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1.
Biosens Bioelectron ; 200: 113920, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34973566

RESUMO

Large-area surface-enhanced Raman spectroscopy (SERS) sensing platforms displaying ultrahigh sensitivity and signal uniformity have potentially enormous sensing applicability, but they are still challenging to prepare in a scalable manner. In this study, silver nanopaste (AgNPA) was employed to prepare a wafer-scale, ultrasensitive SERS substrate. The self-generated, high-density Ag nanocracks (NCKs) with small gaps could be created on Si wafers via a spin-coating process, and provided extremely abundant hotspots for SERS analyses with ultrahigh sensitivity-down to the level of single molecules (enhancement factor: ca. 1010; detection limit: ca. 10-18 M)-and great signal reproducibility (variation: ca. 3.6%). Moreover, the Ag NCK arrays demonstrated broad applicability and practicability for on-site detection when combined with a portable 785 Raman spectrometer. This method allowed the highly sensitive detection of a diverse range of analytes (benzo[a]pyrene, di-2-ethylhexyl phthalate, aflatoxins B1, zearalenone, ractopamine, salbutamol, sildenafil, thiram, dimethoate, and methamidophos). In particular, pesticides are used extensively in agricultural production. Unfortunately, they can affect the environment and human health as a result of acute toxicity. Therefore, the simultaneous label-free detection of three different pesticides was demonstrated. Finally, the SERS substrates are fabricated through a simple, efficient, and scalable process that offers new opportunities for mass production.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Humanos , Reprodutibilidade dos Testes , Prata , Análise Espectral Raman , Tiram
2.
Biomater Sci ; 10(2): 410-422, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-34860214

RESUMO

Healthcare-associated infections are common causes of morbidity and mortality. Advanced nanotechnology provides a means of overcoming this problem, but it remains challenging to develop universal coating strategies for decorating antimicrobial nanomaterials onto various clinical devices. In this paper, we propose a general silane-based method for immobilizing monolayer metal nanoparticle (NP) arrays onto any type of substrate surface-especially for a diverse range of clinical implantable devices. The surface silanization was achieved simply through the adsorption of N1-(3-trimethoxysilylpropyl)diethylenetriamine (TMS), regardless of the material (polymer, metal, oxide) or morphology (flat, curved, textured) of the substrate, with no need for pretreatment or expensive instrumentation. Monolayers of various nanostructures (Ag, Au, and hollow Au NPs) were then decorated rapidly onto the TMS-treated substrates, thereby further functionalizing their surfaces. In particular, immobilization of the Ag NPs resulted in excellent anti-biofilm efficacy against three clinically life-threatening pathogens: Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. Sustained release of Ag+ ions led to durable inhibition of bacterial attachment for up to 28 days. Studies with NIH3T3 fibroblasts revealed that the Ag NP arrays displayed no cytotoxicity toward mammalian cells. Overall, this universal coating process appears to be an innovative method for the surface-functionalization of diverse materials and devices employed in the fields of energy, sensing, and medicine-especially to prevent healthcare-associated infections arising from the use of clinical implantable devices in hospitals.


Assuntos
Biofilmes , Nanopartículas Metálicas , Adsorção , Animais , Antibacterianos/farmacologia , Camundongos , Células NIH 3T3 , Staphylococcus aureus
3.
Gut ; 71(9): 1843-1855, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34921062

RESUMO

OBJECTIVE: Stromal barriers, such as the abundant desmoplastic stroma that is characteristic of pancreatic ductal adenocarcinoma (PDAC), can block the delivery and decrease the tumour-penetrating ability of therapeutics such as tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), which can selectively induce cancer cell apoptosis. This study aimed to develop a TRAIL-based nanotherapy that not only eliminated the extracellular matrix barrier to increase TRAIL delivery into tumours but also blocked antiapoptotic mechanisms to overcome TRAIL resistance in PDAC. DESIGN: Nitric oxide (NO) plays a role in preventing tissue desmoplasia and could thus be delivered to disrupt the stromal barrier and improve TRAIL delivery in PDAC. We applied an in vitro-in vivo combinatorial phage display technique to identify novel peptide ligands to target the desmoplastic stroma in both murine and human orthotopic PDAC. We then constructed a stroma-targeted nanogel modified with phage display-identified tumour stroma-targeting peptides to co-deliver NO and TRAIL to PDAC and examined the anticancer effect in three-dimensional spheroid cultures in vitro and in orthotopic PDAC models in vivo. RESULTS: The delivery of NO to the PDAC tumour stroma resulted in reprogramming of activated pancreatic stellate cells, alleviation of tumour desmoplasia and downregulation of antiapoptotic BCL-2 protein expression, thereby facilitating tumour penetration by TRAIL and substantially enhancing the antitumour efficacy of TRAIL therapy. CONCLUSION: The co-delivery of TRAIL and NO by a stroma-targeted nanogel that remodels the fibrotic tumour microenvironment and suppresses tumour growth has the potential to be translated into a safe and promising treatment for PDAC.

