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Photonic crystal hydrogels (PCHs), with smart stimulus-responsive abilities, have been widely exploited as colorimetric sensors for years. However, the current fabrication technologies are mostly applicable to produce PCHs with simple geometries at the sub-millimeter scale, limiting the introduction of structural design into PCH sensors as well as the accompanied advanced applications. This paper reports the microfabrication of three-dimensional (3D) PCHs with the help of supramolecular agarose PCH as a sacrificial scaffold by two-photon lithography (TPL). The supramolecular PCHs, formulated with SiO2 colloidal nanoparticles and agarose aqueous solutions, show bright structural color and are degradable upon short-time dimethyl sulfoxide treatment. Leveraging the supramolecular PCH as a sacrificial scaffold, PCHs with precise 3D geometries can be fabricated in an economical and efficient way. This work demonstrates the application of such a strategy in the creation of structural-designed PCH mechanical microsensors that have not been explored before.
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Pleurisy and pleural effusion caused by Brucella infection are rare. However, clinicians lack an understanding of these possibilities, and the underlying disorder is easy to misdiagnose. We report a 52-year-old male farmer who was admitted to hospital with a fever, chest pain, and shortness of breath. Closed chest drainage was performed by thoracocentesis, and the concentration of adenosine deaminase (ADA) in the pleural fluid was >45 U/L. Mononuclear cells in the pleural fluid accounted for 90% of the cells, and pathology indicated a large number of lymphocytes. The clinical diagnosis was tuberculosis with tuberculous pleurisy. However, subsequent pleural fluid culture results did not support tuberculous pleurisy. The results of pleural fluid culture indicated Brucella, and the results of Brucella tiger red plate agglutination indicated a titer of 1:400 (+++). The final diagnosis was brucellosis with pneumonia and pleurisy. After 12 weeks of oral treatment, the patient underwent follow-up chest radiographs. Radiography indicated complete resolution of the hydrothorax and pneumonia, and the patient reported no discomfort. The short-term curative effect was excellent. Pleurisy associated with brucellosis should be considered a differential for pleurisy in regions where brucellosis is endemic, to minimize the risk of misdiagnosis.
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Brucella , Brucelosis , Derrame Pleural , Pleuresia , Neumonía , Tuberculosis Pleural , Masculino , Humanos , Persona de Mediana Edad , Tuberculosis Pleural/diagnóstico , Pleuresia/diagnóstico , Derrame Pleural/diagnóstico , Brucelosis/diagnóstico , Brucelosis/complicaciones , Neumonía/complicaciones , Errores DiagnósticosRESUMEN
Silicosis is an important industrial health problem for those workers exposed to silica. The present study aimed to investigate the sensitivity and specificity of combined detection of biomarkers in early auxiliary diagnosis of silicosis, the risk factors of silicosis were also studied. The study sample comprised 65 workers who had clinical silicosis and 70 matched control subjects who were exposed to silica but did not have clinical silicosis. The levels of superoxide dismutase, malondialdehyde, interleukin 6 (IL-6), tumor necrosis factor-alpha, and cholinesterases in the serum of 135 subjects were measured. After completing the biochemical assays, a logistic regression model based on the above biochemical determination results was established, and the receiver operating characteristic curve was used for judging the discrimination ability of different statistical indexes. The expression levels of MDA, IL-6, and TNF-alpha in serum samples of patients with stage I silicosis and MDA and IL-6 in serum samples of patients with stage II silicosis were all significantly higher. Results from logistic regression analysis showed that ChEs were protective factors for silicosis, while age, chronic respiratory symptoms, IL-6, and MDA were risk factors. The areas under the ROC curve (AUC) were 0.86 (IL-6), 0.81 (MDA), and 0.65 (TNF-alpha or ChEs). AUC-ROC = 0.90 (95%CI:0.84-0.95). The diagnostic efficiency of IL-6 combined with MDA and TNF-alpha was better than that of any single biomarker.
