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1.
Nano Lett ; 24(21): 6353-6361, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38757814

RESUMO

Polydopamine (PDA)-derived melanin-like materials exhibit significant photothermal conversion owing to their broad-spectrum light absorption. However, their low near-infrared (NIR) absorption and inadequate hydrophilicity compromise their utilization of solar energy. Herein, we developed metal-loaded poly(norepinephrine) nanoparticles (PNE NPs) by predoping metal ions (Fe3+, Mn3+, Co2+, Ca2+, Ga3+, and Mg2+) with norepinephrine, a neuron-derived biomimetic molecule, to address the limitations of PDA. The chelation between catechol and metal ions induces a ligand-to-metal charge transfer (LMCT) through the formation of donor-acceptor pairs, modulating the light absorption behavior and reducing the band gap. Under 1 sun illumination, the Fe-loaded PNE coated wood evaporator achieved a high seawater evaporation rate and efficiency of 1.75 kg m-2 h-1 and 92.4%, respectively, owing to the superior hydrophilicity and photothermal performance of PNE. Therefore, this study offers a comprehensive exploration of the role of metal ions in enhancing the photothermal properties of synthetic melanins.


Assuntos
Melaninas , Norepinefrina , Melaninas/química , Norepinefrina/química , Polimerização/efeitos da radiação , Polímeros/química , Neurotransmissores/química , Indóis/química , Oxirredução , Metais/química , Nanopartículas/química
2.
Biomacromolecules ; 25(1): 522-531, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-38087829

RESUMO

Ferroptosis has attracted significant attention as a new mechanism of cell death. Sorafenib (SRF) is widely considered a prototypical ferroptosis-inducing drug, particularly for liver cancer treatment. However, the low solubility and hydrophobic nature of SRF, along with the absence of synergistic therapeutic strategies, still limit its application in cancer treatment. Herein, we report a dual therapeutic method incorporating photothermal therapy and ferroptosis by using Fe-doped mesoporous polydopamine nanoparticles (Fe-mPDA@SRF-TPP) as a carrier for loading SRF and targeting triphenylphosphine (TPP). SRF molecules are efficiently encapsulated within the polydopamine nanospheres with a high loading ratio (80%) attributed to the porosity of Fe-mPDA, and the inherent biocompatibility and hydrophilicity of Fe-mPDA@SRF-TPP facilitate the transport of SRF to the target cancer cells. Under the external stimuli of acidic environment (pH 5.0), glutathione (GSH), and laser irradiation, Fe-mPDA@SRF-TPP shows sustained release of SRF and Fe ions with the ratio of 72 and 50% within 48 h. Fe-mPDA@SRF-TPP nanoparticles induce intracellular GSH depletion, inhibit glutathione peroxidase 4 (GPX4) activity, and generate hydroxyl radicals, all of which are essential components of the therapeutic ferroptosis process for killing MDA-MB-231 cancer cells. Additionally, the excellent near-infrared (NIR) light absorption of Fe-mPDA@SRF-TPP nanoparticles demonstrates their capability for photothermal therapy and further enhances the therapeutic efficiency. Therefore, this nanosystem provides a multifunctional therapeutic platform that overcomes the therapeutic limitations associated with standalone ferroptosis and enhances the therapeutic efficacy of SRF for breast cancer.


Assuntos
Ferroptose , Neoplasias Hepáticas , Nanopartículas , Neoplasias , Humanos , Sorafenibe/farmacologia , Terapia Fototérmica , Ferro , Nanopartículas/química , Neoplasias/terapia , Concentração de Íons de Hidrogênio , Linhagem Celular Tumoral
3.
Langmuir ; 39(29): 10145-10153, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37436959

