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1.
Environ Sci Technol ; 58(32): 14158-14168, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39088650

RESUMO

The widespread use of plastic products in daily life has raised concerns about the health hazards associated with nanoplastics (NPs). When exposed, NPs are likely to infiltrate the bloodstream, interact with plasma proteins, and trigger macrophage recognition and clearance. In this study, we focused on establishing a correlation between the unique protein coronal signatures of high-density (HDPE) and low-density (LDPE) polyethylene (PE) NPs with their ultimate impact on macrophage recognition and cytotoxicity. We observed that low-density and high-density lipoprotein receptors (LDLR and SR-B1), facilitated by apolipoproteins, played an essential role in PE-NP recognition. Consequently, PE-NPs activated the caspase-3/GSDME pathway and ultimately led to pyroptosis. Advanced imaging techniques, including label-free scattered light confocal imaging and cryo-soft X-ray transmission microscopy with 3D-tomographic reconstruction (nano-CT), provided powerful insights into visualizing NPs-cell interactions. These findings underscore the potential risks of NPs to macrophages and introduce analytical methods for studying the behavior of NPs in biological systems.


Assuntos
Macrófagos , Polietileno , Coroa de Proteína , Macrófagos/metabolismo , Coroa de Proteína/metabolismo , Coroa de Proteína/química , Animais , Camundongos , Nanopartículas/química , Humanos
2.
J Environ Manage ; 360: 121090, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38772228

RESUMO

Microplastics (MPs) and antibiotic resistance genes (ARGs) are important pollutants in waste activated sludge (WAS), but their interactions during anaerobic digestion (AD) still need to be further explored. This study investigated variations in ARGs, mobile genetic elements (MGEs), and host bacteria during AD under the pressure of polyamide (PA), polyethylene (PE), and polypropylene (PP). The results showed that the MPs increased methane production by 11.7-35.5%, and decreased ARG abundance by 5.6-24.6%. Correlation analysis showed that the decrease of MGEs (plasmid, prophage, etc.) promoted the decrease of the abundance of multidrug, aminoglycoside and tetracycline resistance genes. Metagenomic annotation revealed that the reduction of key host bacteria (Arenimonas, Lautropia, etc.) reduced the abundance of major ARGs (rsmA, rpoB2, etc.). Moreover, PP MPs contributed to a reduction in the abundance of functional genes related to the production of reactive oxygen species, ATP synthesis, and cell membrane permeability, which was conducive to reducing the potential for horizontal gene transfer of ARGs. These findings provide insights into the treatment of organic waste containing MPs.


Assuntos
Resistência Microbiana a Medicamentos , Transferência Genética Horizontal , Microplásticos , Esgotos , Resistência Microbiana a Medicamentos/genética , Anaerobiose , Esgotos/microbiologia , Antibacterianos/farmacologia
3.
Ecotoxicol Environ Saf ; 243: 113997, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35988380

RESUMO

Concerns about the micro/nano plastics (MNPs) exposure risks have risen in recent years. The ecological corona (EC), which is generated by the interaction between MNPs and environmental substances, has a significant impact on their environmental fate and ecological risks. As the largest sink of MNPs, the aquatic environment is of great significance for understanding the environmental behaviour of MNPs. Transmission Electron Microscope (TME), Fourier Transform Infra-Red (FTIR), Scanning Electron Microscope (SEM), Dynamic Light Scattering (DLS) and other analytical methods have been used as effective methods to analyse the formation process of EC and detect the existing EC directly or indirectly on the surface of MNPs. The physicochemical properties of MNPs, complex aquatic environments and ageing time have been identified as the key factors affecting EC formation in aquatic environments. Moreover, the EC absorbed on MNPs significantly changed their environmental behaviour and toxicity to aquatic organisms. This review gives a full understanding of the EC formation progress on the surface of MNPs and different analytical methods for EC have been summarised which can further assist the ecological risk assessment of MNPs in the aquatic environment.


Assuntos
Organismos Aquáticos , Poluentes Químicos da Água , Microplásticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
J Integr Neurosci ; 21(3): 91, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35633172

RESUMO

BACKGROUND: The rat sciatic nerve crush injury model is one of the most commonly used models to research peripheral nerve injury (PNI), however, the evaluation of the model preparation lacks exact standards. This study aimed to investigate accurately assessment methods for research concerning the rat sciatic nerve crush injury. METHODS: The sciatic nerve crush injury model of was performed using the FST toothless forceps. The corresponding locations and pressures of different ratchet strengths were assessed by using CMAP, behavioral, and morphological methods. RESULTS: In each group of PNI, motor and sensory functions were gradually restricted on the injured side of rats as the applied pressure increased. CMAP was more sensitive to nerve injury arising out of the force values obtained from the forceps. CONCLUSIONS: As a sensitive indicator for PNI, the neuroelectrophysiological examination was more likely to reflect the morphological changes of injured nerves. These findings may provide a standardized approach to sciatic crush injury modelling.


Assuntos
Lesões por Esmagamento , Traumatismos dos Nervos Periféricos , Neuropatia Ciática , Animais , Ratos , Nervo Isquiático/lesões
5.
Angew Chem Int Ed Engl ; 61(37): e202209849, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-35876073

RESUMO

Electrochemical reduction of biomass-derived 5-hydroxymethylfurfural (HMF) represents an elegant route toward sustainable value-added chemicals production that circumvents the use of fossil fuel and hydrogen. However, the reaction efficiency is hampered by the high voltage and low activity of electrodes (Cu, Bi, Pb). Herein, we report a Ru1 Cu single-atom alloy (SAA) catalyst with isolated Ru atoms on Cu nanowires that exhibits an electrochemical reduction of HMF to 2,5-dihydroxymethylfuran (DHMF) with promoted productivity (0.47 vs. 0.08 mmol cm-2 h-1 ) and faradic efficiency (FE) (85.6 vs. 71.3 %) at -0.3 V (vs. RHE) compared with Cu counterpart. More importantly, the FE (87.5 %) is largely retained at high HMF concentration (100 mM). Kinetic studies by using combined electrochemical techniques suggest disparate mechanisms over Ru1 Cu and Cu, revealing that single-atom Ru promotes the dissociation of water to produce H* species that effectively react with HMF via an electrocatalytic hydrogenation (ECH) mechanism.


Assuntos
Ligas , Furaldeído , Furaldeído/análogos & derivados , Hidrogenação , Cinética
6.
Heart Surg Forum ; 24(3): E418-E421, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34173762

RESUMO

PURPOSE: The optimal surgical strategy of aortic root in acute type A aortic dissection (ATAAD) is controversial. The aim of this study was to evaluate the feasibility and safety of "Sleeve" Sinus of Valsalva repair for AAD limited to the non-coronary sinus or partial left and right coronary sinus without involvement coronary artery ostia. METHODS: From September 2016 to March 2019, 20 patients with AAD involving non-coronary sinus or partial left and right coronary sinus Valsalva underwent "Sleeve" Sinus of Valsalva repair. A tailored Dacron patch was inserted into the dissected layers and two Dacron strips were placed inside and outside of the aorta, and the new five-layers root was sutured with 3/0 prolene continuous stitches. The artificial vessel was reversed about 1cm and anastomosed with the reconstructed root. Then, the reversed artificial vessel was pulled and anastomosed with the Dacron strip of the new proximal aorta. RESULTS: There was no early death in hospital and one death occurred during the 30-day postoperative period. Re-thoracotomy due to bleeding was necessary in only one patient and no bleeding was related to the proximal anastomosis. The postoperative drainage was 390.5 ± 229.3 mL. During follow up, the echocardiography showed the normal sinus of Valsalva and aortic valvular function. Computed tomography angiography showed normal aortic root without endovascular leak or dissection around the sinus of Valsalva. All patients were free from reoperation. CONCLUSIONS: "Sleeve" Sinus of Valsalva repair with Dacron patch for aortic dissection limited to the non-coronary sinus or partial left and right coronary sinus without involvement coronary artery ostia was technically feasible and safe.


Assuntos
Aorta Torácica/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Dissecção Aórtica/cirurgia , Implante de Prótese Vascular/métodos , Seio Aórtico/cirurgia , Técnicas de Sutura/instrumentação , Suturas , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Dissecção Aórtica/diagnóstico , Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico , Angiografia por Tomografia Computadorizada/métodos , Ecocardiografia/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Polietilenotereftalatos , Estudos Retrospectivos , Seio Aórtico/diagnóstico por imagem , Resultado do Tratamento
7.
Angew Chem Int Ed Engl ; 60(50): 26357-26362, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34580967

RESUMO

Polymer nanocapsules have demonstrated significant value in materials science and biomedical technology, but require complicated and time-consuming synthetic steps. We report here the facile synthesis of monodisperse polymer nanocapsules via a redox-mediated kinetic strategy from two simple molecules: dopamine and benzene-1,4-dithiol (BDT). Specifically, BDT forms core templates and modulates the oxidation kinetics of dopamine into polydopamine (PDA) shells. These uniform nanoparticles can be tuned between ≈70 and 200 nm because the core diameter directly depends on BDT while the shell thickness depends on dopamine. The supramolecular core can then rapidly disassemble in organic solvents to produce PDA nanocapsules. Such nanocapsules exhibit enhanced physicochemical performance (e.g., loading capacity, photothermal transduction, and anti-oxidation) versus their solid counterparts. Particularly, this method enables a straightforward encapsulation of functional nanoparticles providing opportunities for designing complex nanostructures such as yolk-shell nanoparticles.


Assuntos
Indóis/química , Nanocápsulas/química , Polímeros/química , Compostos de Sulfidrila/química , Dopamina/química , Indóis/síntese química , Estrutura Molecular , Oxirredução , Tamanho da Partícula , Polímeros/síntese química
8.
Mol Pharm ; 17(2): 541-553, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31876426

RESUMO

Ultrasound-induced microbubble sonoporation has been shown to effectively improve drug/gene delivery efficiency by enhancing tissue and cell permeability. However, the microscale size and short duration of ultrasound contrast agents limit their accumulation in target areas. Here, a kind of ultrasound-triggered phase-transitioning and size-changing cationic nanodroplet, perfluoropentane/C9F17-PAsp(DET)/miR-122/poly(glutamic acid)-g-MeO-poly(ethylene glycol) (PGA-g-mPEG) ternary nanodroplets (PFP-TNDs/miR-122), was developed to deliver microRNA-122 (miR-122) for hepatocellular carcinoma (HCC) treatment. PFP served as an ultrasound-sensitive core for ultrasound-triggered phase transition and size change from the nanoscale to the microscale. Positively charged C9F17-PAsp(DET) ensured adequate miRNA loading. PGA-g-mPEG, which served as the shell of the nanodroplet, modified the nanodroplets, enhanced their stability in serum, and protected miR-122 from degradation in vivo. The results exhibited that PFP-TNDs/miR-122 has a nanosize diameter (362 ± 15 nm) and remained stable for 24 h. After treatment with PFP-TNDs/miR-122 combined with ultrasound irradiation, the miR-122 expression level was significantly increased by approximately 600-fold in HepG2 cells, 500-fold in SMMC-7721 cells, and 30-fold in human HCC xenografts. Moreover, PFP-TNDs/miR-122 combined with ultrasound radiation effectively suppressed the growth, migration, and invasion of HCC cells, and inhibited tumor proliferation in mice. This study revealed that the biodegradable PFP-TNDs is a promising therapeutic gene carrier with functions of gene protection and effective gene delivery for clinical applications. Furthermore, PFP-TNDs/miR-122 associated with ultrasound irradiation may pave a new way to improve the prognosis of patients with HCC.


Assuntos
Carcinoma Hepatocelular/terapia , Portadores de Fármacos/administração & dosagem , Terapia Genética/métodos , Neoplasias Hepáticas/terapia , MicroRNAs/administração & dosagem , Nanopartículas/administração & dosagem , Polietilenoglicóis/administração & dosagem , Ondas Ultrassônicas , Células A549 , Animais , Feminino , Fluorocarbonos/administração & dosagem , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Nanopartículas/química , Transição de Fase/efeitos da radiação , Ácido Poliglutâmico/administração & dosagem , Transfecção , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Mol Pharm ; 17(3): 817-826, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-31910019

RESUMO

Biomedical nanoplatforms have been widely investigated for ultrasound (US) imaging and cancer therapy. Herein, perfluorocarbon (PFC) is encapsulated into biocompatible polydopamine (PDA) to form a theranostic nanosystem, followed by the modification of polyethylene glycol (PEG) to stabilize the nanoparticle via a facile one-pot method. Under 808 nm near-infrared laser irradiation, PDA can generate hyperthermia to transform PFC droplets to bubbles with high US imaging sensitivity. The US imaging detection of the PFC-PDA-PEG nanosystem is achievable in a time span of up to 25 min in vitro at a low US frequency and mechanical index, manifesting a US imaging performance for in vivo application. Moreover, tumor cells incubated with the nanosystem are ablated effectively under laser irradiation at 808 nm. The results illustrate the potential of the PDA-based theranostic agent in US imaging-guided photothermal therapy of tumor.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Fluorocarbonos/administração & dosagem , Hipertermia Induzida/métodos , Indóis/administração & dosagem , Raios Infravermelhos/uso terapêutico , Nanopartículas/química , Terapia Fototérmica/métodos , Polímeros/administração & dosagem , Animais , Cápsulas , Sobrevivência Celular/efeitos dos fármacos , Meios de Contraste , Feminino , Fluorocarbonos/química , Células HCT116 , Células Endoteliais da Veia Umbilical Humana , Humanos , Indóis/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Polietilenoglicóis/química , Polímeros/química , Carga Tumoral/efeitos dos fármacos , Ultrassonografia/métodos , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Bioconjug Chem ; 29(7): 2316-2324, 2018 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-29864273

RESUMO

Covalent immobilization of enzymes on solid supports provides an alternative approach to homogeneous biocatalysis by adding the benefits of simple enzyme removal, improved stability, and adaptability to automation and high-throughput applications. Nevertheless, immobilized (IM) enzymes generally suffer from reduced activity compared to their soluble counterparts. The nature and hydrophobicity of the supporting material surface can introduce enzyme conformational change, spatial confinement, and limited substrate accessibility, all of which will result in loss of the immobilized enzyme activity. In this work, we demonstrate through kinetic studies that flexible polyethylene glycol (PEG) moieties modifying the surface of magnetic beads improve the activity of covalently immobilized DNA replication enzymes. PEG-modified immobilized enzymes were utilized in library construction for Illumina next-generation sequencing (NGS) increasing the read coverage across AT-rich regions.


Assuntos
Enzimas Imobilizadas/química , Microesferas , Polietilenoglicóis/química , Biocatálise , Replicação do DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Cinética , Magnetismo , Propriedades de Superfície
11.
Molecules ; 23(11)2018 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-30373235

RESUMO

Recent evidence has extensively demonstrated the anticancer potential of nutraceuticals, including plant polyphenols. Polymeric nanocarrier systems have played an important role in improving the physicochemical and pharmacological properties of polyphenols, thus ameliorating their therapeutic effectiveness. This article summarizes the benefits and shortcomings of various polymeric systems developed for the delivery of polyphenols in cancer therapy and reveals some ideas for future work.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Nanopartículas/química , Polímeros/química , Polifenóis/química , Polifenóis/farmacologia , Nanomedicina Teranóstica , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Portadores de Fármacos/química , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Humanos , Nanoestruturas/química , Neoplasias/tratamento farmacológico , Polifenóis/uso terapêutico
12.
J Environ Sci (China) ; 69: 217-226, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29941257

RESUMO

As well-known persistent organic pollutants (POPs), organofluorine pollutants such as perfluorooctane sulfonate (PFOS) have been proven to be bioaccumulated and harmful to health. However, toxicological assessment of organofluorinated nanoparticles, which have emerged as a novel tool for biomedical and industrial applications, is lacking, to the best of our knowledge. To assess the biological effects and health risk of fluorinated nanoparticles, trifluoroethyl aryl ether-based fluorinated poly(methyl methacrylate) nanoparticles (PTFE-PMMA NPs) were synthesized with various fluorine contents (PTFE-PMMA-1 NPs 12.0wt.%, PTFE-PMMA-2 NPs 6.1wt.% and PTFE-PMMA-3 NPs 5.0wt.%), and their cytotoxicity was investigated in this study. The in vitro experimental results indicated that the cytotoxicity of PTFE-PMMA NPs was mild, and was closely related to their fluorine (F) contents and F-containing side chains. Specifically, the cytotoxicity of PTFE-PMMA NPs decreased with increasing F content and F-containing side chains. After exposure to PTFE-PMMA NPs at a sublethal dose (50µg/mL) for 24hr, the phospholipid bilayer was damaged, accompanied by increasing permeability of the cell membrane. Meanwhile, the intracellular accumulation of reactive oxygen species (ROS) occurred, resulting in the increase of DNA damage, cell cycle arrest and cell death. Overall, the PTFE-PMMA NPs were found to be relatively safe compared with typical engineered nanomaterials (ENMs), such as silver nanoparticles and graphene oxide, for biomedical and industrial applications.


Assuntos
Polímeros de Fluorcarboneto/toxicidade , Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Testes de Toxicidade , Ácidos Alcanossulfônicos/toxicidade , Morte Celular , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Fluorocarbonos/toxicidade , Nanopartículas Metálicas/química , Polimetil Metacrilato/toxicidade , Espécies Reativas de Oxigênio
13.
Mol Pharm ; 14(4): 984-998, 2017 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-28282145

RESUMO

For successful gene therapy, it is imperative to accumulate therapeutic gene in tumor tissues followed by efficiently delivering gene into targeted cells. Ultrasound irradiation, as a noninvasive and cost-effective external stimulus, has been proved to be one of the most potential external-stimulating gene delivery strategies recently in further improving gene transfection. In this study, we developed tumor-targeting ultrasound-triggered phase-transition nanodroplets AHNP-PFP-TNDs comprising a perfluorinated poly(amino acid) C11F17-PAsp (DET) as a core for simultaneously loading perfluoropentane (PFP) and nucleic acids, and a polyanionic polymer PGA-g-PEG-AHNP as the shell for not only modifying the surface of nanodroplets but also introducing an anti-Her2/neu peptide (AHNP) aiming to targeted treatment of Her2-overexpressing breast cancer. The results showed the average diameter of AHNP-PFP-TNDs was below 400 nm, nearly spherical in shape. The modification of PGA-g-PEG-AHNP not only increased the serum stability of the nanodroplets but also improved the affinity between nanodroplets and Her2-overexpressing breast cells. Both intratumor and intravenous injection of AHNP-PFP-TNDs into nude mice bearing HGC-27 xenografts showed that the gene transfection efficiency and the ultrasound contrast effect were significantly enhanced after exposed to the ultrasound irradiation with optimized ultrasound parameters. Therefore, this targeting nanodroplets system could be served as a potential theranostic vector for tumor targeting ultrasound diagnosis and gene therapy.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Nanopartículas/administração & dosagem , Receptor ErbB-2/metabolismo , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Fluorocarbonos/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/química , Ácidos Nucleicos/metabolismo , Peptídeos/metabolismo , Transição de Fase , Polieletrólitos , Polímeros/química , Polímeros/metabolismo , Transfecção/métodos , Ultrassonografia/métodos
14.
Soft Matter ; 11(21): 4235-41, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25892460

RESUMO

We present a facile strategy to synthesize self-healable tough and highly stretchable hydrogels. Our design rationale for the creation of ionic cross-linked hydrogels is to graft an acrylic acid monomer on the surface of vinyl hybrid silica nanoparticles (VSNPs) for the growth of poly(acrylic) acid (PAA), and the obtained VSNP-PAA nanobrush can be used as a gelator. Physical cross-linking through hydrogen bonding and ferric ion-mediated ionic interactions between PAA polymer chains of the gelators yielded ionic nanocomposite physical hydrogels with excellent and balanced mechanical properties (tensile strength 860 kPa, elongation at break ∼2300%), and the ability to self-repair (tensile strength ∼560 kPa, elongation at break ∼1800%). The toughness and stretchability arise from the reversible cross-linking interactions between the polymer chains that help dissipate energy through stress (deformation) triggered dynamic processes. These unique properties will enable greater application of these hydrogel materials, especially in tissue engineering.


Assuntos
Hidrogéis/química , Nanocompostos/química , Resinas Acrílicas/química , Íons/química , Dióxido de Silício/química , Resistência à Tração , Engenharia Tecidual
15.
J Nanobiotechnology ; 13: 22, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25880868

RESUMO

BACKGROUND: The combination of chemotherapeutic drugs with different pharmacological action has emerged as a promising therapeutic strategy in the treatment of cancers. Present study examines the antitumor potential of paclitaxel (PTX) and etoposide (ETP)-loaded PLGA nanoparticles for the treatment of osteosarcoma. RESULTS: The resulting drug-loaded PLGA NP exhibited a nanosize dimension with uniform spherical morphology. The NP exhibited a sustained release profile for both PTX and ETP throughout the study period without any sign of initial burst release. The combinational drug-loaded PLGA NP enhanced the cytotoxic effect in MG63 and Saos-2 osteosarcoma cell lines, in comparison to either native drug alone or in cocktail combinations. Additionally, NPs showed an appreciable uptake in MG63 cells in a time-based manner. Co-delivery of anticancer drugs resulted in enhanced cell cycle arrest and cell apoptosis. The results clearly showed that combinational drugs remarkably improved the therapeutic index of chemotherapeutic drugs. The greater inhibitory effect of nanoparticle combination would be of great advantage during systemic cancer therapy. CONCLUSION: Taken together, our study demonstrated that PTX-ETP/PLGA NP based combination therapy holds significant potential towards the treatment of osteosarcoma.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Nanopartículas/administração & dosagem , Nanopartículas/química , Osteossarcoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose/efeitos dos fármacos , Neoplasias Ósseas/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Etoposídeo/administração & dosagem , Etoposídeo/química , Humanos , Ácido Láctico/química , Osteossarcoma/patologia , Paclitaxel/administração & dosagem , Paclitaxel/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
16.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(1): 62-6, 2015 Feb 18.
Artigo em Zh | MEDLINE | ID: mdl-25686331

RESUMO

OBJECTIVE: To explore the reinforcement of polyglycidyl methacrylate (PGMA) pre-impregnated quartz fiber mesh in denture base materials by investigation of interface compatibility and fracture resistance. METHODS: 1-layer, 2-layer, 3-layer PGMA pre-impregnated quartz fiber meshes, electrolyzed cobalt-chromium alloy mesh and cobalt-chromium alloy mesh conditioned by metal primer were integrated in polymethyl methacrylate (PMMA) resin by sandwich embedding method. Block samples of 5 groups were prepared (40 mm×15 mm×2 mm). Fracture resistance was determined in a 3-point bending test at 2 mm/min. Scanning electron microscope (SEM), micrographs were taken from the fractured surfaces to analyze the bonding interface compatibility. RESULTS: The group of 3-layer PGMA pre-impregnated quartz fiber mesh presented the highest elastic modulus of 6 406 MPa and flexural strength of 227 MPa among the five groups, while the 1-layer and 2-layer expressed the similar elastic modulus and flexural strength to the pure PMMA group. The metal groups demonstrated better mechanical properties, while the metal surface conditioner played much better. The metal surface conditioner pre-impregnated cobalt-chromium alloy and PGMA pre-impregnated quartz fiber mesh showed compatible interface with PMMA. CONCLUSION: The mechanical properties were improved by the increasing of the fiber by adding the more meshed. Although the benign interface did help the compatibility, the quantity of the fibers played an important role in the strength.


Assuntos
Bases de Dentadura , Ácidos Polimetacrílicos , Polimetil Metacrilato , Resinas Acrílicas , Ligas de Cromo , Teste de Materiais , Metacrilatos , Maleabilidade , Quartzo
17.
Mol Biol Rep ; 41(4): 2143-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24442318

RESUMO

Clodronate liposome injection is an effective approach to selectively and specifically depleting macrophages. Macrophages play a crucial role in cutaneous wound healing and are associated with excessive scar formation. Use of clodronate liposomes to enhance cutaneous wound healing and reduce scar formation could represent a major advance in wound therapy and hypertrophic scar treatment. This study aimed to investigate the effects of subcutaneous or intraperitoneal injection of clodronate liposomes on cutaneous wound healing and scar formation. A burn injury mouse model was used. Mice were treated with subcutaneous or intraperitoneal injection of clodronate liposomes. Wound healing time was analyzed and scar tissues were harvested for hematoxylin and eosin (HE) staining, reverse transcription polymerase chain reaction (RT-PCR) and Western blot analyses. Wound healing time in treated mice was extended. HE showed that the basal layer of the epidermis in treated scars was flattened, the dermis layer was not significantly thickened, and collagen fibers were well arranged, with few cells and micro vessels. RT-PCR and Western blot analyses showed that the levels of TGF-ß1 and collagen I-α2 were decreased in treated mice. Clodronate liposomes reduce excessive scar formation and delay cutaneous wound healing possibly by reducing collagen deposition and macrophage-derived TGF-ß1 expression.


Assuntos
Queimaduras/metabolismo , Queimaduras/patologia , Cicatriz/metabolismo , Ácido Clodrônico/administração & dosagem , Colágeno/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Queimaduras/tratamento farmacológico , Cicatriz/tratamento farmacológico , Cicatriz/patologia , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Lipossomos , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Fatores de Tempo , Cicatrização/efeitos dos fármacos , Cicatrização/imunologia
18.
Drug Dev Ind Pharm ; 40(1): 126-35, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23336809

RESUMO

OBJECTIVE: The aim of this study was to evaluate the applicability of POVACOAT™, a hydrophilic PVA copolymer, as a solid dispersion (SD) carrier for hot-melt extrusion (HME). METHODS: Bifendate (DDB), a water-insoluble drug, was chosen as the model drug. DDB was hot-melt extruded by a co-rotating twin screw extruder with POVACOAT™. The SD formability of POVACOAT™ was investigated by varying the composition ratios. Solid state characterization was evaluated by differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy and Fourier transformation infrared spectroscopy. In order to have a better knowledge of the mechanism of dissolution enhancement, dissolution study, phase solubility study and crystallization study of DDB from supersaturated solutions were performed. In addition, the storage stability of the extrudate containing 10% DDB was investigated. RESULTS: Physical characterizations showed that DDB was amorphous up to 15% drug loading. The phase solubility study revealed an AL-type curve. Moreover, POVACOAT™ was found to have an inhibitory effect on crystallization from supersaturated solutions. Compared with the pure DDB and physical mixture, the dissolution rate and solubility of extrudates were significantly enhanced and the drug loading markedly affected the dissolution of SDs. Furthermore, the stability test indicated that 10% DDB-SD was stable during storage (40 °C/75% RH). CONCLUSION: The results of this study demonstrate that POVACOAT™ is a valuable excipient for the formulation of solid dispersions prepared by HME to improve dissolution of poorly water-soluble drugs.


Assuntos
Compostos de Bifenilo/administração & dosagem , Portadores de Fármacos/química , Polímeros/química , Acrilatos/química , Compostos de Bifenilo/química , Química Farmacêutica/métodos , Cristalização , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Metilmetacrilato/química , Álcool de Polivinil/química , Solubilidade
19.
Sci Total Environ ; 912: 168313, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38007128

RESUMO

Wastewater treatment plants (WWTPs) pose a potential threat to the environment because of the accumulation of antibiotic resistance genes (ARGs) and microplastics (MPs). However, the interactions between ARGs and MPs, which have both indirect and direct effects on ARG dissemination in WWTPs, remain unclear. In this study, spatiotemporal variations in different types of MPs, ten ARGs (sul1, sul2, tetA, tetO, tetM, tetX, tetW, qnrS, ermB, and ermC), class 1 integron integrase (intI1) and transposon Tn916/1545 in three typical WWTPs were characterized. Sul1, tetO, and sul2 were the predominant ARGs in the targeted WWTPs, whereas the intI1 and transposon Tn916/1545 were positively correlated with most of the targeted ARGs. Saccharimonadales (4.15 %), Trichococcus (2.60 %), Nitrospira (1.96 %), Candidatus amarolinea (1.79 %), and SC-I-84 (belonging to phylum Proteobacteria) (1.78 %) were the dominant genera. Network and redundancy analyses showed that Trichococcus, Faecalibacterium, Arcobacter, and Prevotella copri were potential hosts of ARGs, whereas Candidatus campbellbacteria and Candidatus kaiserbacteria were negatively correlated with ARGs. The potential hosts of ARGs had a strong positive correlation with polyethylene terephthalate, silicone resin, and fluor rubber and a negative correlation with polyurethane. Candidatus campbellbacteria and Candidatus kaiserbacteria were positively correlated with polyurethane, whereas potential hosts of ARGs were positively correlated with polypropylene and fluor rubber. Structural equation modeling highlighted that intI1, transposon Tn916/1545 and microbial communities, particularly microbial diversity, dominated the dissemination of ARGs, whereas MPs had a significant positive correlation with microbial abundance. Our study deepens the understanding of the relationships between ARGs and MPs in WWTPs, which will be helpful in designing strategies for inhibiting ARG hosts in WWTPs.


Assuntos
Águas Residuárias , Purificação da Água , Genes Bacterianos , Microplásticos , Plásticos , Antibacterianos , Poliuretanos , Borracha , Resistência Microbiana a Medicamentos/genética , Interações Microbianas
20.
Waste Manag ; 184: 28-36, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38795538

RESUMO

Carbon fiber-reinforced polymer composites (CFRPs) have gained widespread usage due to their promising physiochemical properties, while this causes large amounts of waste CFRPs worldwide. In this study, carbon fibers were successfully recovered from waste CFRPs through the pyrolysis-oxidation method, and the recovered fibers were reused in remanufacturing the secondary generation CFRPs. Moreover, the individual and interactive effects of pyrolysis-oxidation recovering parameters on the mechanical strength of the resulting remanufactured CFRPs (reCFRPs) were investigated. The recovered carbon fibers displayed surface chemical structures similar to virgin fibers but with high contents of oxygen-containing bonds. The tensile strength retention (TSR) of the reCFRPs was primarily influenced by oxidation temperature. Notably, a higher oxidation temperature, especially exceeding 560 °C, amplified the impact of oxidation duration on the TSR value. Similarly, concerning interlaminar shear strength retention (ISSR), the oxidation stage had a more substantial effect compared to the pyrolysis stage. As the oxidation temperature increased from 500 °C to 600 °C, the ISSR value initially increased and then decreased, irrespective of variations in pyrolysis parameters. Additionally, through integrating the response surface methodology (RSM) analysis and multi-island genetic algorithm (MIGA) global optimization, three recovery strategies, along with the corresponding processing parameters, were proposed to meet diverse requirements. The conclusions could provide valuable insights for optimizing the recovery and reuse of carbon fibers from waste CFRPs.


Assuntos
Fibra de Carbono , Oxirredução , Pirólise , Reciclagem , Fibra de Carbono/química , Reciclagem/métodos , Resistência à Tração , Polímeros/química , Carbono/química
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