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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Pyroptosis, ferroptosis, and autophagy in spinal cord injury: regulatory mechanisms and therapeutic targets

Regulated cell death is a form of cell death that is actively controlled by biomolecules. Several studies have shown that regulated cell death plays a key role after spinal cord injury. Pyroptosis and ferroptosis are newly discovered types of regulated cell deaths that have been shown to exacerbate inflammation and lead to cell death in damaged spinal cords. Autophagy, a complex form of cell death that is interconnected with various regulated cell death mechanisms, has garnered significant attention in the study of spinal cord injury. This injury triggers not only cell death but also cellular survival responses. Multiple signaling pathways play pivotal roles in influencing the processes of both deterioration and repair in spinal cord injury by regulating pyroptosis, ferroptosis, and autophagy. Therefore, this review aims to comprehensively examine the mechanisms underlying regulated cell deaths, the signaling pathways that modulate these mechanisms, and the potential therapeutic targets for spinal cord injury. Our analysis suggests that targeting the common regulatory signaling pathways of different regulated cell deaths could be a promising strategy to promote cell survival and enhance the repair of spinal cord injury. Moreover, a holistic approach that incorporates multiple regulated cell deaths and their regulatory pathways presents a promising multi-target therapeutic strategy for the management of spinal cord injury.

Development of a regression equation to estimate a quantifiable basic compound by the reduction prepeak measurement of quinone derived from surplus acid

We have previously reported the electrochemical analysis that is coupled with the concept of acid-base back titration and the electrochemical sensing for acids based on the reduction of 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) for determining inorganic basic compounds and amino acids. The purpose of this study is to develop a regression equation to estimate quantifiable basic compounds by this electrochemical analysis. Through the analysis of 23 compounds with various basic and acidic groups, we found that there are some quantifiable and non-quantifiable basic compounds. For example, 4-aminophenol is quantifiable because the reduction prepeak current height of DBBQ derived from surplus HCl after neutralization with 4-aminophenol was linearly decreased with increasing 4-aminophenol concentration (r2 = 0.988). In contrast, 4-aminobenzoic acid is non-quantifiable because the above voltammetric behaviors were not observed. From the relationships between the predicted pKb and pKa values of the quantifiable and non-quantifiable compounds, we found that a quantifiable basic compound without an acidic group satisfies pKb < 12, and a quantifiable basic compound with an acidic group satisfies the following equation: pKb < -0.0399(pKa)2 + 1.25pKa + 2.12. These findings are useful to predict interfering substances in analyses of real samples with complicated matrixes and to estimate quantifiable basic compounds by this electrochemical analysis.

A tumor heterogeneity-independent antigen-responsive nanocarrier enabled by bioorthogonal pre-targeting and click-activated self-immolative polymer

Bioorthogonal pre-targeting alleviate the limitations of traditional nanomedicines in passive and active targeting delivery. However, the high selectivity of bioorthogonal pre-targeting depends on the high expression level of antigens in lesion sites, and there are very limited targets with sufficient overexpression. Herein, we propose a tumor heterogeneity-independent antigen-responsive nanocarrier utilizing bioorthogonal pre-targeting and click-activated self-immolative polymers for stimulus signal conversion and amplification. This approach comprises a tetrazine (Tz) conjugated with trastuzumab (T-Tz), and a bioorthogonally activatable nanocarrier CONP which self-assembled by isocyanide and polyethylene glycol-modified poly (thiocarbamate) (NC-PTC-PEG) and hydrogen sulfide (H2S)-responsive self-immolative polymers. In practice, T-Tz is first injected to actively pretarget HER2-positive tumor cells and followed by the second injection of nanocarrier CONP. The NC-PTC-PEG in CONP undergoes a click reaction with Tz to generate H2S, thereby achieving the transformation from antigen signal to H2S signal. Finally, NO2-PTC-PEG responds to H2S stimulation and undergoes a head-to-tail depolymerization process similar to dominoes to produce a large amount of H2S, further amplifying the stimulus signal. This bioorthogonal pre-targeting combine with click-activated self-immolative polymers is anticipated to enhance the effectiveness of existing pre-targeting strategies for tumor imaging and therapy, with the potential to overcome challenges posed by tumor heterogeneity.

Engineering multifunctional surface topography to regulate multiple biological responses

Surface topography or curvature plays a crucial role in regulating cell behavior, influencing processes such as adhesion, proliferation, and gene expression. Recent advancements in nano- and micro-fabrication techniques have enabled the development of biomimetic systems that mimic native extracellular matrix (ECM) structures, providing new insights into cell-adhesion mechanisms, mechanotransduction, and cell-environment interactions. This review examines the diverse applications of engineered topographies across multiple domains, including antibacterial surfaces, immunomodulatory devices, tissue engineering scaffolds, and cancer therapies. It highlights how nanoscale features like nanopillars and nanospikes exhibit bactericidal properties, while many microscale patterns can direct stem cell differentiation and modulate immune cell responses. Furthermore, we discuss the interdisciplinary use of topography for combined applications, such as the simultaneous regulation of immune and tissue cells in 2D and 3D environments. Despite significant advances, key knowledge gaps remain, particularly regarding the effects of topographical cues on multicellular interactions and dynamic 3D contexts. This review summarizes current fabrication methods, explores specific and interdisciplinary applications, and proposes future research directions to enhance the design and utility of topographically patterned biomaterials in clinical and experimental settings.

Emerging screening platform characterises aminoquinoline structure-activity relationships with phospholipid layers

Aminoquinolines (AQ) and substituted aminoquinolines (s-AQ) interact with electrochemically monitored supported dioleoyl phosphatidylcholine (DOPC) monolayers and immobilised artificial membranes (IAM) on HPLC column. The electrochemical sensor records adsorption/partition of the compound on and into the layer as well as specific interactions due to the location of the compound in the layer. HPLC-IAM technology measures the partition coefficient between the solution and phospholipid including partition due to interaction of the positive molecular charge with the phospholipid polar heads. The monolayer interaction results were combined and normalised for the neutral compounds' lipophilicity as a log biomembrane affinity index ('log BAI') to exemplify charge and structural features in the interaction. A ChimeraX molecular modelling procedure was used to aid in the results interpretation. A compound ToxScore value was derived from 5 in vitro assays. The 'log BAI' exhibited a linear relationship with the AQ pKa values showing that the interaction was related to the molecular positive charge and to the electron donating properties of the -NH2 group. The correlation outliers showed a tendency/no tendency to H-bonding with the polar groups and a superficial/deeper location respectively in the phospholipid layer. The s-AQ 'log BAI' value displayed a power correlation with the compounds' ToxScore values.

A turn on fluorescent probe for nitroreductase activity and its application in real-time imaging of tumor hypoxia

Nitroreductase (NTR) is an endogenous reductase overexpressed in hypoxic tumors, with its levels closely correlated to the degree of hypoxia. This correlation has significant clinical implications for the analysis of tumor hypoxia, as it allows for the indirect detection of nitroreductases. Due to their simplicity, noninvasive nature, and excellent spatiotemporal resolution, various fluorescence methods have been developed for the analysis of nitroreductase and tumor hypoxia. In this study, we present the design, synthesis, in vitro evaluation, and biological application of an NTR-activated fluorescent probe, F-NTR. Utilizing an oxanthrene fluorophore as the core component, F-NTR incorporates a 4-nitrobenzene recognition group. This innovative probe, which introduces a nitro group, demonstrates high selectivity and reactivity towards nitroreductase (NTR) due to its reducing properties. Furthermore, probe F-NTR is capable of accurately identifying hypoxic environments, which provides a basis for precise detection and localization of tumors. This work lays the groundwork for future investigations into cell metabolism, tumor metabolism, and the surgical management of solid tumors under hypoxic conditions.

Enhancement of dry-hopped cider aroma through selection of apple cultivar, hop variety and yeast strain

Consumers increasingly seek more complex and tropical flavors in their alcoholic beverages. In beer and wine, yeast can release glutathione and cysteine-bound thiols from hops and grapes enhancing their tropical and fruity aromas. This study aimed to enhance cider aroma by combining yeast strains, hop and apple varieties. Yeast strains were screened for the presence and functionality of the IRC7 gene encoding the β-lyase and low temperature. Two strains showed a combination of desirable aromatic characteristics and good low temperature fermentation performance. These were used to study the impact of different hop varieties and apple cultivars. Results showed that the apple variety has the most significant impact on both chemical and sensory properties of the cider. This study suggests that dry hopping and yeast selection are effective for enhancing aroma and increasing flavor diversity in cider production.

Manganese dioxide coupled metal-organic framework as mitophagy regulator alleviates periodontitis through SIRT1-FOXO3-BNIP3 signaling axis

Periodontitis is a prevalent chronic inflammatory disease characterized by alveolar bone resorption. Its progression is closely linked to oxidative stress where reactive oxygen species (ROS) generated by mitochondria exacerbate inflammation in positive feedback loops. Strategies for mitochondrial regulation hold potential for therapeutic advances. Metal-organic frameworks (MOFs) have shown promise as nanozymes for ROS scavenging. However, inability to directly regulate cellular processes to prevent further ROS production from damaged mitochondria during persistent inflammation makes MOFs insufficient in treating periodontitis. This study synthesizes MnO2@UiO-66(Ce) by introducing MnO2 within nanoscale mesoporous UiO-66 type MOFs. MnO2 coupled with Ce clusters in MOF channels, forms a superoxide dismutase/catalase cascade catalytic system. More importantnly, manganese endows the MOFs with bioactive effects which enhances mitophagy, facilitating the removal of damaged mitochondria, thereby restoring long-term cellular homeostasis. The results demonstrate that this synergistic antioxidant solution MnO2@UiO-66 restores mitochondrial homeostasis and osteogenic activity of periodontal ligament cells in vitro and alleviates inflammatory bone resorption in a ligature-induced periodontitis model in vivo. The SIRT1-FOXO3-BNIP3 signaling axis plays a key role in this process. This study may provide a design strategy that combines a highly efficient cascade catalytic system with long-term regulation of cellular homeostasis to combat oxidative stress in chronic inflammation.

Imaging and measuring of oxygen flux produced by disproportionation of hydrogen peroxide by immobilized catalase with scanning electrochemical microscopy (SECM)

The immobilization of catalase, with the formation of protein deposits with maintained activity and a homogeneous distribution of active sites, is crucial for neutralizing reactive oxygen species in biological and industrial applications. Thus, mapping the spatial distribution of activity towards hydrogen peroxide decomposition is essential for validating immobilization procedures and analyzing heterogeneous activity. For imaging the activity of immobilized catalase, we propose the use of mercury deposited on platinum (Hg@Pt) and mercury-gold amalgam microelectrodes as tips for scanning electrochemical microscopy (SECM). Hg@Pt or Hg-Au amalgam microelectrodes allow for the selective determination of local concentrations of dissolved oxygen in solutions containing hydrogen peroxide. These SECM tips can also locally deliver H2O2 via a 2-electron oxygen reduction reaction (ORR). Asymmetric loop feedback mode (FB) and substrate generation/tip collection mode (SG/TC) were applied to image samples of catalase immobilized on glutaraldehyde-modified glass slides and spots of adsorbed enzyme on polystyrene Petri dishes delivered by means of a micropipette. Hg@Pt microelectrodes obtained by electrodeposition possess inlaid disk geometry at open circuit and become slightly recessed convex planes upon cathodic polarization. SG/TC SECM imaging results indicate that the decomposition rate of H2O2 at micrometer-sized spots of adsorbed catalase is predominantly diffusion-limited. The proposed immobilization and activity imaging methods can be applied to samples with low surface concentrations of immobilized enzymes.

Challenges and material innovations in drug delivery to central nervous system tumors

Central nervous system (CNS) tumors, encompassing a diverse array of neoplasms in the brain and spinal cord, pose significant therapeutic challenges due to their intricate anatomy and the protective presence of the blood-brain barrier (BBB). The primary treatment obstacle is the effective delivery of therapeutics to the tumor site, which is hindered by multiple physiological, biological, and technical barriers, including the BBB. This comprehensive review highlights recent advancements in material science and nanotechnology aimed at surmounting these delivery challenges, with a focus on the development and application of nanomaterials. Nanomaterials emerge as potent tools in designing innovative drug delivery systems that demonstrate the potential to overcome the limitations posed by CNS tumors. The review delves into various strategies, including the use of lipid nanoparticles, polymeric nanoparticles, and inorganic nanoparticles, all of which are engineered to enhance drug stability, BBB penetration, and targeted tumor delivery. Additionally, this review highlights the burgeoning role of theranostic nanoparticles, integrating therapeutic and diagnostic functionalities to optimize treatment efficacy. The exploration extends to biocompatible materials like biodegradable polymers, liposomes, and advanced material-integrated delivery systems such as implantable drug-eluting devices and microfabricated devices. Despite promising preclinical results, the translation of these material-based strategies into clinical practice necessitates further research and optimization.

BBPs-functionalized tetrahedral framework nucleic acid hydrogel scaffold captures endogenous BMP-2 to promote bone regeneration

Bone Morphogenetic Protein-2 (BMP-2) is a key growth factor for inducing osteogenic differentiation and promoting bone remodeling. However, the exogenous application of delivery systems for BMP-2 has been hampered by various postoperative complications, poor stability and high price. Hence, in situ enrichment of endogenous BMP-2 is promising. The discovery of a small molecule BMP-2 binding peptide (BBP) that binds specifically to BMP-2 with high affinity lays the foundation for the construction of bioactive materials that capture endogenous BMP-2. In contrast, conventional enrichment strategies have low binding efficiency due to steric hindrance caused by the disordered arrangement of BBPs. Tetrahedral framework nucleic acid (tFNA) exhibits good editability and unique three-dimensional spatial structure that enables topological control of multivalent ligands in spatial distribution. The BBPs are further designed to be stably modified on tFNA (BBPs-tFNA) via click chemistry of the azide-alkyne addition to achieve the orderly arrangement of BBPs in spatial organization, to improve the binding efficiency of BMP-2. Therefore, in this study, BBPs-tFNA is modified on biocompatible hyaluronic acid methacryloyl (HAMA) to construct the functionalized bioactive composite hydrogel scaffolds, with the aim of achieving precise and efficient capture of endogenous BMP-2, stimulating osteogenic differentiation and promoting in situ osteogenesis for bone defect repair.

An electrochemical biosensing platform initiated simultaneously from multi-directions with programmable enzyme-free strategy for DNA variant detection

Single-nucleotide variations (SNVs) represent vital clinical and biological information in the onset and progression of many cancers, but lacking of cost-effective, high-sensitive and reliable SNVs detection method. In this study, we propose a programmable electrochemical biosensing strategy initiated simultaneously from multi-directions by enzyme-free amplifying circuit for high-sensitivity SNVs detection. Through elaborate design, we utilized the power of conventional enzyme-free catalytic reaction to activate a multidirectional initiation self-assembly process, enabling multiple amplification. This innovative cascade strategy significantly improved the amplification performance and detection sensitivity. Subsequently, KRAS gene of cancer cells was used as proof-of concept model for SNVs recognition to demonstrate the capability. With the help of cascade design, the single-base differences between SNV sequence and wild-type sequence (WT) could be differentiated and amplified effectively. Consequently, abundant Y-shaped DNA structure efficiently was induced by DNA variant to generate on the electrode surface, facilitating the incorporation of methylene blue (MB) redox indicator. Therefore, a "signal-on" electrochemical biosensing platform was constructed. Our enzyme-free biosensor achieved a low detection limit of 36 aM and a broader linear range spanning from 100 aM to 1 nM under optimal experimental conditions. The capability of proposed cascaded DNA network to detect DNA variants in complex cancer cells and serum samples indicated the potential applicability in real sample analysis.

Electrochemical and computational studies on the interaction between calf-thymus DNA and skin whitening agent arbutin

The interaction between double-stranded calf thymus DNA (ctDNA) and the skin whitening agent arbutin (AR) examined by applying electrochemical and computational methods for the first time in literature. A single-use pencil graphite electrode via cyclic (CV) and differential pulse voltammetry (DPV) techniques were applied to determine the kinetic and thermodynamic parameters in the absence and presence of ctDNA. To examine the interaction process, oxidation peak currents and potentials of AR were observed prior to the addition of various ctDNA concentrations. The binding constants (KAR-DNA) and Gibbs free energy (ΔG°) values for the AR-DNA complex were determined as 1.82 × 104L/mol and -24.30 kJ/mol at 298 K, respectively. Temperature evaluation of the interaction was examined using thermodynamic parameters (ΔH°: -30.30 kJ/mol and ΔS°: -0.00197 kJ/mol) applying the Van't Hoff equation. The local interaction sites in the molecule structure were determined by applying Fukui functions and second-order perturbation theory in view of potential hydrogen binding centers. The optimized structure of AR was applied with a DNA structure revealing the binding position for AR-DNA complex. Experimental and computational examinations suggested that AR-DNA binds to ctDNA through a minor groove mode via conventional hydrogen bonds, hydrophobic interactions and van der Waals forces.

Ferredoxin NADP+ reductase for NADPH and NADH regeneration in a flow bioelectrochemical reactor

Ferredoxin-NADP+ reductase (FNR) is an efficient and selective biocatalyst to continuously regenerate the NADPH cofactor consumed in biomolecular synthesis for the chemical and pharmaceutical sectors. In this work, FNR from Chlamydomonas reinhardtii was applied to electrochemical regeneration of the nicotinamide cofactors, by combining this enzymatic catalyst in a flow reactor with the oxidation of hydrogen, a clean source of electrons and protons. FNR was immobilized on the surface of oxidized multi-walled carbon nanotubes, which allowed maintaining its activity for over six days under high flow rate. Surprisingly, this modified FNR electrode was effective not only in regenerating NADPH but also NADH. The cofactor regeneration was then applied to the NADH-dependent production of lactate from pyruvate, using L-lactate dehydrogenase (LDH) in the presence of low NAD+ concentration (10 µM). Both FNR and LDH enzymes were immobilized in the bioelectrochemical system that achieved a remarkable total turnover number (TTN) of 104 for the nicotinamide cofactor and a faradaic efficiency higher than 80 %.

Characterization of boron doped diamond electrodes with engineered sp2 carbon content and their application to structure-dependent DNA hybridization

Boron doped diamond electrodes brought a new potential in bioanalytical chemistry including studies of structure and interactions of nucleic acids. Herein, deposition conditionswere optimized to produce a set of polycrystalline BDD electrodes with comparable boron concentration in solid phase of (1.8 - 2.1) · 1021 cm-3 akin to metallic-type conductivity but with increasing sp2carbon content. Increase of[CH4]/[H2]from 0.25 % to 2.0 % during deposition led to an obvious decrease in grain size from ca.300 nm (BDD0.25) to < 100 nm (BDD2.0). Adsorption of oligodeoxynucleotides and their structural changes in the presence of K+ and Li+ ions were evaluated through enzyme-linked DNA hybridization assay in which oxidizable 1-naphthol was released from its phosphoesterbystreptavidin-alkaline phosphatase conjugate upon successful hybridization of the target oligodeoxynucleotide with a biotinylated complementary probe. With increasing sp2carbon content, the hybridization assay showed improved discrimination between a target forming guanine quadruplex (stabilized by K+ ions), yielding by 40 % - 60 % lower hybridization signal with the complementary probe, compared to the same but unstructured target oligodeoxynucleotide in the presence of Li+ions that don't stabilize the quadruplex structure. Such behaviour was observed also for commercial BDD electrode with surface roughness < 10 nm.

Matrix-designed bright near-infrared fluorophores for precision peripheral nerve imaging

The FDA's recent approval of pafolacianine, the first molecular targeted contrast agent for fluorescence-guided surgery (FGS), signifies a remarkable milestone in precision medicine. This advance offers new hope for cancer patients by enabling guided removal of cancerous tissues, where completed surgical removal remains a consistent challenge without real-time intraoperative guidance. For optimal surgical outcomes, delicate nerve tissues must be preserved to maintain patient quality of life. Despite advances in the clinical translation pipeline, the development of clinically viable nerve-specific contrast agents for FGS remains a significant challenge. Herein, a medicinal chemistry-based matrix design strategy was applied to effectively generate a synthetic roadmap permitting management of nerve-specificity within the near-infrared (NIR) oxazine fluorophore family. Many of these newly developed fluorophores demonstrated robust nerve-specificity and superior safety profiles, while also offering spectral profiles that are compatible with the clinical surgical FGS infrastructure. Notably, improving observed brightness in vivo enabled exceptional visibility of buried nerve tissue, a priority during surgical procedures. Critically, the lead probe showed a large dosage safety window capable of generating substantial contrast at doses 100x lower than the maximum tolerated dose. Following clinical translation, such NIR nerve-specific fluorophores stand poised to significantly improve outcomes for surgical patients by improving identification and visualization of surface and buried nerve tissues in real time within the surgical arena.

Interaction of major facilitator superfamily domain containing 2A with the blood-brain barrier

The functional and structural integrity of the blood-brain barrier is crucial in maintaining homeostasis in the brain microenvironment; however, the molecular mechanisms underlying the formation and function of the blood-brain barrier remain poorly understood. The major facilitator superfamily domain containing 2A has been identified as a key regulator of blood-brain barrier function. It plays a critical role in promoting and maintaining the formation and functional stability of the blood-brain barrier, in addition to the transport of lipids, such as docosahexaenoic acid, across the blood-brain barrier. Furthermore, an increasing number of studies have suggested that major facilitator superfamily domain containing 2A is involved in the molecular mechanisms of blood-brain barrier dysfunction in a variety of neurological diseases; however, little is known regarding the mechanisms by which major facilitator superfamily domain containing 2A affects the blood-brain barrier. This paper provides a comprehensive and systematic review of the close relationship between major facilitator superfamily domain containing 2A proteins and the blood-brain barrier, including their basic structures and functions, cross-linking between major facilitator superfamily domain containing 2A and the blood-brain barrier, and the in-depth studies on lipid transport and the regulation of blood-brain barrier permeability. This comprehensive systematic review contributes to an in-depth understanding of the important role of major facilitator superfamily domain containing 2A proteins in maintaining the structure and function of the blood-brain barrier and the research progress to date. This will not only help to elucidate the pathogenesis of neurological diseases, improve the accuracy of laboratory diagnosis, and optimize clinical treatment strategies, but it may also play an important role in prognostic monitoring. In addition, the effects of major facilitator superfamily domain containing 2A on blood-brain barrier leakage in various diseases and the research progress on cross-blood-brain barrier drug delivery are summarized. This review may contribute to the development of new approaches for the treatment of neurological diseases.

Bystander effect of metal byproducts released from electroporated cells after electroporation in vitro

Electrodes dissolution during electroporation releases metal ions into the medium, altering the microenvironment of electroporated cells and allowing metal ions to penetrate cell membrane. During cell membrane repair, homeostasis restoration or activation of cell death pathways, cells eliminate excess metals from the cytoplasm and membrane. This study assessed the effects of post-electroporation metal byproducts on untreated (non-electroporated) cells in vitro. CHO and HCT116 cells were electroporated with three pulse protocols (unipolar: 100 μs, 5 ms; bipolar: 2 μs) using either aluminum or stainless-steel electrodes. After electroporation, cells were transferred to fresh growth medium and incubated for 2 or 4 h. Incubation period allowed either cell recovery or the activation of cell death pathways, leading to the accumulation of metal byproducts in the incubation medium. Stainless-steel electrodes with the 5 ms pulse protocol caused a considerable increase in iron, chromium and nickel ions in incubation medium compared to aluminum electrodes or other protocols. Metal ions in incubation medium caused toxicity in non-electroporated cells, disrupting cell cycle function or inducing cell death. The observed toxicity results from combined effects of metal ions on cellular functions and the mechanisms the cells use to protect themselves from metal overload.

