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1.
Proc Natl Acad Sci U S A ; 121(25): e2322264121, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38865265

RESUMO

Despite the tremendous clinical potential of nucleic acid-based vaccines, their efficacy to induce therapeutic immune response has been limited by the lack of efficient local gene delivery techniques in the human body. In this study, we develop a hydrogel-based organic electronic device (µEPO) for both transdermal delivery of nucleic acids and in vivo microarrayed cell electroporation, which is specifically oriented toward one-step transfection of DNAs in subcutaneous antigen-presenting cells (APCs) for cancer immunotherapy. The µEPO device contains an array of microneedle-shaped electrodes with pre-encapsulated dry DNAs. Upon a pressurized contact with skin tissue, the electrodes are rehydrated, electrically triggered to release DNAs, and then electroporate nearby cells, which can achieve in vivo transfection of more than 50% of the cells in the epidermal and upper dermal layer. As a proof-of-concept, the µEPO technique is employed to facilitate transdermal delivery of neoantigen genes to activate antigen-specific immune response for enhanced cancer immunotherapy based on a DNA vaccination strategy. In an ovalbumin (OVA) cancer vaccine model, we show that high-efficiency transdermal transfection of APCs with OVA-DNAs induces robust cellular and humoral immune responses, including antigen presentation and generation of IFN-γ+ cytotoxic T lymphocytes with a more than 10-fold dose sparing over existing intramuscular injection (IM) approach, and effectively inhibits tumor growth in rodent animals.


Assuntos
Eletroporação , Imunoterapia , Vacinas de DNA , Animais , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Eletroporação/métodos , Camundongos , Imunoterapia/métodos , Administração Cutânea , Neoplasias/terapia , Neoplasias/imunologia , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/administração & dosagem , Ovalbumina/imunologia , Ovalbumina/administração & dosagem , Células Apresentadoras de Antígenos/imunologia , Feminino , Camundongos Endogâmicos C57BL , Humanos , Vacinação/métodos
2.
Brief Bioinform ; 24(2)2023 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-36892174

RESUMO

Large-scale multiple perturbation experiments have the potential to reveal a more detailed understanding of the molecular pathways that respond to genetic and environmental changes. A key question in these studies is which gene expression changes are important for the response to the perturbation. This problem is challenging because (i) the functional form of the nonlinear relationship between gene expression and the perturbation is unknown and (ii) identification of the most important genes is a high-dimensional variable selection problem. To deal with these challenges, we present here a method based on the model-X knockoffs framework and Deep Neural Networks to identify significant gene expression changes in multiple perturbation experiments. This approach makes no assumptions on the functional form of the dependence between the responses and the perturbations and it enjoys finite sample false discovery rate control for the selected set of important gene expression responses. We apply this approach to the Library of Integrated Network-Based Cellular Signature data sets which is a National Institutes of Health Common Fund program that catalogs how human cells globally respond to chemical, genetic and disease perturbations. We identified important genes whose expression is directly modulated in response to perturbation with anthracycline, vorinostat, trichostatin-a, geldanamycin and sirolimus. We compare the set of important genes that respond to these small molecules to identify co-responsive pathways. Identification of which genes respond to specific perturbation stressors can provide better understanding of the underlying mechanisms of disease and advance the identification of new drug targets.


Assuntos
Redes Reguladoras de Genes , Redes Neurais de Computação , Humanos , Biblioteca Gênica , Expressão Gênica
3.
Catheter Cardiovasc Interv ; 103(4): 626-636, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38353507

