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1.
BMJ Open ; 10(7): e034156, 2020 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-32624467

RESUMO

OBJECTIVE: This study developed a surveillance system suitable for monitoring epidemic outbreaks and assessing public opinion in non-English-speaking countries. We evaluated whether social media reflects social uneasiness and fear during epidemic outbreaks and natural catastrophes. DESIGN: Cross-sectional study. SETTING: Freely available epidemic data in Taiwan. MAIN OUTCOME MEASURE: We used weekly epidemic incidence data obtained from the Taiwan Centers for Disease Control and online search query data obtained from Google Trends between 4 October 2015 and 2 April 2016. To validate whether non-English query keywords were useful surveillance tools, we estimated the correlation between online query data and epidemic incidence in Taiwan. RESULTS: With our approach, we noted that keywords ('common cold'), ('fever') and ('cough') exhibited good to excellent correlation between Google Trends query data and influenza incidence (r=0.898, p<0.001; r=0.773, p<0.001; r=0.796, p<0.001, respectively). They also displayed high correlation with influenza-like illness emergencies (r=0.900, p<0.001; r=0.802, p<0.001; r=0.886, p<0.001, respectively) and outpatient visits (r=0.889, p<0.001; r=0.791, p<0.001; r=0.870, p<0.001, respectively). We noted that the query ('enterovirus') exhibited excellent correlation with the number of enterovirus-infected patients in emergency departments (r=0.914, p<0.001). CONCLUSIONS: These results suggested that Google Trends can be a good surveillance tool for epidemic outbreaks, even in Taiwan, the non-English-speaking country. Online search activity indicates that people are concerned about epidemic diseases, even if they do not visit hospitals. This prompted us to develop useful tools to monitor social media during an epidemic because such media usage reflects infectious disease trends more quickly than does traditional reporting.


Assuntos
Epidemias , Idioma , Estudos Transversais , Surtos de Doenças , Humanos , Internet , Ferramenta de Busca , Taiwan/epidemiologia
2.
Photodiagnosis Photodyn Ther ; 23: 111-118, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29894822

RESUMO

Photodynamic therapy (PDT) is a treatment utilizing the combined action of photosensitizers and light for the treatment of various cancers. The mechanisms for tumor destruction after PDT include direct tumor cell kill by singlet oxygen species (OS), indirect cell kill via vascular damage, and an elicited immune response. However, it has been reported that many cellular activators, including vascular endothelial growth factor (VEGF), are produced by tumor cells after PDT. In this study, we demonstrate that meta-tetra(hydroxyphenyl) chlorin (mTHPC)-based photodynamic therapy combined with bevacizumab (Avastin™), an anti-VEGF neutralizing monoclonal antibody that blocks the binding of VEGF to its receptor, can enhance the effectiveness of each treatment modality. We evaluated the efficacy of bevacizumab-based anti-angiogenesis in combination with PDT as well as the resulting VEGF levels and microvessel density (MVD) in a mouse model of human colon cancer. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) were performed to assess VEGF concentrations and microvessel density in the various treatment groups, and confocal imaging and high performance liquid chromatography (HPLC) analyses were used to measure the distribution and concentration of mTHPC in tumors. Our results demonstrate that combination of PDT followed by bevacizumab significantly elicits a greater tumor response whereas bevacizumab treatment prior to PDT led to a reduced tumor response. Immunostaining and ELISA analyses revealed a lower expression of VEGF in tumors treated with combination therapy of PDT followed by bevacizumab. However, bevacizumab treatment decreased the accumulation of mTHPC in tumors 24 h after administration, which complemented the results of decreased anti-tumor efficacy of bevacizumab followed by PDT.


Assuntos
Inibidores da Angiogênese/farmacologia , Bevacizumab/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Mesoporfirinas/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Ensaio de Imunoadsorção Enzimática , Feminino , Estimativa de Kaplan-Meier , Mesoporfirinas/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Carga Tumoral , Fator A de Crescimento do Endotélio Vascular/metabolismo
4.
Biomaterials ; 101: 241-50, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27294541

RESUMO

Combination chemotherapy with multiple drugs commonly requires several injections on various schedules, and the probability that the drug molecules reach the diseased tissues at the proper time and effective therapeutic concentrations is very low. This work elucidates an injectable co-delivery system that is based on cationic liposomes that are adsorbed on anionic hollow microspheres (Lipos-HMs) via electrostatic interaction, from which the localized sequence-specific release of a chemopreventive agent (1,25(OH)2D3) and an anticancer drug (doxorubicin; DOX) can be thermally driven in a time-controllable manner by an externally applied high-frequency magnetic field (HFMF). Lipos-HMs can greatly promote the accumulation of reactive oxygen species (ROS) in tumor cells by reducing their cytoplasmic expression of an antioxidant enzyme (superoxide dismutase) by 1,25(OH)2D3, increasing the susceptibility of cancer cells to the cytotoxic action of DOX. In nude mice that bear xenograft tumors, treatment with Lipos-HMs under exposure to HFMF effectively inhibits tumor growth and is the most effective therapeutic intervention among all the investigated. These empirical results demonstrate that the synergistic anticancer effects of sequential release of 1,25(OH)2D3 and DOX from the Lipos-HMs may have potential for maximizing DOX cytotoxicity, supporting more effective cancer treatment.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Calcitriol/administração & dosagem , Preparações de Ação Retardada/química , Doxorrubicina/administração & dosagem , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Calcitriol/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/uso terapêutico , Feminino , Humanos , Lipossomos/química , Células MCF-7 , Campos Magnéticos , Camundongos Endogâmicos BALB C , Camundongos Nus , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
5.
J Control Release ; 199: 53-62, 2015 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-25499553

RESUMO

Eradicating subcutaneous bacterial infections remains a significant challenge. This work reports an injectable system of hollow microspheres (HMs) that can rapidly produce localized heat activated by near-infrared (NIR) light and control the release of an antibiotic via a "molecular switch" in their polymer shells, as a combination strategy for treating subcutaneous abscesses. The HMs have a shell of poly(d,l-lactic-co-glycolic acid) (PLGA) and an aqueous core that is comprised of vancomycin (Van) and polypyrrole nanoparticles (PPy NPs), which are photothermal agents. Experimental results demonstrate that the micro-HMs ensure efficiently the spatial stabilization of their encapsulated Van and PPy NPs at the injection site in mice with subcutaneous abscesses. Without NIR irradiation, the HMs elute a negligible drug concentration, but release substantially more when exposed to NIR light, suggesting that this system is suitable as a photothermally-responsive drug delivery system. The combination of photothermally-induced hyperthermia and antibiotic therapy with HMs increases cytotoxicity for bacteria in abscesses, to an extent that is greater than the sum of the two treatments alone, demonstrating a synergistic effect. This treatment platform may find other clinical applications, especially for localized hyperthermia-based cancer therapy.


Assuntos
Abscesso/terapia , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Sistemas de Liberação de Medicamentos , Dermatopatias/terapia , Abscesso/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Temperatura Alta , Raios Infravermelhos , Injeções Subcutâneas , Ácido Láctico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Microesferas , Nanopartículas , Fotoquímica , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Pirróis , Dermatopatias/tratamento farmacológico , Distribuição Tecidual , Vancomicina/administração & dosagem , Vancomicina/farmacologia , Vancomicina/uso terapêutico , Cicatrização/efeitos dos fármacos
6.
Small ; 10(20): 4100-5, 2014 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-24976002

RESUMO

Treating inflammation with a dual-switch-controlled release system: The release of a drug from the developed microbead system occurs only in response to both an increase in local temperature and an acidic environmental pH. This dual-switch-controlled release system has the advantages of distinguishing between inflamed and healthy tissues to improve treatment efficacy.


