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1.
J Gastrointestin Liver Dis ; 32(1): 39-50, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-37004233

RESUMO

BACKGROUND AND AIMS: Cirrhosis is associated with an increased risk of acute kidney injury (AKI) and hepatorenal syndrome (HRS). Healthcare utilization and cost burden of AKI and HRS in cirrhosis is unknown. We aimed to analyze the health care use and cost burden associated with AKI and HRS in patients with cirrhosis in the United States by using real-world claims data. METHODS: We conducted a case-control study using the Truven Health MarketScan Commercial Claims databases from 2007-2017. A total of 34,398 patients with cirrhosis with or without AKI and 4,364 patients with cirrhosis with or without HRS were identified using International Classification of Diseases, Ninth or Tenth Revision, codes and matched 1:1 by sociodemographic characteristics and comorbidities using propensity scores. Total and service-specific were quantified for the 12-months following versus the 12-months before the first date of AKI or HRS diagnosis and over 12-months following a randomly selected date for cirrhosis controls to capture entire disease burdens. RESULTS: The AKI and HRS group had a higher number of comorbidities and were associated with higher rates of readmission and mortality. The AKI and HRS groups had a significantly higher prevalence of ascites, spontaneous bacterial peritonitis (SBP), encephalopathy, gastrointestinal bleeding, septic shock, pulmonary edema, and respiratory failure. Compared to patients with cirrhosis only, AKI was associated with higher number of claims per person (AKI vs. cirrhosis only, 60.30 vs. 47.09; p<0.0001) and total annual median health care costs (AKI vs. cirrhosis only, $46,150 vs. $26,340; p<0.0001). Compared to patients with cirrhosis only, the HRS cohort was associated with a higher number of claims per person (HRS vs. cirrhosis only, 44.96 vs. 43.50; p<0.0009) and total annual median health care costs (HRS vs. cirrhosis only, $34,912 vs. $23,354; p<0.0001). Inpatient costs were higher than the control cohort for AKI (AKI vs. cirrhosis only, $72,720 vs. $29,111; p<0.0001) and HRS (HRS vs. cirrhosis only, $ 98,246 vs. $27,503; p<0.0001). Compared to the control cohort, AKI and HRS had a higher rate of inpatient admission, mean number of inpatient admissions, and mean total length of stay. CONCLUSIONS: AKI and HRS are associated with higher health care utilization and cost burden compared to cirrhosis alone, highlighting the importance for improved screening and treatment modalities.


Assuntos
Injúria Renal Aguda , Síndrome Hepatorrenal , Humanos , Estados Unidos/epidemiologia , Síndrome Hepatorrenal/diagnóstico , Síndrome Hepatorrenal/epidemiologia , Síndrome Hepatorrenal/terapia , Estudos de Casos e Controles , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico , Cirrose Hepática/epidemiologia , Custos de Cuidados de Saúde , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/terapia
2.
Artigo em Inglês | MEDLINE | ID: mdl-35548475

RESUMO

Endoscopic bariatric therapies (EBTs) are endoscopic procedures indicated for weight loss in the obese population. They are shown to be safe and effective for patients who do not quality for bariatric surgery. There are currently no randomized controlled studies comparing bariatric surgery with EBTs. However, EBTs are more cost effective and have fewer complications. This review will examine currently available EBTs with published data.

3.
Small Methods ; 5(7): e2001188, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34927993

RESUMO

The global demand for plastic foam materials is enormous (annual worth of ≈$341.3 billion) and still surging with an annual growth rate of 4.8%, driven by increasing modern societal needs. The majority of existing foam materials are made of plastics, which take hundreds of years to degrade, leading to severe global pollution issues. Here, a degradable, recyclable, and cost-effective solution to foam materials based on 3D graphite-cellulose nanofibers (G-CNF) foam fabricated from resource-abundant graphite and cellulose via advanced 3D printing is reported. The CNFs can directly disperse the graphite under physical sonication without the need for any chemical reactions. The interaction of the CNFs with graphite through the function of hydrophilic and hydrophobic faces in CNFs renders the dispersion polymer-like rheological properties and good processability with tunable viscosity for 3D printing. A robust, degradable, and recyclable G-CNF foam with designed shapes can be printed in a large scale, demonstrating higher mechanical strength (3.72 MPa versus 0.28 MPa in tensile strength and 2.34 MPa versus 1.11 MPa in compressive stiffness), better fire resistance, degradability, and recyclability than commercial polystyrene foam material. The demonstrated G-CNF foam can potentially replace the commercial plastic foam materials, representing a sustainable solution toward white pollution.

4.
Front Glob Womens Health ; 2: 647072, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34816200

RESUMO

Amidst the COVID-19 pandemic, there is a need for further research on its manifestation in pregnant women, since they are particularly prone to respiratory pathogens, like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), due to physiological changes during pregnancy. Its effects on infants born to mothers with COVID-19 are also not well-studied, and more evidence is needed on vertical transmission of the disease from mother to infant and on the transmission of IgG/IgM antibodies between mother and infant. We aim to systematically review and evaluate the effects of COVID-19 among SARS-CoV-2-positive pregnant women in late pregnancy and neonates with SARS-CoV-2-positive pregnant mothers using blood assays to find indicators of maternal and neonatal complications. We searched for original published articles in Google Scholar, Medline (PubMed), and Embase databases to identify articles in the English language from December 2019 to July 20, 2020. Duplicate entries were searched by their titles, authors, date of publication, and Digital Object Identifier. The selected studies were included based on patient pregnancy on admission, pregnant mothers with laboratory-confirmed COVID-19 virus, maternal/neonatal complications, and blood test results. We excluded duplicate studies, articles where full text was not available, other languages than English, opinions, and perspectives. The meta-analysis using the Generalized Linear Mixed model was conducted using the "meta" and "metaprop" packages in R code. Of the 1,642 studies assessed for eligibility, 29 studies (375 mothers and neonates) were included. Preterm birth rate was 34.2%, and cesarean section rate was 82.7%. Maternal laboratory findings found elevated neutrophils (71.4%; 95% CI: 38.5-90.9), elevated CRP (67.7%; 95%: 50.6-81.1), and low hemoglobin (57.3%; 95% CI: 26.0-87.8). We found platelet count, lactate dehydrogenase, and procalcitonin to be less strongly correlated with preterm birth than between high neutrophil counts (P = 0.0007), low hemoglobin (P = 0.0188), and risk of preterm birth. There is little evidence for vertical transmission. Elevated procalcitonin levels (23.2%; 95% CI: 8.4-49.8) are observed in infants born to mothers with COVID-19, which could indicate risk for neonatal sepsis. These infants may gain passive immunity to COVID-19 through antibody transfer via placenta. These results can guide current obstetrical care during the current SARS-CoV-2 pandemic.

5.
World J Gastroenterol ; 27(46): 7969-7981, 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-35046624

RESUMO

The coronavirus disease 2019 (COVID-19) has caused one of the worst public health crises in modern history. Even though severe acute respiratory syndrome coronavirus 2 primarily affects the respiratory tract, gastrointestinal manifestations are well described in literature. This review will discuss the epidemiology, virology, manifestations, immunosuppressant states, and lessons learned from COVID-19. Observations: At the time of writing, COVID-19 had infected more than 111 million people and caused over 2.5 million deaths worldwide. Multiple medical comorbidities including obesity, pre-existing liver condition and the use of proton pump inhibitor have been described as risk factor for severe COVID-19. COVID-19 most frequently causes diarrhea (12.4%), nausea/vomiting (9%) and elevation in liver enzymes (15%-20%). The current data does not suggest that patients on immunomodulators have a significantly increased risk of mortality from COVID-19. The current guidelines from American Gastroenterological Association and American Association for the Study of Liver Diseases do not recommend pre-emptive changes in patients on immunosuppression if the patients have not been infected with COVID-19. Conclusions and relevance: The COVID-19 pandemic has prompted a change in structure and shape of gastroenterology departmental activities. Endoscopy should be performed only when necessary and with strict protective measures. Online consultations in the form of telehealth services and home drug deliveries have revolutionized the field.


Assuntos
COVID-19 , Gastroenteropatias , Gastroenteropatias/diagnóstico , Gastroenteropatias/epidemiologia , Trato Gastrointestinal , Humanos , Fígado , Pandemias , SARS-CoV-2
6.
RSC Adv ; 10(40): 23743-23748, 2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35517316

RESUMO

Methylammonium lead triiodide perovskites, CH3NH3PbI3 (MAPbI3), are solution-processable materials with photovoltaic properties capable of surpassing those of silicon solar cells. However, concerns over lead toxicity and lack of exploration into transition metal perovskites drove this ab initio Density Functional Theory screening for environmentally friendly perovskite materials by incorporating transition and post-transition metals at the B-site of MAPbI3. This revealed fourteen replacements to be suitable: their band structures are highly dispersive while band gaps of such materials fall within ideal ranges for single-junction and tandem cells. Transition metal monoreplacements are shown to be viable perovskites after reducing the size of the halide, corroborating that tunability of the band gap is observed in halide replacement at the X-site. Strong peaks in the imaginary output of the dielectric function below 3.5 eV indicate high sunlight absorption efficiency for select materials. Excellent carrier mobility is expected of studied materials as their effective mass is low. This work helps gain further insight into the viability of transition metals for lower toxicity and higher absorption divalent perovskites.

7.
J Control Release ; 262: 37-46, 2017 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-28694032

RESUMO

The discovery of powerful genetic targets has spurred clinical development of gene therapy approaches to treat patients with malignant brain tumors. However, lack of success in the clinic has been attributed to the inability of conventional gene vectors to achieve gene transfer throughout highly disseminated primary brain tumors. Here, we demonstrate ex vivo that small nanocomplexes composed of DNA condensed by a blend of biodegradable polymer, poly(ß-amino ester) (PBAE), with PBAE conjugated with 5kDa polyethylene glycol (PEG) molecules (PBAE-PEG) rapidly penetrate healthy brain parenchyma and orthotopic brain tumor tissues in rats. Rapid diffusion of these DNA-loaded nanocomplexes observed in fresh tissues ex vivo demonstrated that they avoided adhesive trapping in the brain owing to their dense PEG coating, which was critical to achieving widespread transgene expression throughout orthotopic rat brain tumors in vivo following administration by convection enhanced delivery. Transgene expression with the PBAE/PBAE-PEG blended nanocomplexes (DNA-loaded brain-penetrating nanocomplexes, or DNA-BPN) was uniform throughout the tumor core compared to nanocomplexes composed of DNA with PBAE only (DNA-loaded conventional nanocomplexes, or DNA-CN), and transgene expression reached beyond the tumor edge, where infiltrative cancer cells are found, only for the DNA-BPN formulation. Finally, DNA-BPN loaded with anti-cancer plasmid DNA provided significantly enhanced survival compared to the same plasmid DNA loaded in DNA-CN in two aggressive orthotopic brain tumor models in rats. These findings underscore the importance of achieving widespread delivery of therapeutic nucleic acids within brain tumors and provide a promising new delivery platform for localized gene therapy in the brain.


Assuntos
Neoplasias Encefálicas , Encéfalo/metabolismo , DNA , Nanopartículas , Polietilenoglicóis , Polímeros , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/terapia , DNA/administração & dosagem , DNA/uso terapêutico , Feminino , Expressão Gênica , Terapia Genética , Proteínas de Fluorescência Verde/genética , Nanopartículas/administração & dosagem , Nanopartículas/uso terapêutico , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/uso terapêutico , Polímeros/administração & dosagem , Polímeros/uso terapêutico , Ratos , Ratos Endogâmicos F344 , Timidina Quinase/genética , Transgenes , Proteína Supressora de Tumor p53/genética , Proteínas Virais/genética
8.
J Control Release ; 267: 232-239, 2017 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-28739449

