Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 528
Filtrar
1.
ACS Omega ; 9(24): 25429-25447, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38911814

RESUMO

Ultrawide bandgap (UWBG) semiconductors, including Ga2O3, diamond, Al x Ga1-x N/AlN, featuring bandgaps greater than 4.4 eV, hold significant promise for solar-blind ultraviolet photodetection, with applications spanning in environmental monitoring, chemical/biological analysis, industrial processes, and military technologies. Over recent decades, substantial strides in synthesizing high-quality UWBG semiconductors have facilitated the development of diverse high-performance solar-blind photodetectors (SBPDs). This review comprehensively examines recent advancements in UWBG semiconductor-based SBPDs across various device architectures, encompassing photoconductors, metal-semiconductor-metal photodetectors, Schottky photodiodes, p-n (p-i-n) photodiodes, phototransistors, etc., with a systematic introduction and discussion of their operational principles. The current state of device performance for SBPDs employing these UWBG semiconductors is evaluated across different device configurations. Finally, this review outlines key challenges to be addressed, aiming to steer future research endeavors in this critical domain.

2.
Front Immunol ; 15: 1381735, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38840923

RESUMO

Background: Acute liver injury (ALI), which is a type of inflammation-mediated hepatocellular injury, is a clinical syndrome that results from hepatocellular apoptosis and hemorrhagic necrosis. Apoptosis stimulating protein of p53-2 (ASPP2) is a proapoptotic member of the p53 binding protein family. However, the role of ASPP2 in the pathogenesis of ALI and its regulatory mechanisms remain unclear. Methods: The expression of ASPP2 were compared between liver biopsies derived from patients with CHB, patients with ALI, and normal controls. Acute liver injury was modelled in mice by administration of D-GalN/LPS. Liver injury was demonstrated by serum transaminases and histological assessment of liver sections. ASPP2-knockdown mice (ASPP2+/-) were used to determine its role in acute liver injury. Mouse bone marrow macrophages (BMMs) were isolated from wildtype and ASPP2+/- mice and stimulated with LPS, and the supernatant was collected to incubate with the primary hepatocytes. Quantitative real-time PCR and western blot were used to analyze the expression level of target. Results: The expression of ASPP2 was significantly upregulated in the liver tissue of ALI patients and acute liver injury mice. ASPP2+/- mice significantly relieved liver injury through reducing liver inflammation and decreasing hepatocyte apoptosis. Moreover, the conditioned medium (CM) of ASPP2+/- bone marrow-derived macrophages (BMMs) protected hepatocytes against apoptosis. Mechanistically, we revealed that ASPP2 deficiency in BMMs specifically upregulated IL-6 through autophagy activation, which decreased the level of TNF-α to reduce hepatocytes apoptosis. Furthermore, up-regulation of ASPP2 sensitizes hepatocytes to TNF-α-induced apoptosis. Conclusion: Our novel findings show the critical role of ASPP2 in inflammatory immunoregulatory mechanism of ALI and provide a rationale to target ASPP2 as a refined therapeutic strategy to ameliorate acute liver injury.


Assuntos
Proteínas Reguladoras de Apoptose , Apoptose , Animais , Humanos , Camundongos , Masculino , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/genética , Camundongos Knockout , Fígado/patologia , Fígado/metabolismo , Fígado/imunologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Inflamação/imunologia , Inflamação/metabolismo , Feminino , Lipopolissacarídeos , Pessoa de Meia-Idade , Macrófagos/imunologia , Macrófagos/metabolismo , Adulto , Proteínas Supressoras de Tumor
3.
Front Vet Sci ; 11: 1410371, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38872805

RESUMO

Background: Gonadotrophin-releasing hormone (GnRH) administration significantly decreases the pregnancy rate of recipient ewes after embryo transfer, possibly because GnRH affects endometrial epithelial cell function. Therefore, this study investigated the effect of GnRH on endometrial epithelial cells. Methods: Transcriptome sequencing was used to determine the regulatory effect of GnRH on the ewe endometrium, and the S100A4 gene, which showed altered transcription, was screened as a candidate regulator of this effect. Endometrial epithelial cells were further isolated, the S100A4 protein was immunoprecipitated, and host proteins that interacted with S100A4 were identified by mass spectrometry. We further verified the effects of S100A4 and GNAI2 on the proliferation of endometrial epithelial cells via overexpression/knockdown experiments and subsequent CCK-8 and EdU assays. The effect of S100A4 deletion in endometrial cells on reproduction was verified in mice with S100A4 knockout. Results: Our results showed that S100A4 gene transcription in endometrial cells was significantly inhibited after GnRH administration. GNAI2 was identified as a downstream interacting protein of S100A4, and S100A4 was confirmed to activate the MAPK signaling pathway to promote cell proliferation by targeting GNAI2. Conclusion: GnRH can suppress the expression of S100A4 in the endometrium, consequently inhibiting the proliferation of endometrial cells through the S100A4/GNAI2/MAPK signaling pathway. These findings suggest a potential explanation for the limited efficacy of GnRH in promoting embryo implantation.

4.
Int Dent J ; 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38914506

RESUMO

BACKGROUND AND PURPOSE: Long noncoding RNA (lncRNA) dysregulation has been reported to play a pivotal role in the development of cancers. In this study, we aimed to screen the key lncRNA in oral squamous cell carcinoma (OSCC) via bioinformatics analysis and further validate the function of lncRNA in vitro and in vivo. METHODS: Bioinformatics analysis was conducted to identify differentially expressed lncRNAs between control and OSCC samples. Quantitative real-time-polymerase chain reaction was employed to detect the expression of differentially expressed lncRNAs in human tongue squamous cell carcinoma and human oral keratinocytes cell lines. The biological function of lncRNA and its mechanism were examined via the experimental assessment of the cell lines with the lncRNA overexpressed and silenced. Additionally, to further explore the function of lncRNA in the progression of OSCC, xenograft tumour mouse models were established using 25 mice (5 groups, each with 5 mice). Tumour formation was observed at 2 weeks after the cell injection, and the tumours were resected at 5 weeks post-implantation. RESULTS: Two lncRNAs, LINC00958 and AFAP1-AS1, were found to be correlated with the prognosis of OSCC. The results of the quantitative real-time-polymerase chain reaction indicated that the 2 lncRNAs were highly expressed in OSCC. In combination with the previous literature, we found AFAP1-AS1 to be a potentially important biomarker for OSCC. Thus, we further investigated its biological function and found that AFAP1-AS1 silencing inhibited cell proliferation, migration, and invasion whereas AFAP1-AS1 overexpression reversed the effect of AFAP1-AS1 silencing (P < .05). Mechanism analysis revealed that AFAP1-AS1 regulated the development of OSCC through the ubiquitin-mediated proteolysis pathway. CONCLUSIONS: AFAP1-AS1 is an oncogene that aggravates the development of OSCC via the ubiquitin-mediated proteolysis pathway. It also provides a novel potential therapy for OSCC.

5.
Lab Chip ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904306

RESUMO

Urinalysis is a heavily used diagnostic test in clinical laboratories; however, it is chronically held back by urine sediment microscopic examination. Current instruments are bulky and expensive to be widely adopted, making microscopic examination a procedure that still relies on manual operations and requires large time and labor costs. To improve the efficacy and automation of urinalysis, this study develops an acoustofluidic-based microscopic examination system. The system utilizes the combination of acoustofluidic manipulation and a passive hydrodynamic mechanism, and thus achieves a high throughput (1000 µL min-1) and a high concentration factor (95.2 ± 2.1 fold) simultaneously, fulfilling the demands for urine examination. The concentrated urine sample is automatically dispensed into a hemocytometer chamber and the images are then analyzed using a machine learning algorithm. The whole process is completed within 3 minutes with detection accuracies of erythrocytes and leukocytes of 94.6 ± 3.5% and 95.1 ± 1.8%, respectively. The examination outcome of urine samples from 50 volunteers by this device shows a correlation coefficient of 0.96 compared to manual microscopic examination. Our system offers a promising tool for automated urine microscopic examination, thus it has potential to save a large amount of time and labor in clinical laboratories, as well as to promote point-of-care urine testing applications in and beyond hospitals.

6.
Trends Pharmacol Sci ; 45(6): 478-489, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38777670

RESUMO

Traf2- and Nck-interacting kinase (TNIK) has emerged as a key regulator of pathological metabolic signaling in several diseases and is a promising drug target. Originally studied for its role in cell migration and proliferation, TNIK possesses several newly identified functions that drive the pathogenesis of multiple diseases. Specifically, we evaluate TNIK's newfound roles in cancer, metabolic disorders, and neuronal function. We emphasize the implications of TNIK signaling in metabolic signaling and evaluate the translational potential of these discoveries. We also highlight how TNIK's role in many biological processes converges upon several hallmarks of aging. We conclude by discussing the therapeutic landscape of TNIK-targeting drugs and the recent success of clinical trials targeting TNIK.


Assuntos
Envelhecimento , Neoplasias , Proteínas Serina-Treonina Quinases , Humanos , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Envelhecimento/metabolismo , Animais , Proteínas Serina-Treonina Quinases/metabolismo , Doenças Metabólicas/metabolismo , Doenças Metabólicas/tratamento farmacológico , Transdução de Sinais
7.
Adv Healthc Mater ; : e2400760, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38703026

RESUMO

Near-infrared-II (NIR-II) fluorescence imaging is pivotal in biomedical research. Organic probes exhibit high potential in clinical translation, due to advantages such as precise structure design, low toxicity, and post-modifications convenience. In related preparation, enhancement of NIR-II tail emission from NIR-I dyes is an efficient method. In particular, the promotion of twisted intramolecular charge transfer (TICT) of relevant NIR-I dyes is a convenient protocol. However, present TICT-type probes still show disadvantages in relatively low emission, large particle sizes, or limited choice of NIR-I dyes, etc. Herein, the synthesis of stable small-sized polymer NIR-II fluoroprobes (e.g., 7.2 nm), integrating TICT and Förster resonance energy transfer process to synergistically enhance the NIR-II emission is reported. Strong enhanced emissions can be obtained from various NIR-I dyes and lanthanide elements (e.g., twelvefold at 1250 nm from Nd-DTPA/IR-808 sample). The fluorophore provides high-resolution angiography, with high-contrast imaging on middle cerebral artery occlusion model mice for distinguishing occlusion. The fluorophore can be rapidly excreted from the kidney (urine ≈65% within 4 h) in normal mice and exhibits long-term renal retention on acute kidney injury mice, showing potential applications in the prognosis of kidney diseases. This development provides an effective strategy to design and synthesize effective NIR-II fluoroprobes.

8.
Opt Lett ; 49(10): 2821-2824, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748170

RESUMO

Waveguide Bragg grating (WBG) blood glucose sensing, as a biological sensing technology with broad application prospects, plays an important role in the fields of health management and medical treatment. In this work, a polymer-based cascaded WBG is applied to glucose detection. We investigated photonic devices with two different grating structures cascaded-a crossed grating and a bilateral grating-and analyzed the effects of the crossed grating period, bilateral grating period, and number of grating periods on the sensing performance of the glucose sensor. Finally, the spectral reflectance characteristics, response time, and sensing specificity of the cascaded WBG were evaluated. The experimental results showed that the glucose sensor has a sensitivity of 175 nm/RIU in a glucose concentration range of 0-2 mg/ml and has the advantages of high integration, a narrow bandwidth, and low cost.


Assuntos
Glicemia , Polímeros , Polímeros/química , Glicemia/análise , Técnicas Biossensoriais/instrumentação
9.
Health Secur ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38815144

RESUMO

The purpose of this study was to investigate the feasibility and effectiveness of COVID-19 throat swab samples delivered by medical drones in epidemic prevention and control. This study was carried out in both southern and northern hospital districts of the Affiliated Hospital of Jiangnan University from May to October 2022. The main participants were the Affiliated Hospital of Jiangnan University and Zhejiang Antwork Technology Co., Ltd. We first constructed an urban medical unmanned aerial vehicle (UAV) delivery system and developed a UAV-specific storage box for COVID-19 samples. The UAV system was used to transport COVID-19 throat swab samples from the northern hospital district to the southern hospital district, and the following indexes were obtained: (1) flight time of COVID-19 samples delivered by UAV, (2) real-time temperature of COVID-19 nucleic acid samples during transportation, and (3) the time of distribution of COVID-19 nucleic acid samples by road traffic as measured using the Baidu Maps application, compared with the flight time of UAV. The COVID-19 sample delivery system for urban medical UAV mainly consists of intelligent logistics UAV, low-temperature COVID-19 throat swab sample storage box, unmanned logistics hub, and cloud operation control platform. The flight distance between the northern and southern districts of the Affiliated Hospital of Jiangnan University was 10 km, and the ground distance was 24 km. From May 11 to October 28, 2022, a total of 1,190 UAV flights occurred. The average flight time was 13 minutes, which was 40 to 70 minutes faster than the average road travel time required for manual delivery of COVID-19 throat swab samples. At different time points in the day, UAV delivery efficiency increased by 67.5% to 82%. The use of 5G with the Internet of Things and UAV technology to deliver nucleic acid samples has the characteristics of fast speed, being unaffected by ground traffic conditions, and the ability to ensure the safety of nucleic acid samples in the transportation process, which is worthy of further study.

10.
J Med Chem ; 67(10): 8161-8171, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38690856

RESUMO

The mediator kinases CDK8 and CDK19 control the dynamic transcription of selected genes in response to various signals and have been shown to be hijacked to sustain hyperproliferation by various solid and liquid tumors. CDK8/19 is emerging as a promising anticancer therapeutic target. Here, we report the discovery of compound 12, a novel small molecule CDK8/19 inhibitor. This molecule demonstrated not only decent enzymatic and cellular activities but also remarkable selectivity in CDK and kinome panels. Besides, compound 12 also displayed favorable ADME profiles including low CYP1A2 inhibition, acceptable clearance, and high oral bioavailability in multiple preclinical species. Robust in vivo PD and efficacy studies in mice models further demonstrated its potential use as mono- and combination therapy for the treatment of cancers.


Assuntos
Antineoplásicos , Quinase 8 Dependente de Ciclina , Quinases Ciclina-Dependentes , Inibidores de Proteínas Quinases , Quinase 8 Dependente de Ciclina/antagonistas & inibidores , Quinase 8 Dependente de Ciclina/metabolismo , Humanos , Animais , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/síntese química , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Antineoplásicos/síntese química , Camundongos , Descoberta de Drogas , Linhagem Celular Tumoral , Relação Estrutura-Atividade , Proliferação de Células/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Ratos
11.
Eur J Med Chem ; 270: 116390, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38604096

RESUMO

Protein tyrosine phosphatases PTPN2 and PTPN1 (also known as PTP1B) have been implicated in a number of intracellular signaling pathways of immune cells. The inhibition of PTPN2 and PTPN1 has emerged as an attractive approach to sensitize T cell anti-tumor immunity. Two small molecule inhibitors have been entered the clinic. Here we report the design and development of compound 4, a novel small molecule PTPN2/N1 inhibitor demonstrating nanomolar inhibitory potency, good in vivo oral bioavailability, and robust in vivo antitumor efficacy.


Assuntos
Proteína Tirosina Fosfatase não Receptora Tipo 1 , Proteína Tirosina Fosfatase não Receptora Tipo 2 , Proteína Tirosina Fosfatase não Receptora Tipo 2/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Transdução de Sinais
12.
Artigo em Inglês | MEDLINE | ID: mdl-38684204

RESUMO

OBJECTIVE: To investigate the diagnostic value of urine luteinizing hormone (ULH) after triptorelin stimulation test detected by immunochemiluminometric assay (ICMA) in girls with central precocious puberty (CPP). METHODS: The girls with precocious puberty were involved. The triptorelin stimulation test at 8:30 a.m.were performed. Two consecutive 12-hour urine samples were collected after the test, defined as first 12-hour and second 12-hour urine, respectively. ICMA measured ULH. Urine creatinine (Cr) concentration was measured. CPP and peripheral precocious puberty (PPP) were diagnosed by the same pediatric endocrinologist based on clinical symptoms, signs, and progression of clinical development. RESULTS: A total of 97 cases (CPP n=69; PPP n=28) were included, with 12 cases not meeting the receiver operating characteristic analysis criteria. The first and second 12-hour ULH/Cr in CPP group were higher than those in PPP group. When first 12-hour ULH/Cr was ≥ 287.252 IU/mol, the sensitivity and specificity for diagnosing CPP were 87.3% and 90.9%, respectively. When second 12-hour ULH/Cr was ≥ 152.769 IU/mol, the sensitivity and specificity for diagnosing CPP were 92.1% and 90.9%, respectively. The area under the curve of first and second 12-hour ULH/Cr were 0.933 and 0.954, respectively. CONCLUSION: The ULH detection method after the triptorelin stimulation test has clinical significance for diagnosing CPP in girls. When the compliance of blood sampling in girls with precocious puberty is poor, first 12-hour ULH/Cr ≥ 288 IU/mol (or second 12-hour ≥ 153 IU/mol) after the triptorelin stimulation test can serve as a laboratory indicator for diagnosis of CPP.

13.
Int Wound J ; 21(4): e14838, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38577937

RESUMO

Wound infection is a serious complication that impacts the prognosis of patients after colorectal surgery (CS). Probiotics and synbiotics (Pro and Syn) are live bacteria that produce bacteriostatic agents in the intestinal system and have a positive effect on postoperative wound infections. The purpose of this study was to evaluate the effect of Pro and Syn on complications of wound infection after CS. In November 2023, we searched relevant clinical trial reports from Pubmed, Cochrane Library, and Embase databases and screened the retrieved reports, extracted data, and finally analysed the data by using RevMan 5.3. A total of 12 studies with 1567 patients were included in the study. Pro and Syn significantly reduced total infection (OR, 0.44; 95% CI, 0.35, 0.56; p < 0.00001), surgical incision site infection (SSI) (OR, 0.61; 95% CI, 0.45, 0.81; p = 0.002), pneumonia (OR, 0.43; 95% CI, 0.25, 0.72; p = 0.001), urinary tract infection (OR, 0.28; 95% CI, 0.14, 0.56; p = 0.0003), and Pro and Syn did not reduce anastomotic leakage after colorectal surgery (OR, 0.84; 95% CI, 0.50, 1.41; p = 0.51). Pro and Syn can reduce postoperative wound infections in patients with colorectal cancer, which benefits patients' postoperative recovery.


Assuntos
Cirurgia Colorretal , Procedimentos Cirúrgicos do Sistema Digestório , Probióticos , Simbióticos , Humanos , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Cirurgia Colorretal/efeitos adversos , Probióticos/uso terapêutico , Complicações Pós-Operatórias/prevenção & controle
14.
Nat Biotechnol ; 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459338

RESUMO

Idiopathic pulmonary fibrosis (IPF) is an aggressive interstitial lung disease with a high mortality rate. Putative drug targets in IPF have failed to translate into effective therapies at the clinical level. We identify TRAF2- and NCK-interacting kinase (TNIK) as an anti-fibrotic target using a predictive artificial intelligence (AI) approach. Using AI-driven methodology, we generated INS018_055, a small-molecule TNIK inhibitor, which exhibits desirable drug-like properties and anti-fibrotic activity across different organs in vivo through oral, inhaled or topical administration. INS018_055 possesses anti-inflammatory effects in addition to its anti-fibrotic profile, validated in multiple in vivo studies. Its safety and tolerability as well as pharmacokinetics were validated in a randomized, double-blinded, placebo-controlled phase I clinical trial (NCT05154240) involving 78 healthy participants. A separate phase I trial in China, CTR20221542, also demonstrated comparable safety and pharmacokinetic profiles. This work was completed in roughly 18 months from target discovery to preclinical candidate nomination and demonstrates the capabilities of our generative AI-driven drug-discovery pipeline.

17.
Bioorg Chem ; 146: 107285, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38547721

RESUMO

Cyclin-dependent kinases (CDKs) are critical cell cycle regulators that are often overexpressed in tumors, making them promising targets for anti-cancer therapies. Despite substantial advancements in optimizing the selectivity and drug-like properties of CDK inhibitors, safety of multi-target inhibitors remains a significant challenge. Macrocyclization is a promising drug discovery strategy to improve the pharmacological properties of existing compounds. Here we report the development of a macrocyclization platform that enabled the highly efficient discovery of a novel, macrocyclic CDK2/4/6 inhibitor from an acyclic precursor (NUV422). Using dihedral angle scan and structure-based, computer-aided drug design to select an optimal ring-closing site and linker length for the macrocycle, we identified compound 8 as a potent new CDK2/4/6 inhibitor with optimized cellular potency and safety profile compared to NUV422. Our platform leverages both experimentally-solved as well as generative chemistry-derived macrocyclic structures and can be deployed to streamline the design of macrocyclic new drugs from acyclic starting compounds, yielding macrocyclic compounds with enhanced potency and improved drug-like properties.


Assuntos
Quinases Ciclina-Dependentes , Inibidores de Proteínas Quinases , Relação Estrutura-Atividade , Quinase 2 Dependente de Ciclina/química , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Desenho de Fármacos , Descoberta de Drogas
18.
Bioorg Med Chem ; 103: 117662, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38493730

RESUMO

Inhibition of the low fidelity DNA polymerase Theta (Polθ) is emerging as an attractive, synthetic-lethal antitumor strategy in BRCA-deficient tumors. Here we report the AI-enabled development of 3-hydroxymethyl-azetidine derivatives as a novel class of Polθ inhibitors featuring central scaffolding rings. Structure-based drug design first identified A7 as a lead compound, which was further optimized to the more potent derivative B3 and the metabolically stable deuterated compound C1. C1 exhibited significant antiproliferative properties in DNA repair-compromised cells and demonstrated favorable pharmacokinetics, showcasing that 3-hydroxymethyl-azetidine is an effective bio-isostere of pyrrolidin-3-ol and emphasizing the potential of AI in medicinal chemistry for precise molecular modifications.


Assuntos
Azetidinas , Neoplasias , Humanos , Reparo do DNA , Azetidinas/química
19.
ACS Appl Mater Interfaces ; 16(13): 16011-16028, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38529951

RESUMO

Superbug infections and transmission have become major challenges in the contemporary medical field. The development of novel antibacterial strategies to efficiently treat bacterial infections and conquer the problem of antimicrobial resistance (AMR) is extremely important. In this paper, a bimetallic CuCo-doped nitrogen-carbon nanozyme-functionalized hydrogel (CuCo/NC-HG) has been successfully constructed. It exhibits photoresponsive-enhanced enzymatic effects under near-infrared (NIR) irradiation (808 nm) with strong peroxidase (POD)-like and oxidase (OXD)-like activities. Upon NIR irradiation, CuCo/NC-HG possesses photodynamic activity for producing singlet oxygen(1O2), and it also has a high photothermal conversion effect, which not only facilitates the elimination of bacteria but also improves the efficiency of reactive oxygen species (ROS) production and accelerates the consumption of GSH. CuCo/NC-HG shows a lower hemolytic rate and better cytocompatibility than CuCo/NC and possesses a positive charge and macroporous skeleton for restricting negatively charged bacteria in the range of ROS destruction, strengthening the antibacterial efficiency. Comparatively, CuCo/NC and CuCo/NC-HG have stronger bactericidal ability against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AmprE. coli) through destroying the cell membranes with a negligible occurrence of AMR. More importantly, CuCo/NC-HG plus NIR irradiation can exhibit satisfactory bactericidal performance in the absence of H2O2, avoiding the toxicity from high-concentration H2O2. In vivo evaluation has been conducted using a mouse wound infection model and histological analyses, and the results show that CuCo/NC-HG upon NIR irradiation can efficiently suppress bacterial infections and promote wound healing, without causing inflammation and tissue adhesions.


Assuntos
Infecções Bacterianas , Staphylococcus aureus Resistente à Meticilina , Animais , Hidrogéis/farmacologia , Escherichia coli , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Fototerapia , Infecções Bacterianas/tratamento farmacológico , Antibacterianos/farmacologia , Carbono , Modelos Animais de Doenças , Nitrogênio
20.
Polymers (Basel) ; 16(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38543382

RESUMO

The cell structure and compressive properties of extruded polyethylene terephthalate (PET) foam with different densities were studied. The die of the PET foaming extruder is a special multi-hole breaker plate, which results in a honeycomb-shaped foam block. The SEM analysis showed that the aspect ratio and cell wall thickness of the strand border is greater than that of the strand body. The cells are elongated and stronger in the extruding direction, and the foam anisotropy of the structure and compressive properties decrease with increasing density. The compression results show typical stress-strain curves even though the extruded PET foam is composed of multiple foamed strands. The compression properties of PET foam vary in each of the three directions, with the best performing direction (i.e., extrusion direction) showing stretch-dominated structures, while the other two directions show bending-dominated structures. Foam mechanics models based on both rectangular and elongated Kelvin cell geometries were considered to predict the compressive properties of PET foams in terms of relative density, structure anisotropy, and the properties of the raw polymer. The results show that the modulus and strength anisotropy of PET foam can be reasonably predicted by the rectangular cell model, but more accurate predictions were obtained with an appropriately assumed elongated Kelvin model.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...