Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Eur J Med Res ; 28(1): 457, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37876003

RESUMO

BACKGROUND: Migraine is one of four major chronic diseases that cause disability. Decreases in regional cerebral blood flow (rCBF) occur during migraine attacks. Laser therapy is extensively employed in treating other vascular diseases; nevertheless, its effectiveness in migraine management remains largely unknown. Therefore, we evaluated the effect of low-level intravascular laser irradiation of blood (ILIB) therapy in patients with migraine. METHODS: We performed an observational case-control study in 24 patients suffering from migraine. Patients were divided into an ILIB treatment group and a traditional rehabilitation group. This study performed clinical assessments and single-photon emission computed tomography (SPECT) prior to and after the treatment and 1 month later. Changes in rCBF-SPECT between groups and between timepoints were compared to clinical outcomes. RESULTS: Nine patients undergoing rehabilitation and fifteen patients undergoing ILIB were studied from baseline to 1 month follow-up. The ILIB group, visual analog scale for pain (P = 0.001), Montreal Cognitive Assessment (P = 0.003), and Athens Insomnia Scale (P < 0.001) symptom scores significantly improved after treatment. SPECT imaging showed a 1.27 ± 0.27 fold increase in rCBF after ILIB treatment, and no significant differences in the rehabilitation group. CONCLUSIONS: Low-level ILIB therapy is associated with better clinical and vascular outcomes, and may be a feasible treatment option for migraine. Although our sample size was small, our data provide a starting point for migraine laser therapy research.


Assuntos
Terapia a Laser , Terapia com Luz de Baixa Intensidade , Transtornos de Enxaqueca , Humanos , Estudos de Casos e Controles , Transtornos de Enxaqueca/radioterapia , Doença Crônica , Terapia com Luz de Baixa Intensidade/métodos , Tomografia Computadorizada de Emissão de Fóton Único , Circulação Cerebrovascular
2.
PLoS One ; 17(7): e0270823, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35830440

RESUMO

PURPOSE: Atrial fibrillation (AF) is a significant independent risk factor for 1-year mortality in patients with first acute ischemic stroke (AIS). The CHA2DS2-VASc score was initially developed to assess the risk of stroke in patients with AF. Recently, this scoring system has been demonstrated to have clinical value for predicting long-term clinical outcomes in AIS but the evidence is insufficient. This large-scale prospective cohort study investigated the independent predictive value of the score in such patients. METHODS: We included patients with AIS from the Taiwan Stroke Registry (TSR) during 2006-2016 as the present study population. Patients were divided into those with high (≥2) and low (<2) CHA2DS2-VASc scores. We further analyzed and classified patients according to the presence of AF. The clinical endpoint was major adverse cardiac and cerebrovascular events (MACCEs) at 1 year after the index AIS. RESULTS: A total of 62,227 patients with AIS were enrolled. The median age was 70.3 years, and 59% of the patients were women. After confounding factors were controlled, patients with high CHA2DS2-VASc scores had significantly higher incidence of 1-year MACCEs (adjusted hazard ratio [HR] = 1.63; 95% confidence interval [CI] = 1.52, 1.76), re-stroke (adjusted HR = 1.28; 95% CI = 1.16, 1.42), and all-cause mortality (adjusted HR = 2.03; 95% CI = 1.83, 2.24) than those with low CHA2DS2-VASc scores did. In the comparison between AF and non-AF groups, the AF group had increased MACCEs (adjusted HR = 1.74; 95% CI = 1.60, 1.89), myocardial infarction (adjusted HR = 4.86; 95% CI = 2.07, 11.4), re-stroke (adjusted HR = 1.47; 95% CI = 1.26, 1.71), and all-cause mortality (adjusted HR = 1.90; 95% CI = 1.72, 2.10). The Kaplan-Meier curve revealed that both CHA2DS2-VASc scores and AF were independent risk predictors for 1-year MACCEs and mortality. CONCLUSIONS: The CHA2DS2-VASc score and AF appeared to consistently predict 1-year MACCEs of AIS patients and provide more accurate risk stratification. Therefore, increased use of the CHA2DS2-VASc score may help improve the holistic clinical assessment of AIS patients with or without AF.


