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1.
J Med Chem ; 67(20): 18512-18525, 2024 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-39365559

RESUMEN

Noninvasive and real-time nitric oxide (NO) visualization in vivo is still a challenge. Herein, we constructed a series of NO-responsive magnetic resonance imaging (MRI) contrast agents Gd1b-e by modifying Gd-DO3A using a bis-pyridyl-ethylamine side chain as a signal-amplifying moiety and o-phenylenediamine as a NO-responsive linker. It was found that Gd1b, d, and e can form macromolecular ternary complexes (Gd-Zn2+-HSA) with high longitudinal relaxivity (r1) (12.2-16.2 mM-1 s-1). Once reacting with NO, the o-phenylenediamine linker was hydrolyzed to produce a small molecular Gd complex with sharply decreased r1 (4.7-6.3 mM-1 s-1). Among them, Gd1d with a desirable pharmacokinetic profile (t1/2 = 5.91 h) could clearly distinguish the ischemia-reperfusion (IR) liver with excessive NO in rats. Meanwhile, the temporarily reduced amount of NO in the IR liver and brain by the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl could enhance the signal of Gd1d, suggesting anticipated NO-responsive property. This research offers a new avenue for insight into the NO spatiotemporal property in multiple IR organs.


Asunto(s)
Medios de Contraste , Gadolinio , Hígado , Imagen por Resonancia Magnética , Óxido Nítrico , Daño por Reperfusión , Animales , Humanos , Masculino , Ratas , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Medios de Contraste/química , Medios de Contraste/farmacocinética , Complejos de Coordinación/química , Complejos de Coordinación/farmacocinética , Complejos de Coordinación/síntesis química , Gadolinio/química , Hígado/metabolismo , Hígado/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Óxido Nítrico/metabolismo , Ratas Sprague-Dawley , Daño por Reperfusión/diagnóstico por imagen , Daño por Reperfusión/metabolismo , Zinc/química , Zinc/metabolismo , Imidazoles/química , Imidazoles/metabolismo
2.
Exp Hematol Oncol ; 13(1): 97, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39354638

RESUMEN

BACKGROUND: Aberrant activation of mesenchymal epithelial transition (MET) has been considered to mediate primary and acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC). However, mechanisms underlying this process are not wholly clear and the effective therapeutic strategy remains to be determined. METHODS: The gefitinib-resistant NSCLC cell lines were induced by concentration increase method in vitro. Western blot and qPCR were used to investigate the relationship between MET and vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling pathway. Double luciferase reporter gene and co-immunoprecipitation were used to further reveal the regulation mechanism between MET and VEGF/VEGFR2. The effect of combined inhibition of MET and VEGF/VEGFR2 signaling pathway on the therapeutic sensitivity of EGFR-TKI in gefitinib resistant cell lines with MET aberration was verified ex vivo and in vivo. RESULTS: We successfully obtained two gefitinib-resistant NSCLC cell lines with EGFR mutation and abnormal activation of MET. We observed that MET formed a positive feedback loop with the VEGF/VEGFR2 signaling, leading to persistent downstream signaling activation. Specifically, MET up-regulated VEGFR2 expression in a MAPK/ERK/ETS1-dependent manner, while VEGF promoted physical interaction between VEGFR2 and MET, thereby facilitating MET phosphorylation. A MET inhibitor, crizotinib, combined with an anti-VEGF antibody, bevacizumab, enhanced the sensitivity of NSCLC cells to gefitinib and synergistically inhibited the activation of downstream signaling in vitro. Dual inhibition of MET and VEGF combined with EGFR TKIs markedly restrained tumor growth in both human NSCLC xenograft models and in an EGFR/MET co-altered case. CONCLUSIONS: Our work reveals a positive feedback loop between MET and VEGF/VEGFR2, resulting in continuous downstream signal activation. Combined inhibition of MET and VEGF/VEGFR2 signaling pathway may be beneficial for reversing EGFR TKIs resistance.