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Silicosis , Factor de Necrosis Tumoral alfa , Humanos , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-6 , Silicosis/diagnóstico , Dióxido de Silicio , BiomarcadoresRESUMEN
In order to scientifically evaluate the characteristics and impact outcomes of transportation carbon emissions, this paper uses the panel statistics of 286 cities to measure transportation carbon emissions and analyze their spatial correlation characteristics. Afterwards, primarily based on the current research, a system of indicators for the impact factors of transportation carbon emissions was established. After that, ordinary least squares regression, geographically weighted regression, and multiscale geographically weighted regression models were used to evaluate and analyze the data, and the outcomes of the multiscale geographically weighted regression model were selected to analyze the spatial heterogeneity of the elements influencing transportation carbon emissions. The effects exhibit that: (1) The spatial characteristics of China's transportation carbon emissions demonstrate that emissions are high in the east, low in the west, high in the north, and low in the south, with high-value areas concentrated in the central cities of Beijing-Tianjin-Hebei, the Yangtze River Delta, the Guangdong-Hong Kong-Macao region, and the Chengdu-Chongqing regions, and the low values concentrated in the Western Sichuan region, Yunnan, Guizhou, Qinghai, and Gansu. (2) The spatial heterogeneity of transportation carbon emissions is on the rise, but the patten of local agglomeration is obvious, showing a clear high-high clustering, and the spatial distribution of high-high agglomeration and low-low agglomeration is positively correlated, with high-high agglomeration concentrated in the eastern region and low-low agglomeration concentrated in the western region. (3) The effects of three variables-namely, GDP per capita, vehicle ownership, and road mileage-have a predominantly positive effect on transportation carbon emissions within the study area, while another three variables-namely, constant term, population density, and number of people employed in transportation industry-have different mechanisms of influence in different regions. Constant term, vehicle ownership, and road mileage have greater impacts on transportation carbon emissions.
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Carbono , Urbanización , Humanos , Ciudades , China , Carbono/análisis , Beijing , Emisiones de Vehículos/análisis , Dióxido de Carbono/análisis , Desarrollo EconómicoRESUMEN
This study aimed to investigate the effects of perfluorooctanesulfonic acid (PFOS) exposure on glucose-stimulated insulin secretion (GSIS) of rat insulinoma (INS-1) cells and the potential protective effects of procyanidins (PC). The effects of PFOS and/or PC on GSIS of INS-1 cells were investigated after 48 h of exposure (protein level: insulin; gene level: glucose transporter 2 (Glut2), glucokinase (Gck), and insulin). Subsequently, the effects of exposure on the intracellular reactive oxygen species (ROS) activity were measured. Compared to the control group, PFOS exposure (12.5, 25, and 50 µM) for 48 h had no significant effect on the viability of INS-1 cells. PFOS exposure (50 µM) could reduce the level of insulin secretion and reduce the relative mRNA expression levels of Glut2, Gck, and insulin. It is worth noting that PC could partially reverse the damaging effect caused by PFOS. Significantly, there was an increase in ROS after exposure to PFOS and a decline after PC intervention. PFOS could affect the normal physiological function of GSIS in INS-1 cells. PC, a plant natural product, could effectively alleviate the damage caused by PFOS by inhibiting ROS activity.
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The forkhead box O (FoxO) protein is the main transcriptional effector downstream of the insulin/insulin-like signaling pathway and regulates many developmental and physiological processes. Holometabolous insects with loss-of-function mutations in FoxO exhibit phenotypes distinct from those of hemimetabolous insects in which RNA interference was used. Despite the functional importance of FoxO, whether hemimetabolous insects share an evolutionally conserved function of FoxO with holometabolous insects remains to be clarified. We used the clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) genome editing-system to establish a homozygous FoxO-null mutant (NlFoxO4E ) of the wing-dimorphic brown planthopper (BPH) Nilaparvata lugens, an economically important insect pest of rice fields. The phenotypes of NlFoxO4E mutants included extended nymphal duration, shortened lifespan, reduced reproduction, and decreased stress resistance. In addition, depletion of NlFoxO promoted cell proliferation in wing buds and led to 100% long-winged morphs, in stark contrast to short-winged wild-type BPHs. These findings indicate that NlFoxO is highly functionally conserved with its counterpart in holometabolous insects, and is required for optimal fitness of N. lugens. The insights from FoxO studies may facilitate the identification of potential target genes for BPH control applications.