Assuntos
Fibrilação Atrial , AVC Isquêmico , Acidente Vascular Cerebral , Idoso , Fibrilação Atrial/epidemiologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia
3.
J Control Release ; 345: 417-432, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35331784

RESUMO

In this study, a plasmon-semiconductor nanotheranostic system comprising Au nanostars/graphene quantum dots (AuS/QD) hybrid nanoparticles loaded with BNN6 and surface modified with PEG-pyrene was developed for the photo-triggered hyperthermia effect and NO production as the dual modality treatment against orthotopic triple-negative breast cancer. The structure and morphology of the hybrid nanodevice was characterized and the NIR-II induced thermal response and NO production was determined. The hybrid nanodevice has shown enhanced plasmonic energy transfer from localized surface plasmonic resonance of Au nanostars to QD semiconductor that activates the BNN6 species loaded on QD surfaces, leading to the effective NO production and the gas therapy in addition to the photothermal response. The increased accumulation of the NIR-II-responsive hybrid nanotheranostic in tumor via the enhanced permeation and retention effects was confirmed by both in vivo fluorescence and photoacoustic imaging. The prominent therapeutic efficacy of the photothermal/NO combination therapy from the BNN6-loaded AuS@QD nanodevice with the NIR-II laser irradiation at 1064 nm against 4T1 breast cancer was observed both in vitro and in vivo. The NO therapy for the cancer treatment was evidenced with the increased cellular nitrosative and oxidative stress, nitration of tyrosine residues of mitochondrial proteins, vessel eradication and cell apoptosis. The efficacy of the photothermal treatment was corroborated directly by severe tissue thermal ablation and tumor growth inhibition. The NIR-II triggered thermal/NO combination therapy along with the photoacoustic imaging-guided therapeutic accumulation in tumor shows prominent effect to fully inhibit tumor growth and validates the promising strategy developed in this study.


Assuntos
Hipertermia Induzida , Nanopartículas , Neoplasias , Linhagem Celular Tumoral , Terapia Combinada , Humanos , Hipertermia Induzida/métodos , Nanopartículas/química , Neoplasias/terapia , Fototerapia/métodos
4.
Artigo em Inglês | MEDLINE | ID: mdl-34457016

RESUMO

INTRODUCTION: Patients with type 2 diabetes are widely prescribed metformin for controlling blood glucose levels to avoid related comorbidities. In Taiwan, traditional Chinese medicine (TCM) is also commonly used, especially Liu Wei Di Huang Wan (LWDHW), which has been reported to delay the occurrence of kidney failure. However, the effect of combinational therapy of TCM and oral antidiabetic drugs is still unclear. This study aims to estimate their efficacy in delaying insulin use. MATERIALS AND METHODS: This case-control study was conducted using one million randomized samples from the National Health Insurance Research Database in Taiwan. The effects of TCM and LWDHW were estimated using the Cox proportional hazards model. RESULTS: In this study, 70,036 diabetic patients were enrolled; of them, 17,451 (24.9%) used insulin, while the rest (52,585, 75.1%) did not. TCM users had a lower risk for insulin use (HR: 0.58, 95% CI: 0.56-0.60). LWDHW users had a lower risk compared with patients who used other TCM (HR: 0.86, 95% CI: 0.82-0.90) and presented a dose-dependent effect. CONCLUSION: The use of LWDHW and oral antidiabetic drugs is highly associated with the delay in the use of insulin. Clinical practitioners may take them into consideration when treating patients with type 2 diabetes.

5.
Biomaterials ; 257: 120229, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32738654

RESUMO

Radiotherapy (RT) is one of the most commonly employed approaches in the treatment of malignant tumors and is often combined with radiosensitizers to enhance the therapeutic efficacy for clinical use. For developing a smart therapeutic strategy leveraging local tissue response to photo-mediated reactions and the combination of multiple treatment modalities involving ROS-induced sensitization of RT, a novel nanophototherapeutic system has been developed. The nanotherapeutics prepared from the assembly of poly (thiodiethylene malonate) (PSDEM) and PEG-PSDEM-PEG and loaded with suberoylanilide hydroxamic acid (SAHA) employed as the RT sensitizer and indocyanine green (ICG) as the photothermal/photodynamic agent, demonstrated the capability of undergoing structural change and releasing therapeutic payloads in response to near-infrared irradiation and X-ray radiotherapy. With highly localized and controllable reactions within the tumor site, the reactive oxygen species (ROS)-triggered SAHA unloading and the hyperthermia-induced vascular permeability of oxygen led to a significant sensitization of the target tissue in RT, which, in turn, led to the promotion of therapeutic effect in conjunction with photodynamic/photothermal therapies (PDT/PTT). In vitro studies demonstrated the damage in intracellular DNA double strands and the inhibition of cell proliferation in 4T1 breast cancer cells treated with ROS-induced sensitized RT. A substantial reduction in cell viability was also observed owing to the effects of the combination of photo-mediated treatments with sensitized RT compared to the effects of RT administration alone. Complete eradication of the primary tumor and the inhibition of lung metastasis was observed in five of six orthotopic 4T1 breast cancer-bearing mice subjected to combined PDT/PTT in nanophototherapeutics with ROS-induced sensitized RT at a low dosage (6 Gy), leading to the prominent survival fraction of ca. 83% over 60 days.


