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1.
J Clin Immunol ; 44(3): 69, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38393459

RESUMO

Congenital heart disease (CHD) is the most common birth defect, and up to 50% of infants with CHD require cardiovascular surgery early in life. Current clinical practice often involves thymus resection during cardiac surgery, detrimentally affecting T-cell immunity. However, epidemiological data indicate that CHD patients face an elevated risk for infections and immune-mediated diseases, independent of thymectomy. Hence, we examined whether the cardiac defect impacts thymus function in individuals with CHD. We investigated thymocyte development in 58 infants categorized by CHD complexity. To assess the relationship between CHD complexity and thymic function, we analyzed T-cell development, thymic output, and biomarkers linked to cardiac defects, stress, or inflammation. Patients with highly complex CHD exhibit thymic atrophy, resulting in low frequencies of recent thymic emigrants in peripheral blood, even prior to thymectomy. Elevated plasma cortisol levels were detected in all CHD patients, while high NT-proBNP and IL-6 levels were associated with thymic atrophy. Our findings reveal an association between complex CHD and thymic atrophy, resulting in reduced thymic output. Consequently, thymus preservation during cardiovascular surgery could significantly enhance immune function and the long-term health of CHD patients.


Assuntos
Cardiopatias Congênitas , Timo , Lactente , Humanos , Linfócitos T , Cardiopatias Congênitas/cirurgia , Cardiopatias Congênitas/patologia , Atrofia/patologia
2.
Biomaterials ; 305: 122448, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38218121

RESUMO

Gas-loaded nanobubbles have potential as a method of oxygen delivery to increase tumour oxygenation and therapeutically alleviate tumour hypoxia. However, the mechanism(s) whereby oxygen-loaded nanobubbles increase tumour oxygenation are unknown; with their calculated oxygen-carrying capacity being insufficient to explain this effect. Intra-tumoural hypoxia is a prime therapeutic target, at least partly due to hypoxia-dependent stimulation of the formation and function of bone-resorbing osteoclasts which establish metastatic cells in bone. This study aims to investigate potential mechanism(s) of oxygen delivery and in particular the possible use of oxygen-loaded nanobubbles in preventing bone metastasis via effects on osteoclasts. Lecithin-based nanobubbles preferentially interacted with phagocytic cells (monocytes, osteoclasts) via a combination of lipid transfer, clathrin-dependent endocytosis and phagocytosis. This interaction caused general suppression of osteoclast differentiation via inhibition of cell fusion. Additionally, repeat exposure to oxygen-loaded nanobubbles inhibited osteoclast formation to a greater extent than nitrogen-loaded nanobubbles. This gas-dependent effect was driven by differential effects on the fusion of mononuclear precursor cells to form pre-osteoclasts, partly due to elevated potentiation of RANKL-induced ROS by nitrogen-loaded nanobubbles. Our findings suggest that oxygen-loaded nanobubbles could represent a promising therapeutic strategy for cancer therapy; reducing osteoclast formation and therefore bone metastasis via preferential interaction with monocytes/macrophages within the tumour and bone microenvironment, in addition to known effects of directly improving tumour oxygenation.


Assuntos
Neoplasias Ósseas , Reabsorção Óssea , Humanos , Osteoclastos , Oxigênio/farmacologia , Diferenciação Celular , Neoplasias Ósseas/patologia , Hipóxia , Nitrogênio/farmacologia , Ligante RANK , Microambiente Tumoral
3.
Ultrasound Med Biol ; 47(7): 1826-1843, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33820668