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The orderly arrangement of nanomaterials' tiny units at the nanometer-scale accounts for a substantial part of their remarkable properties. Maintaining this orderness and meanwhile endowing the nanomaterials with highly precise and free-designed 3D micro architectures will open an exciting prospect for various novel applications. In this paper, we developed a sacrificial-scaffold-mediated two-photon lithography (TPL) strategy that enables the fabrication of complex 3D colloidal crystal microstructures with orderly-arranged nanoparticles inside. We show that, with the help of a degradable hydrogel scaffold, the disturbance effect of the femtosecond laser to the nanoparticle self-assembling could be overcome. Therefore, hydrogel-state and solid-state colloidal crystal microstructures with diverse compositions, free-designed geometries and variable structural colors could be easily fabricated. This enables the possibility to create novel colloidal crystal microsensing systems that have not been achieved before.
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Hexameric structure formation through packing of three C-terminal helices and an N-terminal trimeric coiled-coil core has been proposed as a general mechanism of class I enveloped virus entry. In this process, the C-terminal helical repeat (HR2) region of viral membrane fusion proteins becomes transiently exposed and accessible to N-terminal helical repeat (HR1) trimer-based fusion inhibitors. Herein, we describe a mimetic of the HIV-1 gp41 HR1 trimer, N3G, as a promising therapeutic against HIV-1 infection. Surprisingly, we found that in addition to protection against HIV-1 infection, N3G was also highly effective in inhibiting infection of human ß-coronaviruses, including MERS-CoV, HCoV-OC43, and SARS-CoV-2, possibly by binding the HR2 region in the spike protein of ß-coronaviruses to block their hexameric structure formation. These studies demonstrate the potential utility of anti-HIV-1 HR1 peptides in inhibiting human ß-coronavirus infection. Moreover, this strategy could be extended to the design of broad-spectrum antivirals based on the supercoiling structure of peptides.
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Antivirales/farmacología , Infecciones por Coronavirus/tratamiento farmacológico , Diseño de Fármacos , Proteína gp41 de Envoltorio del VIH/antagonistas & inhibidores , VIH-1/efectos de los fármacos , Péptidos/farmacología , Antivirales/síntesis química , Antivirales/química , Línea Celular , Infecciones por Coronavirus/metabolismo , Relación Dosis-Respuesta a Droga , Proteína gp41 de Envoltorio del VIH/metabolismo , VIH-1/metabolismo , Humanos , Pruebas de Sensibilidad Microbiana , Péptidos/síntesis química , Péptidos/química , Relación Estructura-ActividadRESUMEN
Dynamic fluorescence patterns with variable output in response to external stimulus can make the current information storage technologies more flexible and intelligent. Yet it remains a great challenge to create such dynamic patterns because of the complicated synthesis process, high cost, limited stability, and biocompatibility of the functional fluorophores. Herein, a facile approach is presented for creating dynamic fluorescence patterns using the photodynamic surface chemistry based on disulfide bonds. By this method, high-resolution (≈20 µm) multicolor dynamic fluorescence patterns that are low-cost and dynamically rewritable can be easily fabricated using classical fluorophores such as fluorescein, rhodamine, and dansyl acid. Owing to the spatio-temporal controllability of light, the fluorescence patterns can be partly or entirely erased/rewritten on demand, and complex gray-level fluorescence images with increased information capacity can be easily generated. The obtained fluorescence patterns exhibit little changes after storing in air and solvent environments for 100 days, demonstrating their high stability. In addition, static patterns can also be created on the same disulfide surface using irreversible disulfide-ene chemistry, to selectively control the dynamicity of the generated fluorescence patterns. The authors show the successful application of this strategy on information protection and transformation.
