RESUMEN
The purpose of this study was to analyze the encapsulation of superparamagnetic iron oxide nanoparticles (SPION) by the lipid nanoparticle conjugated with the 12-mer peptides (RLLDTNRPLLPY, L-peptide), and the delivery of this complex into living cells. The lipid nanoparticles employed in this work were highly hydrophilic, stable, and contained poly(ethylene-glycol) for conjugation to the bioactive L-peptide. The particle sizes of two different magnetic lipid nanoparticles, L-peptide modified (LML) and non-L-peptide modified (ML), were both around 170 nm with a narrow range of size disparity. The transversal relaxivity, r2, for both LML and ML nanoparticles were found to be significantly higher than the longitudinal relaxivity r1 (r2/r1 > 20). The in vitro tumor cell targeting efficacy of the LML nanoparticles were evaluated and compared to the ML nanoparticles, upon observing cellular uptake of magnetic lipid nanoparticles by the nasopharyngeal carcinoma cells, which express cell surface specific protein for the L-peptide binding revealed. In the Prussian blue staining experiment, cells incubated with LML nanoparticles indicated much higher intracellular iron density than cells incubated with only the ML and SPION nanoparticles. In addition, the MTT assay showed the negligible cell cytotoxicity for LML, ML and SPION nanoparticles. The MR imaging studies demonstrate the better T2-weighted images for the LML-nanoparticle-loaded nasopharyngeal carcinoma cells than the ML- and SPION-loaded cells.
Asunto(s)
Medios de Contraste , Imagen por Resonancia Magnética/métodos , Magnetismo , Nanopartículas , Neoplasias Nasofaríngeas/diagnóstico , Humanos , Técnicas In Vitro , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Difracción de PolvoRESUMEN
This study explores the potential of applying health belief models to studies of mothers who participate in newborn hearing screening (NHS) in order to establish a reference for the future research. The study was designed prospectively, with 653 effective samples enrolled between November 1991 and April 1992 and data collected using a self-constructed questionnaire. The return rate for the questionnaire was 68.6%. Main conclusions include: (1) the decision to participate in newborn hearing screening correlates in a significant manner with potential participant backgrounds and actions clues; (2) "knowledge of NHS" and "perceived benefits of action in NHS" were the most important factors in this study associated with NHS participation; (3) subjects who participated in the NHS demonstrated significantly higher scores in "knowledge of NHS" and "perceived benefits of action in NHS" than those who did not participate. Significant negative correlation was identified between education level and perceived barriers to joining NHS. Significant positive correlation was observed between education level and NHS knowledge. Also, a significant positive relationship was identified between "perceived benefits of action in NHS" and both "clues of inner action" and "knowledge of NHS". However, "perceived barriers to NHS action" was found to share no significant relationship with any of the others. A positive relationship was also identified between "perceived benefits of action in NHS" and both "clues of outer action" and "amount of information resources"; and (4) "clues of outer action", "NHS knowledge", and "perceived benefits of NHS action" were found to be the most important indicators affecting study subjects' decision regarding whether or not to join NHS.