3.
Int J Mol Sci ; 25(19)2024 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-39408814

RESUMEN

The tumor microenvironment (TME) can be regarded as a complex and dynamic microecosystem generated by the interactions of tumor cells, interstitial cells, the extracellular matrix, and their products and plays an important role in the occurrence, progression and metastasis of tumors. In a previous study, we constructed an IEO model (prI-, prE-, and pOst-metastatic niche) according to the chronological sequence of TME development. In this paper, to fill the theoretical gap in spatial heterogeneity in the TME, we defined an MCIB model (Metabolic, Circulatory, Immune, and microBial microenvironment). The MCIB model divides the TME into four subtypes that interact with each other in terms of mechanism, corresponding to the four major links of metabolic reprogramming, vascular remodeling, immune response, and microbial action, providing a new way to assess the TME. The combination of the MCIB model and IEO model comprehensively depicts the spatiotemporal evolution of the TME and can provide a theoretical basis for the combination of clinical targeted therapy, immunotherapy, and other comprehensive treatment modalities for tumors according to the combination and crosstalk of different subtypes in the MCIB model and provide a powerful research paradigm for tumor drug-resistance mechanisms and tumor biological behavior.


Asunto(s)
Neoplasias , Microambiente Tumoral , Humanos , Neoplasias/patología , Neoplasias/metabolismo , Modelos Biológicos , Animales , Inmunoterapia/métodos
4.
Bioact Mater ; 40: 634-648, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39253616

RESUMEN

Articular cartilage injury (ACI) remains one of the key challenges in regenerative medicine, as current treatment strategies do not result in ideal regeneration of hyaline-like cartilage. Enhancing endogenous repair via microRNAs (miRNAs) shows promise as a regenerative therapy. miRNA-140 and miRNA-455 are two key and promising candidates for regulating the chondrogenic differentiation of mesenchymal stem cells (MSCs). In this study, we innovatively synthesized a multifunctional tetrahedral framework in which a nucleic acid (tFNA)-based targeting miRNA codelivery system, named A-T-M, was used. With tFNAs as vehicles, miR-140 and miR-455 were connected to and modified on tFNAs, while Apt19S (a DNA aptamer targeting MSCs) was directly integrated into the nanocomplex. The relevant results showed that A-T-M efficiently delivered miR-140 and miR-455 into MSCs and subsequently regulated MSC chondrogenic differentiation through corresponding mechanisms. Interestingly, a synergistic effect between miR-140 and miR-455 was revealed. Furthermore, A-T-M successfully enhanced the endogenous repair capacity of articular cartilage in vivo and effectively inhibited hypertrophic chondrocyte formation. A-T-M provides a new perspective and strategy for the regeneration of articular cartilage, showing strong clinical application value in the future treatment of ACI.

6.
Bioact Mater ; 41: 455-470, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39188379

RESUMEN

Utilizing transplanted human umbilical cord mesenchymal stem cells (HUMSCs) for cartilage defects yielded advanced tissue regeneration, but the underlying mechanism remain elucidated. Early after HUMSCs delivery to the defects, we observed substantial apoptosis. The released apoptotic vesicles (apoVs) of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment. ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs. Mechanistically, in macrophages, miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization. In MSCs, let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis. Consequently, a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix (DCM) scaffold effectively promoted the regeneration of osteochondral defects. Overall, new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study. Moreover, we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.