RESUMO

A combination of ultrahigh-speed optical imaging (5 × 106 frames/s), B-mode ultrasound and passive cavitation detection was used to study the vaporization process and determine both the acoustic droplet vaporization (ADV) and inertial cavitation (IC) thresholds of phospholipid-coated perfluorobutane nanodroplets (PFB NDs, diameter = 237 ± 16 nm). PFB NDs have not previously been studied with ultrahigh-speed imaging and were observed to form individual microbubbles (1-10 µm) within two to three cycles and subsequently larger bubble clusters (10-50 µm). The ADV and IC thresholds did not statistically significantly differ and decreased with increasing pulse length (20-20,000 cycles), pulse repetition frequency (1-100 Hz), concentration (108-1010 NDs/mL), temperature (20°C-45°C) and decreasing frequency (1.5-0.5 MHz). Overall, the results indicate that at frequencies of 0.5, 1.0 and 1.5 MHz, PFB NDs can be vaporized at moderate peak negative pressures (<2.0 MPa), pulse lengths and pulse repetition frequencies. This finding is encouraging for the use of PFB NDs as cavitation agents, as these conditions are comparable to those required to achieve therapeutic effects with microbubbles, unlike those reported for higher-boiling-point NDs. The differences between the optically and acoustically determined ADV thresholds, however, suggest that application-specific thresholds should be defined according to the biological/therapeutic effect of interest.


Assuntos
Acústica , Fluorocarbonos , Nanopartículas , Imagem Óptica , Fosfolipídeos , Volatilização , Imagem Óptica/métodos
4.
Ultrason Sonochem ; 73: 105482, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33588208

RESUMO

Liquid perfluorocarbon nanodroplets (NDs) are an attractive alternative to microbubbles (MBs) for ultrasound-mediated therapeutic and diagnostic applications. ND size and size distribution have a strong influence on their behaviour in vivo, including extravasation efficiency, circulation time, and response to ultrasound stimulation. Thus, it is desirable to identify ways to tailor the ND size and size distribution during manufacturing. In this study phospholipid-coated NDs, comprising a perfluoro-n-pentane (PFP) core stabilised by a DSPC/PEG40s (1,2-distearoyl-sn-glycero-3-phosphocholine and polyoxyethylene(40)stearate, 9:1 molar ratio) shell, were produced in phosphate-buffered saline (PBS) by sonication. The effect of the following production-related parameters on ND size was investigated: PFP concentration, power and duration of sonication, and incorporation of a lipophilic fluorescent dye. ND stability was also assessed at both 4 °C and 37 °C. When a sonication pulse of 6 s and 15% duty cycle was employed, increasing the volumetric concentration of PFP from 5% to 15% v/v in PBS resulted in an increase in ND diameter from 215.8 ± 16.8 nm to 408.9 ± 171.2 nm. An increase in the intensity of sonication from 48 to 72 W (with 10% PFP v/v in PBS) led to a decrease in ND size from 354.6 ± 127.2 nm to 315.0 ± 100.5 nm. Increasing the sonication time from 20 s to 40 s (using a pulsed sonication with 30% duty cycle) did not result in a significant change in ND size (in the range 278-314 nm); however, when it was increased to 60 s, the average ND diameter reduced to 249.7 ± 9.7 nm, which also presented a significantly lower standard deviation compared to the other experimental conditions investigated (i.e., 9.7 nm vs. > 49.4 nm). The addition of the fluorescent dye DiI at different molar ratios did not affect the ND size distribution. NDs were stable at 4 °C for up to 6 days and at 37 °C for up to 110 min; however, some evidence of ND-to-MB phase transition was observed after 40 min at 37 °C. Finally, phase transition of NDs into MBs was demonstrated using a tissue-mimicking flow phantom under therapeutic ultrasound exposure conditions (ultrasound frequency: 0.5 MHz, acoustic pressure: 2-4 MPa, and pulse repetition frequency: 100 Hz).


