Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 910
Filtrer
1.
Bioelectromagnetics ; 2024 Aug 04.
Article de Anglais | MEDLINE | ID: mdl-39099158

RÉSUMÉ

With the development and widespread application of electromagnetic technology, the health hazards of electromagnetic radiation have attracted much attention and concern. The effect of electromagnetic radiation on the nervous system, especially on learning, memory, and cognitive functions, is an important research topic in the field of electromagnetic biological effects. Most previous studies were conducted with rodents, which are relatively mature. As research has progressed, studies using non-human primates as experimental subjects have been carried out. Compared to rodents, non-human primates such as macaques not only have brain structures more similar to those of humans but also exhibit learning and memory processes that are similar. In this paper, we present a behavioral test system for the real-time evaluation of the working memory (WM) of macaques in a microwave environment. The system consists of two parts: hardware and software. The hardware consists of four modules: the operation terminal, the control terminal, the optical signal transmission, and detection module and the reward feedback module. The software program can implement the feeding learning task, the button-pressing learning task, and the delayed match-to-sample task. The device is useful for the real-time evaluation of the WM of macaques in microwave environments, showing good electromagnetic compatibility, a simple and reliable structure, and easy operation.

2.
Small ; : e2403869, 2024 Aug 05.
Article de Anglais | MEDLINE | ID: mdl-39101346

RÉSUMÉ

Cancer metastasis poses significant challenges in current clinical therapy. Osthole (OST) has demonstrated efficacy in treating cervical cancer and inhibiting metastasis. Despite these positive results, its limited solubility, poor oral absorption, low bioavailability, and photosensitivity hinder its clinical application. To address this limitation, a glutathione (GSH)-responded nano-herb delivery system (HA/MOS@OST&L-Arg nanoparticles, HMOA NPs) is devised for the targeted delivery of OST with cascade-activatable nitric oxide (NO) release. The HMOA NPs system is engineered utilizing enhanced permeability and retention (EPR) effects and active targeting mediated by hyaluronic acid (HA) binding to glycoprotein CD44. The cargoes, including OST and L-Arginine (L-Arg), are released rapidly due to the degradation of GSH-responsive mesoporous organic silica (MOS). Then abundant reactive oxygen species (ROS) are produced from OST in the presence of high concentrations of NAD(P)H quinone oxidoreductase 1 (NQO1), resulting in the generation of NO and subsequently highly toxic peroxynitrite (ONOO-) by catalyzing guanidine groups of L-Arg. These ROS, NO, and ONOO- molecules have a direct impact on mitochondrial function by reducing mitochondrial membrane potential and inhibiting adenosine triphosphate (ATP) production, thereby promoting increased apoptosis and inhibiting metastasis. Overall, the results indicated that HMOA NPs has great potential as a promising alternative for the clinical treatment of cervical cancer.

3.
J Environ Manage ; 367: 122022, 2024 Aug 05.
Article de Anglais | MEDLINE | ID: mdl-39106802

RÉSUMÉ

Identifying the driving forces of surface water quality variations is crucial for urban environmental management, especially in densely populated regions. Statistic mapping is an approach that allows researchers to directly explore the response of surface water quality to potential drivers. Conventionally, these methods encounter a mixture of issues, including nonlinear relationships and information on multiple time-scale, caused by disparities in the influencing frequencies and degrees of driving factors. In this research, a nonlinear direct-mapping approach was developed to quantitatively analyze the driving force of surface water quality under multiple time scales. This approach separated the fluctuation and trend information from water quality data and then established a direct-mapping relationship, thereby achieving the visible multilayer structure containing both linear and nonlinear information from the time scale. Typical water pollutants including total nitrogen (TN) and total phosphorus (TP) in the Pearl River Delta (PRD), were used to verify the methodology and compare its ability to analyze driving forces with traditional statistic approaches. The results demonstrated that this approach could establish a visual multilayer mapping structure with strong interpretability, which effectively captured the contained nonlinear information, thus improving the fitting degree by 12.43% compared with traditional methods. Moreover, it successfully identified the dominant driving forces of TN and TP in the PRD as human activities related to NO2 and PM and natural factors. Its application in the changing environment demonstrated a potentially increased risk of TP in the PRD under multiple scenarios. Overall, this approach could serve as a reliable reference for pollution early warning in the short term and for industrial structure adjustment planning in the long term.