4.
ACS Appl Mater Interfaces ; 13(32): 38090-38104, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34342219

RESUMO

Much effort has been focused on novel nanomedicine for cancer therapy. However, tumor hypoxia limits the efficacy of various cancer therapeutics. Herein, we constructed a self-sufficient hybrid enzyme-based silk fibroin hydrogel system, consisting of Pt-decorated hollow Ag-Au trimetallic nanocages (HGN@Pt) and glucose oxidase (GOx), to supply O2 continuously and consume glucose concurrently and, thereby, synergistically enhance the anti-cancer efficacy of a combined starvation and photothermal therapy operating in a hypoxic tumor microenvironment. Thanks to the cooperative effects of the active surface atoms (resulting from the island-like features of the Pt coating), the intrinsically hollow structure, and the strain effect induced by the trimetallic composition, HGN@Pt displayed efficient catalase-like activity. The enhancement in the generation of O2 through the decomposition of H2O2 mediated by the as-designed nanozyme was greater than 400% when compared with that of hollow Ag-Pt bimetallic nanospheres or tiny Pt nanoparticles. Moreover, in the presence of HGN@Pt, significant amounts of O2 could be generated within a few minutes, even in an acidic buffer solution (pH 5.8-6.5) containing a low concentration of H2O2 (100-500 µM). Because HGN@Pt exhibited a strong surface plasmon resonance peak in the near-infrared wavelength range, it could be used as a photothermal agent for hyperthermia therapy. Furthermore, GOx was released gradually from the SF hydrogel into the tumor microenvironment to mediate the depletion of glucose, leading to glucose starvation-induced cancer cell death. Finally, the O2 supplied by HGN@Pt overcame the hypoxia of the microenvironment and, thereby, promoted the starvation therapeutic effect of the GOx-mediated glucose consumption. Meanwhile, the GOx-produced H2O2 from the oxidation of glucose could be used to regenerate O2 and, thereby, construct a complementary circulatory system. Accordingly, this study presents a self-sufficient hybrid enzyme-based system that synergistically alleviates tumor hypoxia and induces an anti-cancer effect when combined with irradiation of light from a near-infrared laser.


Assuntos
Nanopartículas/uso terapêutico , Neoplasias/terapia , Terapia Fototérmica/métodos , Hipóxia Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Animais , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Feminino , Camundongos , Camundongos Endogâmicos BALB C
5.
Mater Sci Eng C Mater Biol Appl ; 123: 111985, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812613

RESUMO

Urinary tract infections (UTI) represent one of the most common problem within the urological disorders, and it is mainly caused by biofilm formation which leads to bacterial infection. Anti-adhesion and antibacterial agents are two primary mechanisms to prevent biofilm formation; however, current strategies are insufficiently effective. In this study, we developed an effective antibiofilm biodegradable polymer with high biocompatibility. Here we embedded silver nanoparticles (AgNPs) in poly(glycerol sebacate) acrylate (PGSA) followed by superhydrophilic modification on the polymer surfaces. The modified surfaces were characterized using SEM, AFM and contact angle measurements. This anti-adhesive surface prevented the adhesion of E. coli and limited the biofilm coverage percentage to less than 3% in 24 h. In the in vitro degradation, the long-term antibiofilm performance was evaluated in Nowatzki-Stoodley artificial urine (NSAU). The surface modified AgNPs embedded PGSA (sPGSA-AgNPs) was able to effectively inhibit the formation of biofilm by reducing the biofilm coverage to less than 0.01%, and it also showed low cytotoxicity with human bladder carcinoma cell. With the effective antibiofilm, biocompatibility and biodegradability, it is possible to be applied in urological devices to ameliorate the situation of UTIs.


Assuntos
Nanopartículas Metálicas , Prata , Antibacterianos/farmacologia , Biofilmes , Escherichia coli , Humanos , Polímeros , Prata/farmacologia
6.
Anal Chem ; 93(9): 4299-4307, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33635644

RESUMO

The localized surface plasmon resonance of plasmonic nanoparticles (NPs) can be coupled with a noble metal substrate (S) to induce a localized augmented electric field (E-field) concentrated at the NP-S gap. Herein, we analyzed the fundamental near-field properties of metal NPs on diverse substrates numerically (using the 3D finite-difference time-domain method) and experimentally [using surface-enhanced Raman scattering (SERS)]. We systematically examined the effects of plasmonic NPs on noble metals (Ag and Au), non-noble metals (Al, Ti, Cu, Fe, and Ni), semiconductors (Si and Ge), and dielectrics (TiO2, ZnO, and SiO2) as substrates. For the AgNPs, the Al (11,664 times) and Si (3969 times) substrates produced considerable E-field enhancements, with Al in particular generating a tremendous E-field enhancement comparable in intensity to that induced by a Ag (28,224 times) substrate. Notably, we found that a superior metallic character of the substrate gave rise to easier induction of image charges within the metal substrate, resulting in a greater E-field at the NP-S gap; on the other hand, the larger the permittivity of the nonmetal substrate, the greater the ability of the substrate to store an image charge distribution, resulting in stronger coupling to the charges of localized surface plasmon resonance oscillation on the metal NP. Furthermore, we measured the SERS spectra of rhodamine 6G (a commonly used Raman spectral probe), histamine (a biogenic amine used as a food freshness indicator), creatinine (a kidney health indicator), and tert-butylbenzene [an extreme ultraviolet (EUV) lithography contaminant] on AgNP-immobilized Al and Si substrates to demonstrate the wide range of potential applications. Finally, the NP-S gap hotspots appear to be widely applicable as an ultrasensitive SERS platform (∼single-molecule level), especially when used as a powerful analytical tool for the detection of residual contaminants on versatile substrates.

7.
J Mater Chem B ; 9(5): 1325-1335, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33443514

RESUMO

Neural stem cells (NSCs) represent significant potential and promise in the treatment of neurodegenerative diseases and nerve injuries. An efficient methodology or platform that can help in specifically directing the stem cell fate is important and highly desirable for future clinical therapy. In this study, a biodegradable electrical conductive film composed of an oxidative polymerized carboxyl-capped aniline pentamer (CCAP) and ring-opening polymerized tetra poly(d,l-lactide) (4a-PLA) was designed with the addition of the dopant, namely chondroitin sulfate. This conductive film acts as a biological substrate for the exogenous/endogenous electric field transmission in tissue, resulting in the control of NSC fate, as well as improvement in neural tissue regeneration. The results show that CCAP is successfully synthesized and then conjugated onto 4a-PLA to form a network structure with electrical conductivity, cell adhesion capacity, and biodegradability. The neuronal differentiation of NSCs can be induced on 4a-PLAAP, and the neuronal maturation process can be facilitated by the manipulation of the electrical field. This biocompatible and electroactive material can serve as a platform to determine the cell fate of NSCs and be employed in neural regeneration. For future perspectives, its promising performance shows potential in applications, such as electrode-tissue integration interfaces, coatings on neuroprosthetics devices and neural probes, and smart drug delivery system in neurological systems.