Assuntos
Neoplasias da Mama , Hipertermia Induzida , Fotoquimioterapia , Animais , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Verde de Indocianina , Camundongos , Fototerapia , Espécies Reativas de Oxigênio
6.
Biomaterials ; 197: 86-100, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30641267

RESUMO

Although oral formulations of anticancer chemotherapies are clinically available, the therapeutic action relies mostly on drug absorption, being inevitably accompanied with systemic side effects. It is thus desirable to develop oral therapy systems for the local treatment of colon cancers featured with highly selective delivery to cancer cells and minimized systemic drug absorption. The present study demonstrates the effective accumulation and cell uptake of the doxorubicin and superparamagnetic iron oxide nanoparticles-loaded solid lipid nanoparticle (SLN) delivery system for chemo/magnetothermal combination therapy at tumors by hierarchical targeting of folate (FA) and dextran coated on SLN surfaces in a sequential layer-by-layer manner. Both the in vitro and in vivo characterizations strongly confirmed that the dextran shells on SLN surfaces not only retarded the cellular transport of the FA-coated SLNs by the proton-coupled FA transporter on brush border membranes in small intestine, but also enhanced the particle residence in colon by specific association with dextranase. The enzymatic degradation and removal of dextran coating led to the exposure of the FA residues, thereby further facilitating the cellular-level targeting and uptake of the SLNs by the receptor-mediated endocytosis. The evaluation of the in vivo antitumor efficacy of the hierarchically targetable SLN therapy system by oral administration showed the effective inhibition of primary colon tumors and peritoneal metastasis in terms of the ascites volume and tumor nodule number and size, along with the absence of systemic side effects.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Neoplasias do Colo/terapia , Doxorrubicina/uso terapêutico , Nanopartículas/uso terapêutico , Polissacarídeos/uso terapêutico , Animais , Antibióticos Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Doxorrubicina/administração & dosagem , Portadores de Fármacos/química , Portadores de Fármacos/uso terapêutico , Sistemas de Liberação de Medicamentos , Ácido Fólico/química , Ácido Fólico/uso terapêutico , Hipertermia Induzida/métodos , Lipídeos/química , Lipídeos/uso terapêutico , Camundongos , Nanopartículas/química , Polissacarídeos/química
7.
Theranostics ; 8(5): 1435-1448, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29507632

RESUMO

Therapeutic efficacy of glioblastoma multiforme (GBM) is often severely limited by poor penetration of therapeutics through blood-brain barrier (BBB) into brain tissues and lack of tumor targeting. In this regard, a functionalized upconversion nanoparticle (UCNP)-based delivery system which can target brain tumor and convert deep tissue-penetrating near-infrared (NIR) light into visible light for precise phototherapies on brain tumor was developed in this work. Methods: The UCNP-based phototherapy delivery system was acquired by assembly of oleic acid-coated UCNPs with angiopep-2/cholesterol-conjugated poly(ethylene glycol) and the hydrophobic photosensitizers. The hybrid nanoparticles (ANG-IMNPs) were characterized by DLS, TEM, UV/vis and fluorescence spectrophotometer. Cellular uptake was examined by laser scanning confocal microscopy and flow cytometry. The PDT/PTT effect of ANG-IMNPs was evaluated using MTT assay. Tumor accumulation of NPs was determined by a non-invasive in vivo imaging system (IVIS). The in vivo anti-glioma effect of ANG-IMNPs was evaluated by immunohistochemical (IHC) examination of tumor tissues and Kaplan-Meier survival analysis. Results: In vitro data demonstrated enhanced uptake of ANG-IMNPs by murine astrocytoma cells (ALTS1C1) and pronounced cytotoxicity by combined NIR-triggered PDT and PTT. In consistence with the increased penetration of ANG-IMNPs through endothelial monolayer in vitro, the NPs have also shown significantly enhanced accumulation at brain tumor by IVIS. The IHC tissue examination confirmed prominent apoptotic and necrotic effects on tumor cells in mice receiving targeted dual photo-based therapies, which also led to enhanced median survival (24 days) as compared to the NP treatment without angiopep-2 (14 days). Conclusion: In vitro and in vivo data strongly indicate that the ANG-IMNPs were capable of selectively delivering dual photosensitizers to brain astrocytoma tumors for effective PDT/PTT in conjugation with a substantially improved median survival. The therapeutic efficacy of ANG-IMNPs demonstrated in this study suggests their potential in overcoming BBB and establishing an effective treatment against GBM.