6.
Arch Pathol Lab Med ; 2024 Aug 02.
Article de Anglais | MEDLINE | ID: mdl-39089688

RÉSUMÉ

CONTEXT.­: The Japanese Society of Hepato-Biliary-Pancreatic Surgery guidelines propose a classification scheme that differs from the Union for International Cancer Control (UICC) system, in which the anatomic U-P point is the boundary between intrahepatic cholangiocarcinoma and perihilar cholangiocarcinoma (PCC). OBJECTIVE.­: To investigate whether this classification system improves clinicopathologic and genomic differentiation. DESIGN.­: Fifty-eight PCC cases defined by the UICC system were collected and classified into intrahepatic PCC (IPCC) and extrahepatic PCC (EPCC) categories using U-P point division. They were analyzed by next-generation sequencing using a panel that targeted 425 cancer-related genes. RESULTS.­: The IPCC group exhibited a significant larger tumor size compared with the EPCC group (4.67 ± 2.44 cm versus 2.50 ± 0.91 cm, P = .002). The mutation frequency of KRAS proto-oncogene, GTPase (KRAS) Q61 was also significantly higher in the IPCC group than in the EPCC group (16.7% versus 0.0%, P = .03). There were no statistically significant differences in other pathologic features or genomic characteristics, including tumor mutation burden and microsatellite instability. Significant differences in gene mutation rates, such as phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA; 0.0% versus 15.8%, P = .01) and tumor protein p53 (TP53; 34.5% versus 63.2%, P = .04), were observed between PCC and adjacent biliary tract cancers. CONCLUSIONS.­: This study offers valuable insight into the clinicopathologic and genomic features of PCC. It is proposed that the U-P point division may have limited potential to refine the characterization of PCC regarding these features, and that the UICC classification system can readily demonstrate the molecular specificity of PCC.

7.
Anal Chem ; 2024 Aug 02.
Article de Anglais | MEDLINE | ID: mdl-39093612

RÉSUMÉ

The coculture of patient-derived tumor organoids (PDOs) and autologous immune cells has been considered as a useful ex vivo surrogate of in vivo tumor-immune environment. However, the immune interactions between PDOs and autologous immune cells, including immune-mediated killing behaviors and immune-related cytokine variations, have yet to be quantitatively evaluated. This study presents a microfluidic chip for quantifying interactions between PDOs and autologous immune cells (IOI-Chip). A baffle-well structure is designed to ensure efficient trapping, long-term coculturing, and in situ fluorescent observation of a limited amount of precious PDOS and autologous immune cells, while a microbeads-based immunofluorescence assay is designed to simultaneously quantify multiple kinds of immune-related cytokines in situ. The PDO apoptosis and 2 main immune-related cytokines, TNF-α and IFN-γ, are simultaneously quantified using samples from a lung cancer patient. This study provides, for the first time, a capability to quantify interactions between PDOs and autologous immune cells at 2 levels, the immune-mediated killing behavior, and multiple immune-related cytokines, laying the technical foundation of ex vivo assessment of patient immune response.

8.
Med ; 2024 Jun 28.
Article de Anglais | MEDLINE | ID: mdl-38964334

RÉSUMÉ

Intestinal bacteria help keep humans healthy by regulating lipid and glucose metabolism as well as the immunological and neurological systems. Oral treatment using intestinal bacteria is limited by the high acidity of stomach fluids and the immune system's attack on foreign bacteria. Scientists have created coatings and workarounds to overcome these limitations and improve bacterial therapy. These preparations have demonstrated promising outcomes, with advances in synthetic biology and optogenetics improving their focused colonization and controlled release. Engineering bacteria preparations have become a revolutionary therapeutic approach that converts intestinal bacteria into cellular factories for medicinal chemical synthesis. The present paper discusses various aspects of engineering bacteria preparations, including wrapping materials, biomedical uses, and future developments.