7.
Eur Heart J Imaging Methods Pract ; 2(1): qyae007, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39045205

RESUMEN

Aims: Aortic root motion is suspected to contribute to proximal aortic dissection. While motion of the aorta in four dimensions can be traced with real-time imaging, displacement and rotation in quantitative terms remain unknown. The hypothesis was to show feasibility of quantification of three-dimensional aortic root motion from dynamic CT imaging. Methods and results: Dynamic CT images of 40 patients for coronary assessment were acquired using a dynamic protocol. Scans were ECG-triggered and segmented in 10 time-stepped phases (0-90%) per cardiac cycle. With identification of the sinotubular junction (STJ), a patient-specific co-ordinate system was created with the z-axis (out-of-plane) parallel to longitudinal direction. The left and right coronary ostia were traced at each time-step to quantify downward motion in reference to the STJ plane, motion within the STJ plane (in-plane), and the degree of rotation. Enrolled individuals had an age of 65 ± 12, and 14 were male (35%). The out-of-plane motion was recorded with the largest displacement of 10.26 ± 2.20 and 8.67 ± 1.69 mm referenced by left and right coronary ostia, respectively. The mean downward movement of aortic root was 9.13 ± 1.86 mm. The largest in-plane motion was recorded at 9.17 ± 2.33 mm and 6.51 ± 1.75 mm referenced by left and right coronary ostia, respectively. The largest STJ in-plane motion was 7.37 ± 1.96 mm, and rotation of the aortic root was 11.8 ± 4.60°. Conclusion: In vivo spatial and temporal displacement of the aortic root can be identified and quantified from multiphase ECG-gated contrast-enhanced CT images. Knowledge of normal 4D motion of the aortic root may help understand its biomechanical impact in patients with aortopathy and pre- and post-surgical or transcatheter aortic valve replacement.

8.
Nanoscale ; 16(30): 14310-14318, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39012341

RESUMEN

Designing antibacterial agents with rapid bacterial eradication performance is paramount for the treatment of bacteria-infected wounds. Metal nanoclusters (NCs) with aggregation-induced emission (AIE) have been considered as novel photodynamic antibacterial agents without drug resistance, but they suffer from poor photostability and low charge carrier separation efficiency. Herein, we report the design of a photodynamic antibacterial agent by encapsulating AIE-type AgAu NCs (Ag28Au1 NCs) into a zeolitic Zn(2-methylimidazole)2 framework (ZIF-8). The encapsulation of AIE-type Ag28Au1 NCs into porous ZIF-8 could not only enhance the photostability of Ag28Au1 NCs by inhibiting their aggregation but also promote the separation of photoinduced charge carriers, resulting in the rapid generation of destructive reactive oxygen species (ROS) for bacterial killing under visible-light irradiation. Consequently, the as-designed photodynamic Ag28Au1 NCs@ZIF-8 antibacterial agent could rapidly eliminate 97.7% of Escherichia coli (E. coli) and 91.6% of Staphylococcus aureus (S. aureus) within 5 min in vitro under visible light irradiation. Furthermore, in vivo experimental results have highlighted the synergistic effect created by AIE-type Ag28Au1 NCs and ZIF-8, enabling Ag28Au1 NCs@ZIF-8 to effectively eradicate bacteria in infected areas, reduce inflammation, and promote the generation of blood vessels, epithelial tissue, and collagen. This synergistic effect promoted the healing of S. aureus-infected wound, with nearly 100% of wound recovery within 11 days. This work may be interesting because it sheds light on the design of metal NC-based photodynamic nanomedicine for bacteria-infected disease treatment.


Asunto(s)
Antibacterianos , Escherichia coli , Imidazoles , Estructuras Metalorgánicas , Fotoquimioterapia , Staphylococcus aureus , Cicatrización de Heridas , Cicatrización de Heridas/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Antibacterianos/química , Antibacterianos/farmacología , Animales , Staphylococcus aureus/efectos de los fármacos , Estructuras Metalorgánicas/química , Estructuras Metalorgánicas/farmacología , Ratones , Imidazoles/química , Imidazoles/farmacología , Zeolitas/química , Zeolitas/farmacología , Plata/química , Plata/farmacología , Especies Reactivas de Oxígeno/metabolismo , Nanopartículas del Metal/química , Nanopartículas del Metal/uso terapéutico , Oro/química , Oro/farmacología , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Luz
9.
Inflammation ; 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38867118

