Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 19(5): e0303641, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753745

RESUMO

OBJECTIVE: The objective of this review is to conduct a comprehensive and systematic assessment of the efficacy of Yoga as an intervention for knee osteoarthritis (KOA). METHODS: We searched PubMed, Cochrane Library, Embase, Web of Science, and PEDro as of January 3, 2024. Retrieved a total of 200 articles. Standardised mean differences (SMDs) and 95% confidence intervals (CI) were calculated. RESULTS: The study included a total of 8 trials and involved 756 KOA patients. The results indicated that compared to the control group, Yoga exercise showed significant improvements in alleviating pain (SMD = -0.92; 95% CI = -1.64 ~ - 0.20; P = 0.01, I2 = 94%), stiffness (SMD = -0.51; 95% CI = -0.91 ~ -0.12; P = 0.01; I2 = 66%) and physical function (SMD = -0.53; 95% CI = -0.89 ~ -0.17; P = 0.004; I2 = 59%) among KOA patients. However, there was no significant improvement observed in terms of activities of activity of daily living (ADL) (SMD = 1.03; 95% CI = -0.01 ~ 2.07; P = 0.05; I2 = 84%), and quality of life (QOL) (SMD = 0.21; 95% CI = -0.33 ~ 0.74; P = 0.44; I2 = 83%) with the practice of Yoga. CONCLUSIONS: In general, Yoga has been found to be effective in reducing pain and stiffness in KOA patients, it can also improve the physical function of patients. However, there is limited evidence to suggest significant improvements in terms of ADL and QOL.


Assuntos
Osteoartrite do Joelho , Ensaios Clínicos Controlados Aleatórios como Assunto , Yoga , Humanos , Osteoartrite do Joelho/terapia , Osteoartrite do Joelho/fisiopatologia , Qualidade de Vida , Atividades Cotidianas , Resultado do Tratamento
2.
J Health Popul Nutr ; 42(1): 105, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37784192

RESUMO

BACKGROUND: A virus infection may lead the body to produce more immune cells of particular types or stimulate the production of new ones, both of which may have anti-leukemic effects. There has been no research on whether immune cells stimulated by varicella-zoster virus (VZV) infection have anti-leukemic effects. The objective of this investigation is to assess the impact of VZV infection on patients' long-term survival following allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: This retrospective study investigated the association between varicella-zoster virus (VZV) reactivation and outcomes in 219 individuals who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the Sun Yat-sen University's First Affiliated Hospital. According to being diagnosed with VZV infection or not, these patients were grouped into two groups. The comparison of cumulative incidence of relapse, non-recurrent mortality, and overall survival (OS) was conducted between the two groups. RESULTS: Analyzing multivariate data, VZV reactivation was linked to lower relapse incidence in the group containing all individuals (hazard ratio [HR] = 0.27; 95% confidence interval [CI], 0.12-0.64), patients suffering from acute myeloid leukaemia (HR = 0.10; 95% CI, 0.01-0.83), and patients suffering from acute lymphoblastic leukaemia (HR = 0.25; 95% CI, 0.08-0.77). Moreover, VZV reactivation was linked with decreased non-relapse mortality in all individuals (HR = 0.20; 95% CI, 0.05-0.79), but no statistical significance was found for any disease subgroup. Further, VZV reactivation was an independent predictor for improved OS in the group containing all individuals (HR = 0.10; 95% CI, 0.03-0.29), patients suffering from acute myeloid leukaemia (HR = 0.09; 95% CI, 0.01-0.66), and patients suffering from acute lymphoblastic leukaemia (HR = 0.16; 95% CI, 0.04-0.68). CONCLUSION: This is the first study to show that VZV reactivation following allo-HSCT is an independent predictor for lower relapse rates and improved OS, providing novel therapeutic approaches to improve patients' long-term survival following allo-HSCT.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Herpes Zoster , Leucemia Mieloide Aguda , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Herpesvirus Humano 3/fisiologia , Herpes Zoster/diagnóstico , Herpes Zoster/tratamento farmacológico , Estudos Retrospectivos , Transplante Homólogo/efeitos adversos , Recidiva Local de Neoplasia/complicações , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/complicações , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações
3.
Regen Ther ; 24: 507-514, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37841661

RESUMO

The facial nerve, also known as the seventh cranial nerve, is critical in controlling the movement of the facial muscles. It is responsible for all facial expressions, such as smiling, frowning, and moving the eyebrows. However, damage to this nerve can occur for a variety of reasons, including maxillofacial surgery, trauma, tumors, and infections. Facial nerve injuries can cause severe functional impairment and can lead to different degrees of facial paralysis, significantly affecting the quality of life of patients. Over the past ten years, significant progress has been made in the field of facial nerve repair. Different approaches, including direct suture, autologous nerve grafts, and tissue engineering, have been utilized for the repair of facial nerve injury. This article mainly summarizes the clinical methods and basic research progress of facial nerve repair in the past ten years.

4.
Med Phys ; 50(3): 1614-1622, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36308503

RESUMO

BACKGROUND: Intravoxel incoherent motion (IVIM) is a type of diffusion-weighted imaging (DWI), and IVIM model parameters (water molecule diffusion rate Dt , pseudo-diffusion coefficient Dp , and tissue perfusion fraction Fp ) have been widely used in the diagnosis and characterization of malignant lesions. PURPOSE: This study proposes a deep-learning model with synthetic-to-real domain adaptation to fit the IVIM model parameters of DWI. METHODS: Ninety-eight consecutive patients diagnosed with hepatocellular carcinoma between January 2017 and September 2020 were included in the study, and routine IVIM-DWI serial examinations were performed using a 3.0 T magnetic resonance imaging system in preoperative MR imaging. The proposed method is mainly composed of two modules: a convolutional neural network-based IVIM model fitting network to map b-value images to the IVIM parameter maps and a domain discriminator to improve the accuracy of the IVIM parameter maps in the real data. The proposed method was compared with previously reported fitting methods, including the nonlinear least squares (NLSs), IVIM-NEToptim , and self-supervised U-network methods. The IVIM parameter-fitting performance was assessed by measuring the DWI reconstruction performance and testing the robustness of each method against noise using noise-corrupted data. RESULTS: The DWI reconstruction performance demonstrates that the proposed method has better reconstruction accuracy for DWI with a low signal-to-noise ratio, which implies that the proposed method improves the fitting accuracy of the IVIM parameters. Noise-corrupt experiments show that the proposed method is more robust against noise-corrupted signals. With the proposed method, no outliers were found in Dt , and outliers were reduced for Fp in the abnormal regions (proposed method: 1.85%; NLS: 5.90%; IVIM-NEToptim : 6.61%; and self-U-net: 25.36%). Moreover, experiments show that the proposed method has a more stable parameter estimation performance than the existing methods in the absence of real data. CONCLUSIONS: IVIM parameters can be estimated using a synthetic-to-real domain-adaptation framework with deep learning, and the proposed method outperforms previously reported methods.


Assuntos
Aprendizado Profundo , Neoplasias Hepáticas , Humanos , Imagem de Difusão por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética , Movimento (Física)
5.
Comput Methods Programs Biomed ; 227: 107201, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36335751

RESUMO

INTRODUCTION: Hepatocellular carcinoma (HCC) is a primary liver cancer with high mortality rate. The degree of HCC malignancy is an important prognostic factor for predicting recurrence and survival after surgical resection or liver transplantation in clinical practice. Currently, deep features obtained from data-driven machine learning algorithms have demonstrated superior performance in characterising lesion features in medical imaging processing. However, previous convolutional neural network (CNN)-based studies on HCC lesion characterisation were based on traditional local deep features. The aim of this study was to propose a denoised local and non-local deep features fusion network (DLNLF-net) for grading HCC. METHODS: Gadolinium-diethylenetriaminepentaacetic-acid-enhanced magnetic resonance imaging data of 117 histopathologically proven HCCs were collected from 112 patients with resected HCC between October 2012 and October 2018. The proposed DLNLF-net primarily consists of three modules: feature denoising, non-local feature extraction, and bilinear kernel fusion. First, local feature maps were extracted from the original tumour images using convolution operations, followed by a feature denoising block to generate denoised local features. Simultaneously, a non-local feature extraction block was employed on the local feature maps to generate non-local features. Finally, the two generated features were fused using a bilinear kernel model to output the classification results. The dataset was divided into a training set (77 HCC images) and an independent test set (40 HCC images). Training and independent testing were repeated five times to reduce measurement errors. Accuracy, sensitivity, specificity, and area under the curve (AUC) values in the five repetitive tests were calculated to evaluate the performance of the proposed method. RESULTS: Denoised local features (AUC 89.19%) and non-local features (AUC 88.28%) showed better performance than local features (AUC 86.21%) and global average pooling features (AUC 87.1%) that were derived from a CNN for malignancy characterisation of HCC. Furthermore, the proposed DLNFL-net yielded superior performance (AUC 94.89%) than a typical 3D CNN (AUC 86.21%), bilinear CNN (AUC 90.46%), recently proposed local and global diffusion method (AUC 93.94%), and convolutional block attention module method (AUC 93.62%) for malignancy characterisation of HCC. CONCLUSION: The non-local operation demonstrated a better capability of yielding global representation, and feature denoising based on the non-local operation achieved performance gains for lesion characterisation. The proposed DLNLF-net, which integrates denoised local and non-local deep features, evidently outperforms conventional CNN-based methods in the malignancy characterisation of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos
6.
Cancer Nanotechnol ; 12(1): 4, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33603920

RESUMO

BACKGROUND: In this study, we report on the synthesis, imaging, and radiosensitizing properties of ultrasmall ß-NaGdF4:Yb50% nanoparticles as a multifunctional theranostic platform. The synthesized nanoparticles act as potent bimodal contrast agents with superior imaging properties compared to existing agents used for magnetic resonance imaging (MRI) and computed tomography (CT). Clonogenic assays demonstrated that these nanoparticles can act as effective radiosensitizers, provided that the nanoparticles are taken up intracellularly. RESULTS: Our ultrasmall ß-NaGdF4:Yb50% nanoparticles demonstrate improvement in T1-weighted contrast over the standard clinical MR imaging agent Gd-DTPA and similar CT signal enhancement capabilities as commercial agent iohexol. A 2 Gy dose of X-ray induced ~ 20% decrease in colony survival when C6 rat glial cells were incubated with non-targeted nanoparticles (NaGdF4:Yb50%), whereas the same X-ray dose resulted in a ~ 60% decrease in colony survival with targeted nanoparticles conjugated to folic acid (NaGdF4:Yb50%-FA). Intravenous administration of nanoparticles resulted in clearance through urine and feces within a short duration, based on the ex vivo analysis of Gd3+ ions via ICP-MS. CONCLUSION: These biocompatible and in vivo clearable ultrasmall NaGdF4:Yb50% are promising candidates for further evaluation in image-guided radiotherapy applications.

7.
Theranostics ; 9(2): 381-390, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30809281

RESUMO

Near infrared (NIR) dyes are useful for in vivo optical imaging. Liposomes have been used extensively for delivery of diverse cargos, including hydrophilic cargos which are passively loaded in the aqueous core. However, most currently available NIR dyes are only slightly soluble in water, making passive entrapment in liposomes challenging for achieving high optical contrast. Methods: We modified a commercially-available NIR dye (IR-820) via one-step Suzuki coupling with dicarboxyphenylboronic acid, generating a disulfonated heptamethine; dicarboxyphenyl cyanine (DCP-Cy). DCP-Cy was loaded in liposomes and used for optical imaging. Results: Owing to increased charge in mildly basic aqueous solution, DCP-Cy had substantially higher water solubility than indocyanine green (by an order of magnitude), resulting in higher NIR absorption. Unexpectedly, DCP-Cy tended to form J-aggregates with pronounced spectral red-shifting to 934 nm (from 789 nm in monomeric form). J-aggregate formation was dependent on salt and DCP-Cy concentration. Dissolved at 20 mg/mL, DCP-Cy J-aggregates could be entrapped in liposomes. Full width at half maximum absorption of the liposome-entrapped dye was just 25 nm. The entrapped DCP-Cy was readily detectable by fluorescence and photoacoustic NIR imaging. Upon intravenous administration to mice, liposomal DCP-Cy circulated substantially longer than the free dye. Accumulation was largely in the spleen, which was visualized with fluorescence and photoacoustic imaging. Conclusions: DCP-Cy is simple to synthesize and exhibits high aqueous solubility and red-shifted absorption from J-aggregate formation. Liposomal dye entrapment is possible, which facilitates in vivo photoacoustic and fluorescence imaging around 930 nm.


Assuntos
Corantes/administração & dosagem , Corantes Fluorescentes/administração & dosagem , Verde de Indocianina/administração & dosagem , Lipossomos/administração & dosagem , Imagem Óptica/métodos , Técnicas Fotoacústicas/métodos , Administração Intravenosa , Animais , Corantes/síntese química , Corantes/química , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Verde de Indocianina/síntese química , Verde de Indocianina/química , Camundongos , Solubilidade
8.
Biomaterials ; 175: 72-81, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29803105

RESUMO

Photoacoustic computed tomography (PACT) is an emerging imaging modality. While many contrast agents have been developed for PACT, these typically cannot immediately be used in humans due to the lengthy regulatory process. We screened two hundred types of ingestible foodstuff samples for photoacoustic contrast with 1064 nm pulse laser excitation, and identified roasted barley as a promising candidate. Twenty brands of roasted barley were further screened to identify the one with the strongest contrast, presumably based on complex chemical modifications incurred during the roasting process. Individual roasted barley particles could be detected through 3.5 cm of chicken-breast tissue and through the whole hand of healthy human volunteers. With PACT, but not ultrasound imaging, a single grain of roasted barley was detected in a field of hundreds of non-roasted particles. Upon oral administration, roasted barley enabled imaging of the gut and peristalsis in mice. Prepared roasted barley tea could be detected through 2.5 cm chicken breast tissue. When barley tea was administered to humans, photoacoustic imaging visualized swallowing dynamics in healthy volunteers. Thus, roasted barley represents an edible foodstuff that should be considered for photoacoustic contrast imaging of swallowing and gut processes, with immediate potential for clinical translation.


Assuntos
Meios de Contraste/química , Hordeum/química , Administração Oral , Animais , Galinhas , Deglutição , Grão Comestível/química , Feminino , Temperatura Alta , Humanos , Raios Infravermelhos , Intestinos/diagnóstico por imagem , Intestinos/fisiologia , Cinética , Lasers , Carne/análise , Camundongos Endogâmicos ICR , Leite , Peristaltismo , Permeabilidade , Técnicas Fotoacústicas/métodos , Tomografia Computadorizada por Raios X/métodos
9.
Adv Funct Mater ; 27(2)2017 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-28824357

RESUMO

Nanoscale materials have been explored extensively as agents for therapeutic and diagnostic (i.e. theranostic) applications. Research efforts have shifted from exploring new materials in vitro to designing materials that function in more relevant animal disease models, thereby increasing potential for clinical translation. Current interests include non-invasive imaging of diseases, biomarkers and targeted delivery of therapeutic drugs. Here, we discuss some general design considerations of advanced theranostic materials and challenges of their use, from both diagnostic and therapeutic perspectives. Common classes of nanoscale biomaterials, including magnetic nanoparticles, quantum dots, upconversion nanoparticles, mesoporous silica nanoparticles, carbon-based nanoparticles and organic dye-based nanoparticles, have demonstrated potential for both diagnosis and therapy. Variations such as size control and surface modifications can modulate biocompatibility and interactions with target tissues. The needs for improved disease detection and enhanced chemotherapeutic treatments, together with realistic considerations for clinically translatable nanomaterials will be key driving factors for theranostic agent research in the near future.

10.
Biomacromolecules ; 18(2): 562-567, 2017 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-28146351

RESUMO

Tetracarboxy porphyrins can be polymerized with polyethylene glycol (PEG) diamines to generate hydrogels with intense, near-infrared, and transdermal fluorescence following subcutaneous implantation. Here, we show that the high density porphyrins of the preformed polymer can be chelated with tin via simple incubation. Tin porphyrin hydrogels exhibited increasing emission intensities, ratios, and lifetimes from pH 1 to 10. Tin porphyrin hydrogel emission was strongly reversible and pH responsiveness was observed in the physiological range between pH 6 and pH 8. pH-sensitive emission was detected via noninvasive transdermal fluorescence imaging in vivo following subcutaneous implantation in mice.


Assuntos
Fluorescência , Hidrogéis/química , Polietilenoglicóis/química , Polímeros/química , Porfirinas/química , Estanho/química , Animais , Concentração de Íons de Hidrogênio , Camundongos , Polímeros/administração & dosagem , Próteses e Implantes , Espectrometria de Fluorescência
11.
Bioconjug Chem ; 27(7): 1574-8, 2016 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-27259401

RESUMO

Attachment of polyethylene glycol (PEG) can prolong blood circulation of biological molecules, a useful trait for a vascular imaging agent. Here, we present a route for modifying octabutoxy naphthalocyanine (ONc) with PEG, via axial conjugation following ONc chelation with Sn(IV) chloride (Sn-ONc). Tin chelation caused ONc absorbance to shift from 860 to 930 nm. Hydroxy terminated PEG was treated with sodium and then was axially attached to the tin, generating PEG-Sn-ONc. Unlike ONc or Sn-ONc, PEG-Sn-ONc was soluble in methanol. ONc and PEG-Sn-ONc were dissolved in polysorbate solutions and administered to mice intravenously. PEG-Sn-ONc demonstrated substantially longer blood circulation time than ONc, with a 4 times longer half-life and a nearly 10 times greater area under the curve. PEG-Sn-ONc gave rise to photoacoustic contrast and could be used for noninvasive brain vessel imaging even 24 h following injection. This work demonstrates that nonmetallic naphthalocyanines can be chelated with tin, and be axially modified with PEG for enhanced circulation times for long-term vascular imaging with photoacoustic tomography.


Assuntos
Circulação Cerebrovascular , Compostos Organometálicos/química , Técnicas Fotoacústicas/métodos , Polietilenoglicóis/química , Estanho/química , Tomografia/métodos , Animais , Encéfalo/irrigação sanguínea , Camundongos , Naftalenos/química
12.
Biomaterials ; 76: 25-32, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26517562

RESUMO

Tetracarboxylic porphyrins and polyethylene glycol (PEG) diamines were crosslinked in conditions that gave rise to a water-soluble porphyrin polyamide. Using PEG linkers 2 kDa or larger prevented fluorescence self-quenching. This networked porphyrin mesh was retained during dialysis with membranes with a 100 kDa pore size, yet passed through the membrane when centrifugal filtration was applied. Following intravenous administration, the porphyrin mesh, but not the free porphyrin, was rapidly cleared via renal excretion. The process could be monitored by fluorescence analysis of collected urine, with minimal background due to the large Stokes shift of the porphyrin (230 nm separating excitation and emission peaks). In a rhabdomyolysis mouse model of renal failure, porphyrin mesh urinary clearance was significantly impaired. This led to slower accumulation in the bladder, which could be visualized non-invasively via fluorescence imaging. Without further modification, the porphyrin mesh was chelated with (64)Cu for dynamic whole body positron emission tomography imaging of renal clearance. Together, these data show that small porphyrin-PEG polymers can serve as effective multimodal markers of renal function.


Assuntos
Rim/fisiopatologia , Polietilenoglicóis/química , Porfirinas/química , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos ICR , Polietilenoglicóis/farmacocinética , Porfirinas/farmacocinética , Tomografia por Emissão de Pósitrons , Insuficiência Renal/diagnóstico por imagem , Insuficiência Renal/fisiopatologia
13.
Front Phys ; 32015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28553633

RESUMO

Biomedical applications of porphyrins and related molecules have been extensively pursued in the context of photodynamic therapy. Recent advances in nanoscale engineering have opened the door for new ways that porphyrins stand to potentially benefit human health. Metalloporphyrins are inherently suitable for many types of medical imaging and therapy. Traditional nanocarriers such as liposomes, dendrimers and silica nanoparticles have been explored for photosensitizer delivery. Concurrently, entirely new classes of porphyrin nanostructures are being developed, such as smart materials that are activated by specific biochemicals encountered at disease sites. Techniques have been developed that improve treatments by combining biomaterials with photosensitizers and functional moieties such as peptides, DNA and antibodies. Compared to simpler structures, these more complex and functional designs can potentially decrease side effects and lead to safer and more efficient phototherapies. This review examines recent research on porphyrin-derived materials in multimodal imaging, drug delivery, bio-sensing, phototherapy and probe design, demonstrating their bright future for biomedical applications.

14.
ACS Appl Mater Interfaces ; 6(16): 13884-93, 2014 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-25027118

RESUMO

Hexagonal NaYbF4:Tm(3+) upconversion nanoparticles hold promise for use in high contrast near-infrared-to-near-infrared (NIR-to-NIR) in vitro and in vivo bioimaging. However, significant hurdles remain in their preparation and control of their morphology and size, as well as in enhancement of their upconversion efficiency. Here, we describe a systematic approach to produce highly controlled hexagonal NaYbF4:Tm(3+) nanoparticles with superior upconversion. We found that doping appropriate concentrations of trivalent gadolinium (Gd(3+)) can convert NaYbF4:Tm(3+) 0.5% nanoparticles with cubic phase and irregular shape into highly monodisperse NaYbF4:Tm(3+) 0.5% nanoplates or nanospheres in a pure hexagonal-phase and of tunable size. The intensity and the lifetime of the upconverted NIR luminescence at 800 nm exhibit a direct dependence on the size distribution of the resulting nanoparticles, being ascribed to the varied surface-to-volume ratios determined by the different nanoparticle size. Epitaxial growth of a thin NaYF4 shell layer of ∼2 nm on the ∼22 nm core of hexagonal NaYbF4:Gd(3+) 30%/Tm(3+) 0.5% nanoparticles resulted in a dramatic 350 fold NIR upconversion efficiency enhancement, because of effective suppression of surface-related quenching mechanisms. In vivo NIR-to-NIR upconversion imaging was demonstrated using a dispersion of phospholipid-polyethylene glycol (DSPE-PEG)-coated core/shell nanoparticles in phosphate buffered saline.


Assuntos
Diagnóstico por Imagem/métodos , Gadolínio/química , Nanopartículas/química , Ítrio/química
15.
Nat Commun ; 5: 3546, 2014 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-24699423

RESUMO

The delivery of therapeutic compounds to target tissues is a central challenge in treating disease. Externally controlled drug release systems hold potential to selectively enhance localized delivery. Here we describe liposomes doped with porphyrin-phospholipid that are permeabilized directly by near-infrared light. Molecular dynamics simulations identified a novel light-absorbing monomer esterified from clinically approved components predicted and experimentally demonstrated to give rise to a more stable porphyrin bilayer. Light-induced membrane permeabilization is enabled with liposomal inclusion of 10 molar % porphyrin-phospholipid and occurs in the absence of bulk or nanoscale heating. Liposomes reseal following laser exposure and permeability is modulated by varying porphyrin-phospholipid doping, irradiation intensity or irradiation duration. Porphyrin-phospholipid liposomes demonstrate spatial control of release of entrapped gentamicin and temporal control of release of entrapped fluorophores following intratumoral injection. Following systemic administration, laser irradiation enhances deposition of actively loaded doxorubicin in mouse xenografts, enabling an effective single-treatment antitumour therapy.


Assuntos
Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/instrumentação , Lipossomos/química , Neoplasias/tratamento farmacológico , Fosfolipídeos/química , Porfirinas/química , Animais , Antineoplásicos/química , Doxorrubicina/química , Portadores de Fármacos/química , Portadores de Fármacos/efeitos da radiação , Sistemas de Liberação de Medicamentos/métodos , Feminino , Humanos , Raios Infravermelhos , Cinética , Lipossomos/efeitos da radiação , Camundongos , Camundongos Nus
16.
Adv Healthc Mater ; 3(6): 891-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24259519

RESUMO

Development of long-term implantable luminescent biosensors for subcutaneous oxygen has proved challenging due to difficulties in immobilizing a biocompatible matrix that prevents sensor aggregation yet maintains sufficient concentration for transdermal optical detection. Here, Pd-porphyrins can be used as PEG cross-linkers to generate a polyamide hydrogel with extreme porphyrin density (≈5 × 10(-3) m). Dye aggregation is avoided due to the spatially constraining 3D mesh formed by the porphyrins themselves. The hydrogel exhibits oxygen-responsive phosphorescence and can be stably implanted subcutaneously in mice for weeks without degradation, bleaching, or host rejection. To further facilitate oxygen detection using steady-state techniques, an oxygen-non-responsive companion hydrogel is developed by blending copper and free base porphyrins to yield intensity-matched luminescence for ratiometric detection.


Assuntos
Técnicas Biossensoriais , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Mesoporfirinas/química , Metaloporfirinas/química , Oxigênio/análise , Animais , Medições Luminescentes , Camundongos , Camundongos Endogâmicos BALB C , Nylons/química , Polietilenoglicóis/química , Pele/química , Pele/metabolismo
17.
Nanoscale ; 5(9): 3982-91, 2013 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-23546384

RESUMO

Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt conditions, wide pH range and serum or plasma containing media. The AuNPs also show strong resistance to competition from dithiothreitol (as high as 1.5 M). Moreover, the modified AuNPs demonstrate low cytotoxicity investigated by both MTT and LDH assays, and good hemocompatibility evaluated by hemolysis of human red blood cells. In addition, the intracellular fate of AuNPs was investigated by ICP-MS and TEM. It showed that the AuNPs are uptaken by cells in a concentration dependent manner, and they can escape from endosomes/lysosomes to cytosol and tend to accumulate around the nucleus after 24 h incubation but few of them are excreted out of the cells. Gold nanorods are also stabilized by this ligand, which demonstrates robust dispersion stability and excellent hemocompatibility. This kind of multidentate zwitterionic chitosan derivative could be widely used for stabilizing other inorganic nanoparticles, which will greatly improve their performance in a variety of bio-related applications.


Assuntos
Quitosana/química , Ouro/química , Nanopartículas Metálicas/química , Materiais Biomiméticos/química , Sobrevivência Celular/efeitos dos fármacos , Coloides/química , Endocitose/efeitos dos fármacos , Exocitose/efeitos dos fármacos , Hemólise , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/toxicidade , Oligossacarídeos/química , Polímeros/química , Propriedades de Superfície
18.
Langmuir ; 27(9): 5242-51, 2011 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-21476529

RESUMO

Here we report a facile way of stabilizing large gold nanoparticles (AuNPs) by mixed charged zwitterionic self-assembled monolayers (SAMs). The citrate-capped AuNPs with diameters ranging from 16 nm to even ∼100 nm are well stabilized via a simple place exchange reaction with a 1:1 molar ratio mixture of negatively charged sodium 10-mercaptodecanesulfonic acid (HS-C10-S) and positively charged (10-mercaptodecyl)-trimethyl-ammonium bromide (HS-C10-N4). The 16 nm AuNPs protected by mixed charged zwitterionic SAMs not only show much better stability than the single negatively or positively charged AuNPs, but also exhibit exciting stability as well as those modified by monohydroxy (1-mercaptoundec-11-yl) tetraethylene glycol (HS-C11-EG4). Importantly, 16 nm AuNPs protected by mixed SAMs exhibit good stability in cell culture medium with 10% FBS and strong protein resistance, especially with excellent resistance against plasma adsorption. Moreover, the mixed charged zwitterionic SAMs are also able to well-stabilize larger AuNPs with a diameter of 50 nm, and to help remarkably improve their stability in saline solution compared with HS-C11-EG4 protected ones. When it comes to AuNPs with a diameter of 100 nm, the mixed charged zwitterionic SAM protected nanoparticles retain a smaller hydrodynamic diameter and even better long-term stability than those modified by mercaptopolyethylene glycol (M(w) = 2000, HS-PEG2000). The above results demonstrated that the mixed charged zwitterionic SAMs are able to have a similar effect on stabilizing the large gold nanoparticles just like the single-component zwitterionic SAMs. Concerning its ease of preparation, versatility, and excellent properties, the strategy based on the mixed charged zwitterionic SAM protection might provide a promising method to surface tailoring of nanoparticles for biomedical application.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Soluções Tampão , Ácido Cítrico/química , Ouro/sangue , Humanos , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Compostos de Amônio Quaternário/química , Cloreto de Sódio/química , Ácidos Sulfônicos/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...