Assuntos
Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Microesferas , Microscopia Confocal , Microscopia Eletrônica de Varredura
7.
ACS Nano ; 8(2): 1213-21, 2014 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-24386907

RESUMO

Oxidative stress and reduced pH are involved in many inflammatory diseases. This study describes a nanoparticle-based system that is responsive to both oxidative stress and reduced pH in an inflammatory environment to effectively release its encapsulated curcumin, an immune-modulatory agent with potent anti-inflammatory and antioxidant capabilities. Because of the presence of Förster resonance energy transfer between curcumin and the carrier, this system also allowed us to monitor the intracellular release behavior. The curcumin released upon triggering could efficiently reduce the excess oxidants produced by the lipopolysaccharide (LPS)-stimulated macrophages. The feasibility of using the curcumin-loaded nanoparticles for anti-inflammatory applications was further validated in a mouse model with ankle inflammation induced by LPS. The results of these studies demonstrate that the proposed nanoparticle system is promising for treating oxidative stress-related diseases.


Assuntos
Anti-Inflamatórios/administração & dosagem , Portadores de Fármacos , Concentração de Íons de Hidrogênio , Nanopartículas , Estresse Oxidativo
8.
Biomaterials ; 34(1): 1-10, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23044041

RESUMO

Chemotherapy research highly prioritizes overcoming the multi-drug resistance (MDR) effect in cancer cells. To overcome the drug efflux mediated by P-glycoprotein (P-gp) transporters, we developed pH-responsive poly(D,L-lactic-co-glycolic acid) hollow particles (PLGA HPs), capable of delivering doxorubicin (DOX) into MDR cells (MCF-7/ADR). The shell wall of PLGA HPs contained DiO (a hydrophobic dye), and their aqueous core carried DOX hydrochloride salt and sodium bicarbonate, a gas-generating agent when present in acidic environments. Both DiO and DOX could serve as fluorescence probes to localize HPs and visualize their intracellular drug release in real-time. Real-time confocal images provided visible evidences of the acid-responsive intracellular release of DOX from PLGA HPs in MDR cells. Via the macropinocytosis pathway, PLGA HPs taken up by cells experienced an increasingly acidic environment as they trafficked through the early endosomes and then matured into more acidic late endosomes/lysosomes. The progressive acidification of the internalized particles in the late endosomes/lysosomes generated CO(2) bubbles, leading to the disruption of HPs, prompt release of DOX, its accumulation in the nuclei, and finally the death of MDR cells. Conversely, taken up via a passive diffusion mechanism, free DOX was found mainly at the perimembrane region and barely reached the cell nuclei; therefore, no apparent cytotoxicity was observed. These results suggest that the developed PLGA HPs were less susceptible to the P-gp-mediated drug efflux in MDR cells and is a highly promising approach in chemotherapy.


Assuntos
Sistemas Computacionais , Resistência a Múltiplos Medicamentos , Gases/química , Ácido Láctico/química , Nanopartículas/química , Organelas/metabolismo , Ácido Poliglicólico/química , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Citometria de Fluxo , Humanos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Processamento de Imagem Assistida por Computador , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Células MCF-7 , Microscopia Confocal , Nanopartículas/ultraestrutura , Organelas/efeitos dos fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Difração de Raios X
9.
Small ; 8(23): 3584-8, 2012 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-22893436

RESUMO

Pulsatile release: When a high-frequency magnetic field is applied, heat will be generated by coupling to the iron oxide nanoparticles encapsulated in the shells of PLGA hollow microspheres. As the temperature approaches the T(g) of PLGA, the polymer chains become more mobile, subsequently increasing the free volume of PLGA matrix and significantly enhancing the diffusion of drug molecules.


Assuntos
Antineoplásicos/química , Doxorrubicina/química , Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Química Farmacêutica , Portadores de Fármacos , Compostos Férricos/química , Campos Magnéticos , Nanopartículas , Tamanho da Partícula , Permeabilidade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Fluxo Pulsátil , Temperatura
10.
Biomaterials ; 33(20): 5156-65, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22484044

RESUMO

This work presents an approach to codelivering transdermally two model drugs, Alexa 488 and Cy5, in sequence, based on a system of polyvinylpyrrolidone microneedles (PVP MNs) that contain pH-responsive poly(d,l-lactic-co-glycolic acid) hollow microspheres (PLGA HMs). The MN system provides the green fluorescence of Alexa 488 in PVP MNs, the red fluorescence of the DiI-labeled PLGA shell of HMs, and the cyan fluorescence of Cy5 in their aqueous core. Combined together, the prepared MN arrays support the localization of the HMs and the monitoring of the release profiles of model drugs within the skin tissues. The key component of this system is NaHCO(3), which can be easily incorporated into HMs. After HMs are treated with an acidic solution (simulating the skin pH environment), protons (H(+)) can rapidly diffuse through the free volume in the PLGA shells to react with NaHCO(3) and form a large number of CO(2) bubbles. This effect generates pressure inside the HMs and creates pores inside their PLGA shells, releasing the encapsulated Cy5. Test MNs were strong enough to be inserted into rat skin without breaking. The PVP MNs were significantly dissolved within minutes, and the first model drug Alexa 488, together with HMs, were successfully deposited into the tissues. Once in the acidic environment of the skin, the released HMs started to release Cy5 and continued to spread throughout the neighboring tissues, in a second step of the release of the drug. This approach can be used clinically to codeliver sequentially and transcutaneously a broad range of drugs.


Assuntos
Ácido Láctico/química , Microesferas , Agulhas , Ácido Poliglicólico/química , Animais , Dimetilpolisiloxanos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Bicarbonato de Sódio/química
11.
Angew Chem Int Ed Engl ; 50(35): 8086-9, 2011 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-21751316

RESUMO

Prepared to self-destruct: when poly(D, L-lactic-co-glycolic acid) (PLGA) hollow microspheres containing NaHCO(3) entered the endocytic organelles of a live cell, the NaHCO(3) in the aqueous core reacted with protons that infiltrated from the compartment to generate CO(2) gas. The evolution of CO(2) bubbles led to the formation of small holes in the PLGA shell and thus rapid release of the encapsulated drug doxorubicin.


Assuntos
Lisossomos/química , Microesferas , Preparações Farmacêuticas/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/toxicidade , Portadores de Fármacos/química , Humanos , Concentração de Íons de Hidrogênio , Ácido Láctico/química , Lisossomos/metabolismo , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Bicarbonato de Sódio/química
12.
Mol Pharm ; 7(4): 1244-53, 2010 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-20469890

RESUMO

Photodynamic therapy (PDT) is a light-induced chemical reaction that produces localized tissue damage for the treatment of cancers and other nonmalignant conditions. The activation of photosensitizers in a target tissue is accomplished with a specific light source in the presence of molecular oxygen. In the clinic, patients treated with PDT should be kept away from direct sunlight or strong indoor lighting to avoid skin phototoxicity. In this study, a photosensitizer encapsulated within a micelle was developed to overcome this problem. The pH-sensitive micelles were successfully incorporated with meta-tetra(hydroxyphenyl)chlorin (m-THPC), and the cytotoxicity and antitumor effects were investigated in vitro and in vivo. Our results demonstrated that PDT with m-THPC-loaded micelles had no significant adverse effects on the body weight of mice in vivo. Furthermore, after an extended delivery time, m-THPC-loaded micelles and free m-THPC had similar antitumor effects, but the m-THPC-loaded micelles had less skin phototoxicity. Thus, this strategy could be used as a potential nanocarrier for PDT-mediated cancer therapy.


Assuntos
Mesoporfirinas/uso terapêutico , Micelas , Oxazóis/química , Poliésteres/química , Polímeros/química , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Animais , Linhagem Celular Tumoral , Feminino , Células HT29 , Humanos , Mesoporfirinas/química , Camundongos , Camundongos Endogâmicos BALB C , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico , Poliaminas
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