RESUMEN

Brahma-related gene 1 (BRG1) has been implicated in the repair of DNA double-strand breaks (DSBs). Downregulation of BRG1 impairs DSBs repair leading to accumulation of double-stranded DNA (dsDNA). Currently, the role of BRG1 in diabetic cardiomyopathy (DCM) has not been clarified. In this study, we aimed to explore the function and molecular by which BRG1 regulates DCM using mice and cell models. We found that BRG1 was downregulated in the cardiac tissues of DCM mice and in cardiomyocytes cultured with high glucose and palmitic acid (HG/PA), which was accompanied by accumulation of dsDNA and activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. shRNA-mediated Brg1 knockdown aggravated DCM mice cardiac functions, enhanced dsDNA accumulation, cGAS-STING signaling activation, which induced inflammation and apoptosis. In addition, the results were further verified in HG/PA-treated primary neonatal rat cardiomyocytes (NRCMs). Overexpression of BRG1 in NRCMs yielded opposite results. Furthermore, a selective cGAS inhibitor RU.521 or STING inhibitor C-176 partially reversed the BRG1 knockdown-induced inflammation and apoptosis in vitro. In conclusion, our results demonstrate that BRG1 is downregulated during DCM in vivo and in vitro, resulting in cardiomyocyte inflammation and apoptosis due to dsDNA accumulation and cGAS-STING signaling activation. Therefore, targeting the BRG1-cGAS-STING pathway may represent a novel therapeutic strategy for improving cardiac function of patients with DCM.

10.
Adv Mater ; 36(34): e2403641, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38861754

RESUMEN

The repair and functional reconstruction of bone defects resulting from severe trauma, surgical resection, degenerative disease, and congenital malformation pose significant clinical challenges. Bone tissue engineering (BTE) holds immense potential in treating these severe bone defects, without incurring prevalent complications associated with conventional autologous or allogeneic bone grafts. 3D printing technology enables control over architectural structures at multiple length scales and has been extensively employed to process biomimetic scaffolds for BTE. In contrast to inert and functional bone grafts, next-generation smart scaffolds possess a remarkable ability to mimic the dynamic nature of native extracellular matrix (ECM), thereby facilitating bone repair and regeneration. Additionally, they can generate tailored and controllable therapeutic effects, such as antibacterial or antitumor properties, in response to exogenous and/or endogenous stimuli. This review provides a comprehensive assessment of the progress of 3D-printed smart scaffolds for BTE applications. It begins with an introduction to bone physiology, followed by an overview of 3D printing technologies utilized for smart scaffolds. Notable advances in various stimuli-responsive strategies, therapeutic efficacy, and applications of 3D-printed smart scaffolds are discussed. Finally, the review highlights the existing challenges in the development and clinical implementation of smart scaffolds, as well as emerging technologies in this field.


Asunto(s)
Regeneración Ósea , Huesos , Impresión Tridimensional , Ingeniería de Tejidos , Andamios del Tejido , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Humanos , Animales
11.
Eur Heart J Case Rep ; 8(4): ytae186, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38690556

RESUMEN

Background: The frozen elephant trunk (FET) technique as a hybrid combining surgical and endovascular repair is an emerging concept to treat complex aortic dissection. Early experience showed technical feasibility and promising clinical outcomes. However, unsuspected complications still arise. Case summary: A 25-year-old male presented to the emergency department with a 2-day history of chest pain. After exclusion of acute coronary syndrome, a computed tomography angiography (CTA) revealed Type A (DeBakey Type I) aortic dissection. The patient underwent median stenotomy for complete replacement of the ascending aorta, the aortic arch, and FET. Early after rewarming, the patient became unstable due to severe left ventricular dysfunction. Soon veno-arterial extracorporal membrane oxygenation (VA-ECMO) was required for circulatory support. The cause of deterioration remained unclear until repeated CTA showed acute obstruction of the FET. Invasive exploration confirmed a trans-FET gradient of 100 mmHg, successfully managed by repeated balloon inflation with resolution of both obstruction and gradient. The patient recovered completely without any sequela. Discussion: While the mechanism of acute obstruction after FET remains subject to speculation, the rescue intervention of ballooning the obliteration on VA-ECMO was life-saving. Intraoperative ultrasound and videoscopic inspection may be instrumental before chest closure to avoid such critical events.