Assuntos
Compostos de Anilina/metabolismo , Materiais Biocompatíveis/metabolismo , Células-Tronco Neurais/metabolismo , Células 3T3 , Compostos de Anilina/química , Compostos de Anilina/farmacologia , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Condutividade Elétrica , Técnicas Eletroquímicas , Teste de Materiais , Camundongos , Estrutura Molecular , Células-Tronco Neurais/efeitos dos fármacos
8.
ACS Appl Mater Interfaces ; 12(40): 44407-44419, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32865389

RESUMO

Antiangiogenic therapy is widely administered in many cancers, and the antiangiogenic drug sorafenib offers moderate benefits in advanced hepatocellular carcinoma (HCC). However, antiangiogenic therapy can also lead to hypoxia-driven angiogenesis and immunosuppression in the tumor microenvironment (TME) and metastasis. Here, we report the synthesis and evaluation of NanoMnSor, a tumor-targeted, nanoparticle drug carrier that efficiently codelivers oxygen-generating MnO2 and sorafenib into HCC. We found that MnO2 not only alleviates hypoxia by catalyzing the decomposition of H2O2 to oxygen but also enhances pH/redox-responsive T1-weighted magnetic resonance imaging and drug-release properties upon decomposition into Mn2+ ions in the TME. Moreover, macrophages exposed to MnO2 displayed increased mRNA associated with the immunostimulatory M1 phenotype. We further show that NanoMnSor treatment leads to sorafenib-induced decrease in tumor vascularization and significantly suppresses primary tumor growth and distal metastasis, resulting in improved overall survival in a mouse orthotopic HCC model. Furthermore, NanoMnSor reprograms the immunosuppressive TME by reducing the hypoxia-induced tumor infiltration of tumor-associated macrophages, promoting macrophage polarization toward the immunostimulatory M1 phenotype, and increasing the number of CD8+ cytotoxic T cells in tumors, thereby augmenting the efficacy of anti-PD-1 antibody and whole-cell cancer vaccine immunotherapies. Our study demonstrates the potential of oxygen-generating nanoparticles to deliver antiangiogenic agents, efficiently modulate the hypoxic TME, and overcome hypoxia-driven drug resistance, thereby providing therapeutic benefit in cancer.


Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Compostos de Manganês/farmacologia , Nanopartículas/química , Neovascularização Patológica/tratamento farmacológico , Óxidos/farmacologia , Inibidores da Angiogênese/química , Animais , Antineoplásicos/química , Carcinoma Hepatocelular/patologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Humanos , Neoplasias Hepáticas/patologia , Masculino , Compostos de Manganês/química , Camundongos , Camundongos Endogâmicos C3H , Neovascularização Patológica/patologia , Óxidos/química , Tamanho da Partícula , Propriedades de Superfície , Células Tumorais Cultivadas , Evasão Tumoral/efeitos dos fármacos , Hipóxia Tumoral/efeitos dos fármacos
9.
Nat Commun ; 11(1): 534, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988280

RESUMO

A disturbance of reactive oxygen species (ROS) homeostasis may cause the pathogenesis of many diseases. Inspired by natural photosynthesis, this work proposes a photo-driven H2-evolving liposomal nanoplatform (Lip NP) that comprises an upconversion nanoparticle (UCNP) that is conjugated with gold nanoparticles (AuNPs) via a ROS-responsive linker, which is encapsulated inside the liposomal system in which the lipid bilayer embeds chlorophyll a (Chla). The UCNP functions as a transducer, converting NIR light into upconversion luminescence for simultaneous imaging and therapy in situ. Functioning as light-harvesting antennas, AuNPs are used to detect the local concentration of ROS for FRET biosensing, while the Chla activates the photosynthesis of H2 gas to scavenge local excess ROS. The results thus obtained indicate the potential of using the Lip NPs in the analysis of biological tissues, restoring their ROS homeostasis, possibly preventing the initiation and progression of diseases.


Assuntos
Clorofila/metabolismo , Hidrogênio/metabolismo , Lipossomos/metabolismo , Nanopartículas Metálicas/química , Fotossíntese , Espécies Reativas de Oxigênio/metabolismo , Técnicas Biossensoriais , Ouro , Nanoestruturas
10.
ACS Appl Mater Interfaces ; 9(20): 17306-17316, 2017 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-28471650