9.
Int J Biol Macromol ; 275(Pt 1): 133624, 2024 Jul 02.
Article de Anglais | MEDLINE | ID: mdl-38964685

RÉSUMÉ

Golgi membrane protein 1 (Golm1), a transmembrane protein with diverse subcellular localizations, has garnered significant attention in recent years due to its strong association with the development and progression of liver diseases and numerous cancers. Interestingly, although Golm1 is a membrane protein, the C-terminal of Golm1, which contains a coiled coil domain and a flexible acid region, can also be detected in the plasma of patients with various liver diseases. Notably, the coiled coil domain of serum Golm1 is postulated to play a pivotal role in physiological and pathological functions. However, little is currently known about the structure of this coiled coil domain and the full-length protein, which may limit our understanding of Golm1. Therefore, this study aims to address this gap in knowledge and reports the first crystal structure of the coiled coil domain of Golm1 at a resolution of 2.28 Å. Meanwhile, we have also confirmed that the Golm1 coiled coil domain in solution can form tetramer. Our results reveal that Golm1 can form a novel tetrameric structure that differs from the previous reported dimeric structure Golm1 could assemble, which may provide novel insights into the diversity of physiological functions and pathological roles.

10.
Nat Commun ; 15(1): 6305, 2024 Jul 26.
Article de Anglais | MEDLINE | ID: mdl-39060305

RÉSUMÉ

Ionizable lipid nanoparticles (LNPs) are seeing widespread use in mRNA delivery, notably in SARS-CoV-2 mRNA vaccines. However, the expansion of mRNA therapies beyond COVID-19 is impeded by the absence of LNPs tailored for diverse cell types. In this study, we present the AI-Guided Ionizable Lipid Engineering (AGILE) platform, a synergistic combination of deep learning and combinatorial chemistry. AGILE streamlines ionizable lipid development with efficient library design, in silico lipid screening via deep neural networks, and adaptability to diverse cell lines. Using AGILE, we rapidly design, synthesize, and evaluate ionizable lipids for mRNA delivery, selecting from a vast library. Intriguingly, AGILE reveals cell-specific preferences for ionizable lipids, indicating tailoring for optimal delivery to varying cell types. These highlight AGILE's potential in expediting the development of customized LNPs, addressing the complex needs of mRNA delivery in clinical practice, thereby broadening the scope and efficacy of mRNA therapies.


Sujet(s)
COVID-19 , Apprentissage profond , Nanoparticules , ARN messager , SARS-CoV-2 , ARN messager/génétique , ARN messager/métabolisme , ARN messager/administration et posologie , Humains , SARS-CoV-2/génétique , Nanoparticules/composition chimique , Lipides/composition chimique , Techniques de transfert de gènes , Vaccins contre la COVID-19 , Vaccins à ARNm , Lignée cellulaire , Techniques de chimie combinatoire , Liposomes
11.
Brief Bioinform ; 25(4)2024 May 23.
Article de Anglais | MEDLINE | ID: mdl-38975893

RÉSUMÉ

The process of drug discovery is widely known to be lengthy and resource-intensive. Artificial Intelligence approaches bring hope for accelerating the identification of molecules with the necessary properties for drug development. Drug-likeness assessment is crucial for the virtual screening of candidate drugs. However, traditional methods like Quantitative Estimation of Drug-likeness (QED) struggle to distinguish between drug and non-drug molecules accurately. Additionally, some deep learning-based binary classification models heavily rely on selecting training negative sets. To address these challenges, we introduce a novel unsupervised learning framework called DrugMetric, an innovative framework for quantitatively assessing drug-likeness based on the chemical space distance. DrugMetric blends the powerful learning ability of variational autoencoders with the discriminative ability of the Gaussian Mixture Model. This synergy enables DrugMetric to identify significant differences in drug-likeness across different datasets effectively. Moreover, DrugMetric incorporates principles of ensemble learning to enhance its predictive capabilities. Upon testing over a variety of tasks and datasets, DrugMetric consistently showcases superior scoring and classification performance. It excels in quantifying drug-likeness and accurately distinguishing candidate drugs from non-drugs, surpassing traditional methods including QED. This work highlights DrugMetric as a practical tool for drug-likeness scoring, facilitating the acceleration of virtual drug screening, and has potential applications in other biochemical fields.