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Disulfuros , Colorantes Fluorescentes , Fluorescencia , Almacenamiento y Recuperación de la InformaciónRESUMEN
Short peptide-based inhibition of fusion remains an attractive goal in antihuman immunodeficiency virus (HIV) research based on its potential for the development of technically and economically desirable antiviral agents. Herein, we report the use of the dithiol bisalkylation reaction to generate a series of m-xylene thioether-stapled 22-residue α-helical peptides that have been identified as fusion inhibitors targeting HIV-1 glycoprotein 41 (gp41). The peptide sequence is based on the helix-zone binding domain of the gp41 C-terminal heptad repeat region. We found that one of these stapled peptides, named hCS6ERE, showed promising inhibitory potency against HIV-1 Env-mediated cell-cell fusion and viral replication at a level comparable to the clinically used 36-mer peptide T20. Furthermore, combining hCS6ERE with a fusion inhibitor having a different target site, such as HP23, produced synergistic anti-HIV-1 activity. Collectively, our study offers new insight into the design of anti-HIV peptides with short sequences.
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Diseño de Fármacos , Proteína gp41 de Envoltorio del VIH/química , Inhibidores de Fusión de VIH/química , Péptidos/química , Sulfuros/química , Secuencia de Aminoácidos , Animales , Endopeptidasa K/metabolismo , Proteína gp41 de Envoltorio del VIH/metabolismo , Inhibidores de Fusión de VIH/metabolismo , Inhibidores de Fusión de VIH/farmacología , VIH-1/fisiología , Humanos , Hígado/metabolismo , Péptidos/metabolismo , Péptidos/farmacología , Unión Proteica , Conformación Proteica en Hélice alfa , Ratas , Internalización del Virus/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Xilenos/químicaRESUMEN
Pneumoconiosis is a serious occupational disease that often occurs to coal workers with no early diagnosis and effective treatment at present. Diffuse pulmonary fibrosis is the major pathological change of pneumoconiosis, and its mechanism is still unclear. Epigenetics is involved in the development of many diseases, and it is closely associated with fibrosis. In this study, we investigated whether DNA methylation contributes to the pathogenesis of pulmonary fibrosis in pneumoconiosis. By exposure to coal dust or silica dust, we established the models of coal worker's pneumoconiosis (CWP), which showed an increased expression of COL-I, COL-III. We further found that DNMT1, DNMT3a, DNMT3b, MBD2, MeCP2 protein expression changed. Pretreatment with DNMT inhibitor 5-aza-dC reduced expression of COL-I, COL-III, and reduced pulmonary fibrosis. In summary, our results showed that DNA methylation contributes to dust-induced pulmonary fibrosis and that it may serve as a theoretical basis for testing DNA methyltransferase inhibitors in the treatment of CWP.
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Antracosis/etiología , Metilación de ADN/efectos de los fármacos , Polvo , Epigénesis Genética/efectos de los fármacos , Fibrosis Pulmonar/inducido químicamente , Animales , Antracosis/genética , Antracosis/metabolismo , Línea Celular , Carbón Mineral/toxicidad , Minas de Carbón , Colágeno Tipo I/genética , Colágeno Tipo III/genética , ADN (Citosina-5-)-Metiltransferasa 1/antagonistas & inhibidores , ADN (Citosina-5-)-Metiltransferasa 1/genética , Decitabina/farmacología , Modelos Animales de Enfermedad , Humanos , Masculino , Exposición Profesional/efectos adversos , Tamaño de la Partícula , Fibrosis Pulmonar/genética , Fibrosis Pulmonar/metabolismo , Ratas Sprague-Dawley , Dióxido de Silicio/química , Dióxido de Silicio/toxicidadRESUMEN
Chemically optimizing the molecular structure of aptamers may enhance properties such as biological activity or metabolic stability. DNA quadruplex-based HIV-1 fusion inhibitors were found to interact with HIV-1 surface glycoprotein in aptamer mode. In this work, a series of quadruplex-based HIV-1 fusion inhibitors with flexible oligodeoxynucleotide fragments at the 3' terminal was discovered. The flexible extension did not greatly influence quadruplex formation at the 5'-end. Increasing the length of the flexible fragment may increase antifusion activity. Compared with a traditional inhibitor, d(5'TGGGAG3')4, these novel inhibitors showed enhanced interaction with HIV-1 glycoproteins gp120 and gp41, which increased inhibition of 6-helical bundle formation during the course of virus fusion. These inhibitors also showed improved stability, compared with natural oligodeoxynucleotide. This work may inform the design of anti-HIV-1 DNA helix-based inhibitors with new structures or mechanisms.
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G-Cuádruplex/efectos de los fármacos , Inhibidores de Fusión de VIH/farmacología , VIH-1/efectos de los fármacos , Fragmentos de Péptidos/genética , Proteína gp41 de Envoltorio del VIH/genética , VIH-1/genética , Humanos , Oligodesoxirribonucleótidos/genéticaRESUMEN
Antimicrobial peptides (AMPs) are regarded as next-generation antibiotics to replace conventional antibiotics due to their rapid and broad-spectrum antimicrobial properties and far less sensitivity to the development of pathogen resistance. However, they are susceptible to proteolysis in vivo by endogenous or bacterial proteases as well as induce the lysis of red blood cells, which prevent their intravenous applications. In this work, polyion complex (PIC) micelles of the cationic AMP MSI-78 and the anionic copolymer methoxy poly(ethylene glycol)-b-poly(α-glutamic acid) (mPEG-b-PGlu) were prepared to develop novel antimicrobial agents for potential application in vivo. With an increase in molar ratio of mPEG-b-PGlu to MSI-78, the complexation ability of the PIC micelles increased. FITC-labeled MSI-78 showed a sustained release from the PIC micelles. More importantly, these PIC micelles greatly decreased the hemolytic toxicity of MSI-78 to human red blood cells, without influencing its antimicrobial activity. Thus, this approach could be used as a suitable in vivo delivery method of AMPs in the future.
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Antibacterianos/administración & dosificación , Péptidos Catiónicos Antimicrobianos/administración & dosificación , Portadores de Fármacos/química , Polietilenglicoles/química , Ácido Poliglutámico/análogos & derivados , Antibacterianos/farmacología , Antibacterianos/toxicidad , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/toxicidad , Química Farmacéutica/métodos , Preparaciones de Acción Retardada , Hemólisis/efectos de los fármacos , Humanos , Micelas , Ácido Poliglutámico/químicaRESUMEN
Gene therapy as a strategy for disease treatment requires safe and efficient gene delivery systems that encapsulate nucleic acids and deliver them to effective sites in the cell. Due to the insecurity of viral vectors, non-viral vectors have gained great attention recently. Additional advantages of non-viral vectors include their safety, flexibility in packaging nucleic acids, and ease of production. To construct an ideal gene carrier, peptides can be incorporated into non-viral gene delivery systems as functional motifs to overcome the current barriers in gene delivery. In this review, we summarize recent developments in peptide-based gene delivery vector research.
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Técnicas de Transferencia de Gen , Terapia Genética/métodos , Vectores Genéticos , Péptidos , Animales , Línea Celular , Vectores Genéticos/química , Vectores Genéticos/farmacología , Humanos , Ratones , Neoplasias/tratamiento farmacológico , Péptidos/química , Péptidos/farmacologíaRESUMEN
DNA helix-based HIV-1 fusion inhibitors have been discovered as potent drug candidates, but further research is required to enhance their efficiency. The trimeric structure of the HIV-1 envelope glycoprotein provides a structural basis for multivalent drug design. In this work, a "multi-domain" strategy was adopted for design of an oligodeoxynucleotide with assembly, linkage, and activity domains. Built on the self-assembly of higher-order nucleic acid structure, a novel category of multivalent DNA helix-based HIV-1 fusion inhibitor could be easily obtained by a simple annealing course in solution buffer, with no other chemical synthesis for multivalent connection. An optimized multivalent molecule, M4, showed significantly higher anti-HIV-1 fusion activity than did corresponding monovalent inhibitors. Examination of the underlying mechanism indicated that M4 could interact with HIV-1 glycoproteins gp120 and gp41, thereby inhibiting 6HB formation in the fusion course. M4 also showed anti-RDDP and anti-RNase H activity of reverse transcriptase. Besides, these assembled molecules showed improved in vitro metabolic stability in liver homogenate, kidney homogenate, and rat plasma. Moreover, little acute toxicity was observed. Our findings aid in the structural design and understanding of the mechanisms of DNA helix-based HIV-1 inhibitors. This study also provides a general strategy based on a new structural paradigm for the design of other multivalent nucleic acid drugs.