Assuntos
Lipídeos/química , Nanopartículas/química , Sonicação/métodos , Corantes Fluorescentes/química , Tamanho da Partícula , Tensoativos/química
5.
Foot Ankle Surg ; 23(4): 281-284, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29202988

RESUMO

BACKGROUND: In the current United Kingdom population the incidence of diabetic peripheral neuropathy is increasing. The presence of diabetic neuropathy affects decision making and treatment options. This study seeks to evaluate if the vibrations generated from a mobile phone can be used to screen patients for diabetic peripheral neuropathy. METHODS: This study comprised of 61 patients; a control group of 21 patients; a lower limb injury group of 19 patients; a diabetic peripheral neuropathy group of 21 patients. The control and injury group were recruited randomly from fracture clinics. The diabetic peripheral neuropathy group were randomly recruited from the diabetic foot clinic. The 61 patients were examined using a 10g Semmes-Weinstein monofilament, a 128Hz tuning fork and a vibrating mobile phone. The points tested were, index finger, patella, lateral malleoli, medial malleoli, heel, first and fifth metatarsal heads. RESULTS: The most accurate location of all the clinical tests was the head of the 1st metatarsal at 0.86. The overall accuracy of the tuning fork was 0.77, the ten gram monofilament 0.79 and the mobile phone accuracy was 0.88. The control group felt 420 of 441 tests (95%). The injury group felt 349 of 399 tests (87%). The neuropathic group felt 216 of 441 tests (48%). There is a significant difference in the number of tests felt between the control and both the injury and neuropathic groups. p<0.0001 using N-1 Two Proportion Test. CONCLUSION: A mobile phone is an accurate screening tool for diabetic peripheral neuropathy. The most accurate location to test for diabetic peripheral neuropathy is the head of the 1st metatarsal. Screening for diabetic peripheral neuropathy in the index finger and patella were inaccurate. An injury to the lower limb affects the patient's vibration sensation, we would therefore recommend screening the contralateral limb to the injury. LEVEL OF EVIDENCE: This study represents level II evidence of a new diagnostic investigation.


Assuntos
Pé Diabético/diagnóstico , Pé Diabético/fisiopatologia , Exame Neurológico/instrumentação , Sensação , Vibração , Telefone Celular , Neuropatias Diabéticas/diagnóstico , Neuropatias Diabéticas/fisiopatologia , Humanos , Programas de Rastreamento/instrumentação
6.
Injury ; 48(7): 1613-1615, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28545726

RESUMO

OBJECTIVES: To review the outcomes of patients treated with the Ilizarov method for an isolated, closed, simple diaphyseal, Tibial fracture at our institution over the last decade. METHODS: The Ilizarov frame database was used to identify 76 skeletally mature patients who sustained an isolated, closed, extra-articular, simple, diaphyseal Tibial fracture; the injury also known as a "nail-able Tibial fracture." RESULTS: The average age of the patient was 38 (17-70). All 76 patients progressed to union. The average time until union was 148 (55-398) days. The coronal and sagittal alignment was 3° (0-17°) and 4° (0-14°) respectively. No patient suffered from compartment syndrome. No patient developed septic arthritis. No patient had documented anterior knee pain or secondary knee specialist input post frame removal. On average, there were 9(4-29) follow up appointments and 10(5-26) radiographs post frame application. There is a 59% chance of a patient having a difficulty post frame application. The malunion rate was 5%. Persisting pinsite infection post frame removal occurred in 5 patients (6.5%). Drilling of the pinsite sequestrum resolved the infection in four of these patients, giving a deep infection rate of 1.3%. CONCLUSIONS: The Ilizarov method has a role to play in the treatment of simple closed Tibial shaft fractures in patients who need to kneel. Patient education is a priority however; the patient must be made aware of the difficulty rate associated with the Ilizarov method when compared to the complication profile of alternative treatments.


Assuntos
Fixadores Externos , Fraturas Fechadas/cirurgia , Técnica de Ilizarov , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Idoso , Remoção de Dispositivo , Fixadores Externos/efeitos adversos , Feminino , Seguimentos , Consolidação da Fratura/fisiologia , Fraturas Fechadas/fisiopatologia , Humanos , Técnica de Ilizarov/efeitos adversos , Masculino , Pessoa de Meia-Idade , Osteomielite/tratamento farmacológico , Osteomielite/prevenção & controle , Osteomielite/cirurgia , Educação de Pacientes como Assunto , Fatores de Risco , Infecção da Ferida Cirúrgica/tratamento farmacológico , Infecção da Ferida Cirúrgica/prevenção & controle , Infecção da Ferida Cirúrgica/cirurgia , Resultado do Tratamento , Adulto Jovem
7.
Photoacoustics ; 5: 25-35, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28393017