Assuntos
Neoplasias Encefálicas/terapia , Sistemas de Liberação de Medicamentos , Glioblastoma/terapia , Hipertermia Induzida , Nanopartículas/uso terapêutico , Fotoquimioterapia , Fototerapia , Animais , Barreira Hematoencefálica/patologia , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Difusão Dinâmica da Luz , Glioblastoma/patologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Nanopartículas/química , Nanopartículas/ultraestrutura , Oligopeptídeos/química , Peptídeos Cíclicos , Somatostatina/análogos & derivados , Somatostatina/química , Temperatura , Distribuição Tecidual
8.
Epileptic Disord ; 19(1): 76-81, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28287069

RESUMO

We present a case study of a patient with chromosome 22q11.2 deletion syndrome presenting with ictus emeticus, together with a review of the relevant literature. The patient developed generalized tonic-clonic seizures at 3 months old, and seizures eventually remitted after calcium therapy. He then experienced vigorous vomiting that occurred during sleep, with glassy eyes and legs flexion. Video-EEG recordings exhibited a switch in background activity from organized reactivity during normal sleep to left lateralized temporal delta activity, which was bilaterally synchronized during an emetic attack. The ictal vomiting ceased following management with oxcarbazepine, high-dose phenobarbital, and a ketogenic diet. The unique seizure type and rare ictal EEG findings are the first reported in a child with chromosome 22q11.2 deletion syndrome. This case highlights that ictus emeticus without detectable epileptic discharge on EEG is one potential epileptic presentation in this genetic syndrome. [Published with video sequence on www.epilepticdisorders.com].


Assuntos
Síndrome de DiGeorge/complicações , Convulsões/etiologia , Convulsões/fisiopatologia , Vômito/etiologia , Pré-Escolar , Eletroencefalografia , Humanos , Masculino
9.
Childs Nerv Syst ; 32(10): 1895-906, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27659831

RESUMO

BACKGROUND: Tumors with epicenter in the thalamus occur in about 4 % of pediatric brain tumors. The histological diagnosis is mainly gliomas. Among them, low-grade glioma (LGG) constituted of a significant entity of the tumors (Cuccia et al., Childs Nerv Syst 13:514-521, 1997; Puget et al., J Neurosurg 106:354-362, 2007; Bernstein et al., J Neurosurg 61:649-656, 1984; Bilginer et al., Childs Nerv Syst 30:1493-1498, 2014). Since Kelly's report in 1989, >90 % resection of thalamic tumors were achieved in reported series (Ozek and Ture, Childs Nerv Syst 18:450-6, 2002; Villarejo et al., Childs Nerv Syst 10:111-114, 1994; Moshel et al., Neurosurgery 61:66-75, 2007; Albright, J Neurosurg 100(5 Suppl Pediatrics): 468-472, 2004; Kelly, Neurosurgery 25:185-195, 1989; Drake et al., Neurosurgery 29: 27-33, 1991). MATERIALS AND METHODS: Sixty-nine cases of thalamic tumors in children were retrospectively reviewed. There were 25 cases of LGGs. We analyzed our experience and correlated it with reported series. RESULTS: Summing up of 4 reported series and the present series, there were 267 cases of thalamic tumors in children. Among these tumors, 107 (40.1 %) were LGGs and 91 (34.1 %) were low-grade astrocytomas (LGAs). In the present series, all of the 25 LGGs were LGAs that consisted of 11 pilocytic astrocytomas (PAs) and 14 diffuse astrocytomas (DAs). Six cases received biopsy sampling only. The remaining 19 cases received different degrees of surgical resection via several approaches. Radical (>90 %) resection was achieved better in PAs comparing with DAs. There was no operative mortality. Two patients had increased neurological deficits. In a mean follow-up period of 11.9 years, three patients died of tumor progression and one patient died of anaplastic change. The 5- and 10-year overall survival (OS) was 87.1 and 87.1 %, respectively. CONCLUSION: Thalamic LGGs are mainly LGAs and are indolent. The rate of >90 % resection was relatively low in the present series. By applying contemporary diagnostic MRI studies, surgical facilities, and appropriate approaches in selective cases, we may try maximum neuroprotective radical (>90 %) resection.