Self-catalyzed nitrogen-doped carbon nanotubes connected FeCo nanostructures for electrochemical sensitive detection of metol

Metol is a photographic developer that is extremely toxic to aquatic organisms due to its widespread use and improper handling in aquatic environments. Therefore, it is urgent to develop reliable strategies for its detection. Herein, we have designed an efficacious, expeditious and dependable electrochemical sensors for electrochemical determination of metol based on a self-catalyzed nitrogen-doped carbon nanotubes connected FeCo nanostructures (denoted FeCo@NC). The FeCo@NC formed from MOF-on-MOF hybrids of FeCo-MOF@ZIF-8. The porous structure formed by ZIF-8 after pyrolysis enhances diffusion kinetics, while the large number of carbon nanotubes produced by ZIF-8 has a beneficial impact on the field of electrocatalysis. The large electrically active surface area, rapid electron transfer rate and high electrocatalytic capacity exhibited by FeCo@NC were utilized to construct a highly sensitive sensor for the determination of metol. The limit of detection was found to be 0.024 μM, with a linear range of 0.08-450 μM. Furthermore, the developed sensor demonstrated excellent catalytic activity for the detection of metol, along with stability, reproducibility and selectivity. The sensor was employed for the analysis of water samples, yielding promising recovery results.

A critical review on arsenic and antimony adsorption and transformation on mineral facets

Arsenic (As) and antimony (Sb), with analogy structure, belong to VA group in the periodic table and pose a great public concern due to their potential carcinogenicity. The speciation distribution, migration and transformation, enrichment and retention, as well as bioavailability and toxicity of As and Sb are influenced by several environmental processes on mineral surfaces, including adsorption/desorption, coordination/precipitation, and oxidation/reduction. These interfacial reactions are influenced by the crystal facet of minerals with different atomic and electronic structures. This review starts with facets and examines As and Sb adsorption and transformation on mineral facets such hematite, titanium dioxide, and manganese dioxide. The main focus lies on three pressing issues that limit the understanding of the environmental fate of As and Sb: the facet-dependent intricacies of adsorption and transformation, the mechanisms underlying facet-dependent phenomena, and the impact of co-existing chemicals. We first discussed As and Sb adsorption behaviors, structures, and bonding chemistry on diverse mineral facets. Subsequently, the reactivity of various mineral facets was examined, with particular emphasis placed on their significance in the context of environmental catalysis for the oxidation of As(III) and Sb(III). Finally, the impact of co-existing cation, anion, or organic substances on the processes of adsorption and transport of As and Sb was reviewed. This comprehensive review enhances our understanding of the facet-dependent phenomena governing adsorption, transformation, and fate of contaminants. It underscores the critical role of mineral facets in dictating environmental reactions and paves the way for future research in this intriguing field.

Multifunctional injectable hydrogel with self-supplied H2S release and bacterial inhibition for the wound healing with enhanced macrophages polarization via interfering with PI3K/Akt pathway

Hydrogen sulfide (H2S) gas therapy is beneficial for accelerating wound healing and alleviating the inflammatory process, but is seriously hindered by insufficient delivery and unsustainable release in vivo. This study presents a multifunctional injectable hydrogel, OC@ε-PL-SATO, composed of oxidized hyaluronic acid and N-acetylcysteine (NAC) as an initiator, carboxymethyl chitosan and S-aroylthiooxime modified ε-Poly-(l-lysine) (ε-PL-SATO). ε-PL-SATO is a NAC-responsive H2S donor. OC@ε-PL-SATO hydrogel is designed for the desired wound healing process, with rapid gelation (<30 s) and a sustained H2S release. After mixing and gelling, H2S could be long-term released from the hydrogel and effectively drives macrophages toward M2 polarization, thereby ameliorating the inflammatory response. Revealed by transcriptome analysis, the underlying mechanism is that OC@ε-PL-SATO hydrogel releasing H2S inhibits LPS-mediated inflammatory responses in RAW264.7 cells by interfering with phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling and NF-κB activation. Furthermore, the OC@ε-PL-SATO hydrogel effectively eliminates the bacterial burden and alleviates the accompanying inflammation in a rat model of cutaneous wound infection. Importantly, the sustained generation of H2S gas significantly promotes angiogenesis and collagen deposition, ultimately accelerating the wound repair. In conclusion, this study provides a multifunctional injectable hydrogel with rapid gelatinization and continuous H2S release for accelerating the infected wound healing.

Chromium-functionalized metal-organic frameworks as highly sensitive, dual-mode sensors for real time and rapid detection of dopamine

Dopamine (DA): the brain's "feel-good" chemical that keeps us motivated, happy, and ready to take on the world. This essential neurotransmitter is involved in various physiological processes such as motor control, reward, and mood regulation. Dysregulation of DA levels is linked to several neurodegenerative diseases, emphasizing the need for sensitive and accurate detection methods for both diagnostic and therapeutic purposes. Fluorometric sensing presents an appealing, cost-effective approach to detect DA, especially in complex biological fluids. In this study, we report the synthesis and application of chromium-based metal-organic frameworks (MOFs), Cr-IA and Cr-BTC (IA: itaconic acid and BTC: benzene-1,2,4-tricarboxylic acid), as highly sensitive fluorometric sensors for DA detection in bio-fluids. Cr-IA and Cr-BTC MOFs were synthesized using a solvothermal method with their respective ligands and chromium salts, utilizing a mixed solvent system comprising water, ethanol, and dimethylformamide (DMF). Both MOFs were characterized using a variety of techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), zeta potential measurements, and energy-dispersive X-ray spectroscopy (EDS) that provided essential information on the structural integrity, surface morphology, crystallinity, thermal stability, and surface charge properties of the MOFs, confirming the successful synthesis and characterization of both materials. The synthesized MOFs exhibited remarkable fluorometric sensing capabilities for dopamine detection in HEPES buffer, aqueous solution, and human serum, showcasing strong fluorescence response with high sensitivity, selectivity, and stability across a wide pH range. Cr-IA MOF demonstrated a 3.4-fold fluorescence intensity increase in HEPES buffer, while Cr-BTC MOF achieved a 5-fold enhancement. Both MOFs showed low limits of detection, with Cr-IA and Cr-BTC achieving 21 nM and 41 nM in HEPES buffer, and 26 nM and 20 nM in water, respectively. Fluorescence quenching and visible color changes upon dopamine addition enabled real-time and visual detection, while their dose-response behavior in human serum further validated their reliability for bioanalytical applications. Cytotoxicity studies confirmed their biocompatibility, ensuring their safe use in biological systems. These findings establish Cr-IA and Cr-BTC as highly promising materials for diagnostic and therapeutic monitoring, offering potential for clinical diagnostics and broader biomedical applications.

High through-put groundwater arsenic speciation analysis using an automated flow analyzer

The occurrence of geogenic arsenic (As) in groundwater is a global public health concern. However, there remain large gaps in groundwater As data, making it difficult to identify non-compliant domestic wells, partly due to lack of low-cost methods capable of rapid As analysis. Therefore, the development of high through-put and reliable on-site determination methods for inorganic As is essential. Herein, a portable automated analyzer was developed for the determination of arsenite (As(III)), arsenate (As(V)) and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry. After the optimization of the chemical reactions and flow manifold, the system demonstrated a high sample through-put (4.8/h for As(III), As(V) and phosphate analysis), allowing this system to screen 125 samples in 24 h. Other advantages include low operational costs (0.3 CNY per sample), appropriate sensitivity for contaminated groundwater (detection limits of 4.7 µg/L, 8.3 µg/L and 5.4 µg/L for As(III), As(V) and phosphate, respectively), good linearity (R2 > 0.9996 at As concentrations up to 1600 µg/L) and high precision (relative standard deviations of 3.5% and 2.8% for As(III) and As(V), respectively). The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain, northwestern China, with total As concentrations ranging from 75.7 to 295.0 µg/L, independently assessing As speciation, providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.

Inhibition of the cGAS-STING pathway: contributing to the treatment of cerebral ischemia-reperfusion injury

The cGAS-STING pathway plays an important role in ischemia-reperfusion injury in the heart, liver, brain, and kidney, but its role and mechanisms in cerebral ischemia-reperfusion injury have not been systematically reviewed. Here, we outline the components of the cGAS-STING pathway and then analyze its role in autophagy, ferroptosis, cellular pyroptosis, disequilibrium of calcium homeostasis, inflammatory responses, disruption of the blood-brain barrier, microglia transformation, and complement system activation following cerebral ischemia-reperfusion injury. We further analyze the value of cGAS-STING pathway inhibitors in the treatment of cerebral ischemia-reperfusion injury and conclude that the pathway can regulate cerebral ischemia-reperfusion injury through multiple mechanisms. Inhibition of the cGAS-STING pathway may be helpful in the treatment of cerebral ischemia-reperfusion injury.

Solvent volatilization annealing-prepared Janus film with asymmetric bioadhesion and inherent biological functions to expedite oral ulcer healing

Fabrication of layered bioadhesives with asymmetric bioadhesion, on-demand detachment and inherent biological functions remains a great challenge. This work reports a novel and generalizable solvent volatilization-induced annealing (SVA) strategy to prepare a Janus film with an integrated dual layer structure, asymmetric adhesion, on-demand detachment and inherent biological functions. Depositing polyvinyl pyrrolidone/caffeic acid/lipoic acid (PVP/CA/LA) ethanol solutions onto an ethylcellulose (EC) layer and applying SVA strategy can integrate two layers in molecular-level to obtain the dual-layered Janus film. Porous PVP/p(CA-LA) surface pressed onto wet tissues can absorb interfacial water to form tight tissue contact, and their functional groups can form abundant bonds to induce robust bioadhesion. In contrast, dense EC surface limits water absorption and exhibits minimal adhesion of proteins, cells and tissues. Furthermore, the adhered Janus film can be detached by using a glutathione/sodium bicarbonate solution. Additionally, CA and LA provide the film with desired antibacterial, antioxidant, and anti-inflammatory properties. Finally, by providing the antibacterial and anti-inflammatory microenvironment, the Janus film promotes angiogenesis and significantly expedites the healing of the oral ulcers in rats. This work not only introduces a novel approach for preparing multi-layered and asymmetric materials, but also paving the way for developing adhesive materials with inherent biological functions.

Comprehensive analysis of oxidized arachidonoyl-containing glycerophosphocholines using ion mobility spectrometry-mass spectrometry

The biological significance of oxidized arachidonoyl-containing glycerophosphocholines, exemplified by the oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (oxPAPC), in pathological processes is well-established. However, despite their widespread use in redox lipidomics research, the precise chemical composition of the heterogeneous mixtures of oxPAPC generated in vitro -including the high prevalence of isomers and the oxidation mechanisms involved- remain inadequately understood. To address these knowledge gaps, we developed a multidimensional in-house database from a commercial oxPAPC preparation -employing Liquid Chromatography coupled to Quadrupole Time-of-Flight Mass Spectrometry (LC-QTOF-MS) and Ion Mobility Spectrometry-Mass Spectrometry (IMS-MS). This database includes lipid names, retention times, accurate mass values (m/z), adduct profiles, MS/MS information, as well as collision cross-section (CCS) values. Our investigation elucidated 34 compounds belonging to distinct subsets of oxPAPC products, encompassing truncated, full-length, and cyclized variants. The integration of IMS-MS crucially facilitated: (i) structural insights among regioisomers, exemplified by the 5,6-PEIPC and 11,12-PEIPC epoxy-isoprostane derivatives, (ii) novel Collision Cross Section (CCS) values, and (iii) cleaner MS/MS spectra for elucidating the fragmentation mechanisms involved to yield specific fragment ions. These diagnostic ions were employed to successfully characterize full-length isomers present in human plasma samples from patients with mucormycosis. This comprehensive oxPAPC characterization not only advances the understanding of lipid peroxidation products but also enhances analytical capabilities for in vitro-generated oxidized mixtures. The implementation of this robust database, containing multiple orthogonal (i.e., independent) pieces of information, will serve as a comprehensive resource for the field.

