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1.
Colloids Surf B Biointerfaces ; 146: 19-30, 2016 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-27244047

RESUMEN

Lung cancer, the deadliest solid tumor among all types of cancer, remains difficult to treat. This is a result of unavoidable exposure to carcinogens, poor diagnosis, the lack of targeted drug delivery platforms and limitations associated with delivery of drug to deep lung tissues. Development of a non-invasive, patient-convenient formula for the targeted delivery of chemotherapeutics to cancer in deep lung tissue is the aim of this study. The formulation consisted of inhalable polyvinylpyrrolidone (PVP)/maltodextrin (MD)-based microparticles (MPs) encapsulating chitosan (CS) nanoparticles (NPs) loaded with either drug only or drug and magnetic nanoparticles (MNPs). Drug release from CS NPs was enhanced with the aid of MNPs by a factor of 1.7 in response to external magnetic field. Preferential toxicity by CS NPs was shown towards tumor cells (A549) in comparison to cultured fibroblasts (L929). The prepared spray freeze dried (SFD) powders for CS NPs and CS MNPs were of the same size at ∼6µm. They had a fine particle fraction (FPF≤5.2µm) of 40-42% w/w and mass median aerodynamic diameter (MMAD) of 5-6µm as determined by the Next Generation Impactor (NGI). SFD-MPs of CS MNPs possess higher MMAD due to the high density associated with encapsulated MNPs. The developed formulation demonstrates several capabilities including tissue targeting, controlled drug release, and the possible imaging and diagnostic values (due to its MNPs content) and therefore represents an improved therapeutic platform for drug delivery to cancer in deep lung tissue.


Asunto(s)
Quitosano/química , Sistemas de Liberación de Medicamentos , Neoplasias Pulmonares/tratamiento farmacológico , Pulmón/efectos de los fármacos , Nanopartículas/química , Polvos/administración & dosificación , Administración por Inhalación , Química Farmacéutica , Quitosano/administración & dosificación , Portadores de Fármacos/química , Liberación de Fármacos , Liofilización , Humanos , Pulmón/metabolismo , Neoplasias Pulmonares/metabolismo , Magnetismo , Nanopartículas/administración & dosificación , Tamaño de la Partícula , Polvos/química , Células Tumorales Cultivadas
2.
Chem Commun (Camb) ; 49(43): 4896-8, 2013 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-23609342

RESUMEN

Magnetic iron oxide, maghemite (Fe2O3) nanoparticles with covalent surface-bound CO-releasing molecules (CORMs) can be triggered to release CO through heating in an alternating magnetic field. In the proof-of-concept study the rate of CO-release from [RuCl(CO3)(µ-DOPA)]@maghemite nanoparticles was doubled upon exposure to an external alternating magnetic field (31.7 kAm(-1), 247 kHz, 25 °C, 39.9 mTesla, DOPA = dioxyphenyl-alaninato).


Asunto(s)
Monóxido de Carbono/química , Complejos de Coordinación/química , Compuestos Férricos/química , Nanopartículas del Metal/química , Compuestos de Rutenio/química , Dihidroxifenilalanina/química , Calor , Fenómenos Magnéticos
3.
Pediatrics ; 125(5): e1249-54, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20385644

RESUMEN

Molybdenum cofactor deficiency (MoCD) is a rare metabolic disorder characterized by severe and rapidly progressive neurologic damage caused by the functional loss of sulfite oxidase, 1 of 4 molybdenum-dependent enzymes. To date, no effective therapy is available for MoCD, and death in early infancy has been the usual outcome. We report here the case of a patient who was diagnosed with MoCD at the age of 6 days. Substitution therapy with purified cyclic pyranopterin monophosphate (cPMP) was started on day 36 by daily intravenous administration of 80 to 160 microg of cPMP/kg of body weight. Within 1 to 2 weeks, all urinary markers of sulfite oxidase (sulfite, S-sulfocysteine, thiosulfate) and xanthine oxidase deficiency (xanthine, uric acid) returned to almost normal readings and stayed constant (>450 days of treatment). Clinically, the infant became more alert, convulsions and twitching disappeared within the first 2 weeks, and an electroencephalogram showed the return of rhythmic elements and markedly reduced epileptiform discharges. Substitution of cPMP represents the first causative therapy available for patients with MoCD. We demonstrate efficient uptake of cPMP and restoration of molybdenum cofactor-dependent enzyme activities. Further neurodegeneration by toxic metabolites was stopped in the reported patient. We also demonstrated the feasibility to detect MoCD in newborn-screening cards to enable early diagnosis.


Asunto(s)
Encefalopatías Metabólicas Innatas/tratamiento farmacológico , Coenzimas/deficiencia , Metaloproteínas/deficiencia , Pterinas/administración & dosificación , Errores Innatos del Metabolismo de la Purina-Pirimidina/tratamiento farmacológico , Sulfito-Oxidasa/deficiencia , Encefalopatías Metabólicas Innatas/diagnóstico , Diagnóstico Diferencial , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Recién Nacido , Infusiones Intravenosas , Cofactores de Molibdeno , Compuestos Organofosforados/uso terapéutico , Pteridinas , Pterinas/uso terapéutico , Errores Innatos del Metabolismo de la Purina-Pirimidina/diagnóstico
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