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Inhibidores de Fusión de VIH/administración & dosificación , VIH-1/efectos de los fármacos , Oligodesoxirribonucleótidos/administración & dosificación , Animales , Proteína gp120 de Envoltorio del VIH/metabolismo , Proteína gp41 de Envoltorio del VIH/metabolismo , Inhibidores de Fusión de VIH/farmacocinética , Inhibidores de Fusión de VIH/toxicidad , VIH-1/fisiología , Riñón/metabolismo , Hígado/metabolismo , Masculino , Ratones Endogámicos ICR , Oligodesoxirribonucleótidos/farmacocinética , Oligodesoxirribonucleótidos/toxicidad , Ratas Sprague-Dawley , Internalización del Virus/efectos de los fármacosRESUMEN
Class I enveloped viruses share similarities in their apparent use of a hexameric coiled-coil assembly to drive the merging of virus and host cell membranes. Inhibition of coiled coil-mediated interactions using bioactive peptides that replicate an α-helical chain from the viral fusion machinery has significant antiviral potential. Here, we present the construction of a series of lipopeptides composed of a de novo heptad repeat sequence-based α-helical peptide plus a hydrocarbon tail. Promisingly, the constructs adopted stable α-helical conformations and exhibited relatively broad-spectrum antiviral activities against Middle East respiratory syndrome coronavirus (MERS-CoV) and influenza A viruses (IAVs). Together, these findings reveal a new strategy for relatively broad-spectrum antiviral drug discovery by relying on the tunability of the α-helical coiled-coil domains present in all class I fusion proteins and the amphiphilic nature of the individual helices from this multihelix motif.
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Antivirales/farmacología , Infecciones por Coronavirus/tratamiento farmacológico , Descubrimiento de Drogas , Gripe Humana/tratamiento farmacológico , Lipopéptidos/farmacología , Proteínas Virales de Fusión/antagonistas & inhibidores , Secuencia de Aminoácidos , Antivirales/química , Infecciones por Coronavirus/virología , Células HEK293 , Humanos , Gripe Humana/virología , Alphainfluenzavirus/efectos de los fármacos , Lipopéptidos/química , Coronavirus del Síndrome Respiratorio de Oriente Medio/efectos de los fármacos , Conformación Proteica en Hélice alfa , Internalización del VirusRESUMEN
The approval of the erythropoietin (EPO) mimetic peptide drug peginesatide in 2012 was a breakthrough for the treatment of secondary anemia. However, due to severe allergic reactions, peginesatide was recalled a year later. In this study, 12 novel peptides were designed and synthesized by substituting specific amino acids of the monomeric peptide in peginesatide, with the aim of obtaining new EPO mimetic peptides with higher activities and lower side effects than the parent compound. Their cell proliferation activities were evaluated, and the structure-activity relationships were analyzed. Five compounds had equal cell proliferation activity to the control peptide. Among them, one compound showed a higher in vivo activity than the control peptide, with no obvious side effects.