Stromal cell-derived factor-encapsulated nanoparticles target ischemic myocardium and attenuate myocardial injury via proangiogenic effects

Lipid bilayer nanoparticles (NPs) with and without stromal cell-derived factor (SDF) were created to target and treat ischemia/reperfusion (I/R)-injured myocardium. Male Wistar rats were subjected to myocardial I/R insult and, at reperfusion, randomized to receive systemic injections of 5 mL/kg PBS, 6 μg/kg of NPs, SDF, or SDF-NPs. Four days after treatment, SDF-NPs circulated and accumulated selectively in the ischemic myocardium, with an SDF concentration roughly three times that of the other three treatments. SDF-NP-treated rats had more endothelial progenitor cells (EPCs) in the blood and preserved capillaries and arterioles in the ischemic border myocardium four weeks post-treatment, which improved microvascular perfusion, reduced fibrosis, and preserved heart function. Notably, hearts treated with SDF-NPs retained left ventricular function at four weeks compared to 1-day post-treatment, with a 2.7 ± 1.2 % increase in the ejection fraction. The other three treatments decreased left ventricular function at four weeks (PBS: -7.8 ± 1.2 %, P < 0.001; empty NPs: -3.9 ± 1.3 %, P = 0.004; SDF solution: -5.1 ± 1.3 %, P = 0.001). Hence, systemically injected SDF-NPs selectively accumulate in ischemic cardiac tissue, shielding the myocardium from I/R injury via angiogenic effects through increased EPC migration. This novel cardioprotective drug may be clinically translatable.

Ru/Co-N,Zn-doped carbon nanocubes with multiple enzyme-like activities for high-efficiency glucose detection and self-supplying cascaded nanodrug in synergistic cancer therapy

Nanozyme technology is increasingly utilized in biosensing and biomedicine fields. To advancing this technology, it is pivotal for constructing high-quality nanozymes and expanding their multifunctional applications. Herein, Co nanoparticles embedded within N,Zn-doped carbon nanocubes (Co-N,Zn-CNCs) were facilely prepared by pyrolysis, followed by surface modification with Ru nanoparticles (termed Ru/Co-N,Zn-CNCs). The resultant material exhibited peroxidase (POD)-, catalase (CAT)- and glutathione oxidase (GSHOx)-mimic activities. After attachment of glucose oxidase (GOx), a bifunctional self-supply cascaded nanodrug system (Ru/Co-N,Zn-CNCs-GOx) was established. Specifically, the nanozyme based colorimetric sensor was constructed for visually glucose detection, showing a good linear relationship in a range of 10 to 2000 μM and a low detection limit of 0.61 μM. Further, the cascaded nanodrug exhibited high-efficiency for eradicating cancer cells by reactive oxygen species mediated chemodynamic therapy, hypoxia alleviation, and starvation therapy, coupled by realizing ferroptosis of the cancer cells. The versatile cascaded nanozyme shows potential applications in biosensing, cancer therapy, and beyond.

An injectable hydrogel for hemostasis and tumor suppression in intraoperative breast cancer

In the period between surgery and systemic therapy for breast cancer, residual tumor cells may proliferate, leading to tumor recurrence. Additionally, intraoperative wound bleeding may cause surgical failure or the spread of tumor cells. This study introduces an innovative injectable hydrogel composed of oxidized hyaluronic acid (OHA) loaded 5-fluorouracil (5-FU) and N-carboxyethyl chitosan (CEC), designed for intraoperative hemostasis and tumor suppression in intraoperative breast cancer. The CEC/OHA injectable hydrogel was synthesized through a Schiff base reaction between the aldehyde group of OHA and the amino group of CEC, incorporating 5-FU during hydrogel formation. This CEC/OHA injectable hydrogel demonstrated hemostatic effects comparable to gelatin sponges in both an in vivo rat liver hemorrhage model and an in vitro rat tail amputation model. When loaded with 5-FU, the injectable hydrogel effectively inhibited the proliferation of MDA-MB-231 breast cancer cells in vitro, significantly inhibited tumor growth and recurrence in vivo, and did not induce significant damage or inflammatory response in any major organ. This CEC/OHA & 5-FU injectable hydrogel is envisioned as a complementary therapeutic regimen during the intraoperative period in breast cancer surgery to prevent hemostasis and tumor recurrence.

Enhancing biofabrication: Shrink-resistant collagen-hyaluronan composite hydrogel for tissue engineering and 3D bioprinting applications

Biofabrication represents a promising technique for creating tissues for regeneration or as models for drug testing. Collagen-based hydrogels are widely used as suitable matrix owing to their biocompatibility and tunable mechanical properties. However, one major challenge is that the encapsulated cells interact with the collagen matrix causing construct shrinkage. Here, we present a hydrogel with high shape fidelity, mimicking the major components of the extracellular matrix. We engineered a composite hydrogel comprising gallic acid (GA)-functionalized hyaluronic acid (HA), collagen I, and HA-coated multiwall carbon nanotubes (MWCNT). This hydrogel supports cell encapsulation, exhibits shear-thinning properties enhancing injectability and printability, and importantly significantly mitigates shrinkage when loaded with human fibroblasts compared to collagen I hydrogels (∼20 % vs. > 90 %). 3D-bioprinted rings utilizing human fibroblast-loaded inks maintain their shape over 7 days in culture. Furthermore, inclusion of HAGA into collagen I hydrogels increases mechanical stiffness, radical scavenging capability, and tissue adhesiveness. Notably, the here developed hydrogel is also suitable for human induced pluripotent stem cell-derived cardiomyocytes and allows printing of functional heart ventricles responsive to pharmacological treatment. Cardiomyocytes behave similar in the newly developed hydrogels compared to collagen I, based on survival, sarcomere appearance, and calcium handling. Collectively, we developed a novel material to overcome the challenge of post-fabrication matrix shrinkage conferring high shape fidelity.