RESUMO

Frequency analysis of the photoacoustic radiofrequency signals and oxygen saturation estimates were used to monitor the in-vivo response of a novel, thermosensitive liposome treatment. The liposome encapsulated doxorubicin (HaT-DOX) releasing it rapidly (<20 s) when the tumor was exposed to mild hyperthermia (43 °C). Photoacoustic imaging (VevoLAZR, 750/850 nm, 40 MHz) of EMT-6 breast cancer tumors was performed 30 min pre- and post-treatment and up to 7 days post-treatment (at 2/5/24 h timepoints). HaT-DOX-treatment responders exhibited on average a 22% drop in oxygen saturation 2 h post-treatment and a decrease (45% at 750 nm and 73% at 850 nm) in the slope of the normalized PA frequency spectra. The spectral slope parameter correlated with treatment-induced hemorrhaging which increased the optical absorber effective size via interstitial red blood cell leakage. Combining frequency analysis and oxygen saturation estimates differentiated treatment responders from non-responders/control animals by probing the treatment-induced structural changes of blood vessel.

8.
Big Data ; 5(1): 19-31, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28328252

RESUMO

The ability of automatically recognizing and typing entities in natural language without prior knowledge (e.g., predefined entity types) is a major challenge in processing such data. Most existing entity typing systems are limited to certain domains, genres, and languages. In this article, we propose a novel unsupervised entity-typing framework by combining symbolic and distributional semantics. We start from learning three types of representations for each entity mention: general semantic representation, specific context representation, and knowledge representation based on knowledge bases. Then we develop a novel joint hierarchical clustering and linking algorithm to type all mentions using these representations. This framework does not rely on any annotated data, predefined typing schema, or handcrafted features; therefore, it can be quickly adapted to a new domain, genre, and/or language. Experiments on genres (news and discussion forum) show comparable performance with state-of-the-art supervised typing systems trained from a large amount of labeled data. Results on various languages (English, Chinese, Japanese, Hausa, and Yoruba) and domains (general and biomedical) demonstrate the portability of our framework.


Assuntos
Mineração de Dados/métodos , Algoritmos , Humanos , Modelos Teóricos , Processamento de Linguagem Natural , Semântica , Pesquisa Translacional Biomédica
9.
PLoS One ; 12(3): e0174076, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28282469

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0165345.].

10.
Case Rep Obstet Gynecol ; 2017: 5179265, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29430312

RESUMO

We present the case of a 39-year-old G5P5 woman who presented to the emergency department with complaints of shortness of breath, lightheadedness, and excessive uterine bleeding for 14 days, with a heart rate of 123 and a blood pressure of 137/65. Menses had been heavy for several months. A hemoglobin of 1.8 g/dL was discovered. An ultrasound revealed an 11.8 cm fibroid uterus, and the patient was transfused with 6 units of blood and placed on oral contraceptive pills.

11.
PLoS One ; 11(10): e0165345, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27788199

RESUMO

Imaging methods capable of indicating the potential for success of an individualized treatment course, during or immediately following the treatment, could improve therapeutic outcomes. Temperature Sensitive Liposomes (TSLs) provide an effective way to deliver chemotherapeutics to a localized tumoral area heated to mild-hyperthermia (HT). The high drug levels reached in the tumor vasculature lead to increased tumor regression via the cascade of events during and immediately following treatment. For a TSL carrying doxorubicin (DOX) these include the rapid and intense exposure of endothelial cells to high drug concentrations, hemorrhage, blood coagulation and vascular shutdown. In this study, ultrasound-guided photoacoustic imaging was used to probe the changes to tumors following treatment with the TSL, HaT-DOX (Heat activated cytoToxic). Levels of oxygen saturation (sO2) were studied in a longitudinal manner, from 30 min pre-treatment to 7 days post-treatment. The efficacious treatments of HT-HaT-DOX were shown to induce a significant drop in sO2 (>10%) as early as 30 min post-treatment that led to tumor regression (in 90% of cases); HT-Saline and non-efficacious HT-HaT-DOX (10% of cases) treatments did not show any significant change in sO2 at these timepoints. The changes in sO2 were further corroborated with histological data, using the vascular and perfusion markers CD31 and FITC-lectin. These results allowed us to further surmise a plausible mechanism of the cellular events taking place in the TSL treated tumor regions over the first 24 hours post-treatment. The potential for using photoacoustic imaging to measure tumor sO2 as a surrogate prognostic marker for predicting therapeutic outcome with a TSL treatment is demonstrated.


Assuntos
Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Técnicas Fotoacústicas , Temperatura , Animais , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Feminino , Hipertermia Induzida , Lipossomos , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/metabolismo , Neoplasias/patologia , Oxigênio/metabolismo , Fatores de Tempo , Resultado do Tratamento
12.
Bioconjug Chem ; 27(1): 226-37, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26673036

RESUMO

The chemotherapeutic gemcitabine was actively and stably loaded into lipid nanoparticles through the formation of a prodrug. Gemcitabine was chemically modified to increase the lipophilicity and introduce a weak base moiety for remote loading. Several derivatives were synthesized and screened for their potential to be good liposomal drug candidates for remote loading by studying their solubility, stability, cytotoxicity, and loading efficiency. Two morpholino derivatives of GEM (22 and 23) were chosen as the preferred prodrugs for this purpose as they possessed the best loading efficiencies (100% for drug-to-lipid ratio of 0.36 w/w). This is a considerable improvement over a passive loading strategy where typical loading efficiencies are on the order of ∼10-20% for a drug-to-lipid ratio of ∼0.01. Liposomes loaded with these two prodrugs were studied in an s.c. tumor model in vivo and showed improved therapeutic effect over free GEM (∼2-fold) and saline control (8- to 10-fold). This work demonstrates how chemical modification of a known hydrophilic drug can lead to improved loading, stability, and drug delivery in vivo.


Assuntos
Desoxicitidina/análogos & derivados , Lipossomos/química , Pró-Fármacos/síntese química , Animais , Linhagem Celular Tumoral , Técnicas de Química Sintética , Desoxicitidina/química , Desoxicitidina/farmacologia , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Feminino , Concentração Inibidora 50 , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/tratamento farmacológico , Solubilidade , Gencitabina
13.
Chembiochem ; 16(10): 1420-5, 2015 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-26043184

RESUMO

Alpha-amanitin is an exceedingly toxic, naturally occurring, bicyclic octapeptide that inhibits RNA polymerase and results in cellular and organismal death. Here we report the straightforward synthesis of an amanitin analogue that exhibited near-native toxicity. A pendant alkyne was readily installed to enable copper-catalyzed alkyne-azide cycloaddition (CuAAC) to azido-rhodamine and two azide-bearing versions of the RGD peptide. The fluorescent toxin analogue entered cells and provoked morphological changes consistent with cell death. The latter two conjugates are as toxic as the parent alkyne precursor, which demonstrates that conjugation does not diminish toxicity. In addition, we showed that toxicity depends on a single diastereomer of the unnatural amino acid, dihydroxyisoleucine (DHIle), at position 3. The convenient synthesis of a heptapeptide precursor now provides access to bioactive amanitin analogues that may be readily conjugated to biomolecules of interest.


Assuntos
Alcinos/química , Amanitinas/síntese química , Azidas/química , Citotoxinas/síntese química , Amanitinas/química , Amanitinas/toxicidade , Animais , Células CHO , Linhagem Celular Tumoral , Química Click/métodos , Cricetulus , Reação de Cicloadição , Citotoxinas/química , Citotoxinas/toxicidade , Células HeLa , Humanos , Oligopeptídeos/química , Peptídeos , Venenos/síntese química , Venenos/química , Venenos/toxicidade , Rodaminas/química
14.
Pharm Res ; 32(10): 3261-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25964047

RESUMO

PURPOSE: This study was aimed at exploring the use of liposomes to deliver aquated cisplatin (ACP), a metabolite of CDDP, with increased potency and toxicity. Three liposomal formulations were compared for delivery of ACP to a multidrug resistant tumor. METHODS: Three different liposomes (DMPC, DPPC and DSPC as the main lipid components) were loaded with ACP by the thin-film hydration method. In vitro drug release was assessed over 72 h at 37°C in PBS. The pharmacokinetics of free CDDP and the three ACP liposomes was determined using ICP-AES and their efficacy against EMT6-AR1 multidrug resistant murine breast tumor was compared. RESULTS: The DSPC formulation, composed of a C18 acyl chain lipid, exhibited the slowest drug release (~2%) after 72 h at 37°C, compared to the other two formulations with decreased carbon chain lengths (C16 and C14; 7 and 25% release respectively). The pharmacokinetic profile was improved with all liposomal formulations relative to free CDDP, with clearance reduced by 500-fold for DSPC, 200-fold for DPPC and 130-fold for DMPC. The DSPC formulation displayed the highest drug accumulation in the tumor with 2-fold, 3-fold and 100-fold increases compared to DPPC, DMPC and free CDDP respectively. The DSPC formulation significantly inhibited the EMT6-AR1 tumor growth by ~90%, while the other formulations displayed no statistically significant improved activity compared to saline. CONCLUSION: These results suggest that the DSPC liposomal formulation is a promising formulation for MDR tumor therapy over DMPC and DPPC formulations and free drug.


Assuntos
Cisplatino/química , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Lipossomos/química , Neoplasias/tratamento farmacológico , Animais , Proliferação de Células/efeitos dos fármacos , Química Farmacêutica/métodos , Portadores de Fármacos/química , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Fosfatidilcolinas/química , Distribuição Tecidual/efeitos dos fármacos
15.
Biotechnol Bioeng ; 111(12): 2421-35, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24975745

RESUMO

Enhanced biological phosphorus removal (EBPR) from wastewater relies on the preferential selection of active polyphosphate-accumulating organisms (PAO) in the underlying bacterial community continuum. Efficient management of the bacterial resource requires understanding of population dynamics as well as availability of bioanalytical methods for rapid and regular assessment of relative abundances of active PAOs and their glycogen-accumulating competitors (GAO). A systems approach was adopted here toward the investigation of multilevel correlations from the EBPR bioprocess to the bacterial community, metabolic, and enzymatic levels. Two anaerobic-aerobic sequencing-batch reactors were operated to enrich activated sludge in PAOs and GAOs affiliating with "Candidati Accumulibacter and Competibacter phosphates", respectively. Bacterial selection was optimized by dynamic control of the organic loading rate and the anaerobic contact time. The distinct core bacteriomes mainly comprised populations related to the classes Betaproteobacteria, Cytophagia, and Chloroflexi in the PAO enrichment and of Gammaproteobacteria, Alphaproteobacteria, Acidobacteria, and Sphingobacteria in the GAO enrichment. An anaerobic metabolic batch test based on electrical conductivity evolution and a polyphosphatase enzymatic assay were developed for rapid and low-cost assessment of the active PAO fraction and dephosphatation potential of activated sludge. Linear correlations were obtained between the PAO fraction, biomass specific rate of conductivity increase under anaerobic conditions, and polyphosphate-hydrolyzing activity of PAO/GAO mixtures. The correlations between PAO/GAO ratios, metabolic activities, and conductivity profiles were confirmed by simulations with a mathematical model developed in the aqueous geochemistry software PHREEQC.