Sujet(s)
Découverte de médicament , Découverte de médicament/méthodes , Préparations pharmaceutiques/composition chimique , Préparations pharmaceutiques/classification , Algorithmes , Apprentissage profond , Intelligence artificielle
12.
Int J Biol Sci ; 20(9): 3656-3674, 2024.
Article de Anglais | MEDLINE | ID: mdl-38993561

RÉSUMÉ

Ubiquitination plays a pivotal regulatory role in tumor progression. Among the components of the ubiquitin-proteasome system (UPS), ubiquitin-protein ligase E3 has emerged as a key molecule. Nevertheless, the biological functions of E3 ubiquitin ligases and their potential mechanisms orchestrating glycolysis in gastric cancer (GC) remain to be elucidated. In this study, we conducted a comprehensive transcriptomic analysis to identify the core E3 ubiquitin ligases in GC, followed by extensive validation of the expression patterns and clinical significance of Tripartite motif-containing 50 (TRIM50) both in vitro and in vivo. Remarkably, we found that TRIM50 was downregulated in GC tissues, associated with malignant progression and poor patient survival. Functionally, overexpression of TRIM50 suppressed GC cell proliferation and indirectly mitigated the invasion and migration of GC cells by inhibiting the M2 polarization of tumor-associated macrophages (TAMs). Mechanistically, TRIM50 inhibited the glycolytic pathway by ubiquitinating Phosphoglycerate Kinase 1 (PGK1), thereby directly suppressing GC cell proliferation. Simultaneously, the reduction in lactate led to diminished M2 polarization of TAMs, indirectly inhibiting the invasion and migration of GC cells. Notably, the downregulation of TRIM50 in GC was mediated by the METTL3/YTHDF2 axis in an m6A-dependent manner. In our study, we definitively identified TRIM50 as a tumor suppressor gene (TSG) that effectively inhibits glycolysis and the malignant progression of GC by ubiquitinating PGK1, thus offering novel insights and promising targets for the diagnosis and treatment of GC.


Sujet(s)
Glycolyse , Phosphoglycerate kinase , Tumeurs de l'estomac , Protéines à motif tripartite , Ubiquitin-protein ligases , Ubiquitination , Tumeurs de l'estomac/métabolisme , Tumeurs de l'estomac/anatomopathologie , Tumeurs de l'estomac/génétique , Humains , Phosphoglycerate kinase/métabolisme , Phosphoglycerate kinase/génétique , Lignée cellulaire tumorale , Ubiquitin-protein ligases/métabolisme , Ubiquitin-protein ligases/génétique , Protéines à motif tripartite/métabolisme , Protéines à motif tripartite/génétique , Prolifération cellulaire/génétique , Animaux , Souris , Souris nude , Évolution de la maladie , Mouvement cellulaire/génétique , Souris de lignée BALB C , Régulation de l'expression des gènes tumoraux , Methyltransferases/métabolisme , Methyltransferases/génétique
13.
J Chem Inf Model ; 64(14): 5570-5579, 2024 Jul 22.
Article de Anglais | MEDLINE | ID: mdl-38958581

RÉSUMÉ

One of the most challenging tasks in modern medicine is to find novel efficient cancer therapeutic methods with minimal side effects. The recent discovery of several classes of organic molecules known as "molecular jackhammers" is a promising development in this direction. It is known that these molecules can directly target and eliminate cancer cells with no impact on healthy tissues. However, the underlying microscopic picture remains poorly understood. We present a study that utilizes theoretical analysis together with experimental measurements to clarify the microscopic aspects of jackhammers' anticancer activities. Our physical-chemical approach combines statistical analysis with chemoinformatics methods to design and optimize molecular jackhammers. By correlating specific physical-chemical properties of these molecules with their abilities to kill cancer cells, several important structural features are identified and discussed. Although our theoretical analysis enhances understanding of the molecular interactions of jackhammers, it also highlights the need for further research to comprehensively elucidate their mechanisms and to develop a robust physical-chemical framework for the rational design of targeted anticancer drugs.


