichroism and absorption spectroscopies, and performed the Kramers-Kronig analysis. The combined approach of chiroptical MMP and ab-initio, for example, reveals delicate near-infrared chiroptical spectra of a neutral cobalt metal complex. Although MMP is more commonly used for solid state, the developed experimental protocol significantly expands its capabilities to solutions. It allows measurements without the need for both enantiomers and offers new insights into molecular chirality with potential applications across traditional and interdisciplinary branches of science and industry.

Enhanced near-infrared Ru (II) complex fluorescence sensor for sensitive sensing of Al3+ and cell imaging

A near-infrared (NIR) fluorescent sensor (λem = 790 nm), [Ru ((CH3O)2bipy)2 (BIMPY)]2+, was synthesized and thoroughly characterized, which can selectively recognize Al3+ ions in THF. The [Ru ((CH3O)2bipy)2 (BIMPY)]2+ has excellent sensitivity (LOD = 3.48 × 10-8 mol/L) towards Al3+ with a 2:1 (Ru complex/Al3+) complex ratio and opportune binding constant (K = 606.82 mol/L). The change mechanism of photophysical properties was determined by time-dependent density functional theory (TDDFT) method, which illustrates fluorescence enhancement sensing to Al3+ ions. The [Ru ((CH3O)2bipy)2 (BIMPY)]2+ was used as a field-deployable sensor, achieving on-site Al3+ monitoring via the RGB analysis. Furthermore, the [Ru ((CH3O)2bipy)2 (BIMPY)]2+ succeed in imaging Al3+ in living HepG2 cells.

Natural products as probes for the spectral analysis and sensitive detection of metal-containing ionic liquids

A new analytical method was developed for the rapid detection of metal-containing ionic liquids (MCILs) using the natural products (NPs) as fluorescent probes. Based on electrostatic potential (ESP) distribution and conductor-like screening model for real solvents (COSMO-RS) simulation, the possible interactions between quercetin, emodin, curcumin, esculetin and 1-butyl-3-methylimidazole tetrachloroferrate ([Bmim][FeCl4]) were predicted, and the ultraviolet response, concentration titration experiments and fluorescence response of NPs and [Bmim][FeCl4] were studied. Both theoretical and experimental studies indicated that esculetin showed the best corresponding performance to [Bmim][FeCl4] and then was selected as fluorescent probe molecule for the detection of a series of similar ionic liquids containing Zn2+, Cu2+ and Al3+. The linear range of this analytical method towards [Bmim][FeCl4] was 5 ∼ 30 μM (R2 = 0.9957) with the relative standard deviation of 2.1 % and the limit of detection (LOD) of 1.08 μM. Recoveries, measured in the standard ethanol solution with the added concentration of 5 μM, were determined as 98.1 ∼ 102.5 % by the standard addition method. According to all the studied results, the probe of natural product possessed good selectivity, repeatability, and stability, which could be fixed onto filter paper to detect [Bmim][FeCl4] in more intuitive way.

Berberrubine, A plant alkaloid derivative for superb-selective colorimetric quantification of aqueous mercury (II) in real samples and in aquatic plants

A new colorimetric sensor, berberrubine (BER-OH), was designed and synthesized based on berberine for superb selective sensing of Hg2+ in aqueous medium, addressing limitation of existing probes. The sensor exhibited high selectivity and sensitivity to Hg2+ in aqueous solution (CP buffer solution, pH 7.2) over other common metal ions (Na+, K+, Mg2+, Ca2+, Fe3+, Co2+, Fe2+, Cu2+, Al3+, Ba2+, Pb2+, Cd2+, Zn2+ and Sr2+). Upon addition of Hg2+, a distinct color change from reddish-orange to yellowish was observed due to complexation between BER-OH and Hg2+ in 1:1 stoichiometry. The binding of Hg2+ with BER-OH resulted in increasing absorbance at 347 and 430 nm with concurrent decreasing absorbance of the sensor at 377 and 487 nm. The limit of detection (LOD) values were calculated at absorption bands 347, 377, 487 nm and also using absorbance ratio, A347/A377. The sensor quantitatively analysed Hg2+, and the lowest LOD was found to be 46 nM with the range of 0.1 to 1.0 μM. The analytical tools confirmed that the proposed sensing mechanism involves the coordinate bond between lone pair of oxygen atoms of BER-OH and Hg2+. The sensor has great utility to detect trace Hg2+ in real samples like tap water, river water, and drinking water. A noteworthy application of the sensor is to quantify Hg2+ in aquatic plants which can absorb mercury from freshwater ecosystem. This simple yet effective sensing approach may offer a potential platform for the design of plant alkaloid-based sensing probes for environmentally hazardous elements.