RESUMO

Molybdenum-based nanomaterials have shown promise for anticancer treatment due to their strong photothermal and redox-activated capabilities. Herein, we have fabricated cerium-doped MoOx (Ce-MoOv) with tunable Mo/Ce molar ratios by a one-pot method and investigated their effect on chemodynamic therapy (CDT) and photothermal therapy (PTT). It is found that Ce-MoOv can self-assemble into nanoclusters in acidic conditions and the increasing Ce amount will generate oxygen vacancy defects and induce the valence change of Mo6+/Mo5+ and Ce4+/Ce3+, which leads to strong near-infrared absorption with high photothermal conversion efficiency of 71.31 and 49.86% for 808 and 1064 nm. Other than photothermal conversion, the materials demonstrate pH-/glutathione (GSH)-activated photoacoustic (PA) imaging capability in vitro. In addition, Ce-MoOv acts as a CDT reagent capable of converting endogenous H2O2 to two types of reactive oxygen species (•OH, 1O2) while depleting GSH. Ce-MoOv demonstrates an excellent therapeutic effect against HCT116 cells and effectively reduces the intracellular GSH level and significantly increases the number of reactive radicals under 1064 nm laser irradiation as compared with the no-laser group in vitro. This work provides a new paradigm using lanthanide-doped polymetallic oxides for pH-/GSH-responsive photothermal/chemodynamic therapy with PA imaging ability.


Assuntos
Nanopartículas , Neoplasias , Humanos , Óxidos , Peróxido de Hidrogênio , Molibdênio , Microambiente Tumoral , Glutationa , Oxigênio , Concentração de Íons de Hidrogênio , Linhagem Celular Tumoral
4.
Langmuir ; 37(48): 14096-14104, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34808057

RESUMO

Ultrasmall nanoparticles (USNPs) with sizes below 10 nm have shown great potentials in medical applications owing to their outstanding physical, chemical, optical, and biological properties. However, they suffer from a rapid renal clearance and biodegradation rate in the biological environment due to the small size. Liposomes are one of the most promising delivery nanocarriers for loading USNPs because of their excellent biocompatibility and lipid bilayer structure. Encapsulation of USNPs into liposomes in an efficient and controllable manner remains a challenge. In this study, we achieved a high loading of graphene quantum dots (GQDs, ∼4 nm), a typical USNP, into the aqueous core of liposomes (45.68 ± 1.44%), which was controllable by the pressure. The GQDs-loaded liposomes (GQDs-LPs) exhibited a very good aqueous stability for over a month. Furthermore, indocyanine green (ICG), an efficient near-infrared (NIR) photothermal agent, was introduced in the GQDs-LP system that could convert NIR laser energy into thermal energy and break down the liposomes, causing the release of GQDs in 6 min. Moreover, this NIR light-controlled release system (GQDs-ICG-LPs) also exhibited a good photothermal therapeutic performance in vitro, and 75% of cancer cells were killed at a concentration of 200 µg/mL. Overall, the successful development of the NIR light-controlled release system has laid a solid foundation for the future biomedical application of USNPs-loaded liposomes.


Assuntos
Grafite , Nanopartículas , Pontos Quânticos , Lipossomos , Fototerapia
5.
Proc Natl Acad Sci U S A ; 115(1): E34-E43, 2018 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-29255034

RESUMO

To impart biomedical functions to nanoparticles (NPs), the common approach is to conjugate functional groups onto NPs by dint of the functions of those groups per se. It is still beyond current reach to create protein-like specific interactions and functions on NPs by conformational engineering of nonfunctional groups on NPs. Here, we develop a conformational engineering method to create an NP-based artificial antibody, denoted "Goldbody," through conformational reconstruction of the complementary-determining regions (CDRs) of natural antibodies on gold NPs (AuNPs). The seemingly insurmountable task of controlling the conformation of the CDR loops, which are flexible and nonfunctional in the free form, was accomplished unexpectedly in a simple way. Upon anchoring both terminals of the free CDR loops on AuNPs, we managed to reconstruct the "active" conformation of the CDR loops by tuning the span between the two terminals and, as a result, the original specificity was successfully reconstructed on the AuNPs. Two Goldbodies have been created by this strategy to specifically bind with hen egg white lysozyme and epidermal growth factor receptor, with apparent affinities several orders of magnitude stronger than that of the original natural antibodies. Our work demonstrates that it is possible to create protein-like functions on NPs in a protein-like way, namely by tuning flexible surface groups to the correct conformation. Given the apparent merits, including good stability, of Goldbodies, we anticipate that a category of Goldbodies could be created to target different antigens and thus used as substitutes for natural antibodies in various applications.