12.
RSC Adv ; 14(22): 15413-15418, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38741962

RESUMEN

The urgent need to develop biocompatible, non-resistant antibacterial agents to effectively combat Gram-negative bacterial infections, particularly for the treatment of peritonitis, presents a significant challenge. In this study, we introduce our water-soluble Cu30 nanoclusters (NCs) as a potent and versatile antibacterial agent tailored for addressing peritonitis. The as-synthesized atomically precise Cu30 NCs demonstrate exceptional broad-spectrum antibacterial performance, and especially outstanding bactericidal activity of 100% against Gram-negative Escherichia coli (E. coli). Our in vivo experimental findings indicate that the Cu30 NCs exhibit remarkable therapeutic efficacy against primary peritonitis caused by E. coli infection. Specifically, the treatment leads to a profound reduction of drug-resistant bacteria in the peritoneal cavity of mice with peritonitis by more than 5 orders of magnitude, along with the resolution of pathological features in the peritoneum and spleen. Additionally, comprehensive in vivo biosafety assessment underscores the remarkable biocompatibility, low biotoxicity, as well as efficient hepatic and renal clearance of Cu30 NCs, emphasizing their potential for in vivo application. This investigation is poised to advance the development of novel Cu NC-based antibacterial agents for in vivo antibacterial treatment and the elimination of abdominal inflammation.

13.
ACS Appl Mater Interfaces ; 16(15): 18843-18854, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38586920

RESUMEN

Sulfide solid-state electrolytes have garnered considerable attention owing to their notable ionic conductivity and mechanical properties. However, achieving an electrolyte characterized by both high ionic conductivity and a stable interface between the electrode and electrolyte remains challenging, impeding its widespread application. In this work, we present a novel sulfide solid-state electrolyte, Li3.04P0.96Zn0.04S3.92F0.08, prepared through a solid-phase reaction, and explore its usage in all-solid-state lithium sulfur batteries (ASSLSBs). The findings reveal that the Zn, F co-doped solid-state electrolyte exhibits an ionic conductivity of 1.23 × 10-3 S cm-1 and a low activation energy (Ea) of 9.8 kJ mol-1 at room temperature, illustrating the aliovalent co-doping's facilitation of Li-ion migration. Furthermore, benefiting from the formation of a LiF-rich interfacial layer between the electrolyte and the Li metal anode, the Li/Li3.04P0.96Zn0.04S3.92F0.08/Li symmetrical cell exhibits critical current densities (CCDs) of up to 1 mA cm-2 and maintains excellent cycling stability. Finally, the assembled ASSLSBs exhibit an initial discharge capacity of 1295.7 mAh g-1 at a rate of 0.05 C and at room temperature. The cell maintains a capacity retention of 70.5% for more than 600 cycles at a high rate of 2 C, representing a substantial improvement compared to the cell with Li3PS4. This work provides a new idea for the design of solid-state electrolytes and ASSLSBs.

14.
Horm Metab Res ; 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38670123

RESUMEN

The aim of the study was to explore the clinical efficacy of bisphosphonates in patients with osteoporosis in diabetes patients by meta-analysis. Six databases were systematically searched from inception to January 30,2023. Studies evaluating the treatment of diabetic osteoporosis with bisphosphonates were included. Key outcome measures, such as bone mineral density (BMD), bone metabolism markers, pain improvement, and safety assessments, were extracted and analyzed. STATA MP V17.0 was used to calculate the combined effect size. After searching Chinese and English databases, 15 studies met the inclusion criteria of this study. The results of the meta-analysis showed that the BMD of patients with osteoporosis in diabetes increased significantly after bisphosphonate treatment, and the lumbar BMD increased by 0.08 g/cm² (95% CI: 0.05-0.11). Femoral neck BMD increased by 0.06 g/cm² (95% CI: 0.01-0.11); Ward's triangle BMD increased 0.07 g/cm² (95% CI: 0.04-0.09); and trochanter BMD increased by 0.06 g/cm² (95% CI: 0.04-0.08). In addition, bone alkaline phosphatase increased 1.95 µg/l (95% CI: 1.18-2.72), while serum tartrate-resistant acid phosphatase-5b decreased 1.28 U/l (95% CI: -1.81-0.75). Moreover, improvements in pain were statistically significant. The effects of bisphosphonates on osteocalcin (MD: -0.07; 95% CI: -1.12-1.25), serum calcium (MD: 0.01; 95% CI: -0.03-0.04), serum phosphorus (MD: 0.04; 95% CI: -0.03-0.10) and medication safety (OR: 1.75; 95% CI: 1.29-2.37) were not statistically significant. Bisphosphonates have a significant positive effect on bone mineral density and bone metabolism in patients with osteoporosis in diabetes and have good safety.

15.
J Immunother ; 47(5): 149-159, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38557756

RESUMEN

Antibody-drug conjugates (ADCs) combine the high specificity of antibodies with the cytotoxicity of payloads and have great potential in pan-cancer immunotherapy. However, the current payloads for clinical uses have limited the therapeutic window due to their uncontrollable off-site toxicity. There is unmet needs to develop more potent ADC payloads with better safety and efficacy profiles. Nitric oxide (NO) is a special molecule that has low toxicity itself, which can kill tumor cells effectively when highly concentrated, has broad application prospects. Previously, we prepared for the first time an antibody-nitric oxide conjugate (ANC)-HN01, which showed inhibitory activity against hepatocellular carcinoma. However, the random conjugation method made HN01 highly heterogeneous and unstable. Here, we used site-specific conjugation-based engineered cysteine sites (CL-V211C) of anti-CD24 antibody to prepare a second-generation ANC with a drug-to-antibody ratio of 2. The homogeneous ANC, HN02 was stable in human plasma, shown in vitro bystander effect to neighboring cells and antiproliferative activity to CD24-targeted tumor cells. Compared with HN01, HN02 significantly prolonged the survival of tumor-bearing mice. In summary, we developed a stable and homogeneous site-specific conjugated ANC, which showed good antitumor activity and improved safety profile both in vitro and in vivo. This study provides new insight into the development of next generation of ADC candidates.


Asunto(s)
Inmunoconjugados , Óxido Nítrico , Ensayos Antitumor por Modelo de Xenoinjerto , Humanos , Animales , Inmunoconjugados/farmacología , Inmunoconjugados/química , Inmunoconjugados/uso terapéutico , Ratones , Óxido Nítrico/metabolismo , Línea Celular Tumoral , Antígeno CD24/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Antineoplásicos Inmunológicos/farmacología , Antineoplásicos Inmunológicos/química , Proliferación Celular/efectos de los fármacos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias/tratamiento farmacológico
16.
Small ; 20(35): e2311895, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38660823

RESUMEN

The conformation of molecules and materials is crucial in determining their properties and applications. Here, this work explores the reversible transformation between two distinct conformational isomers in metal nanoclusters. This work demonstrates the successful manipulation of a controllable and reversible isomerization of Au18SR14 within an aqueous solution through two distinct methods: ethanol addition and pH adjustment. The initial driver is the alteration of the solution environment, leading to the aggregation of Au18SR14 protected by ligands with smaller steric hindrance. At the atomic level, the folding mode of the unique Au4SR5 staple underpins the observed structural transformation. The reversal of staple conformation leads to color shifting between green and orange-red, and tailors a second emission peak at 725 nm originating from charge transfer from the thiolate to the Au9 core. This work not only deepens the understanding of the surface structure and dual-emission of metal nanoparticles, but also enhances the comprehension of their isomerization.

17.
Nanoscale ; 16(17): 8196-8215, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38572762

RESUMEN

Noble metal (e.g., Au and Ag) nanoclusters (NCs), which exhibit structural complexity and hierarchy comparable to those of natural proteins, have been increasingly pursued in artificial enzyme research. The protein-like structure of metal NCs not only ensures enzyme-mimic catalytic activity, including peroxidase-, catalase-, and superoxide dismutase-mimic activities, but also affords an unprecedented opportunity to correlate the catalytic performance with the cluster structure at the molecular or atomic levels. In this review, we aim to summarize the recent progress in programming and demystify the enzyme-mimic catalytic activity of metal NCs, presenting the state-of-the-art understandings of the structure-property relationship of metal NC-based artificial enzymes. By leveraging on a concise anatomy of the hierarchical structure of noble metal NCs, we manage to unravel the structural origin of the catalytic performance of metal NCs. Noteworthily, it has been proven that the surface ligands and metal-ligand interface of metal NCs are instrumental in influencing enzyme-mimic catalytic activities. In addition to the structure-property correlation, we also discuss the synthetic methodologies feasible to tailoring the cluster structure at the atomic level. Prior to the closure of this review with our perspectives in noble metal NC-based artificial enzymes, we also exemplify the biomedical applications based on the enzyme-mimic catalysis of metal NCs with the theranostics of kidney injury, brain inflammation, and tumors. The fundamental and methodological advancements delineated in this review would be conducive to further development of metal NCs as an alternative family of artificial enzymes.


Asunto(s)
Nanopartículas del Metal , Nanopartículas del Metal/química , Catálisis , Humanos , Oro/química , Animales , Materiales Biomiméticos/química , Plata/química , Enzimas/química , Enzimas/metabolismo
18.
ACS Appl Mater Interfaces ; 16(12): 15143-15155, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38481099

RESUMEN

Realizing controllable input of botanical pesticides is conducive to improving pesticide utilization, reducing pesticide residues, and avoiding environmental pollution but is extremely challenging. Herein, we constructed a smart pesticide-controlled release platform (namely, SCRP) for enhanced treatment of tobacco black shank based on encapsulating honokiol (HON) with mesoporous hollow structured silica nanospheres covered with pectin and chitosan oligosaccharide (COS). The SCRP has a loading capacity of 12.64% for HON and could effectively protect HON from photolysis. Owing to the pH- and pectinase-sensitive property of the pectin, the SCRP could smartly release HON in response to a low pH or a rich pectinase environment in the black shank-affected area. Consequently, the SCRP effectively inhibits the infection of P. nicotianae on tobacco with a controlled rate for tobacco black shank of up to 87.50%, which is mainly due to the SCRP's capability in accumulating ROS, changing cell membrane permeability, and affecting energy metabolism. In addition, SCRP is biocompatible, and the COS layer enables SCRP to show a significant growth-promoting effect on tobacco. These results indicate that the development of a stimuli-responsive controlled pesticide release system for plant disease control is of great potential and value for practical agriculture production.


Asunto(s)
Plaguicidas , Plaguicidas/farmacología , Preparaciones de Acción Retardada/farmacología , Preparaciones de Acción Retardada/química , Poligalacturonasa , Agricultura , Pectinas
19.
Polymers (Basel) ; 16(6)2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38543336

RESUMEN

Hydroxyapatite/polycaprolactone (HA/PCL) composites have been extensively explored in laser powder bed fusion (L-PBF) for bone tissue engineering. However, conventional mechanical mixing methods for preparing composite powders often yield inhomogeneous compositions and suboptimal flowability. In this study, HA/PCL powders were prepared and optimized for L-PBF using the modified emulsion solvent evaporation method. The morphology, flowability and thermal and rheological properties of the powders were systematically investigated, along with the mechanical and biological properties of the fabricated specimens. The HA/PCL powders exhibited spherical morphologies with a homogeneous distribution of HA within the particles. The addition of small amounts of HA (5 wt% and 10 wt%) enhanced the processability and increased the maximum values of the elastic modulus and yield strength of the specimens from 129.8 MPa to 166.2 MPa and 20.2 MPa to 25.1 MPa, respectively, while also improving their biocompatibility. However, excessive addition resulted in compromised sinterability, thereby affecting both mechanical and biological properties.

20.
Int Med Case Rep J ; 17: 93-100, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38344470

RESUMEN

Background: Severe heart failure or cardiogenic shock might arise as a consequence of fulminant myocarditis if it manifests and advances swiftly. The effective implementation of an immunological modulation regimen and mechanical circulatory support has proven instrumental in preserving the lives of individuals experiencing hemodynamic disturbance. Case Presentation: The current report described a severe instance of fulminant myocarditis in an 18-year-old young woman who presented with severe hypoxemia and hemodynamic instability. The patient was treated with a combination of optimal medical therapy, immunological modulation, extracorporeal membrane oxygenation (ECMO), and an intra-aortic balloon pump (IABP) to support him through his critical period of hemodynamic collapse. Conclusion: The case presented herein underscored the prompt reversal of life-threatening fulminant myocarditis subsequent to a comprehensive treatment regimen encompassing optimal medical therapy and aggressive mechanical circulatory support.

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