Sujet(s)
Antinéoplasiques , Chimio-informatique , Humains , Antinéoplasiques/pharmacologie , Antinéoplasiques/composition chimique , Chimio-informatique/méthodes , Tumeurs/traitement médicamenteux , Tumeurs/anatomopathologie , Lignée cellulaire tumorale , Modèles moléculaires
14.
Adv Sci (Weinh) ; : e2401171, 2024 Jul 08.
Article de Anglais | MEDLINE | ID: mdl-38973363

RÉSUMÉ

Ripretinib, a broad-spectrum inhibitor of the KIT and PDGFRA receptor tyrosine kinases, is designated as a fourth-line treatment for gastrointestinal stromal tumor (GIST). It is tailored for patients resistant to imatinib, sunitinib, and regorafenib. As its increasing use, instances of resistance to ripretinib are becoming more frequent. Unfortunately, there are currently no scientifically mature treatment options available for patients resistant to ripretinib. Posttranslational modifications (PTMs) such as ubiquitination, in conjunction with its interplay with other modifications, play a collective role in regulating tumor initiation and progression. However, the specific association between ubiquitination and ripretinib resistance is not reported. Through proteome-ubiquitinome sequencing, increased levels of the USP5 protein and decreased ubiquitination in ripretinib-resistant GISTs are detected. Subsequent examination of the mass spectrometry findings validated the interaction through which TRIM21 governs USP5 expression via ubiquitination, and USP5 regulates MDH2 expression through deubiquitination, consequently fostering ripretinib resistance in GIST. Moreover, ZDHHC18 can palmitoylate MDH2, preventing its ubiquitination and further increasing its protein stability. The research underscores the correlation between posttranslational modifications, specifically ubiquitination, and drug resistance, emphasizing the potential of targeting the USP5-MDH2 axis to counteract ripretinib resistance in GIST.

15.
Radiology ; 312(1): e232387, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-39012251

RÉSUMÉ

Background Preoperative local-regional tumor staging of gastric cancer (GC) is critical for appropriate treatment planning. The comparative accuracy of multiparametric MRI (mpMRI) versus dual-energy CT (DECT) for staging of GC is not known. Purpose To compare the diagnostic accuracy of personalized mpMRI with that of DECT for local-regional T and N staging in patients with GC receiving curative surgical intervention. Materials and Methods Patients with GC who underwent gastric mpMRI and DECT before gastrectomy with lymphadenectomy were eligible for this single-center prospective noninferiority study between November 2021 and September 2022. mpMRI comprised T2-weighted imaging, multiorientational zoomed diffusion-weighted imaging, and extradimensional volumetric interpolated breath-hold examination dynamic contrast-enhanced imaging. Dual-phase DECT images were reconstructed at 40 keV and standard 120 kVp-like images. Using gastrectomy specimens as the reference standard, the diagnostic accuracy of mpMRI and DECT for T and N staging was compared by six radiologists in a pairwise blinded manner. Interreader agreement was assessed using the weighted κ and Kendall W statistics. The McNemar test was used for head-to-head accuracy comparisons between DECT and mpMRI. Results This study included 202 participants (mean age, 62 years ± 11 [SD]; 145 male). The interreader agreement of the six readers for T and N staging of GC was excellent for both mpMRI (κ = 0.89 and 0.85, respectively) and DECT (κ = 0.86 and 0.84, respectively). Regardless of reader experience, higher accuracy was achieved with mpMRI than with DECT for both T (61%-77% vs 50%-64%; all P < .05) and N (54%-68% vs 51%-58%; P = .497-.005) staging, specifically T1 (83% vs 65%) and T4a (78% vs 68%) tumors and N1 (41% vs 24%) and N3 (64% vs 45%) nodules (all P < .05). Conclusion Personalized mpMRI was superior in T staging and noninferior or superior in N staging compared with DECT for patients with GC. Clinical trial registration no. NCT05508126 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Méndez and Martín-Garre in this issue.