RESUMO

Convection enhanced delivery (CED) provides a powerful means to bypass the blood-brain barrier and drive widespread distribution of therapeutics in brain parenchyma away from the point of local administration. However, recent studies have detailed that the overall distribution of therapeutic nanoparticles (NP) following CED remains poor due to tissue inhomogeneity and anatomical barriers present in the brain, which has limited its translational applicability. Using probe NP, we first demonstrate that a significantly improved brain distribution is achieved by infusing small, non-adhesive NP via CED in a hyperosmolar infusate solution. This multimodal delivery strategy minimizes the hindrance of NP diffusion imposed by the brain extracellular matrix and reduces NP confinement within the perivascular spaces. We further recapitulate the distributions achieved by CED of this probe NP using a most widely explored biodegradable polymer-based drug delivery NP. These findings provide a strategy to overcome several key limitations of CED that have been previously observed in clinical trials.


Assuntos
Encéfalo/metabolismo , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Animais , Encéfalo/irrigação sanguínea , Convecção , Feminino , Masculino , Camundongos , Nanopartículas/química , Polímeros/administração & dosagem , Polímeros/química , Ratos Sprague-Dawley
9.
J Control Release ; 263: 120-131, 2017 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-28288892

RESUMO

Systemically administered chemotherapeutic drugs are often ineffective in the treatment of invasive brain tumors due to poor therapeutic index. Within gliomas, despite the presence of heterogeneously leaky microvessels, dense extracellular matrix and high interstitial pressure generate a "blood-tumor barrier" (BTB), which inhibits drug delivery and distribution. Meanwhile, beyond the contrast MRI-enhancing edge of the tumor, invasive cancer cells are protected by the intact blood-brain barrier (BBB). Here, we tested whether brain-penetrating nanoparticles (BPN) that possess dense surface coatings of polyethylene glycol (PEG) and are loaded with cisplatin (CDDP) could be delivered across both the blood-tumor and blood-brain barriers with MR image-guided focused ultrasound (MRgFUS), and whether this treatment could control glioma growth and invasiveness. To this end, we first established that MRgFUS is capable of significantly enhancing the delivery of ~60nm fluorescent tracer BPN across the blood-tumor barrier in both the 9L (6-fold improvement) gliosarcoma and invasive F98 (28-fold improvement) glioma models. Importantly, BPN delivery across the intact BBB, just beyond the tumor edge, was also markedly increased in both tumor models. We then showed that a CDDP loaded BPN formulation (CDDP-BPN), composed of a blend of polyaspartic acid (PAA) and heavily PEGylated polyaspartic acid (PAA-PEG), was highly stable, provided extended drug release, and was effective against F98 cells in vitro. These CDDP-BPN were delivered from the systemic circulation into orthotopic F98 gliomas using MRgFUS, where they elicited a significant reduction in tumor invasiveness and growth, as well as improved animal survival. We conclude that this therapy may offer a powerful new approach for the treatment invasive gliomas, particularly for preventing and controlling recurrence.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Cisplatino/administração & dosagem , Glioma/tratamento farmacológico , Imageamento por Ressonância Magnética/métodos , Ondas Ultrassônicas , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/metabolismo , Cadaverina/administração & dosagem , Cadaverina/química , Cadaverina/uso terapêutico , Carbocianinas/administração & dosagem , Carbocianinas/química , Carbocianinas/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/química , Cisplatino/uso terapêutico , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Feminino , Corantes Fluorescentes/administração & dosagem , Corantes Fluorescentes/química , Corantes Fluorescentes/uso terapêutico , Glioma/diagnóstico por imagem , Glioma/metabolismo , Glioma/patologia , Microbolhas , Peptídeos/administração & dosagem , Peptídeos/química , Peptídeos/uso terapêutico , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Polietilenoglicóis/uso terapêutico , Ratos Sprague-Dawley , Carga Tumoral/efeitos dos fármacos
10.
J Control Release ; 263: 112-119, 2017 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-28279797

RESUMO

Glioblastoma multiforme (GBM) is highly invasive and uniformly fatal, with median survival<20months after diagnosis even with the most aggressive treatment that includes surgery, radiation, and systemic chemotherapy. Cisplatin is a particularly potent chemotherapeutic agent, but its use to treat GBM is limited by severe systemic toxicity and inefficient penetration of brain tumor tissue even when it is placed directly in the brain within standard delivery systems. We describe the development of cisplatin-loaded nanoparticles that are small enough (70nm in diameter) to move within the porous extracellular matrix between cells and that possess a dense polyethylene glycol (PEG) corona that prevents them from being trapped by adhesion as they move through the brain tumor parenchyma. As a result, these "brain penetrating nanoparticles" penetrate much deeper into brain tumor tissue compared to nanoparticles without a dense PEG corona following local administration by either manual injection or convection enhanced delivery. The nanoparticles also provide controlled release of cisplatin in effective concentrations to kill the tumor cells that they reach without causing toxicity-related deaths that were observed when cisplatin was infused into the brain without a delivery system. Median survival time of rats bearing orthotopic glioma was significantly enhanced when cisplatin was delivered in brain penetrating nanoparticles (median survival not reached; 80% long-term survivors) compared to cisplatin in conventional un-PEGylated particles (median survival=40days), cisplatin alone (median survival=12days) or saline-treated controls (median survival=28days).


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Cisplatino/administração & dosagem , Convecção , Glioma/tratamento farmacológico , Nanopartículas/administração & dosagem , Animais , Antineoplásicos/uso terapêutico , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/uso terapêutico , Feminino , Glioma/metabolismo , Masculino , Nanopartículas/uso terapêutico , Ratos Endogâmicos F344 , Ratos Sprague-Dawley
11.
RSC Adv ; 48(6): 41665-41674, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27642512

RESUMO

Gene therapy is a promising strategy for the management of various neurological disorders that do not respond adequately to conventional therapeutics. The development of gene vectors with favorable safety profiles that can achieve uniform distribution and high-level transgene expression in the brain remains challenging. The rod-shaped, non-viral gene delivery platform based on poly-L-lysine (PLL) conjugated to a single segment of polyethylene glycol (PEG) has shown safe transfection in human nares and mouse brains in vivo. However, we have previously demonstrated that a denser PEG coating is required for rapid diffusion of nanoparticles in the brain extracellular space. Here, we engineered a densely PEGylated version of this platform based on PLL polymers conjugated to branched PEG via alkyne-azide cycloaddition. We found that the newly developed gene vectors rapidly diffused in the brain parenchyma, providing significantly improved vector distribution and overall transgene expression in vivo compared to the previously developed platform. These brain-penetrating DNA nanoparticles exhibited enhanced cellular uptake presumably due to their ellipsoidal morphology. By simultaneously improving delivery to target cells and subsequent transfection, our densely PEGylated PLL DNA nanoparticles can provide widespread, high levels of transgene expression, essential for effective targeting of highly disseminated brain diseases.

12.
Small ; 12(5): 678-85, 2016 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-26680637

RESUMO

Successful gene therapy of neurological disorders is predicated on achieving widespread and uniform transgene expression throughout the affected disease area in the brain. However, conventional gene vectors preferentially travel through low-resistance perivascular spaces and/or are confined to the administration site even with the aid of a pressure-driven flow provided by convection-enhanced delivery. Biodegradable DNA nanoparticles offer a safe gene delivery platform devoid of adverse effects associated with virus-based or synthetic nonbiodegradable systems. Using a state-of-the-art biodegradable polymer, poly(ß-amino ester), colloidally stable sub-100 nm DNA nanoparticles are engineered with a nonadhesive polyethylene glycol corona that are able to avoid the adhesive and steric hindrances imposed by the extracellular matrix. Following convection enhanced delivery, these brain-penetrating nanoparticles are able to homogeneously distribute throughout the rodent striatum and mediate widespread and high-level transgene expression. These nanoparticles provide a biodegradable DNA nanoparticle platform enabling uniform transgene expression patterns in vivo and hold promise for the treatment of neurological diseases.