Assuntos
Hidrolases Anidrido Ácido/metabolismo , Reatores Biológicos , Modelos Biológicos , Fósforo/isolamento & purificação , Fósforo/metabolismo , Hidrolases Anidrido Ácido/análise , Anaerobiose , Condutividade Elétrica , Microbiota , Fósforo/química , Esgotos , Biologia de Sistemas
16.
Artigo em Inglês | MEDLINE | ID: mdl-24652678

RESUMO

UNLABELLED: Taxanes are one of the most potent and broadest spectrum chemotherapeutics used clinically, but also induce significant side effects. Different strategies have been developed to produce a safer taxane formulation. Development of polysaccharide drug conjugates has increased in the recent years because of the demonstrated biocompatibility, biodegradability, safety, and low cost of the biopolymers. This review focuses on polysaccharide-taxane conjugates and provides an overview on various conjugation strategies and their effect on the efficacy. Detailed analyses on the designing factors of an effective polysaccharide-drug conjugate are provided with a discussion on the future direction of this field. For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST: The authors have declared no conflicts of interest for this article.


Assuntos
Química Farmacêutica/tendências , Paclitaxel/química , Polissacarídeos/química , Taxoides/química , Antineoplásicos/química , Docetaxel , Humanos , Ácido Hialurônico/química
17.
Mol Pharm ; 10(12): 4499-508, 2013 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-24152292

RESUMO

The majority of ultrafast temperature sensitive liposome (uTSL) formulations reported in the literature deliver the highly membrane permeable drug, doxorubicin (DOX). Here we report on the study of the uTSL formulation, HaT (Heat activated cytoToxic, composed of the phospholipid DPPC and the surfactant Brij78) loaded with the water-soluble, but poorly membrane permeable anticancer drugs, gemcitabine (GEM) and oxaliplatin (OXA). The HaT formulation displayed ultrafast release of these drugs in response to temperature, whereas attempts with LTSL (Lyso-lipid Temperature Sensitive Liposome, composed of DPPC, MSPC, and DSPE-PEG) were unsuccessful. HaT-GEM and HaT-OXA both released >80% of the encapsulated drug within 2 min at 40-42 °C, with <5% drug leakage at 37 °C after 30 min in serum. The pharmacokinetic profile of both drugs was improved by formulating with HaT relative to the free drug, with clearance reduced by 50-fold for GEM and 3-fold for OXA. HaT-GEM and HaT-OXA both displayed improved drug uptake in the heated tumor relative to the unheated tumor (by 9-fold and 3-fold, respectively). In particular, HaT-GEM showed 25-fold improved delivery to the heated tumor relative to free GEM and significantly enhanced antitumor efficacy with complete tumor regression after a single dose of HaT-GEM. These data suggest that uTSL technology can also be used to deliver nonmembrane permeable drugs via an intravascular ultrafast release mechanism to great effect.


Assuntos
Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Lipossomos/farmacologia , Compostos Organoplatínicos/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Química Farmacêutica/métodos , Desoxicitidina/química , Desoxicitidina/farmacocinética , Desoxicitidina/farmacologia , Feminino , Lipossomos/química , Lipossomos/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacocinética , Oxaliplatina , Fosfolipídeos/química , Polietilenoglicóis/química , Tensoativos/química , Temperatura , Distribuição Tecidual , Gencitabina
18.
J Med Pract Manage ; 28(5): 289-91, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23767121

RESUMO

A recent trend has independent medical practices throwing in the towel and selling to hospitals in hopes of eliminating the financial burdens of private practice. Incentive payments, tiered fee schedules, and patient collaboration place the primary care physician at the center of the ever-evolving healthcare payment system. Hospital services represent a high-cost, highly scrutinized line item with reform programs emphasizing a reduction in many of the services hospitals rely on today for their revenue. In an environment moving from volume to value, and featuring Accountable Care Organizations and Patient-Centered Medical Homes, hospitals may soon turn to these same medical practices as the source of their financial future.


Assuntos
Relações Hospital-Médico , Administração da Prática Médica/organização & administração , Prática Privada/organização & administração , Organizações de Assistência Responsáveis/organização & administração , Reforma dos Serviços de Saúde , Humanos , Assistência Centrada no Paciente/organização & administração , Atenção Primária à Saúde , Mecanismo de Reembolso , Reembolso de Incentivo , Estados Unidos
19.
Expert Opin Drug Deliv ; 10(4): 511-27, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23289519

RESUMO

INTRODUCTION: Specific delivery of a drug to a target site is a major goal of drug delivery research. Using temperature-sensitive liposomes (TSLs) is one way to achieve this; the liposome acts as a protective carrier, allowing increased drug to flow through the bloodstream by minimizing clearance and non-specific uptake. On reaching microvessels within a heated tumor, the drug is released and quickly penetrates. A major advance in the field is ThermoDox® (Celsion), demonstrating significant improvements to the drug release rates and drug uptake in heated tumors (∼ 41°C). Most recently, magnetic resonance-guided focused ultrasound (MRgFUS) has been combined with TSL drug delivery to provide localized chemotherapy with simultaneous quantification of drug release within the tumor. AREAS COVERED: In this article the field of hyperthermia-induced drug delivery is discussed, with an emphasis on the development of TSLs and their combination with hyperthermia (both mild and ablative) in cancer therapy. State-of-the-art image-guided heating technologies used with this combination strategy will also be presented, with examples of real-time monitoring of drug delivery and prediction of efficacy. EXPERT OPINION: The specific delivery of drugs by combining hyperthermia with TSLs is showing great promise in the clinic and its potential will be even greater as the use of image-guided focused ultrasound becomes more widespread - a technique capable of penetrating deep within the body to heat a specific area with improved control. In conjunction with this, it is anticipated that multifunctional TSLs will be a major topic of study in this field.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Hipertermia Induzida/métodos , Lipossomos/química , Neoplasias/tratamento farmacológico , Animais , Antibióticos Antineoplásicos/administração & dosagem , Humanos , Espectroscopia de Ressonância Magnética , Tecnologia Farmacêutica , Temperatura
20.
J Control Release ; 161(1): 142-9, 2012 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-22504351

RESUMO

Here we report the development of an enhanced thermosensitive formulation composed of DPPC and Brij78, loaded with doxorubicin (DOX) using a Cu²âº gradient and post-inserted with an additional amount of Brij78. This optimal formulation (HaT-II: Hyperthermia-activated cytoToxic) displayed significantly improved stability in serum at 37 °C, and enhanced drug release rates at 41-42 °C, compared to LTSL (lyso-lipid temperature sensitive liposomes, DPPC/MSPC/DSPE-PEG2000=86/10/4, pH gradient drug loading). HaT-II released 100% DOX within 15-40s at 40-42 °C, with only 5% drug leakage at 37 °C after 30 min in serum, while LTSL lost 30% of its drug content at 37 °C and exhibited ~2-fold decreased release rate constants at 41-42 °C under the same conditions. The pharmacokinetics of DOX was significantly improved in non-heated HaT-II treated healthy mice with 2.5-fold increased area under the curve and 2-fold prolonged circulation half life compared to LTSL. This led to 2-fold improved drug delivery to the heated tumor by HaT-II (~20% injected dose/g tissue), relative to LTSL and significantly enhanced antitumor efficacy with complete inhibition of tumor growth after a single dose of HaT-II. Finally, HaT-II exhibited little toxicity in mice, inducing no body weight loss and no abnormality in the blood chemistry (10 mg DOX/kg).


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/uso terapêutico , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Lipossomos/química , Neoplasias Mamárias Animais/tratamento farmacológico , 1,2-Dipalmitoilfosfatidilcolina/química , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Animais , Antibióticos Antineoplásicos/farmacocinética , Cobre/química , Cobre/metabolismo , Doxorrubicina/farmacocinética , Feminino , Hipertermia Induzida , Lipossomos/metabolismo , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Polietilenoglicóis/química , Polietilenoglicóis/metabolismo
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