Sujet(s)
Stadification tumorale , Tumeurs de l'estomac , Tomodensitométrie , Humains , Tumeurs de l'estomac/imagerie diagnostique , Tumeurs de l'estomac/anatomopathologie , Tumeurs de l'estomac/chirurgie , Mâle , Femelle , Adulte d'âge moyen , Études prospectives , Sujet âgé , Tomodensitométrie/méthodes , Gastrectomie/méthodes , Adulte , Imagerie par résonance magnétique/méthodes , Imagerie par résonance magnétique multiparamétrique/méthodes
16.
Thorac Cancer ; 2024 Jul 17.
Article de Anglais | MEDLINE | ID: mdl-39020500

RÉSUMÉ

In recent years, significant improvement has been made in the management of non-small cell lung cancer (NSCLC), primarily driven by advances in targeted therapy and immunotherapy. Research on neoadjuvant targeted therapy has also experienced considerable development, primarily directed towards NSCLC harboring epidermal growth factor receptor or anaplastic lymphoma kinase mutations. Nevertheless, there remains a dearth of studies investigating neoadjuvant targeted therapy in the context of BRAF (V-Raf murine sarcoma viral oncogene homolog B) V600E mutant NSCLC. Herein, we describe the clinical trajectory of a stage IIIA NSCLC patient who underwent a two-month course of neoadjuvant targeted therapy comprising BRAF and MEK (mitogen-activated extracellular signal-regulated kinase) inhibitors prior to surgical intervention, and subsequent postoperative evaluation unveiled a pathological complete response. The case reported here indicates the efficacy and safety of combining BRAF and MEK inhibitors as neoadjuvant targeted therapy in BRAF V600E-mutant NSCLC and suggests the potential viability of such a therapeutic modality in improving treatment outcomes in this subset of NSCLC.

17.
Int J Ophthalmol ; 17(7): 1273-1282, 2024.
Article de Anglais | MEDLINE | ID: mdl-39026905

RÉSUMÉ

AIM: To evaluate the trending visual performance of different intraocular lenses (IOLs) over time after implantation. METHODS: Ninety-one patients received cataract surgery with implantations of monofocal (Mon) IOLs, segmental refractive (SegRef) IOLs, diffractive (Dif) IOLs, and extended-depth-of-focus (EDoF) IOLs were included. The aberrations and optical quality collected with iTrace and OQAS within postoperative 6mo were followed and compared. RESULTS: Most of the visual parameters improved over the postoperative 6mo. The postoperative visual acuity (POVA) of the Mon IOL, SegRef IOL, and EDoF IOL groups achieved relative stability in earlier states compared with the Dif IOL group. Nevertheless, the overall visual performance of the 3 IOLs continued to upturn in small extents within the postoperative 6mo. The optical quality initially improved in the EDoF IOL group, then in the Mon IOL, SegRef IOL, and Dif IOL groups. POVA and objective visual performance of the Mon IOL and EDoF IOL groups, as well as POVA and visual quality of the Dif IOL group, improved in the postoperative 1mo and stabilized. Within the postoperative 6mo, gradual improvements were observed in the visual acuity and objective visual performance of the SegRef IOL group, as well as in the postoperative optical quality of the Dif IOL group. CONCLUSION: The visual performance is different among eyes implanted with different IOLs. The findings of the current study provide a potential reference for ophthalmologists to choose suitable IOLs for cataract patients in a personalized solution.