Assuntos
Neoplasias Encefálicas/cirurgia , Lateralidade Funcional/fisiologia , Glioma/cirurgia , Procedimentos Neurocirúrgicos/métodos , Tálamo/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Lactente , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Tálamo/diagnóstico por imagem
10.
Theranostics ; 6(3): 302-17, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26909107

RESUMO

To significantly promote tumor uptake and penetration of therapeutics, a nanovehicle system comprising poly(lactic-co-glycolic acid) (PLGA) as the hydrophobic cores coated with pH-responsive N-acetyl histidine modified D-α-tocopheryl polyethylene glycol succinate (NAcHis-TPGS) is developed in this work. The nanocarriers with switchable surface charges in response to tumor extracellular acidity (pHe) were capable of selectively co-delivering indocyanine green (ICG), a photothermal agent, and doxorubicin (DOX), a chemotherapy drug, to tumor sites. The in vitro cellular uptake of ICG/DOX-loaded nanoparticles by cancer cells and macrophages was significantly promoted in weak acidic environments due to the increased protonation of the NAcHis moieties. The results of in vivo and ex vivo biodistribution studies demonstrated that upon intravenous injection the theranostic nanoparticles were substantially accumulated in TRAMP-C1 solid tumor of tumor-bearing mice. Immunohistochemical examination of tumor sections confirmed the active permeation of the nanoparticles into deep tumor hypoxia due to their small size, pHe-induced near neutral surface, and the additional hitchhiking transport via tumor-associated macrophages. The prominent imaging-guided photothermal therapy of ICG/DOX-loaded nanoparticles after tumor accumulation induced extensive tumor tissue/vessel ablation, which further promoted their extravasation and DOX tumor permeation, thus effectively suppressing tumor growth.


Assuntos
Antineoplásicos/farmacocinética , Terapia Combinada/métodos , Portadores de Fármacos , Fármacos Fotossensibilizantes/farmacocinética , Polietilenoglicóis/administração & dosagem , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/terapia , Succinatos/administração & dosagem , Administração Intravenosa , Animais , Modelos Animais de Doenças , Doxorrubicina/farmacocinética , Tratamento Farmacológico/métodos , Hipertermia Induzida/métodos , Verde de Indocianina/farmacocinética , Masculino , Camundongos Endogâmicos C57BL , Nanopartículas/administração & dosagem , Fototerapia/métodos , Nanomedicina Teranóstica/métodos , Distribuição Tecidual
11.
Int J Nanomedicine ; 10: 5035-48, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26346762

RESUMO

In this study, a novel pH-responsive cholesterol-PEG adduct-coated solid lipid nanoparticles (C-PEG-SLNs) carrying doxorubicin (DOX) capable of overcoming multidrug resistance (MDR) breast cancer cells is presented. The DOX-loaded SLNs have a mean hydrodynamic diameter of ~100 nm and a low polydispersity index (under 0.20) with a high drug-loading efficiency ranging from 80.8% to 90.6%. The in vitro drug release profiles show that the DOX-loaded SLNs exhibit a pH-controlled drug release behavior with the maximum and minimum unloading percentages of 63.4% at pH 4.7 and 25.2% at pH 7.4, respectively. The DOX-loaded C-PEG-SLNs displayed a superior ability in inhibiting the proliferation of MCF-7/MDR cells. At a DOX concentration of 80 µM, the cell viabilities treated with C-PEG-SLNs were approximately one-third of the group treated with free DOX. The inhibition activity of C-PEG-SLNs could be attributed to the transport of C-PEG to cell membrane, leading to the change of the composition of the cell membrane and thus the inhibition of permeability glycoprotein activity. This hypothesis is supported by the confocal images showing the accumulation of DOX in the nuclei of cancer cells and the localization of C-PEG on the cell membranes. The results of in vivo study further demonstrated that the DOX delivered by the SLNs accumulates predominantly in tumor via enhanced permeability and retention effect, the enhanced passive tumor accumulation due to the loose intercellular junctions of endothelial cells lining inside blood vessels at tumor site, and the lack of lymphatic drainage. The growth of MCF-7/MDR xenografted tumor on Balb/c nude mice was inhibited to ~400 mm(3) in volume as compared with the free DOX treatment group, 1,140 mm(3), and the group treated with 1,2 distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)] solid lipid nanoparticles, 820 mm(3). Analysis of the body weight of nude mice and the histology of organs and tumor after the administration of DOX-loaded SLNs show that the SLNs have no observable side effects. These results indicate that the C-PEG-SLN is a promising platform for the delivery of therapeutic agents for MDR cancer chemotherapy.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Resistencia a Medicamentos Antineoplásicos , Lipídeos/farmacologia , Nanopartículas/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Animais , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Lipídeos/química , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Polietilenoglicóis/química , Ensaios Antitumorais Modelo de Xenoenxerto
12.
J Control Release ; 220(Pt B): 738-50, 2015 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-26374945