Carbazole-disulfonamide-containing macrocycles as powerful anion receptors with tunable selectivity

The design of synthetic anion receptors with potent anion binding and customizable anion selectivity under competitive solvent conditions remains challenging. Herein, we report easily-synthesized 1,8-disulfonamidocarbazole- and 3,5-diamidopyridine-based hybrid macrocycles 1-3 and reveal their strong anion recognition properties as determined by 1H NMR/UV-vis titration studies, X-ray diffraction measurements, and DFT calculations. While the dithioamidopyridine-based macrocycle 2 displayed strong and selective binding of AcO- in DMSO, modification of the selectivity pattern towards the more basic F- anion was achieved by replacing the thioamides moieties to amides (macrocycle 1). For macrocycle 3 (bearing pyridine N-oxide core), no selectivity was observed among F-, AcO-, and H2PO4- ions. The demonstration of tunable anion selectivity by slight structural modifications in our macrocycles is informative for developing structurally simple anion receptors with the desired selectivity for transmembrane anion transport, anion sensing, and anion sequestration applications.

Development of a near-infrared fluorescent probe for in situ monitoring of hydrogen peroxide in plants

In plants, hydrogen peroxide (H2O2), one of the significant reactive oxygen species, plays a dual function. Investigating its concentration is essential for understanding its production and scavenging mechanisms in plants. In this study, a near-infrared fluorescent probe (Cy-Bo) was developed, which is based on the hemicyanine compound. By introducing indole salts into the oxygenated anthraquinone structure, the conjugated system is expanded, enabling the probe to emit long-wavelength fluorescence in the near-infrared region, thereby minimizing interference from other biomolecules in plant tissues (λex = 650 nm, λem = 720 nm). As for the specific recognition of H2O2, the pinacol phenylborate ester was selected to be the recognition group. It shows good linearity (R2 = 0.998) in the concentration range of 0.5-100 μM, with a detection limit of 0.07 μM. Furthermore, this probe Cy-Bo has been used for in vivo fluorescence imaging in plants due to its good bio-penetration and in-situ imaging capabilities. The results reveal a significant increase in H2O2 concentration in Arabidopsis thaliana under progressively increasing drought, high-temperature, and salt stress. This tool provides a non-invasive, in situ imaging method for detecting H2O2 in plants, which has a fast response, easy operation, and high sensitivity. It enables visual monitoring of H2O2 fluctuations and aids in advancing physiological and pathological studies related to H2O2.

Emerging biomedical applications of surface-enhanced Raman spectroscopy integrated with artificial intelligence and microfluidic technologies

The integration of surface-enhanced Raman spectroscopy (SERS), artificial intelligence (AI), and microfluidics represent a transformative approach for biomedical applications. By combining the molecular sensitivity of SERS, AI-driven spectral analysis, and the precise sample handling of microfluidics, these novel integrated systems enable ultrasensitive, label-free diagnostics with minimal sample processing. The development of portable, cost-effective platforms could democratize advanced diagnostics for resource-limited settings. However, challenges such as reproducibility, clinical validation, and system integration hinder widespread adoption. This review explores these new integrated platforms, beginning with a discussion of SERS principles, their biomedical applications, and the critical roles of AI and microfluidics in enhancing analytical performance. We evaluate recent advances in the application of these integrated systems, while addressing key challenges such as substrate scalability, biocompatibility, and point-of-care translation, with a focus on nanomaterials, AI models, and lab-on-chip designs. Finally, we outline future directions, including multimodal sensing, sustainable materials, and embedded AI for real-time diagnostics, to bridge the gap between technological innovation and clinical implementation.

Dithiophene chemosensor for ultrasensitive intracellular detection of Al3+: Design, DFT analysis, and ESIPT-PET mechanisms

Metal ions play essential roles in living cells, yet their biological functions, which depend on intracellular concentrations, are not fully understood. Therefore, there is a critical need for efficient and sensitive methods to monitor metal ion levels in biological systems. Herein, we report the development of a fluorescent probe, 2-hydroxy-1-naphthaldehyde-(dithiophen-2-yl)ethanediamine (NS), for the precise and sensitive detection of intracellular Al3+ at concentrations as low as 3.92 × 10-8 M. The probe features a bifunctional thienyl ethanol ligand, consisting of two thiophene rings and a hydroxyl group, which forms stable coordination with Al3+. This interaction modifies the electron allocation within the ligand, suppressing the excited-state intramolecular proton transfer (ESIPT) mechanism and significantly increasing fluorescence intensity. Notably, in the presence of Al3+, compared to other ions, the fluorescence intensity of NS at 452 nm increases by 77-fold, with an exceptional sensitivity and selectivity for Al3+. Furthermore, the hydroxyl group enhances the probe's solubility and stability in aqueous solutions, making it highly effective for intracellular detection of Al3+ in prostate cancer RM-1 cells. The response mechanism is further investigated through 1H NMR and DFT studies, revealing the contributions of ESIPT, photoinduced electron transfer (PET), and CN isomerization to the probe's fluorescence behavior. This work provides a promising and advanced tool for ionobiology, opening new avenues for research into metal ion-related biological processes.

Advancing fluoride ion sensing with a fluorene-derived fluorophore: A comprehensive experimental and computational study

This paper discusses the detailed sensing studies of a fluorene-based fluorophore for the sensitive and selective detection of fluoride ions in the solution state. The fluorophore FOPD has been synthesised from 9H-fluoren-9-one and o-phenylene diamine by simple reaction set-up, which was then structurally characterised by various spectroscopic techniques including FT-IR, NMR, and HRMS analyses. Further, the sensing potential of the fluorophore was carried out by UV-visible and fluorescence spectroscopic techniques. Various parameters including sensitivity, selectivity, interference, the influence of pH, and limit of detection were successfully validated experimentally, thereby confirming the excellent ability of FOPD in detecting fluoride ions. Computational studies, including Density Functional Theory (DFT), were employed to optimise the molecular structure of FOPD, explore its Frontier Molecular Orbitals (FMOs), and identify the plausible interaction between fluoride ions. Further, topological analyses such as ELF, LOL, RDG and QTAIM provide valuable insights into the non-bonding and intramolecular hydrogen bonding interactions, enabling a clearer understanding of the sensing mechanism. Finally, the toxicity analysis of FOPD revealed that it is relatively non-toxic with an excellent LOD of 0.125 µM, underscoring its potential as a safe and environmentally friendly fluorophore for the selective detection of fluoride ions.

On the behavior of Hoechst 33258 in DNA-PEG mixtures

Most of the studies on the interaction of fluorescent dyes with DNA have been performed under conditions radically different from those occurring in situ. Among others, this includes diluteness of experimental solutions, their homogeneity, and presence of a large amount of free water. To a certain extent, some model systems can help to approach the biological conditions. Thus, since some features of liquid-crystalline-like packaging of DNA were found in a number of living systems, to shed light on the behavior of Hoechst 33258 in biological-like conditions, we performed a detailed study of its properties in DNA-PEG mixtures, and, in particular, in the dispersed mesophases formed via polymer and salt induced (psi-) condensation. Being in complex with DNA, Hoechst 33258 shows a high sensitivity to the changes in osmotic conditions - the addition of PEG leads to a release of the dye molecules. However, this effect nonlinearly depends on osmolality. Individually, neither PEG nor NaCl at the studied concentrations significantly affect its complex with nucleic acid. The effect is caused precisely by their synergistic action. In cases of the dispersed systems formation, significant fraction of Hoechst 33258 molecules is retained within the resulting particles and is protected even from further increase in osmolality. This is partly due to competition between the processes of the dye releasing and formation of the dispersed particles.

Substituent-induced modulation of competing dual-acceptor hydrogen bond in ESIPT-type HBT derivatives

The 2-(2'-hydroxyphenyl) benzothiazole derivatives (HBT-R) featuring a dual-acceptor hydrogen bond (H-bond) have attracted our attention due to their unique structure and potential applications. There are two distinct acceptor sites located on either side of the central H-bond donor, thereby giving rise to the formation of inter-acceptor competition. In this study, quantum chemical calculations are employed to elucidate that substituents possessing distinct electronic properties modulate H-bond orientations, photophysical characteristics, and excited-state intramolecular proton transfer (ESIPT) in a dual-acceptor H-bond system. The origins of the competition in H-bonds and their effect on the distinct photophysical phenomena were revealed. The relaxed potential energy curves and molecular dynamics conducted for HBT-R indicate that electron-donating groups improve the efficiency of the ESIPT process in molecules with O-H···N H-bond. However, these groups hinder the ESIPT process in molecules with an opposite H-bond orientation. This work is expected to provide comprehensive insights into the mechanisms of substituent-induced modulation of competing dual-acceptor H-bond to inspire the design of more advanced luminescent materials.

Highly sensitive surface plasmon resonance-based sensor using green synthesized Fe3O4/rGO interface layer utilizing plant leaf extracts for alcohol compound detection

In this study, a fast response, real time, accurate, and non destructive alcohol detection method using surface plasmon resonance (SPR) technique was purposed. The SPR measurement was performed using 5-layers Krestchmann configuration with a layer structure of prism/Au thin film/Fe3O4/rGO nanocomposite/alcohol compounds/air. The Fe3O4/rGO nanocomposite was successfully synthesized using the green route utilizing Moringa oleifera and Amaranthus viridis leaf extract. X-ray diffraction analysis showed the nanocomposite has a face-centered cubic with an inverse spinel structure with a crystallite size of 5.6-5.8 nm. The size of Fe3O4 NPs in the Fe3O4/rGO nanocomposite was variated from 10.6-13.0 nm and showed that there is no impurities in the sample. Fourier transform infra-red analysis also validates the existence of Fe3O4 and rGO indicated by the FeO and CC bond, respectively. The interaction between Fe3O4 and rGO can also be observed through the coordinational bonding FeOC, which is validated by the presence of FeO and CO bonds. The optical properties were studied using ultraviolet-visible spectroscopy, which shows an energy gap of 2.36 eV. Magnetic properties of Fe3O4/rGO nanocomposite show a superparamagnetic characteristic with the saturation magnetization of 40.53 emu/g, magnetic susceptibility of 3.62 × 10-2, and the domain size is 6.22 nm. The SPR angle shifts when applied with Fe3O4/rGO nanocomposite. The addition of alcohol compound further shifted the SPR angle by 0.22°, 0.61°, and 1.19° for methanol, ethanol, and IPA, respectively. This noticeable shift shows a possibility for early detection to differentiate these 3 compounds. The presence of a magnetic field further shifts the SPR angle by 0.08°, 0.08°, and 0.10° for 40, 60, and 80 Oe, which indicates an increase in sensitivity. Therefore, the combination of applied magnetic field and green synthesized Fe3O4/rGO nanocomposite as an eco-friendly interface layer are potential to enhance the sensitivity of SPR to detect the alcohol compounds.

Statistical analysis of Raman Spectra of biofuels: The case of myristic acid conformers

Biofuels derived from microalgae offer a sustainable alternative to fossil fuels, but their application is hindered by high production costs. Optimizing photobioreactors for biofuel production requires precise characterization of algal biomass, particularly its organic components. Raman spectroscopy is a powerful tool for this purpose, but the challenge lies in differentiating the spectral contributions of individual compounds and identifying their conformers in complex mixtures. In this study, we employ Raman spectroscopy and statistical analysis to distinguish conformers of fatty acids, using myristic acid as a model. Benchmark calculations of Raman spectra show that the dispersion corrected B3LYP-D3 DFT method in conjunction with the 6-311++G** basis set provides an optimal balance between accuracy and computational efficiency. The inclusion of solvent (water) effects ensures that experimental conditions are realistically modeled. Statistical techniques streamline the analysis of large spectral datasets and enable the classification of conformers into three sets, namely chain, v-shaped, and twisted structures. By isolating key spectral regions, we identify decisive features-such as CH2/CH3 vibrations at about 2900 cm-1 and backbone motions, below 1200 cm-1, that distinguish these conformers. This approach offers a robust framework for the rapid analysis of molecular spectra and the identification of fatty acids in algal biomass.

Optimal structural characteristics of osteoinductivity in bioceramics derived from a novel high-throughput screening plus machine learning approach

Osteoinduction is an important feature of the next generation of bone repair materials. But the key structural factors and parameters of osteoinductive scaffolds are not yet clarified. This study leverages the efficiency of high-throughput screening in identifying key structural factors, performs screening of 24 different porous structures using 3D printed calcium phosphate (CaP) ceramic scaffolds. Based on in vitro and in vivo evaluations, along with machine learning and nonlinear fitting, it explores the complex relationship between osteoinductive properties and scaffold configurations. Results indicate that bone regenerative ability is largely affected by porosity and specific surface area (SSA), while pore geometry has a negligible effect. The optimal structural parameters were identified as a porous structure with SSA of 10.49-10.69 mm2 mm-3 and permeability of 3.74 × 10-9 m2, which enhances osteoinductivity and scaffold properties, corresponding to approximately 65 %-70 % porosity. Moreover, nonlinear fitting reveals specific correlations among SSA, permeability and osteogenic gene expressions. We established a data-driven high-throughput screening methodology and proposed a parametric benchmark for osteoinductive structures, providing critical insights for the design of future osteoinductive scaffolds.

STING-activating layered double hydroxide nano-adjuvants for enhanced cancer immunotherapy

Cancer vaccines represent a promising therapeutic strategy in oncology, yet their effectiveness is often hampered by suboptimal antigen targeting, insufficient induction of cellular immunity, and the immunosuppressive tumor microenvironment. Advanced delivery systems and potent adjuvants are needed to address these challenges, though a restricted range of adjuvants for human vaccines that are approved, and even fewer are capable of stimulating robust cellular immune response. In this work, we engineered a unique self-adjuvanted platform (MLDHs) by integrating STING agonists manganese into a layered double hydroxide nano-scaffold, encapsulating the model antigen ovalbumin (OVA). The MLDHs platform encompasses Mn-doped MgAl-LDH (MLMA) and Mn-doped MgFe-LDH (MLMF). Upon subcutaneous injection, OVA/MLDHs specifically accumulated within lymph nodes (LNs), where they were internalized by resident antigen-presenting cells. The endosomal degradation of MLDHs facilitated the cytoplasmic release of antigen and Mn2+, promoting cross-presentation and triggering the STING pathway, which in turn induced a potent cellular immune response against tumors. Notably, OVA/MLMF induced stronger M1 macrophage polarization and a more potent T-cell response within tumor-infiltrating lymphocytes compared to OVA/MLMA, leading to significant tumor regression in B16F10-OVA bearing mice with minimal adverse effects. Additionally, combining MLMF with the vascular disrupting agent Vadimezan disrupted the tumor's central region, typically resistant to immune cell infiltration, further extending survival in tumor-bearing mice. This innovative strategy may show great potential for improving cancer immunotherapy and offers hope for more effective treatments in the future.

Orally-deliverable liposome-microgel complexes dynamically remodel intestinal environment to enhance probiotic ulcerative colitis therapy via TLR4 inhibition and tryptophan metabolic crosstalk

Probiotics emerges as a promising option for ulcerative colitis (UC) treatment, but its application remains challenging due to insufficient colon-targeted delivery efficiency and survival against the inflammation-associated intestinal oxidative stress. To address these issues, here we report a supramolecular liposome-microgel complex (SLMC) incorporated with Bacillus subtilis spores (BSSs) and dexamethasone (DEX) for orally-deliverable probiotic UC therapy. Specifically, BSSs and cholesterols were conjugated with gelatin via diselenide ligation to prepare microgels, followed by supramolecular complexation with UC-targeted DEX-loaded liposome via microfluidic engineering. The orally-administered SLMC efficiently accumulated in UC-affected colonic sites to release BSSs and DEX. DEX elicited rapid anti-inflammatory effect to reduce ROS generation, which cooperated with the ROS consumption by spore germination and diselenide cleavage to orchestrate an anaerobic intestinal microenvironment, thus promoting Bacillus subtilis colonization to restore gut homeostasis and initiate anti-inflammatory microbiota-macrophage metabolic crosstalk. Indeed, in vivo analysis showed that the SLMC treatment markedly inhibited pro-inflammatory TLR4-NF-κB signaling activities in mucosal macrophages through localized DEX delivery and boosting tryptophan metabolite production, leading to robust and durable UC abolishment. This study offers a practical approach for improving UC treatment in the clinic.

A chiral fluorescent probe enables specific recognition of Threoninol

Chiral threoninol derivatives are crucial compounds in the fine chemical, pharmaceutical, and materials industries due to their optical activity and broad applications in organic synthesis and drug development. Although threoninol derivatives share the same molecular formula and atomic connectivity, their different configurations can exhibit significant chemical reactivity and biological activity variations. Thus, selective detection of the individual enantiomers of threoninol remains challenging. In this work, we report the development of a novel chiral fluorescence probe, (S)-5, which features a binaphthol core with dialdehyde and diacrylate moieties as the active recognition sites. This probe selectively interacts with L-Threoninol, resulting in a marked fluorescence enhancement at 540 nm (ef = 3.34), with negligible interference from other substances. The detection limit (LOD) is 3.26 × 10-8 M. Importantly, (S)-5 itself is nonfluorescent, and its fluorescence is activated upon reaction with L-Threoninol. Additionally, we synthesized the enantiomeric probe (R)-5, which exhibits similar fluorescence enhancement in response to D-Threoninol. To our knowledge, (S)-5 represents the first fluorescent probe specifically designed to detect L-Threoninol. This new probe holds promise as a powerful analytical tool for asymmetric synthesis, chiral resolution, and chiral drug development.

Ratiometric fluorescent sensor CQDx@Co/Mn-MOF for rapid and sensitive detection of quinolone antibiotics

Quinolone antibiotics pose a threat to health and the environment due to their difficulty in decomposition and misuse. A novel fluorescence composite material CQDx@Co/Mn-MOF has been developed, which uses cobalt (Co) and manganese (Mn) as metal centers and 1,3,5-triazobenzene as organic ligands. Meaningfully, CQDx@Co/Mn-MOF can be designed as a ratiometric fluorescence sensor for detecting quinolone antibiotics, especially norfloxacin (NFX). In a series of CQDx@Co/Mn-MOF, CQD6μL@Co/Mn-MOF sensor exhibits good linearity within the NFX concentration range of 1-4 × 10-5 M, with a detection limit of 0.70 μM. Compared with Co/Mn-MOF, introducing CQDs significantly reduces the detection limit from 3.50 μM to 0.70 μM and increases the detection sensitivity by five times. The CQD6μL@Co/Mn-MOF sensor exhibits fast response time (2 s), high selectivity and sensitivity to NFX, making it an ideal ratiometric fluorescent sensor for the detection of these antibiotics. Based on its excellent detection performance, the sensor was further applied to the quantitative determination of NFX in chicken, beef and honey samples and satisfactory results were obtained with recoveries ranging from 97.51 % to 108.60 %. In addition, based on CQD6μL@Co/Mn-MOF test strips, convenient and real-time detection of quinolone antibiotics has been achieved. In conclusion, the CQD6μL@Co/Mn-MOF ratiometric fluorescent sensor provides a reliable, sensitive and efficient analytical method for the detection and evaluation of trace NFX in food, which is of great significance for ensuring food safety and public health.

Advances in memristive gas sensors: A review

With the development of gas sensing technology, traditional semiconductor-based gas sensors are difficult to meet higher performance requirements. To this end, the essence of gas sensor performance improvement depends on the innovation of gas-sensing mechanism. Gas sensors based on the memristor structure (gasistors) have been proposed in recent years, which brings new research ideas for further gas sensors development. Here, we demonstrate a comprehensive overview of the gasistor structures, fabrication, performance, applications and mechanisms. Gasistor structures are compatible with memristors and gas sensors, ranging from typical sandwich structures to those with modified electrodes and porous resistive layers aimed to balance resistive switching and gas sensing functions. Meanwhile, the fabrication process involves common materials such as metals and metal oxides, while novel materials are being explored to optimize performance. It is worth noting that gasistors exhibit unique performance including room temperature sensing, variable gas selectivity, tunable recovery and self-heating against humidity. In applications, apart from gas monitoring, gasistors are used as gas-triggered switches for accident recording, and as olfactory synapses for learning memory. The gas-sensing mechanism is respectively elucidated on the molecular and atomic scales, breaking through the surface conductivity-type mechanism. Finally, the prospects and challenges of gasistors are discussed.

A smartphone-integrated paper-based colorimetric sensor array: Real-time detection and classification of flavonoids

Here, a smartphone-integrated paper-based colorimetric sensor array (PBCSA) was developed for distinguishing flavonoid-rich Citrus herbal products (FRCHPs): Citri reticulatae pericarpium, Aurantii fructus immaturus, Aurantii fructus, Citri grandis exocarpium, Citri reticulatae pericarpium viride, and Citri sarcodactylis fructus. Based on the strategy of indicator displacement assay induced by flavonoids, a 3 × 3 PBCSA with a hydrophobic barrier was constructed using inkjet printing technology. The PBCSA can accurately distinguished different species or concentrations flavonoids, and FRCHPs, demonstrating its broad applicability. After optimization with Genetic Algorithm, the Support Vector Machine (SVM) reduced the number of PBCSA sensor units from nine to five while maintaining an accuracy of 100.00 %, significantly improving the efficiency and accuracy of detection. Furthermore, the optimized SVM was integrated into a self-developed Quick Viewer app for real-time detection, greatly enhancing its practicability. This study not only presents a novel strategy for optimizing sensor arrays but also introduces a simple, economical, and real-time approach for analyzing FRCHPs.

Synthesis of cuprous iodide coordination polymers using pyridine carbohydrazide as ligands and their application in drug detection

Two coordination polymers named α-Copper(I) Iodide-3-pyridinecarbohydrazide (α-CuI-m-iah) and β-Copper(I) Iodide-3-pyridinecarbohydrazide (β-CuI-m-iah) with varying crystal structures and tunable emission wavelengths were obtained by adjusting the ligand (3-pyridinecarbohydrazide, m-iah) -to-metal clusters (CuI) ratio during the preparation process. α-CuI-m-iah was employed for the fluorescence detection of pesticide residues flumetralin, which demonstrated high selectivity, strong resistance to interference, and a wide linear detection range (1 μM-600 μM). It also exhibited a low detection limit (0.49 μM) and a fast response time, making it effective for detecting flumetralin in water samples with recovery rates ranging from 90.53 % to 97.13 %. The detection mechanism involved competitive absorption and fluorescence resonance energy transfer (FRET) between flumetralin and α-CuI-m-iah, resulting in a decrease in fluorescence intensity. This work not only introduces two coordination polymers with tunable emission behaviors but also highlights their potential for applications in pesticide residue detection.

Loading of hyaluronic acid-conjugated MoS2 nanosheets with rhodamine B for sensing hyaluronidase activity in human urine and live cells

Efficient molecule loading onto nanomaterials is a key step for advanced biosensing and imaging because of improved sensitivity and enhanced targeting of the resultant nanoprobe. In contrast to other nanomaterials, MoS2 nanosheets (NSs) possess unique advantageous of large surface area and abundant sulfur defects. Herein, we explored the conjugation of MoS2 NSs with thiol-conjugated hyaluronic acid (HA-SH) for selective detection of hyaluronidase (HAase) and specific binding to CD44 receptor-positive cancer cells. Rhodamine B (RhB) molecules were electrostatically and hydrophobically coupled to the HA-SH-MoS2 NS surface with a binding constant of 7.14 × 1016 M-1. The HA-SH-MoS2 NS-mediated fluorescence quenching of the adsorbed RhB molecules proceeds via a combination of static and dynamic quenching in the ratio of 10:1. Upon the addition of HAase, the adsorbed RhB molecules are liberated from the RB-HA-SH-MoS2 NSs via HAase-mediated hydrolysis of HA-SH. As a result, the restored fluorescence of RhB molecules is proportional to the HAase concentration. The RhB-HA-SH-MoS2 NSs achieve a detection limit of 0.37 U/mL for HAase with a linear response range from 0.05 to 4.5 U/mL and satisfactory selectivity against potential interferents. The RhB-HA-SH-MoS2 NSs not only effectively quantify HAase in urine sample but also enable selective imaging of intracellular HAase activity through CD44 receptor-mediated endocytosis.