Assuntos
DNA/metabolismo , Técnicas de Transferência de Genes , Nanopartículas/química , Animais , Encéfalo/metabolismo , Convecção , Feminino , Nanopartículas/ultraestrutura , Polietilenoglicóis/química , Polímeros/química , Ratos Endogâmicos F344 , Distribuição Tecidual , Transgenes
13.
Hepatology ; 64(1): 209-23, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26710118

RESUMO

UNLABELLED: Liver fibrosis is a common outcome of chronic liver disease that leads to liver cirrhosis and hepatocellular carcinoma. No US Food and Drug Administration-approved targeted antifibrotic therapy exists. Activated hepatic stellate cells (aHSCs) are the major cell types responsible for liver fibrosis; therefore, eradication of aHSCs, while preserving quiescent HSCs and other normal cells, is a logical strategy to stop and/or reverse liver fibrogenesis/fibrosis. However, there are no effective approaches to specifically deplete aHSCs during fibrosis without systemic toxicity. aHSCs are associated with elevated expression of death receptors and become sensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell death. Treatment with recombinant TRAIL could be a potential strategy to ameliorate liver fibrosis; however, the therapeutic application of recombinant TRAIL is halted due to its very short half-life. To overcome this problem, we previously generated PEGylated TRAIL (TRAILPEG ) that has a much longer half-life in rodents than native-type TRAIL. In this study, we demonstrate that intravenous TRAILPEG has a markedly extended half-life over native-type TRAIL in nonhuman primates and has no toxicity in primary human hepatocytes. Intravenous injection of TRAILPEG directly induces apoptosis of aHSCs in vivo and ameliorates carbon tetrachloride-induced fibrosis/cirrhosis in rats by simultaneously down-regulating multiple key fibrotic markers that are associated with aHSCs. CONCLUSION: TRAIL-based therapies could serve as new therapeutics for liver fibrosis/cirrhosis and possibly other fibrotic diseases. (Hepatology 2016;64:209-223).


Assuntos
Células Estreladas do Fígado/efeitos dos fármacos , Cirrose Hepática/tratamento farmacológico , Ligante Indutor de Apoptose Relacionado a TNF/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Tetracloreto de Carbono , Avaliação Pré-Clínica de Medicamentos , Hepatócitos/efeitos dos fármacos , Humanos , Injeções Intravenosas , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Masculino , Ratos Sprague-Dawley , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Regulação para Cima
14.
Adv Healthc Mater ; 4(7): 1023-33, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25761435

RESUMO

Gene delivery to the central nervous system (CNS) has potential as a means for treating numerous debilitating neurological diseases. Nonviral gene vector platforms are tailorable and can overcome key limitations intrinsic to virus-mediated delivery; however, lack of clinical efficacy with nonviral systems to date may be attributed to limited gene vector dispersion and transfection in vivo. It is shown that the brain extracellular matrix (ECM) strongly limits penetration of polymer-based gene vector nanoparticles (NP) through the brain parenchyma, even when they are very small (<60 nm) and coated with a polyethylene glycol (PEG) corona of typical density. Following convection enhanced delivery (CED), conventional gene vectors are confined to the injection site, presumably by adhesive interactions with the brain ECM and do not provide gene expression beyond the point of administration. In contrast, it is found that incorporating highly PEGylated polymers allows the production of compacted (≈43 nm) and colloidally stable DNA NP that avoid adhesive trapping within the brain parenchyma. When administered by CED into the rat striatum, highly PEGylated DNA NP distribute throughout and provide broad transgene expression without vector-induced toxicity. The use of these brain-penetrating gene vectors, in conjunction with CED, offers an avenue to improve gene therapy for CNS diseases.