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Diseño de Fármacos , Eritroblastos/efectos de los fármacos , Péptidos/farmacología , Animales , Peso Corporal/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Inyecciones Subcutáneas , Ratones , Estructura Molecular , Péptidos/administración & dosificación , Péptidos/síntesis química , Relación Estructura-ActividadRESUMEN
DNA helix-based HIV-1 fusion inhibitors have been discovered as potent drug candidates. Introduction of hydrophobic groups to a nucleobase provides an opportunity to design inhibitors with novel structures and mechanisms of action. In this work, two novel nucleoside analogues (1 and 2) were synthesized and incorporated into four DNA duplex- and quadruplex-based inhibitors. All the molecules showed anti-HIV-1 fusion activity. The effect of the p-benzyloxyphenyl group and the attached linker on the helix formation and thermal stability were fully compared and discussed. Surface plasmon resonance analysis further indicated that inhibitors with the same DNA helix may still have variable reaction targets, mainly attributed to the different hydrophobic modifications.
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ADN/metabolismo , Inhibidores de Fusión de VIH/síntesis química , Nucleósidos/química , Dicroismo Circular , ADN/química , Proteína gp41 de Envoltorio del VIH/antagonistas & inhibidores , Proteína gp41 de Envoltorio del VIH/metabolismo , Inhibidores de Fusión de VIH/metabolismo , Inhibidores de Fusión de VIH/farmacología , VIH-1/efectos de los fármacos , Humanos , Cinética , Resonancia por Plasmón de Superficie , Temperatura de TransiciónRESUMEN
Despite extensive investigations, the clinical translation of nanocarrier-based drug delivery systems (NDDS) for cancer therapy is hindered by inefficient delivery and poor tumor penetration. Conventional chemotherapy by administration of free small molecule anticancer drugs remains the standard of care for many cancers. Herein, other than for carrying and releasing drugs, small nanoparticles were used as a potentiator of conventional chemotherapy by co-administration with free chemotherapeutic agents. This strategy avoided the problems associated with drug loading and controlled release encountered in NDDS, and was also much simpler than NDDS. Negatively charged poly(amido amine)-2,3-dimethylmaleic monoamide (PAMAM-DMA) dendrimers were prepared, which possessed low toxicity and can be converted to positively charged PAMAM dendrimers responsive to tumor acidic pH. The in situ formed PAMAM in tumor tissue promoted cellular uptake of co-administered doxorubicin by increasing the cell membrane permeability, and subsequently enhanced the cytotoxicity of doxorubicin. The small size of the dendrimers was favorable for deep penetration in tumor. Co-injection of PAMAM-DMA with doxorubicin into nude mice bearing human tumors almost completely inhibited tumor growth, with a mean tumor weight reducing by 55.9% after the treatment compared with the treatment with doxorubicin alone.
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Antineoplásicos/administración & dosificación , Antineoplásicos/química , Dendrímeros/química , Animales , Línea Celular Tumoral , Permeabilidad de la Membrana Celular/efectos de los fármacos , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Doxorrubicina/administración & dosificación , Doxorrubicina/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos/efectos de los fármacos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Células MCF-7 , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Nanopartículas/química , Poliaminas/químicaRESUMEN
The hexameric α-helical coiled-coil formed between the C-terminal and N-terminal heptad repeat (CHR and NHR) regions of class I viral fusion proteins plays an important role in mediating the fusion of the viral and cellular membranes and provides a clear starting point for molecular mimicry that drives viral fusion inhibitor design. Unfortunately, such peptide mimicry of the short α-helical region in the CHR of Middle East respiratory syndrome coronavirus (MERS-CoV) spike protein has been thwarted by the loss of the peptide's native α-helical conformation when taken out of the parent protein structure. Here, we describe that appropriate all-hydrocarbon stapling of the short helical portion-based peptide to reinforce its bioactive secondary structure remarkably improves antiviral potency. The resultant stapled peptide P21S10 could effectively inhibit infection by MERS-CoV pseudovirus and its spike protein-mediated cell-cell fusion; additionally, P21S10 exhibits improved pharmacokinetic properties than HR2P-M2, suggesting strong potential for development as an anti-MERS-CoV therapeutic.