RESUMO

BACKGROUND: Functional tricuspid regurgitation (FTR) following left-sided valve surgery (LSVS) is of clinical significance due to its high recurrence and mortality rates. Transcatheter therapy presents a potential solution to address this issue. AIMS: The study aimed to assess the safety and efficacy of transcatheter tricuspid valve replacement using the Lux-Valve system in a single center for patients with FTR after LSVS. METHODS: From June 2020 to April 2023, 20 patients with symptomatic severe FTR after LSVS were referred to our center. A multidisciplinary cardiac team evaluated these patients for suitability for transcatheter tricuspid valve replacement with Lux-Valve systems. Primary efficacy and safety endpoints were immediate postoperative tricuspid regurgitation severity ≤ moderate and major adverse events during follow-up. RESULTS: Twenty patients (average age 65.7 ± 7.4 years; 65.0% women) successfully underwent Lux-Valve system implantation after LSVS. All patients achieved ≤ moderate tricuspid regurgitation immediately after the procedure. Only one patient (5.0%) experienced a procedure-related major adverse event, leading to in-hospital mortality due to pulmonary infection. At the 6-month follow-up, 17 patients (89.5%) improved to New York Heart Association functional class I to II (p < 0.001). The overall Kansas City Cardiomyopathy Questionnaire score significantly improved (35.9 ± 6.7 points to 58.9 ± 5.8 points, p < 0.001). CONCLUSION: The Lux-Valve system was found to be safe and effective for treating FTR after LSVS. It resulted in positive early outcomes, including a significant reduction in FTR, improved functional status, and enhanced quality of life, especially in high-risk patients.


Assuntos
Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Tricúspide , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/cirurgia , Valva Tricúspide/diagnóstico por imagem , Valva Tricúspide/cirurgia , Qualidade de Vida , Resultado do Tratamento , Cateterismo Cardíaco/métodos
4.
Surg Innov ; 31(3): 256-262, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38565982

RESUMO

OBJECTIVE: In this case report, the auxiliary role of deep learning and 3-dimensional printing technology in the perioperative period was discussed to guide transcatheter aortic valve replacement and coronary stent implantation simultaneously. CASE PRESENTATION: A 68-year-old man had shortness of breath and chest tightness, accompanied by paroxysmal nocturnal dyspnea, 2 weeks before presenting at our hospital. Echocardiography results obtained in the outpatient department showed severe aortic stenosis combined with regurgitation and pleural effusion. The patient was first treated with closed thoracic drainage. After 800 mL of pleural effusion was collected, the patient's symptoms were relieved and he was admitted to the hospital. Preoperative transthoracic echocardiography showed severe bicuspid aortic valve stenosis combined with calcification and aortic regurgitation (mean pressure gradient, 42 mmHg). Preoperative computed tomography results showed a type I bicuspid aortic valve with severe eccentric calcification. The leaflet could be seen from the left coronary artery plane, which indicated an extremely high possibility of coronary obstruction. After preoperative imaging assessment, deep learning and 3-dimensional printing technology were used for evaluation and simulation. Guided transcatheter aortic valve replacement and a coronary stent implant were completed successfully. Postoperative digital subtraction angiography showed that the bioprosthesis and the chimney coronary stent were in ideal positions. Transesophageal echocardiography showed normal morphology without paravalvular regurgitation. CONCLUSION: The perioperative guidance of deep learning and 3-dimensional printing are of great help for surgical strategy formulation in patients with severe bicuspid aortic valve stenosis with calcification and high-risk coronary obstruction.


Assuntos
Estenose da Valva Aórtica , Aprendizado Profundo , Impressão Tridimensional , Substituição da Valva Aórtica Transcateter , Humanos , Substituição da Valva Aórtica Transcateter/métodos , Masculino , Idoso , Estenose da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Stents , Valva Aórtica/cirurgia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/anormalidades , Insuficiência da Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/diagnóstico por imagem
5.
Adv Exp Med Biol ; 1414: 1-26, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35708844

RESUMO

Three human nucleases, SNM1A, SNM1B/Apollo, and SNM1C/Artemis, belong to the SNM1 gene family. These nucleases are involved in various cellular functions, including homologous recombination, nonhomologous end-joining, cell cycle regulation, and telomere maintenance. These three proteins share a similar catalytic domain, which is characterized as a fused metallo-ß-lactamase and a CPSF-Artemis-SNM1-PSO2 domain. SNM1A and SNM1B/Apollo are exonucleases, whereas SNM1C/Artemis is an endonuclease. This review contains a summary of recent research on SNM1's cellular and biochemical functions, as well as structural biology studies. In addition, protein structure prediction by the artificial intelligence program AlphaFold provides a different view of the proteins' non-catalytic domain features, which may be used in combination with current results from X-ray crystallography and cryo-EM to understand their mechanism more clearly.