Assuntos
Encéfalo/metabolismo , DNA/administração & dosagem , DNA/genética , Nanopartículas/administração & dosagem , Polietilenoglicóis/administração & dosagem , Animais , Linhagem Celular Tumoral , Matriz Extracelular/genética , Técnicas de Transferência de Genes , Terapia Genética/métodos , Vetores Genéticos/genética , Polímeros/administração & dosagem , Coelhos , Ratos , Transfecção/métodos , Transgenes/genética
15.
Biomaterials ; 42: 42-51, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25542792

RESUMO

A major limitation in the treatment of glioblastoma (GBM), the most common and deadly primary brain cancer, is delivery of therapeutics to invading tumor cells outside of the area that is safe for surgical removal. A promising way to target invading GBM cells is via drug-loaded nanoparticles that bind to fibroblast growth factor-inducible 14 (Fn14), thereby potentially improving efficacy and reducing toxicity. However, achieving broad particle distribution and nanoparticle targeting within the brain remains a significant challenge due to the adhesive extracellular matrix (ECM) and clearance mechanisms in the brain. In this work, we developed Fn14 monoclonal antibody-decorated nanoparticles that can efficiently penetrate brain tissue. We show these Fn14-targeted brain tissue penetrating nanoparticles are able to (i) selectively bind to recombinant Fn14 but not brain ECM proteins, (ii) associate with and be internalized by Fn14-positive GBM cells, and (iii) diffuse within brain tissue in a manner similar to non-targeted brain penetrating nanoparticles. In addition, when administered intracranially, Fn14-targeted nanoparticles showed improved tumor cell co-localization in mice bearing human GBM xenografts compared to non-targeted nanoparticles. Minimizing non-specific binding of targeted nanoparticles in the brain may greatly improve the access of particulate delivery systems to remote brain tumor cells and other brain targets.


Assuntos
Encéfalo/metabolismo , Glioblastoma/metabolismo , Nanopartículas/química , Receptores do Fator de Necrose Tumoral/metabolismo , Animais , Anticorpos/metabolismo , Transporte Biológico , Encéfalo/patologia , Linhagem Celular Tumoral , Embrião de Mamíferos/citologia , Proteínas da Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Glioblastoma/patologia , Humanos , Cinética , Camundongos , Ligação Proteica , Estrutura Terciária de Proteína , Ratos Sprague-Dawley , Receptores do Fator de Necrose Tumoral/química , Ressonância de Plasmônio de Superfície , Receptor de TWEAK , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
16.
ACS Nano ; 8(10): 10655-64, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25259648

RESUMO

Poor drug distribution and short drug half-life within tumors strongly limit efficacy of chemotherapies in most cancers, including primary brain tumors. Local or targeted drug delivery via controlled-release polymers is a promising strategy to treat infiltrative brain tumors, which cannot be completely removed surgically. However, drug penetration is limited with conventional local therapies since small-molecule drugs often enter the first cell they encounter and travel only short distances from the site of administration. Nanoparticles that avoid adhesive interactions with the tumor extracellular matrix may improve drug distribution and sustain drug release when applied to the tumor area. We have previously shown model polystyrene nanoparticles up to 114 nm in diameter were able to rapidly diffuse in normal brain tissue, but only if coated with an exceptionally dense layer of poly(ethylene glycol) (PEG) to reduce adhesive interactions. Here, we demonstrate that paclitaxel (PTX)-loaded, poly(lactic-co-glycolic acid) (PLGA)-co-PEG block copolymer nanoparticles with an average diameter of 70 nm were able to diffuse 100-fold faster than similarly sized PTX-loaded PLGA particles (without PEG coatings). Densely PEGylated PTX-loaded nanoparticles significantly delayed tumor growth following local administration to established brain tumors, as compared to PTX-loaded PLGA nanoparticles or unencapsulated PTX. Delayed tumor growth combined with enhanced distribution of drug-loaded PLGA-PEG nanoparticles to the tumor infiltrative front demonstrates that particle penetration within the brain tumor parenchyma improves therapeutic efficacy. The use of drug-loaded brain-penetrating nanoparticles is a promising approach to achieve sustained and more uniform drug delivery to treat aggressive gliomas and potentially other brain disorders.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Encéfalo/metabolismo , Glioma/tratamento farmacológico , Nanopartículas , Paclitaxel/uso terapêutico , Humanos
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