Grain boundary/doping/architecture engineering in hierarchical N-doped CuO microflowers derived from Cu-based metal-organic framework architectures for highly efficient nonenzymatic glucose detection

Glucose detection is essential in clinical medicine, and the reasonable design of metal oxide electrocatalysts plays a crucial role in developing efficient nonenzymatic glucose (NEG) sensors. Herein, grain boundary/doping/architecture engineering is used to tailor the structures of CuO nanomaterials and tune their surface/electron-transfer properties toward enhanced electrocatalytic oxidation of glucose. Hierarchical N-doped CuO microflowers (N-CuO-MF) are synthesized using a facile hydrothermal method, followed by calcination. N-CuO-MF consist of ultrathin nanoflakes (ca. 20 nm), endowing them with a large specific surface area. Moreover, the nanoflakes are composed of ultrasmall nanoparticles, resulting in abundant grain boundaries. Notably, N-CuO-MF are derived from a precursor of Cu-based metal-organic framework (Cu-MOF) architectures, which is fabricated through a bottom-up route using glycerol as the capping agent/solvent and 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br) as the template/N source. Glycerol competitively coordinates with Cu2+, leading to the formation of 2D subunits. Moreover, [C16mim]+ cations attach to the subunit surfaces via electrostatic interaction, thus achieving Cu-MOF with a 3D hierarchical structure. As expected, the synergistic effect of rich grain boundaries, N doping, ultrathin nanoflakes, and hierarchical architecture enhances the adsorption of glucose on the electrode surfaces, accelerates electron transfer, and exposes more active sites for glucose oxidation. Accordingly, N-CuO-MF exhibit wide linear ranges, high sensitivity, fast response time, low detection limit, excellent selectivity, and good stability. Owing to their highly efficient electrocatalytic properties, N-CuO-MF could be explored as potential electrocatalysts in NEG sensors for rapid diagnostic tests and health monitoring.

Arsenic speciation in more than 1600 freshwater fish samples from fifty-three waterbodies in Alberta, Canada

We report here arsenic speciation in 1643 freshwater fish samples, representing 14 common fish species from 53 waterbodies in Alberta, Canada. Arsenic species were extracted from fish muscle tissue. Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography (HPLC) and quantified using inductively coupled plasma mass spectrometry (ICPMS). The total arsenic concentrations in fish ranged from 2.8 to 1200 µg/kg (in wet weight of sample) (mean 71 ± 101 µg/kg), which are all below the 2000 µg/kg (wet weight) maximum allowable total arsenic in fish, recommended by the Ontario Ministry of the Environment. In 99.7%, or 1638 of all 1643 freshwater fish samples analyzed, arsenobetaine (AsB) was detectable, with concentrations higher than the method detection limit of 0.25 µg/kg (wet weight). Dimethylarsinic acid (DMA) was detectable (concentration >0.25 µg/kg) in 92.1%, or 1514 of the 1643 freshwater fish samples. Inorganic arsenate (iAsV) was detectable (>0.25 µg/kg) in 1119 fish (i.e., 68.1% of 1643 samples). Monomethylarsonic acid (MMA) was detectable (>0.25 µg/kg) in 418 fish (25.4% of 1643 samples). The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude, ranging from below the method detection limit of 0.25 µg/kg to the maximum concentrations of 380 µg/kg for AsB, 150 µg/kg for DMA, 70 µg/kg for iAsV, and 51 µg/kg for MMA. AsB made up 46.1% ± 26.2% of total arsenic species. Arsenic speciation patterns varied between lake whitefish, northern pike, and walleye, the three most common types of fish analyzed. The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye, and conversely, the relative proportion of iAsV was lower in northern pike. Seven unknown arsenic species were detected, and their chromatographic retention time did not match with those of available arsenic standards. At least one unknown arsenic species was detected in 33.4%, or 549 of 1643 freshwater fish samples. The concentrations of unknown arsenic species were as high as 61 µg/kg. Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.

Photochemical bomb: Precision nuclear targeting to activate cGAS-STING pathway for enhanced bladder cancer immunotherapy

Activating the cGAS-STING pathway presents a promising strategy to enhance the innate immunity and combat the immunosuppressive tumor microenvironment. One key mechanism for triggering this pathway involves the release of damaged DNA fragments caused by nuclear DNA damage. However, conventional cGAS-STING agonists often suffer from limited nucleus-targeting efficiency and potential biotoxicity. In this study, we develop a novel nucleus-targeting theranostic nanoplatform designed to synergistically activate the cGAS-STING pathway through the combination of photodynamic therapy (PDT) and cisplatin chemotherapy for orthotopic bladder cancer treatment. The nanoplatform integrates a new high-performance type-I photosensitizer with near-infrared-II emission, a TATSA peptide for enhanced nuclear targeting, and a biosafe platinum (IV) cisplatin prodrug. Upon NIR laser irradiation, the nanoagent delivers synergistic nucleus-targeted PDT and chemotherapy, causing substantial DNA damage and the release of double-stranded DNA, which subsequently activates the cGAS-STING pathway and triggers potent immunomodulation. This activation promotes dendritic cells maturation, enhances cytotoxic T infiltration, and facilitates the formation of memory T cells, leading to immune microenvironment remodeling, and long-lasting immune memory, thus effectively inhibiting orthotopic bladder tumors and reducing the risk of metastasis. These findings highlight the substantial potential of this strategy to overcome the limitations of current immunotherapies by leveraging nucleus-targeted PDT to activate the cGAS-STING pathway for cancer treatment.

Arsenic speciation in freshwater fish using high performance liquid chromatography and inductively coupled plasma mass spectrometry

Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption. While marine fish have attracted much research interest due to their higher arsenic content, research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels. We describe here a sensitive method and its application to the quantification of arsenic species in freshwater fish. Arsenic species from fish tissues were extracted using a methanol/water mixture (1:1 vol. ratio) and ultrasound sonication. Anion-exchange high-performance liquid chromatography (HPLC) enabled separation of arsenobetaine (AsB), inorganic arsenite (iAsIII), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), inorganic arsenate (iAsV), and three new arsenic species. Inductively coupled plasma mass spectrometry (ICPMS) provided highly sensitive and specific detection of arsenic. A limit of detection of 0.25 µg/kg (wet weight fish tissue) was achieved for the five target arsenic species: AsB, iAsIII, DMA, MMA, and iAsV. A series of experiments were conducted to ensure the accuracy and validity of the analytical method. The method was successfully applied to the determination of arsenic species in lake whitefish, northern pike, and walleye, with AsB, DMA, and iAsV being frequently detected. Three new arsenic species were detected, but their chromatographic retention times did not match with those of any available arsenic standards. Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.