Assuntos
Enzimas Reparadoras do DNA , Reparo do DNA , Humanos , Inteligência Artificial , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , Exodesoxirribonucleases/genética , Exodesoxirribonucleases/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Ciclo Celular/metabolismo
6.
Angew Chem Int Ed Engl ; 62(18): e202302156, 2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-36878864

RESUMO

Although multitargeted PtIV anticancer prodrugs have shown significant activities in reducing drug resistance, the types of bioactive ligands and drugs that can be conjugated to the Pt center remain limited to O-donors. Herein, we report the synthesis of PtIV complexes bearing axial pyridines via ligand exchange reactions. Unexpectedly, the axial pyridines are quickly released after reduction, indicating their potential to be utilized as axial leaving groups. We further expand our synthetic approach to obtaining two multitargeted PtIV prodrugs containing bioactive pyridinyl ligands: a PARP inhibitor and an EGFR tyrosine kinase inhibitor; these conjugates exhibit great potential for overcoming drug resistance, and the latter conjugate inhibits the growth of Pt-resistant tumor in vivo. This research adds to the array of synthetic methods for accessing PtIV prodrugs and significantly increases the types of bioactive axial ligands that can be conjugated to a PtIV center.


Assuntos
Antineoplásicos , Pró-Fármacos , Platina , Ligantes , Pró-Fármacos/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral
7.
Small ; 18(16): e2108102, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35253997

RESUMO

Leaf venation provides a promising template for engineering capillary-like vasculature in vitro due to its highly efficient fluid transport capability and remarkable similarities to native capillary networks. A key challenge in exploring the potential biological applications of leaf-inspired capillary networks (LICNs) is to accurately and quantitively understand its internal fluid transport characteristics. Here, a centerline-induced partition-assembly modeling strategy is proposed to establish a 3D computational model, which can accurately simulate the flow conditions in LICNs. Based on the 3D flow simulation, the authors demonstrate the excellent defect-resistant fluid transport capability of LICNs. Interestingly, structural defects in the primary channel can effectively accelerate the overall perfusion efficiency. Flow patterns in LICNs with multiple defects can be estimated by simple superposition of the simulation results derived from the corresponding single-defect models. The 3D computational model is further used to determine the optimal perfusion parameter for the in-vitro formation of endothelialized capillary networks by mimicking native microvascular flow conditions. The endothelialized networks can recapitulate the vascular colonization process and reveal a strong correlation between cancer cell adhesion and flow-induced shear stress. This study offers a quantitative tool to scrutinize the fluid and biological transport mechanisms within LICNs for various biomedical applications.


Assuntos
Capilares , Simulação por Computador , Transporte Biológico , Humanos , Estresse Mecânico
8.
Invest New Drugs ; 40(5): 1125-1132, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35793038

RESUMO

BACKGROUND: Conversion therapy has been widely applied in various cancer types including intrahepatic cholangiocarcinoma (ICC). The aim of this retrospective study was to evaluate the efficacy and safety of transarterial chemoembolization combined with lenvatinib (TACE-L) as a novel conversion therapy in patients with initially unresectable ICC. METHODS: Enrolled in this retrospective study were patients with unresectable ICC who received TACE-L between January 2015 and May 2018. The patients were evaluated every 2 months for possible secondary resection. RESULTS: Of the 44 eligible patients, 28 (63.6%) were successfully downstaged to receive surgical resection and the other 16 patients were included into the unsuccessfully downstaged group. The overall adverse events during TACE-L were moderate, including 12 patients (27.3%) with Grade 3 or 4 toxicities. Of the 28 downregulated patients, 23 (82.1%) achieved an R0 resection, and 6 (21.4%) had Clavien-Dindo grade ≥ 3 complications, including one postoperative death. Kaplan-Meier curves showed that the successfully downstaged patients had better overall survival (OS) than the unsuccessfully downstaged patients (P = 0.006). Multivariable analysis identified successful TACE-L conversion therapy as a significantly favorable prognostic factor for OS. CONCLUSIONS: TACE-L proves to be a safe and efficacious conversion therapy modality that allows for secondary resectability in patients with initially unresectable ICC.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Quimioembolização Terapêutica , Colangiocarcinoma , Neoplasias Hepáticas , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/patologia , Quimioembolização Terapêutica/efeitos adversos , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/cirurgia , Humanos , Neoplasias Hepáticas/patologia , Compostos de Fenilureia , Quinolinas , Estudos Retrospectivos , Resultado do Tratamento
9.
Phys Chem Chem Phys ; 24(38): 23817-23824, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36164942

RESUMO

In recent years, the material preparation technology has ushered into a stage of rapid development, increasingly more carbon materials are found to display superior properties, making them suitable for designing nano-scale devices. Within the applications of electronic devices, a considerable amount of consumed energy has to be converted into heat; thus the efficiency of heat transport inside these devices can largely determine their overall performance. Decent elucidations of the heat transport mechanisms within low-dimensional materials will be helpful to achieve thermal management control of the related devices and furthermore, to improve their conversion efficiency. It is well understood that the heat transport within these kinds of materials is largely associated with their structural features. In this study, we focused on a novel material, body centered cubic carbon (C14), which is composed of sp3 hybridized carbon atoms. Such a novel material displays superior electronic properties; however, its thermal properties remain to be investigated. In order to systematically evaluate the practical applicability of this novel material, first-principles calculations were employed to systematically solve its structure; furthermore, its thermal conductivity, phonon dispersion spectrum, phonon properties, Grüneisen parameters, scattering phase space and mechanical properties were all described in detail. We found that C14 performs well in heat transport; and via systematical comparison with another allotrope, diamond, its transport mechanism was further summarized. We hope the physical insights provided by this study could serve as theoretical support for nano-scale device design.

10.
Angew Chem Int Ed Engl ; 61(28): e202204603, 2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35474275

RESUMO

Medium-sized N,S-heterocycles have received tremendous interest due to their biological activities and potential medical applications. However, asymmetric synthesis of these compounds are extremely rare. Described herein is a catalyst-dependent [3,3]-sigmatropic rearrangement of sulfoxide-ynamides, enabling divergent and atom-economic synthesis of a series of valuable medium-sized N,S-heterocycles in moderate to good yields with broad substrate scope. Importantly, excellent enantioselectivities have been achieved via an unprecedented chirality-transfer. Moreover, theoretical calculations are employed to elucidate the origins of the catalyst-dependent stereospecific [3,3]-rearrangement.


Assuntos
Sulfóxidos , Catálise , Ciclização , Estrutura Molecular , Estereoisomerismo
11.
Angew Chem Int Ed Engl ; 61(25): e202203838, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35352863

RESUMO

The short circulatory half-lives and low tumor accumulation of carboplatin greatly limit the drug's efficacy in vivo. Herein, we address these challenges by using a prodrug strategy and present the rational design of a novel platinum(IV) anticancer prodrug that can hitchhike on erythrocytes. This prodrug, designated as ERY1-PtIV , can bind to erythrocytes efficiently and stably, possessing a circulatory half-life 18.5 times longer than that of carboplatin in mice. This elongated circulatory half-life enables platinum to accumulate at levels 7.7 times higher than with carboplatin, with steady levels in the tumors. As a consequence, the ERY1-PtIV prodrug is proved to exhibit significantly enhanced antitumor activity and reduced side effects compared with carboplatin. Collectively, our novel approach highlights an efficient strategy to utilize intrinsic erythrocytes as auto-binding carriers to enhance the tumor accumulation and subsequent antitumor efficacy of platinum drugs.


Assuntos
Antineoplásicos , Neoplasias , Pró-Fármacos , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carboplatina/farmacologia , Linhagem Celular Tumoral , Cisplatino/uso terapêutico , Eritrócitos , Camundongos , Neoplasias/tratamento farmacológico , Platina/uso terapêutico , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico
12.
J Biol Chem ; 295(35): 12368-12377, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32576658

RESUMO

The endonuclease Artemis is responsible for opening DNA hairpins during V(D)J recombination and for processing a subset of pathological DNA double-strand breaks. Artemis is an attractive target for the development of therapeutics to manage various B cell and T cell tumors, because failure to open DNA hairpins and accumulation of chromosomal breaks may reduce the proliferation and viability of pre-T and pre-B cell derivatives. However, structure-based drug discovery of specific Artemis inhibitors has been hampered by a lack of crystal structures. Here, we report the structure of the catalytic domain of recombinant human Artemis. The catalytic domain displayed a polypeptide fold similar overall to those of other members in the DNA cross-link repair gene SNM1 family and in mRNA 3'-end-processing endonuclease CPSF-73, containing metallo-ß-lactamase and ß-CASP domains and a cluster of conserved histidine and aspartate residues capable of binding two metal atoms in the catalytic site. As in SNM1A, only one zinc ion was located in the Artemis active site. However, Artemis displayed several unique features. Unlike in other members of this enzyme class, a second zinc ion was present in the ß-CASP domain that leads to structural reorientation of the putative DNA-binding surface and extends the substrate-binding pocket to a new pocket, pocket III. Moreover, the substrate-binding surface exhibited a dominant and extensive positive charge distribution compared with that in the structures of SNM1A and SNM1B, presumably because of the structurally distinct DNA substrate of Artemis. The structural features identified here may provide opportunities for designing selective Artemis inhibitors.


Assuntos
Endonucleases/química , Dobramento de Proteína , Zinco/química , Animais , Domínio Catalítico , Proteínas de Ligação a DNA , Endonucleases/genética , Humanos , Células Sf9 , Spodoptera , Relação Estrutura-Atividade
13.
Invest New Drugs ; 39(5): 1383-1388, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33754235

RESUMO

Background To investigate the clinical efficiency of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) for advanced hepatocellular carcinoma (HCC). Methods This retrospective study enrolled 177 HCC patients, and they were divided into TACE monotherapy group (n = 129) and TACE + RFA group (n = 48) between January 2015 and October 2017. The objective response rate (ORR), disease control rate (DCR), and the survival outcomes were compared between the TACE monotherapy and the treatment of TACE + RFA after propensity score matching (PSM). Results After PSM matching, the confounding factors had no significant differences between the 48 pairs of patients. The DCR was calculated as 33 (69 %) and 42 (88 %) for the TACE monotherapy group and TACE + RFA group, respectively (P < 0.05). And the ORR was calculated as 23 (48 %) and 35 (73 %), respectively (P < 0.05). Moreover, the PFS rate of the TACE + RFA group was significantly higher than the TACE alone group (P < 0.001). Conclusions The treatment of TACE combined with RFA has better tumor response rate and survival rate than the TACE monotherapy for patients with advanced HCC.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Ablação por Radiofrequência/métodos , Adulto , Idoso , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica/efeitos adversos , Terapia Combinada , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Pontuação de Propensão , Ablação por Radiofrequência/efeitos adversos , Radiografia Intervencionista , Estudos Retrospectivos , Taxa de Sobrevida
14.
Ecol Appl ; 31(5): e02345, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33817898

RESUMO

Marine food webs are structured through a combination of top-down and bottom-up processes. In coral reef ecosystems, fish size is related to life-history characteristics and size-based indicators can represent the distribution and flow of energy through the food web. Thus, size spectra can be a useful tool for investigating the impacts of both fishing and habitat condition on the health and productivity of coral reef fisheries. In addition, coral reef fisheries are often data-limited and size spectra analysis can be a relatively cost-effective and simple method for assessing fish populations. Abundance size spectra are widely used and quantify the relationship between organism size and relative abundance. Previous studies that have investigated the impacts of fishing and habitat condition together on the size distribution of coral reef fishes, however, have aggregated all fishes regardless of taxonomic identity. This leads to a poor understanding of how fishes with different feeding strategies, body size-abundance relationships, or catchability might be influenced by top-down and bottom-up drivers. To address this gap, we quantified size spectra slopes of carnivorous and herbivorous coral reef fishes across three regions of Indonesia representing a gradient in fishing pressure and habitat conditions. We show that fishing pressure was the dominant driver of size spectra slopes such that they became steeper as fishing pressure increased, which was due to the removal of large-bodied fishes. When considering fish functional groups separately, however, carnivore size spectra slopes were more heavily impacted by fishing than herbivores. Also, structural complexity, which can mediate predator-prey interactions and provisioning of resources, was a relatively important driver of herbivore size spectra slopes such that slopes were shallower in more complex habitats. Our results show that size spectra slopes can be used as indicators of fishing pressure on coral reef fishes, but aggregating fish regardless of trophic identity or functional role overlooks differential impacts of fishing pressure and habitat condition on carnivore and herbivore size distributions.


Assuntos
Recifes de Corais , Ecossistema , Animais , Conservação dos Recursos Naturais , Pesqueiros , Peixes
15.
Bioorg Med Chem Lett ; 43: 128058, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33895276

RESUMO

The protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is one of the three endoplasmic reticulum (ER) transmembrane sensors of the unfolded protein response (UPR) that regulates protein synthesis, alleviates cellular ER stress and has been implicated in tumorigenesis and prolonged cancer cell survival. In this study, we report a series of 2-amino-3-amido-5-aryl-pyridines that we have identified as potent, selective, and orally bioavailable PERK inhibitors. Amongst the series studied herein, compound (28) a (R)-2-Amino-5-(4-(2-(3,5-difluorophenyl)-2-hydroxyacetamido)-2-ethylphenyl)-N-isopropylnicotinamide has demonstrated potent biochemical and cellular activity, robust pharmacokinetics and 70% oral bioavailability in mice. Given these data, this compound (28) was studied in the 786-O renal cell carcinoma xenograft model. We observed dose-dependent, statistically significant tumor growth inhibition, supporting the use of this tool compound in additional mechanistic studies.


Assuntos
Descoberta de Drogas , Piridinas/farmacologia , eIF-2 Quinase/antagonistas & inibidores , Administração Oral , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Piridinas/administração & dosagem , Piridinas/química , Relação Estrutura-Atividade , eIF-2 Quinase/metabolismo
16.
Org Biomol Chem ; 19(16): 3687-3697, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33908569

RESUMO

An efficient organocatalytic diastereo- and enantioselective formal [3 + 2] cycloaddition reaction of α-isocyanoacetates with saccharin-derived 1-azadienes catalyzed by a dihydroquinine derived squaramide catalyst has been investigated, and it furnished the corresponding directly linked benzo[d]isothiazole 1,1-dioxide-dihydropyrroles with two adjacent tertiary-quaternary stereocenters in high yields (up to 98%), with moderate to excellent stereoselectivities (up to >20 : 1 dr and 97% ee) under mild conditions.

17.
Nanotechnology ; 32(31)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33853051

RESUMO

This paper investigates the electrical and thermal properties of pure epoxy resin (EP) and its micro-nano hybrid composites (20 wt% micro-AlN fillers with 1 wt% and 3 wt% nano-Al2O3fillers; 50% micro-AlN with 3% nano-Al2O3fillers) for power electronic packaging applications. Electrical properties such as space charge distribution, electrical conductivity and surface potential decay are measured. The thermal performance of the fabricated samples is estimated using thermal analysis devices. The hybrid composite consisting of 20 wt% micro-AlN and 1 wt% nano-Al2O3fillers exhibits the least space charge accumulation, higher thermal conductivity and better thermal stability. However, the excessive addition adversely affects space charge and electrical conductivity properties. The micro-nano hybrid composites significantly exhibit higher electrical conductivity than pure EP. The microfiller addition from 20 wt% to 50 wt% significantly improves the thermal conductivity of the EP. The reduced space charge injection and accumulation in the hybrid micro-nano composites are attributed to the enhancement of the injection barrier and reduction of the charge carrier traps in these materials. A theoretical mechanism of the charge dynamics inside the samples under different test conditions is proposed to support the experimental results.

18.
J Am Chem Soc ; 142(17): 7803-7812, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32216337

RESUMO

Targeted anticancer prodrugs that can be controllably activated are highly desired for personalized precision medicine in cancer therapy. Such prodrugs with unique action modes are also promising to overcome drug resistance. Herein, we report coumaplatin, an oxaliplatin-based and photocaged Pt(IV) prodrug, to realize nuclear accumulation along with "on-demand" activation. This prodrug is based on a Pt(IV) complex that can be efficiently photoactivated via water oxidation without the requirement of a reducing agent. Coumaplatin accumulates very efficiently in the nucleoli, and upon photoactivation, this prodrug exhibits a level of photocytotoxicity up to 2 orders of magnitude higher than that of oxaliplatin. Unexpectedly, this prodrug presents strikingly enhanced tumor penetration ability and utilizes a distinct action mode to overcome drug resistance; i.e., coumaplatin but not oxaliplatin induces cell senescence, p53-independent cell death, and immunogenic cell death along with T cell activation. Our findings not only provide a novel strategy for the rational design of controllably activated and nucleolus-targeted Pt(IV) anticancer prodrugs but also demonstrate that accumulating conventional platinum drugs to the nucleus is a practical way to change its canonical mechanism of action and to achieve reduced resistance.


Assuntos
Antineoplásicos/uso terapêutico , Nucléolo Celular/efeitos dos fármacos , Platina/uso terapêutico , Água/química , Antineoplásicos/farmacologia , Humanos , Platina/farmacologia
19.
J Am Chem Soc ; 142(16): 7618-7626, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32237743

RESUMO

The generation of metal-containing 1,3-dipoles from metal carbenes represents a significant advance in 1,3-dipolar cycloaddition reactions. However, these transformations have so far been limited to reactions based on diazo compounds or triazoles as precursors. Herein, we disclose a copper-catalyzed enantioselective reaction of alkenyl N-propargyl ynamides with styrene derivatives by formal [3 + 2] cycloaddition via Cu-containing all-carbon 1,3-dipoles, which constitutes a novel way for the generation of metal-containing 1,3-dipoles via metal carbenes. This protocol allows the practical and atom-economical synthesis of valuable chiral pyrrole-fused bridged [2.2.1] skeletons in moderate to good yields (up to 90% yield) with excellent diastereoselectivities (dr > 50/1) and generally excellent enantioselectivities (up to >99% ee).

20.
Inorg Chem ; 59(16): 11676-11687, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32799457

RESUMO

Platinum(IV) complexes containing carboxylate and carbamate ligands at the axial position have been reported previously. A better understanding of the similarity and difference between the two types of ligands will provide us with new insights and more choices to design novel Pt(IV) complexes. In this study, we systematically investigated and compared the properties of Pt(IV) complexes bearing the two types of ligands. Ten pairs of unsymmetric Pt(IV) complexes bearing axial carbamate or carboxylate ligands were synthesized and characterized. The stability of these Pt(IV) complexes in a PBS buffer with or without a reducing agent was investigated, and most of these complexes exhibited good stability. Besides, most Pt(IV) prodrugs with carbamate axial ligands were reduced faster than the corresponding ones with carboxylate ligands. Furthermore, the aqueous solubilities and lipophilicities of these Pt(IV) complexes were tested. All the carbamate complexes showed better aqueous solubility and decreased lipophilicity as compared to those of the corresponding carboxylate complexes, due to the increased polarity of carbamate ligands. Biological properties of these complexes were also evaluated. Many carbamate complexes showed cytotoxicity similar to that of the carboxylate complexes, which may derive from the lower cellular accumulation but faster reduction of the former. Our research highlights the differences between the Pt(IV) prodrugs containing carbamate and carboxylate axial ligands and may contribute to the future rational design of Pt-based anticancer prodrugs.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Carbamatos/química , Ácidos Carboxílicos/química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Estabilidade de Medicamentos , Ligantes , Oxirredução
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