18.
ACS Biomater Sci Eng ; 2024 Jul 16.
Article de Anglais | MEDLINE | ID: mdl-39013076

RÉSUMÉ

Neuropathic pain is a prevalent form of intermittent chronic pain, affecting approximately 7-10% of the global population. However, the current clinical administration methods, such as injection and oral administration, are mostly one-time administration, which cannot achieve accurate control of pain degree and drug dose. Herein, we developed near-infrared (NIR) light-responsive microneedle patches (MNPs) to spatiotemporally control the drug dose released to treat neuropathic pain according to the onset state. The mechanism of action utilizes upconversion nanoparticles to convert NIR light into visible and ultraviolet light. This conversion triggers the rapid rotation of the azobenzene molecular motor in the mesoporous material, enabling the on-demand controlled release of a drug dose. Additionally, MNs are used to overcome the barrier of the stratum corneum in a minimally invasive and painless manner, effectively promoting the transdermal penetration of drug molecules. The effectiveness of these patches has been demonstrated through significant results. Upon exposure to NIR light for five consecutive cycles, with each cycle lasting 30 s, the patches achieved a precise release of 318 µg of medication. In a mouse model, maximum pain relief was observed within 1 h of one cycle of NIR light exposure, with the effects lasting up to 6 h. The same level of precise treatment efficacy was maintained for subsequent pain episodes with similar light exposure. The NIR-controlled drugs precision-released MNPs provide a novel paradigm for the treatment of intermittent neuropathic pain.

19.
Angew Chem Int Ed Engl ; : e202408918, 2024 Jul 16.
Article de Anglais | MEDLINE | ID: mdl-39013139

RÉSUMÉ

The excessive and prolonged use of antibiotics contributes to the emergence of drug-resistant S. aureus strains and potential dysbacteriosis-related diseases, necessitating the exploration of alternative therapeutic approaches. Herein, we present a light-activated nanocatalyst for synthesizing in-situ antimicrobials through photoredox-catalytic click reaction, achieving precise, site-directed elimination of S. aureus skin infections. Methylene blue (MB), a commercially available photosensitizer, was encapsulated within the CuII-based metal-organic framework, MOF-199, and further enveloped with Pluronic F-127 to create the light-responsive nanocatalyst MB@PMOF. Upon exposure to red light, MB participates in a photoredox-catalytic cycle, driven by the 1,3,5-benzenetricarboxylic carboxylate salts (BTC-) ligand presented in the structure of MOF-199. This light-activated MB then catalyzes the reduction of CuII to CuI through a single-electron transfer (SET) process, efficiently initiating the click reaction to form active antimicrobial agents under physiological conditions. Both in vitro and in vivo results demonstrated the effectiveness of MB@PMOF-catalyzed drug synthesis in inhibiting S. aureus, including their methicillin-resistant strains, thereby accelerating skin healing in severe bacterial infections. This study introduces a novel design paradigm for controlled, on-site drug synthesis, offering a promising alternative to realize precise treatment of bacterial infections without undesirable side effects.

20.
J Am Chem Soc ; 146(31): 21837-21846, 2024 Aug 07.
Article de Anglais | MEDLINE | ID: mdl-39058396

RÉSUMÉ

The interest in the discovery and development of skeletal editing processes that selectively insert, exchange, or delete an atom in organic molecules has significantly increased over the last few years. However, processes of this class that proceed through the creation of a chiral center with high asymmetric induction have been largely unexplored. Herein, we report an enantioselective single-carbon insertion in aryl- and alkyl-substituted alkenes mediated by a catalytically generated chiral Rh-carbynoid and phosphate nucleophiles that produce enantioenriched allylic phosphates (enantiomeric ratio (e.r.) = 89.5:10.5-99.5:0.5). The key to the process was a diastereo- and enantioselective cyclopropanation of the alkene with a chiral Rh-carbynoid and the formation of a transient cyclopropyl-I(III) intermediate. The addition of the phosphate nucleophile provided a cyclopropyl-I(III)-phosphate intermediate that undergoes disrotatory ring opening following the Woodward-Hoffmann-DePuy rules. This process led to a chiral intimate allyl cation-phosphate pair that evolved with excellent enantioretention. The evidence of an SN1-like SNi mechanism is provided by linear free-energy relationship studies, kinetic isotope effects, X-ray crystallography, and control experiments. We demonstrated the utility of the enantioenriched allylic phosphates in late-stage N-H allylations of natural products and drug molecules and in cross-coupling reactions that occurred with excellent enantiospecificity.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE