RESUMO
The interest on plants has been focalized due to their biological activities. Extracts or fractions from plants in biodegradable polymeric nanoparticles (NP) provide many advantages on application studies. The encapsulation of the extract or fraction in NP is determined for the establishment of the test dose. HPLC method is an alternative to calculate this parameter. An analytical method based on HPLC for quantification of a hexane fraction from L. frutescens was developed and validated according to ICH. Different concentrations of the hexane fraction from leaves (HFL) were prepared (100-600 µg/mL). Linearity, limit of detection, limit of quantification, and intra- and interday precision parameters were determined. HFL was encapsulated by nanoprecipitation technique and analyzed by HPLC for quantitative aspect. The method was linear and precise for the quantification of the HFL components. NP size was 190 nm with homogeneous size distribution. Through validation method, it was determined that the encapsulation of components (1), (2), (3), and (4) was 44, 74, 86, and 97%, respectively. A simple, repeatable, and reproducible methodology was developed for the propose of quantifying the components of a vegetable material loaded in NP, using as a model the hexane fraction of L. frutescens leaves.
RESUMO
Aminodextran (AMD) polymer was prepared via chemical grafting of hexamethylenediamine on oxidized dextran. Magnetic latex particles were successfully obtained by adsorption of positively charged AMD on negatively charged submicron magnetic emulsion. The adsorbed amount was found to be ranged from 20 to 1280mg of AMD per gram of dried magnetic dispersion. The AMD-coated magnetic emulsions were characterized by positive zeta potential in the pH range from 3 to 9 compared to bare seed magnetic emulsion. All the samples showed to be superparamagnetic property, even after the adsorption of the polymer. The developed magnetic submicron particles exhibited good potential for in vivo biomedical diagnosis applications as demonstrated by their higher T2 contrast-ability compared to Gd in magnetic resonance imaging (MRI) and hyperthermia.
Assuntos
Emulsões/química , Polímeros/química , Meios de Contraste/química , Compostos Férricos/química , Hipertermia Induzida , Imageamento por Ressonância Magnética , Nanomedicina TeranósticaRESUMO
Magnetic particles are of great interest in various biomedical applications, such as, sample preparation, in vitro biomedical diagnosis, and both in vivo diagnosis and therapy. For in vitro applications and especially in labs-on-a-chip, microfluidics, microsystems, or biosensors, the needed magnetic dispersion should answer various criteria, for instance, submicron size in order to avoid a rapid sedimentation rate, fast separations under an applied magnetic field, and appreciable colloidal stability (stable dispersion under shearing process). Then, the aim of this work was to prepare highly magnetic particles with a magnetic core and conducting polymer shell particles in order to be used not only as a carrier, but also for the in vitro detection step. The prepared magnetic seed dispersions were functionalized using pyrrole and pyrrole-2-carboxylic acid. The obtained core-shell particles were characterized in terms of particle size, size distribution, magnetization properties, FTIR analysis, surface morphology, chemical composition, and finally, the conducting property of those particles were evaluated by cyclic voltammetry. The obtained functional submicron highly magnetic particles are found to be conducting material bearing function carboxylic group on the surface. These promising conducting magnetic particles can be used for both transport and lab-on-a-chip detection.
Assuntos
Magnetismo , Polímeros/química , Pirróis/química , Técnicas Eletroquímicas , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Tamanho da Partícula , Prolina/análogos & derivados , Prolina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
Recently, significant research efforts have been devoted to the finding of efficient approaches in order to reduce the side effects of traditional cancer therapy and diagnosis. In this context, magnetic nanoparticles have attracted much attention because of their unique physical properties, magnetic susceptibility, biocompatibility, stability and many more relevant characteristics. Particularly, magnetic nanoparticles for in vivo biomedical applications need to fulfill special criteria with respect to size, size distribution, surface charge, biodegradability or bio-eliminability and optionally bear well selected ligands for specific targeting. In this context, many routes have been developed to synthesize these materials, and tune their functionalities through intriguing techniques including functionalization, coating and encapsulation strategies. In this review article, the use of magnetic nanoparticles for cancer therapy and diagnosis is evaluated addressing potential applications in MRI, drug delivery, hyperthermia, theranostics and several other domains. In view of potential biomedical applications of magnetic nanoparticles, the review focuses on the most recent progress made with respect to synthetic routes to produce magnetic nanoparticles and their salient accomplishments for in vivo cancer diagnosis and therapy.