Assuntos
Anticorpos Monoclonais/química , Regiões Determinantes de Complementaridade/química , Ouro/química , Nanopartículas Metálicas/química , Conformação Proteica
6.
J Nanosci Nanotechnol ; 18(4): 2304-2309, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442896

RESUMO

In this study, silver decorated graphene oxide (Ag/GO) composite was fabricated through a reduction process in the presence of potassium borohydride solution. Subsequently, physicochemical properties of the resulting Ag/GO composite were studied by scanning electron microscope, X-ray diffraction, Raman spectra, Fourier transformation infrared spectroscopy and UV-visible diffuse reflectance spectrum. Results indicated that Ag species existed in the form of Ag0, which greatly facilitated the visible light absorbance ability. Furthermore, the performance of Ag/GO was evaluated by PC inactiviation of Escherichia coli under Xenon lamp illumination. It was found that Ag/GO sample could kill the Escherichia coli within 60 min illumination by the non-selective attack of ⋅OH radicals. This study provides a novel and facile strategy to fabricate high-efficient catalyst to kill the bacteria in drinking water treatment.


Assuntos
Escherichia coli , Grafite , Prata , Catálise , Nanocompostos , Óxidos
7.
J Appl Toxicol ; 35(10): 1169-78, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26106068

RESUMO

Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food-related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco-2 cells, differentiated Caco-2 cells and Caco-2 monolayer. TiO2 NPs with a concentration less than 200 µg ml(-1) did not induce any toxicity in differentiated cells and Caco-2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml(-1) inhibited the growth of undifferentiated Caco-2 cells. Undifferentiated Caco-2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco-2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food.


Assuntos
Aditivos Alimentares/toxicidade , Intestinos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Células CACO-2 , Diferenciação Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Mucosa Intestinal/metabolismo , Espécies Reativas de Oxigênio/metabolismo
8.
Macromol Rapid Commun ; 35(12): 1148-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24700484

RESUMO

A pH-responsive core cross-linked star (CCS) polymer containing poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) arms was used as an interfacial stabilizer for emulsions containing toluene (80 v%) and water (20 v%). In the pH range of 12.1-9.3, ordinary water-in-oil emulsions were formed. Intermediate multiple emulsions of oil-in-water-in-oil and water-in-oil-in-water were formed at pH 8.6 and 7.5, respectively. Further lowering the pH resulted in the formation of gelled high internal phase emulsions of oil-in-water type in the pH range of 6.4-0.6. The emulsion behavior was correlated with interfacial tension, conductivity and configuration of the CCS polymer at different pH.


Assuntos
Reagentes de Ligações Cruzadas/química , Metacrilatos/química , Nylons/química , Óleos/química , Água/química , Reagentes de Ligações Cruzadas/síntese química , Emulsões/química , Concentração de Íons de Hidrogênio , Metacrilatos/síntese química , Nylons/síntese química , Tamanho da Partícula , Propriedades de Superfície
9.
J Biomater Sci Polym Ed ; 35(1): 45-62, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37773055

RESUMO

Bacterial infections pose a significant threat to human health and safety, necessitating the urgent resolution of the problem through the development and implementation of highly effective antibacterial agents. However, the emergence of multidrug-resistant bacteria has diminished the satisfactory effectiveness of antibacterial treatments. To overcome this obstacle, we developed effective antibacterial agents by chemical reduction for inhibiting bacterial proliferation and inducing membrane damage. Specifically, four different types of chitosan/Ag nanoparticle (CS-AgNPs-i) (i-1, 2, 3, 4) complexes were synthesized by varying the quantity of chitosan added during the synthesis process. We found that the amount of CS does not affect the morphology and size of CS-AgNPs-i, which remained at approximately 20 nm and all CS-AgNPs were mostly spherical. The zeta potential measurements indicated that the surface of CS-AgNPs carries a positive charge. Notably, elevating the chitosan concentration led to a more pronounced antibacterial impact, particularly evident in its interaction with the peptidoglycan layer on the bacterial surface. Our experimental results undeniably establish the potent antibacterial efficacy of CS-AgNPs against both Escherichia coli and Staphylococcus aureus. Employing live/dead bacterial staining, we reveal the marked capability of CS-AgNPs to effectively hinder bacterial proliferation. Furthermore, our experimental investigations revealed that CS-AgNPs possess broad-spectrum antimicrobial activity. The results of in vitro cytotoxicity experiments substantiated the high biocompatibility of CS-AgNPs with elevated chitosan loading. The study provides valuable insights into the development of nano-antibacterial agents that exhibit significant potential as a substitute to replace traditional antibiotics for medical applications.


Assuntos
Quitosana , Nanopartículas Metálicas , Humanos , Prata/farmacologia , Prata/química , Nanopartículas Metálicas/química , Quitosana/farmacologia , Quitosana/química , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus , Escherichia coli , Testes de Sensibilidade Microbiana
10.
Int J Biol Macromol ; 259(Pt 2): 129200, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38218266

RESUMO

Food packaging films play a vital role in preserving and protecting food. However, due to their non-biodegradability, conventional packaging materials have led to significant environmental pollution. To overcome this hurdle, we have developed safe, innovative, sustainable and biodegradable packaging materials that can effectively extend the shelf life of food. In this study, two types of cellulose materials cellulose nanofibers (CNF) and carboxymethyl cellulose (CMC) with complementary roles were combined to prepare nanocellulose composite films with high transparency (90.3 %) of a certain thickness (30 ± 0.019 µm) by solution casting method, and their mechanical properties were further optimized by the addition of plasticizer-glycerol (Gly) and cross-linking agent-glutaraldehyde (GA), so as to maintain the strong tensile strength (≈112.60 MPa) and better malleability (4.12 %). In addition, we loaded the natural active agent tea polyphenols (TPs) with different concentrations to study the inhibition effect on E.coli and S.aureus and to simulate food packaging. Finally, we also found that the synthesized nanocellulose composite films can also achieve rapid degradation in a short time through soil burial, water flushing and immersion. The excellent performance demonstrated in this study provides reference value for further replacing petroleum-based materials with biomass materials in the field of food packaging.


Assuntos
Antibacterianos , Embalagem de Alimentos , Embalagem de Alimentos/métodos , Antibacterianos/farmacologia , Água , Glutaral , Celulose
11.
J Hazard Mater ; 463: 132916, 2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-37951169

RESUMO

Vacuum UV (VUV) irradiation has advantage in coupling oxidants for organics removal because VUV can dissociate water to produce reactive oxygen species (ROS) in situ and decompose oxidants rapidly. In this study, the synergistic activation of peroxymonosulfate (PMS) by VUV and ozone (O3) was explored via developing a novel integrated VUV/O3/PMS process, and the performance and mechanisms of VUV/O3/PMS for levofloxacin (LEV) degradation were investigated systematically. Results indicated that VUV/O3/PMS could effectively degrade LEV, and the degradation rate was 1.67-18.79 times of its sub-processes. Effects of PMS dosage, O3 dosage, solution pH, anions, and natural organic matter on LEV removal by VUV/O3/PMS were also studied. Besides, hydroxyl radical and sulfate radical were main ROS with contributions of 49.7% and 17.4%, respectively. Moreover, the degradation pathways of LEV in VUV/O3/PMS process were speculated based on density functional theory calculation and by-products detection. Furthermore, synergistic reaction mechanisms in VUV/O3/PMS process were proposed. The energy consumption of VUV/O3/PMS decreased by 22.6%- 88.1% compared to its sub-processes. Finally, the integrated VUV/O3/PMS process showed satisfactory results in removing LEV in actual waters, manifesting VUV/O3/PMS had great application potential and feasibility in removing organics in wastewater reuse.


Assuntos
Ozônio , Poluentes Químicos da Água , Levofloxacino , Espécies Reativas de Oxigênio , Vácuo , Oxirredução , Poluentes Químicos da Água/análise , Peróxidos , Oxidantes
12.
ACS Appl Mater Interfaces ; 16(3): 3001-3018, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38195388

RESUMO

Synthetic melanin is a mimic of natural melanin analogue with intriguing properties such as metal-ion chelation, redox activity, adhesion, and broadband absorption. Melanin-inspired composite materials are formulated by assembly of melanin with other types of inorganic and organic components to target, combine, and build up the functionality, far beyond their natural capabilities. Developing efficient and universal methodologies to prepare melanin-based composite materials with unique functionality is vital for their further applications. In this review, we summarize three types of synthetic approaches, predoping, surface engineering, and physical blending, to access various melanin-inspired composite materials with distinctive structure and properties. The applications of melanin-inspired composite materials in free radical scavenging, bioimaging, antifouling, and catalytic applications are also reviewed. This review also concludes current challenges that must be addressed and research opportunities in future studies.

13.
Drug Deliv Transl Res ; 14(10): 2771-2787, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38478324

RESUMO

Cerebrovascular impairment represents one of the main causes of death worldwide with a mortality rate of 5.5 million per year. The disability of 50% of surviving patients has high social impacts and costs in long period treatment for national healthcare systems. For these reasons, the efficacious clinical treatment of patients, with brain ischemic stroke, remains a medical need. To this aim, a liposome nanomedicine, with monosialic ganglioside type 1 (GM1), OX26 (an anti-transferrin receptor antibody), and CDP-choline (a neurotrophic drug) (CDP-choline/OX26Lip) was prepared. CDP-choline/OX26Lip were prepared by a freeze and thaw method and then extruded through polycarbonate filters, to have narrow size distributed liposomes of ~80 nm. CDP-choline/OX26Lip were stable in human serum, they had suitable pharmacokinetic properties, and 30.0 ± 4.2% of the injected drug was still present in the blood stream 12 h after its systemic injection. The post-ischemic therapeutic effect of CDP-choline/OX26Lip is higher than CDP-choline/Lip, thus showing a significantly high survival rate of the re-perfused post-ischemic rats, i.e. 96% and 78% after 8 days. The treatment with CDP-choline/OX26Lip significantly decreased the peroxidation rate of ~5-times compared to CDP-choline/Lip; and the resulting conjugated dienes, that was 13.9 ± 1.1 mmol/mg proteins for CDP-choline/Lip and 3.1 ± 0.8 for CDP-choline/OX26Lip. OX26 increased the accumulation of GM1-liposomes in the brain tissues and thus the efficacious of CDP-choline. Therefore, this nanomedicine may represent a strategy for the reassessment of CDP-choline to treat post-ischemic events caused by brain stroke, and respond to a significant clinical need.


Assuntos
Citidina Difosfato Colina , Lipossomos , Animais , Citidina Difosfato Colina/administração & dosagem , Citidina Difosfato Colina/farmacocinética , Masculino , Ratos , Humanos , Ratos Sprague-Dawley , Isquemia Encefálica/tratamento farmacológico , Gangliosídeo G(M1)/administração & dosagem
14.
J Colloid Interface Sci ; 677(Pt B): 79-90, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39137565

RESUMO

Photothermal therapy combined with chemotherapy has shown great promise in the treatment of cancer. In this synergistic system, a safe, stable, and efficient photothermal agent is desired. Herein, an effective photothermal agent, carbon quantum dots (CQDs), was initially synthesized and then rationally constructed a folic acid (FA)-targeted photothermal multifunctional nanoplatform by encapsulating CQDs and the anticancer drug doxorubicin (DOX) in the liposomes. Indocyanine green (ICG), a near infrared (NIR) photothermal agent, approved by the U.S. Food and Drug Administration, was embedded in the bilayer membrane to further enhance the photothermal effects and facilitate the rapid cleavage of liposomes for drug release. Triggered by the NIR laser, this engineered photothermal multifunctional nanoplatform, not only exhibited an excellent performance with the photothermal conversion efficiency of up to 47.14%, but also achieved controlled release of the payloads. In vitro, and in vivo experiments demonstrated that the photothermal multifunctional nanoplatform had excellent biocompatibility, enhanced tumor-specific targeting, stimuli-responsive drug release, effective cancer cell killing and tumor suppression through multi-modal synergistic therapy. The successful construction of this NIR light-triggered targeted photothermal multifunctional nanoplatform will provide a promising strategy for the design and development of synergistic chemo-photothermal combination therapy and improve the therapeutic efficacy of cancer treatment.

15.
Biotechnol Genet Eng Rev ; 40(1): 202-216, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39312182

RESUMO

To prospective research the efficacy of dual-energy computed tomography (DECT) in predicting contrast medium extravasation and secondary cerebral hemorrhage after stent thrombectomy in acute ischemic cerebral infarction. Ninety-two patients with acute ischemic stroke who underwent intra-arterial thrombolysis in our hospital from December 2019 to January 2022 have opted as the study subjects. DECT was performed immediately after stent thrombectomy. Images were generated through the image workstation and routine diagnosis was performed 24 hours after the operation. To analyze the diagnostic value of To analyze the diagnostic value of DECT, and to explore the diagnostic status of lesions with hemorrhagic transformation or increased hemorrhage and their correlation with iodine concentration. (1) 68 situations were confirmed, 56 positive and 12 negative with detection rates of 10.71% for hemorrhage, 75.00% for contrast agent extravasation, and 14.29% for extravasation combined with hemorrhage; (2) DECT diagnosed 8 cases of postoperative bleeding and 44 cases of extravasation of contrast media and 4 cases of extravasation of contrast media with hemorrhage ; The accuracy of DECT in diagnosing postoperative hemorrhage was 96.43%. The accuracy of diagnosis of extravasation was 96.43%. (3) The mean iodine concentration of lesions with increased hemorrhage or hemorrhagic transformation was higher compared to those without; (4) There was a correlation between hemorrhagic transformation or increased hemorrhage and iodine concentration. Dual-energy CT (DECT) can accurately distinguish the extravasation of contrast agent and secondary cerebral hemorrhage, and can predict the increased bleeding and bleeding transformation, with good diagnostic value and good predictive efficacy.


Assuntos
Hemorragia Cerebral , Meios de Contraste , Stents , Trombectomia , Tomografia Computadorizada por Raios X , Humanos , Masculino , Feminino , Meios de Contraste/efeitos adversos , Pessoa de Meia-Idade , Idoso , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/etiologia , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/etiologia , Extravasamento de Materiais Terapêuticos e Diagnósticos/diagnóstico por imagem , Estudos Prospectivos , Idoso de 80 Anos ou mais , Adulto , Isquemia Encefálica/diagnóstico por imagem
16.
Langmuir ; 29(23): 6815-22, 2013 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-23672683

RESUMO

It is of great interest to develop a simple, general, and easy-handling procedure for mesoporous silica coating. A facile, single-step method to coat iron oxide nanoparticles has been reported by Hyeon's group. However, up to present, this method only successfully applied to those zero-dimensional nanostructures heavily capped by cetyltrimethyl ammonium bromide (CTAB); no others are reported. It is unknown how this simple method is feasible in coating those nanostructures not capped by CTAB. Herein, using carbon nanotubes (CNTs) as the model, through an analogous layer-by-layer assembly method, many more CTAB molecules were found to anchor to CNTs, on which uniform mesoporous silica shells can successfully be formed by Hyeon's coating method. We believe that this contribution will pave the way for advancing the single-step method to become a general protocol in the mesoporous silica coating field.


Assuntos
Nanotubos de Carbono/química , Dióxido de Silício/química , Cetrimônio , Compostos de Cetrimônio/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície
17.
Bioact Mater ; 23: 53-68, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36406253

RESUMO

The high occurrence rate and difficulties in symptom control are listed as the major problems of oral mucosal disease by medical professionals. Following the development of oral mucosal lesions, the oral microenvironment changes, immunity declines, and continuous bacterial stimulation causes wound infection. Traditional antibacterial drugs are ineffective for oral mucosal lesions. To overcome this problem, a light-responsive antibacterial hydrogel containing sustained-release BMSCs was inspired by the trauma environment in the oral cavity, which is different from that on the body surface since it mostly remains under dark conditions. In the absence of light, the hydrogel seals the wound to form a barrier, exerts a natural bacteriostatic effect, and prevents invasion by foreign bacteria. Simultaneously, mesenchymal stem cells are presented, and the released growth factors and other substances have excellent anti-inflammatory and angiogenic effects, which result in rapid repair of the damaged site. Under light conditions, after photo-induced shedding of the hydrogel, RuB2A exerts an antibacterial effect accompanied by degradation of the hydrogel. Results in a rat oral mucosal repair model demonstrate that DCS-RuB2A2-BMSCs could rapidly repair the oral mucosa within 4 days. Sequencing data provide ideas for further analysis of the intrinsic molecular mechanisms and signaling pathways. Taken together, our results suggest that this light-responsive antibacterial hydrogel loaded with BMSCs can be used for rapid wound repair and may advance the development of therapeutic strategies for the treatment of clinical oral mucosal defects.

18.
J Nanosci Nanotechnol ; 12(1): 274-83, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22523976

RESUMO

Carbon nanotubes may be applied in different fields including biomedicine and mechanical engineering. It is important to understand the potential hazards of carbon nanotubes. In the present study, the toxicological effects of the pristine multi-walled carbon nanotubes (p-MWCNTs) and taurine functionalized multi-walled carbon nanotubes (tau-MWCNTs) were assessed on RAW 264.7 macrophages. We tested cell viability, GSH/GSSG ratio, apoptosis, intracellular calcium concentration, ultrastructural changes of cell morphology, and the release of IL-8. We observed the loss of cell viability, decline in the cellular GSH/GSSG ratio, increase of IL-8, and the increase of intracellular calcium concentration in RAW 264.7 macrophages when exposed to p-MWCNTs at high dosage. Additionally, exposure to p-MWCNTs resulted in ultrastructural and morphological changes in RAW 264.7 macrophages. In contrast, the RAW 264.7 macrophages exposed to the tau-MWCNTs did not exhibit altered morphology. Our results conclude that the tau-MWCNTs show lower toxicity than that of p-MWCNTs.


Assuntos
Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Teste de Materiais , Camundongos , Nanotubos de Carbono/ultraestrutura
19.
World J Clin Cases ; 10(5): 1747-1753, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35211618

RESUMO

BACKGROUND: Subclavian artery stenosis refers to the stenosis in the lumen caused by the presence of plaque or thrombus in the subclavian artery. It is a common problem in endovascular interventions. In fact, conventional subclavian artery stenting via the femoral artery approach is effective and safe. Nevertheless, because femoral artery puncture is not easy to stop bleeding, it requires longer femoral artery compression or more expensive hemostatic materials, such as staplers. Patients need to be catheterized and bedridden for a longer time, which may lead to many complications, such as pseudoaneurysm. CASE SUMMARY: Herein, we reported a new interventional therapy of subclavian artery. From March 1, 2020 to August 31, 2021, we operated on four patients with subclavian artery stenting via bilateral radial artery access. CONCLUSION: After reviewing four cases of successful placement of clavicular artery stents via bilateral radial arteries, we concluded that bilateral radial artery approach is feasible. Clavicular artery stenting is safe, effective, and timesaving. It is an excellent alternative to the traditional femoral artery procedure, with few complications and high comfort degree.

20.
Chemosphere ; 286(Pt 3): 131964, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426296

RESUMO

Fluoroquinolones in water environments have caused worldwide concern due to negative effects on human health and ecological environment. Heretofore, synergistic mechanisms of Fe3+/H2O2 process enhanced via vacuum ultraviolet (VUV) irradiation for fluoroquinolones removal, and generation ways and contribution evaluations of reactive oxygen species (ROS) in integrated VUV/Fe3+/H2O2 were not reported systematically. This work comparatively investigated norfloxacin (NOR, typical fluoroquinolones) degradation in VUV/Fe3+/H2O2 and its sub-processes. Compared with its sub-processes, VUV/Fe3+/H2O2 process could not only increase degradation rate constant by 2.1-10.2 times and increase mineralization rate by 14.5%-49.5%, but also reduce energy consumption by 53.1%-89.9% and reduce economic cost by 33.3%-68.0%. Effect mechanisms of Fe3+ and H2O2 doses on decontamination capability of VUV/Fe2+/H2O2 were elaborated, and 3 mM H2O2 and 90 µM Fe3+ were determined as optimal doses. The synergetic factor in integrated VUV/Fe3+/H2O2 was 3.33, which was mainly ascribed to VUV photons accelerating iron cycle. In VUV/Fe3+/H2O2 process, superoxide radical and hydroxyl radical were confirmed as primary ROS, contributing 20.86% and 76.32% to NOR oxidation, separately. Organic and inorganic products of NOR and its degradation pathways in integrated VUV/Fe3+/H2O2 were also investigated. Besides, the synergistic reaction pathways in VUV/Fe3+/H2O2 were elaborated. Effects of water matrices on decontamination capability of VUV/Fe3+/H2O2 were also studied. All results indicated VUV/Fe3+/H2O2 as an efficient and cost-effective process suitable for NOR removal.


Assuntos
Norfloxacino , Poluentes Químicos da Água , Humanos , Peróxido de Hidrogênio , Oxirredução , Raios Ultravioleta , Vácuo , Poluentes Químicos da Água/análise
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