RESUMO

This paper describes the fabrication of paper-based plasmonic refractometric sensors through the embedding of metal nanoparticles (NPs) onto flexible papers using reversal nanoimprint lithography. The NP-embedded papers can serve as gas sensors for the detection of volatile biogenic amines (BAs) released from spoiled food. Commercial inkjet papers were employed as sensor substrates-their high reflectance (>80%) and smooth surfaces (roughness: ca. 4.9 nm) providing significant optical signals for reflection-mode plasmonic refractometric sensing and high particle transfer efficiency, respectively; in addition, because inkjet papers have lightweight and are burnable and flexible, they are especially suitable for developing portable, disposable, cost-effective, eco-friendly sensing platforms. Solid silver NPs (SNPs), solid gold NPs (GNPs), and hollow Au-Ag alloyed NPs (HGNs) were immobilized on a solid mold and then transferred directly onto the softened paper surfaces. The particle number density and exposure height of the embedded NPs were dependent on two imprinting parameters: applied pressure and temperature. The optimal samples exhibited high particle transfer efficiency (ca. 85%), a sufficient exposure surface area (ca. 50% of particle surface area) presented to the target molecules, and a strong resonance reflectance dip for detection. Moreover, the HGN-embedded paper displayed a significant wavelength dip shift upon the spontaneous adsorption of BA vapors (e.g., Δλ = 33 nm for putrescine; Δλ = 24 nm for spermidine), indicating high refractometric sensitivity; in contrast, no visible spectroscopic responses were observed with respect to other possibly coexisting gases (e.g., air, N2, CO2, water vapor) during the food storage process, indicating high selectivity. Finally, the plasmonic sensing papers were used to monitor the freshness of a food product (salmon).


Assuntos
Qualidade dos Alimentos , Aminas Biogênicas , Ouro , Nanopartículas Metálicas , Odorantes
11.
ACS Appl Mater Interfaces ; 9(4): 3873-3884, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28071899

RESUMO

This paper describes the synthesis of near-infrared (NIR)-absorbing gold nanoframes (GNFs) and a systematic study comparing their physiological stability and biocompatibility with those of hollow Au-Ag nanoshells (GNSs), which have been used widely as photothermal agents in biomedical applications because of their localized surface plasmon resonance (LSPR) in the NIR region. The GNFs were synthesized in three steps: galvanic replacement, Au deposition, and Ag dealloying, using silver nanospheres (SNP) as the starting material. The morphology and optical properties of the GNFs were dependent on the thickness of the Au coating layer and the degree of Ag dealloying. The optimal GNF exhibited a robust spherical skeleton composed of a few thick rims, but preserved the distinctive LSPR absorbance in the NIR region-even when the Ag content within the skeleton was only 10 wt %, 4-fold lower than that of the GNSs. These GNFs displayed an attractive photothermal conversion ability and great photothermal stability, and could efficiently kill 4T1 cancer cells through light-induced heating. Moreover, the GNFs preserved their morphology and optical properties after incubation in biological media (e.g., saline, serum), whereas the GNSs were unstable under the same conditions because of rapid dissolution of the considerable silver content with the shell. Furthermore, the GNFs had good biocompatibility with normal cells (e.g., NIH-3T3 and hepatocytes; cell viability for both cells: >90%), whereas the GNSs exhibited significant dose-dependent cytotoxicity (e.g., cell viability for hepatocytes at 1.14 nM: ca. 11%), accompanied by the induction of reactive oxygen species. Finally, the GNFs displayed good biocompatibility and biosafety in an in vivo mouse model; in contrast, the accumulation of GNSs caused liver injury and inflammation. Our results suggest that GNFs have great potential to serve as stable, biocompatible NIR-light absorbers for in vivo applications, including cancer detection and combination therapy.


Assuntos
Nanoconchas , Animais , Sobrevivência Celular , Ouro , Camundongos , Prata , Ressonância de Plasmônio de Superfície
12.
Biomaterials ; 93: 48-59, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27070992

RESUMO

The nonspecific distribution of therapeutic agents and nontargeted heating commonly produce undesirable side effects during cancer treatment since the optimal timing of triggering the carrier systems is unknown. This work proposes a multifunctional liposomal system that can intracellularly and simultaneously deliver the therapeutic drug doxorubicin (DOX), heat, and a bubble-generating agent (ammonium bicarbonate, ABC) into targeted tumor cells to have a cytotoxic effect. Gold nanocages that are encapsulated in liposomes effectively convert near-infrared light irradiation into localized heat, which causes the decomposition of ABC and generates CO2 bubbles, rapidly triggering the release of DOX. Additionally, a hybridized Mucin-1 aptamer is conjugated on the surface of the test liposomes, which then function as a recognition probe to enhance the uptake of those liposomes by cells, and as a molecular beacon to signal when the internalized particles have been maximized, which is the optimal time for photothermally triggering the release of the drug following the systemic administration of the liposomes. Empirical results reveal that this combined treatment effectively controls targeted drug release in a spatially and temporally precise fashion and so significantly increases the potency of the drug while minimizing unwanted side effects, making it a promising treatment for cancer.


Assuntos
Sistemas de Liberação de Medicamentos , Transferência Ressonante de Energia de Fluorescência , Raios Infravermelhos , Lipossomos/química , Animais , Antineoplásicos/farmacologia , Peso Corporal/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/farmacologia , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Endocitose , Fluorescência , Células Hep G2 , Humanos , Células MCF-7 , Camundongos Endogâmicos BALB C , Camundongos Nus , Simulação de Dinâmica Molecular , Imagem Molecular , Nanopartículas/química , Temperatura , Fatores de Tempo , Carga Tumoral/efeitos dos fármacos
13.
J Control Release ; 221: 62-70, 2016 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-26551344

RESUMO

Sorafenib is a tyrosine kinase inhibitor that has recently been shown to be a potential antifibrotic agent. However, a narrow therapeutic window limits the clinical use and therapeutic efficacy of sorafenib. Herein, we have developed and optimized nanoparticle (NP) formulations prepared from a mixture of poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (PEG-PLGA) copolymers with poly(lactic-co-glycolic acid) (PLGA) for the systemic delivery of sorafenib into the fibrotic livers of CCl4-induced fibrosis mouse models. We characterized and compared the pharmaceutical and biological properties of two different PLGA nanoparticles (NPs)--PEG-PLGA NPs (PEG-PLGA/PLGA=10/0) and PEG-PLGA/PLGA NPs (PEG-PLGA/PLGA=5/5). Increasing the PLGA content in the PEG-PLGA/PLGA mixture led to increases in the particle size and drug encapsulation efficacy and a decrease in the drug release rate. Both PEG-PLGA and PEG-PLGA/PLGA NPs significantly prolonged the blood circulation of the cargo and increased the uptake by the fibrotic livers. The systemic administration of PEG-PLGA or PEG-PLGA/PLGA NPs containing sorafenib twice per week for a period of 4 weeks efficiently ameliorated liver fibrosis, as indicated by decreased α-smooth muscle actin (α-SMA) content and collagen production in the livers of CCl4-treated mice. Furthermore, sorafenib-loaded PLGA NPs significantly shrank the abnormal blood vessels and decreased microvascular density (MVD), leading to vessel normalization in the fibrotic livers. In conclusion, our results reflect the clinical potential of sorafenib-loaded PLGA NPs for the prevention and treatment of liver fibrosis.


Assuntos
Portadores de Fármacos/química , Cirrose Hepática/tratamento farmacológico , Fígado/efeitos dos fármacos , Nanopartículas/química , Niacinamida/análogos & derivados , Compostos de Fenilureia/uso terapêutico , Polietilenoglicóis/química , Poliglactina 910/química , Inibidores de Proteínas Quinases/uso terapêutico , Animais , Tetracloreto de Carbono , Células Endoteliais da Veia Umbilical Humana , Ácido Láctico/química , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/patologia , Masculino , Camundongos , Nanopartículas/ultraestrutura , Niacinamida/administração & dosagem , Niacinamida/uso terapêutico , Compostos de Fenilureia/administração & dosagem , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Inibidores de Proteínas Quinases/administração & dosagem , Sorafenibe
14.
ACS Nano ; 9(12): 12045-59, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26552041

RESUMO

This paper describes a systematic investigation of the phenomenon of white-light-induced heating in silk fibroin films embedded with gold nanoparticles (Au NPs). The Au NPs functioned to develop an ultrahigh broadband absorber, allowing white light to be used as a source for photothermal generation. With an increase of the Au content in the composite films, the absorbance was enhanced significantly around the localized surface plasmon resonance (LSPR) wavelength, while non-LSPR wavelengths were also increased dramatically. The greater amount of absorbed light increased the rate of photoheating. The optimized composite film exhibited ultrahigh absorbances of approximately 95% over the spectral range from 350 to 750 nm, with moderate absorbances (>60%) at longer wavelengths (750-1000 nm). As a result, the composite film absorbed almost all of the incident light and, accordingly, converted this optical energy to local heat. Therefore, significant temperature increases (ca. 100 °C) were readily obtained when we irradiated the composite film under a light-emitting diode or halogen lamp. Moreover, such composite films displayed linear light-to-heat responses with respect to the light intensity, as well as great photothermal stability. A broadband absorptive film coated on a simple Al/Si Schottky diode displayed a linear, significant, stable photo-thermo-electronic effect in response to varying the light intensity.


Assuntos
Bombyx/química , Fibroínas/química , Ouro/química , Nanocompostos/química , Animais , Temperatura Alta , Luz , Ressonância de Plasmônio de Superfície
15.
Biomaterials ; 56: 26-35, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25934276

RESUMO

Repeated cancer treatments are common, owing to the aggressive and resistant nature of tumors. This work presents a chitosan (CS) derivative that contains self-doped polyaniline (PANI) side chains, capable of self-assembling to form micelles and then transforming into hydrogels driven by a local change in pH. Analysis results of small-angle X-ray scattering indicate that the sol-gel transition of this CS derivative may provide the mechanical integrity to maintain its spatial stability in the microenvironment of solid tumors. The micelles formed in the CS hydrogel function as nanoscaled heating sources upon exposure to near-infrared light, thereby enabling the selective killing of cancer cells in a light-treated area. Additionally, photothermal efficacy of the micellar hydrogel is evaluated using a tumor-bearing mouse model; hollow gold nanospheres (HGNs) are used for comparison. Given the ability of the micellar hydrogel to provide spatial stability within a solid tumor, which prevents its leakage from the injection site, the therapeutic efficacy of this hydrogel, as a photothermal therapeutic agent for repeated treatments, exceeds that of nanosized HGNs. Results of this study demonstrate that this in situ-formed micellar hydrogel is a highly promising modality for repeated cancer treatments, providing a clinically viable, minimally invasive phototherapeutic option for therapeutic treatment.


Assuntos
Quitosana/química , Hidrogéis/química , Raios Infravermelhos , Micelas , Neoplasias/terapia , Fototerapia/métodos , Animais , Linhagem Celular Tumoral , Quitosana/análogos & derivados , Humanos , Concentração de Íons de Hidrogênio , Luz , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , Camundongos Nus , Nanosferas/química , Transplante de Neoplasias , Transição de Fase , Fenilenodiaminas/química , Polímeros/química , Espalhamento de Radiação , Espectrofotometria Ultravioleta , Viscosidade
16.
J Phys Chem B ; 118(49): 14132-9, 2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25243840

RESUMO

We report our observation of changes to the crystallinity or morphology during seed-mediated growth of Au nanocrystals. When single-crystal Au seeds with a spherical or rod-like shape were treated with a chemical species such as S2O3(2-) ions, twin defects were developed during the growth process to generate multiply twinned nanostructures. X-ray photoelectron spectroscopy analysis indicated that the S2O3(2-) ions were chemisorbed on the surfaces of the seeds during the treatment. The chemisorbed S2O3(2-) ions somehow influenced the crystallization of Au atoms added onto the surface during a growth process, leading to the formation of twin defects. In contrast to the spherical and rod-like Au seeds, the single-crystal structure was retained to generate a concave morphology when single-crystal Au seeds with a cubic or octahedral shape were used for a similar treatment and then seed-mediated growth. The different outcomes are likely related to the difference in spatial distribution of S2O3(2-) ions chemisorbed on the surface of a seed. This approach based on surface modification is potentially extendable to other noble metals for engineering the crystallinity and morphology of nanocrystals formed via seed-mediated growth.


Assuntos
Ouro/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Compostos de Enxofre/química , Cristalização/métodos , Nanotecnologia/métodos
17.
Acta Crystallogr C ; 69(Pt 9): 1070-2, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24005524

RESUMO

The title compound, C25H22NO2P, was synthesized in high yield by a three-component Kabachnik-Fields reaction of diphenylphosphine oxide, salicylaldehyde and aniline in dry toluene at room temperature. It precipitates as racemic crystals, in which strong hydrogen bonds between the hydroxy group and the P=O group of a neighbouring molecule form one-dimensional heterochiral chains along the crystallographic a axis, with an O···O separation of 2.568 (2) Å. The pseudo-tetrahedral environment of the P atom is distorted, with O-P-C bond angles significantly larger than the C-P-C angles.


Assuntos
Compostos de Anilina/química , Compostos de Anilina/síntese química , Cristalografia por Raios X , Fenóis/química , Fenóis/síntese química , Aldeídos/química , Ligação de Hidrogênio , Estrutura Molecular , Fosfinas/química
18.
ACS Nano ; 7(5): 4586-94, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23631674

RESUMO

Silver octahedra with edge lengths controlled in the range of 20-72 nm were synthesized via seed-mediated growth. The key to the success of this synthesis is the use of single-crystal Ag seeds with uniform and precisely controlled sizes to direct the growth and the use of citrate as a selective capping agent for the {111} facets. Our mechanistic studies demonstrated that Ag seeds with both cubic and quasi-spherical shapes could evolve into octahedra. For the first time, we were able to precisely control the edge lengths of Ag octahedra below 100 nm, and the lower limit of size could even be pushed down to 20 nm. Using the as-obtained Ag octahedra as sacrificial templates, Au nanocages with an octahedral shape and precisely tunable optical properties were synthesized through a galvanic replacement reaction. Such hollow nanostructures are promising candidates for a broad range of applications related to optics, catalysis, and biomedicine.


Assuntos
Nanotecnologia/métodos , Fenômenos Ópticos , Tamanho da Partícula , Prata/química , Modelos Moleculares , Conformação Molecular
19.
Small ; 9(18): 3111-7, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-23457090

RESUMO

A facile, robust approach to the synthesis of Au cubic nanoframes is described. The synthesis involves three major steps: 1) preparation of Au-Ag alloyed nanocages using a galvanic replacement reaction between Ag nanocubes and HAuCl4 ; 2) deposition of thin layers of pure Au onto the surfaces of the nanocages by reducing HAuCl4 with ascorbic acid, and; 3) formation of Au cubic nanoframes through a dealloying process with HAuCl4 . The key to the formation of Au cubic nanoframes is to coat the surfaces of the Au-Ag nanocages with sufficiently thick layers of Au before they are dealloyed. The Au layer could prevent the skeleton of a nanocage from being fragmented during the dealloying step. The as-prepared Au cubic nanoframes exhibit tunable localized surface plasmon resonance peaks in the near-infrared region, but with much lower Ag content as compared with the initial Au-Ag nanocages.


Assuntos
Ligas/química , Ouro/química , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Prata/química
20.
ACS Nano ; 7(3): 2068-77, 2013 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-23383982

RESUMO

Gold nanohexapods represent a novel class of optically tunable nanostructures consisting of an octahedral core and six arms grown on its vertices. By controlling the length of the arms, their localized surface plasmon resonance peaks could be tuned from the visible to the near-infrared region for deep penetration of light into soft tissues. Herein we compare the in vitro and in vivo capabilities of Au nanohexapods as photothermal transducers for theranostic applications by benchmarking against those of Au nanorods and nanocages. While all these Au nanostructures could absorb and convert near-infrared light into heat, Au nanohexapods exhibited the highest cellular uptake and the lowest cytotoxicity in vitro for both the as-prepared and PEGylated nanostructures. In vivo pharmacokinetic studies showed that the PEGylated Au nanohexapods had significant blood circulation and tumor accumulation in a mouse breast cancer model. Following photothermal treatment, substantial heat was produced in situ and the tumor metabolism was greatly reduced for all these Au nanostructures, as determined with (18)F-flourodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT). Combined together, we can conclude that Au nanohexapods are promising candidates for cancer theranostics in terms of both photothermal destruction and contrast-enhanced diagnosis.


Assuntos
Hipertermia Induzida/métodos , Nanopartículas Metálicas/uso terapêutico , Fototerapia/métodos , Animais , Linhagem Celular Tumoral , Feminino , Ouro/química , Humanos , Neoplasias Mamárias Experimentais/terapia , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Camundongos , Camundongos Nus , Nanotecnologia , Nanotubos/química , Nanotubos/ultraestrutura , Polietilenoglicóis/química
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