RESUMO

Photodynamic therapy (PDT) is a powerful technique photochemically tailored for activating apoptosis of malignant cells. Although PDT has shown promise in several clinical applications, malignant cells in hypoxic regions are often resistant to PDT due to the transport limitation of therapeutics and the oxygen-dependent nature of PDT. Herein, we present an innovative strategy for overcoming the limits of PDT in tumor hypoxia using bone marrow-derived monocytes as cellular vehicles for co-transport of oxygen and red light activatable photosensitizer, chlorin e6 (Ce6). Superparamagnetic iron oxide nanoparticle/Ce6/oxygen-loaded polymer bubbles were prepared and internalized into tumortropic monocytes. These functional bubbles were found harmless to cellular hosts without external triggers. Nevertheless, the therapeutic monocytes exhibited a superior performance in inhibiting tumor growth on Tramp-C1 tumor-bearing mice (C57BL/6J) upon the treatments of tumors with high frequency magnetic field and red light laser (660 nm). Histological examinations of the tumor sections confirmed the successful cellular transport of therapeutic payloads to tumor hypoxia and the pronounced antitumor effect elicited by combined hyperthermia/photodynamic therapy along with the additional oxygen supply. This work demonstrates that this oxygen/therapeutic co-delivery via tumortropic monocytes toward tumor hypoxia is promising for improving PDT efficacy.


Assuntos
Técnicas de Ablação , Transplante de Medula Óssea/métodos , Hipertermia Induzida , Microbolhas , Monócitos/transplante , Oxigênio/metabolismo , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Porfirinas/administração & dosagem , Neoplasias da Próstata/terapia , Microambiente Tumoral , Animais , Apoptose , Hipóxia Celular , Linhagem Celular Tumoral , Clorofilídeos , Lasers , Nanopartículas de Magnetita/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/metabolismo , Fotoquimioterapia/instrumentação , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Células RAW 264.7 , Fatores de Tempo , Carga Tumoral
13.
J Biomater Sci Polym Ed ; 24(4): 470-84, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23565688

RESUMO

Scaffolds made of chitosan nanofibers are often too mechanically weak for their application and often their manufacturing processes involve the use of harmful and flammable organic solvents. In the attempt to improve the mechanical properties of nanofibrous scaffolds made of chitosan without the use of harmful chemicals, pectin, an anionic polymer was blended with chitosan, a cationic polymer, to form a polyelectrolyte complex and electrospun into nanofibers for the first time. The electrospun chitosan-pectin scaffolds, when compared to electrospun chitosan scaffolds, had a 58% larger diameter, a 21% higher Young's modulus, a 162% larger strain at break, and a 104% higher ultimate tensile strength. Compared to the chitosan scaffolds, the chitosan-pectin scaffolds' swelling ratios decreased by 55% after 60 min in a saline solution and more quickly released the preloaded tetracycline HCl. The L929 fibroblast cells proliferated slightly slower on the chitosan-pectin scaffolds than on the chitosan scaffolds. Nonetheless, cells on both materials deposited similar levels of extracellular type I collagen on a per DNA basis. In conclusion, a novel chitosan-pectin nanofibrous scaffold with superior mechanical properties than a chitosan nanofibrous scaffold was successfully made without the use of harmful solvents.


Assuntos
Quitosana/química , Fibroblastos/citologia , Nanofibras/química , Pectinas/química , Pele Artificial , Alicerces Teciduais/química , Animais , Antibacterianos/administração & dosagem , Linhagem Celular , Proliferação de Células , Colágeno Tipo I/metabolismo , Portadores de Fármacos/química , Técnicas Eletroquímicas , Fibroblastos/metabolismo , Camundongos , Nanofibras/ultraestrutura , Resistência à Tração , Tetraciclina/administração & dosagem , Engenharia Tecidual
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA