RESUMEN
Magnetic nanoparticles are the next tool in medical diagnoses and treatment in many different biomedical applications, including magnetic hyperthermia as alternative treatment for cancer and bacterial infections, as well as the disruption of biofilms. The colloidal stability of the magnetic nanoparticles in a biological environment is crucial for efficient delivery. A surface that can be easily modifiable can also improve the delivery and imaging properties of the magnetic nanoparticle by adding targeting and imaging moieties, providing a platform for additional modification. The strategy presented in this work includes multiple nitroDOPA anchors for robust binding to the surface tied to the same polymer backbone as multiple poly(ethylene oxide) chains for steric stability. This approach provides biocompatibility and enhanced stability in fetal bovine serum (FBS) and phosphate buffer saline (PBS). As a proof of concept, these polymer-particles complexes were then modified with a near infrared dye and utilized in characterizing the integration of magnetic nanoparticles in biofilms. The work presented in this manuscript describes the synthesis and characterization of a nontoxic platform for the labeling of near IR-dyes for bioimaging.
Asunto(s)
Biopelículas , Dihidroxifenilalanina/química , Colorantes Fluorescentes/química , Legionella pneumophila , Nanopartículas/química , Polietilenglicoles/química , Animales , Bovinos , Legionella pneumophila/citología , Legionella pneumophila/fisiología , Ratones , Microscopía FluorescenteRESUMEN
This study examined whether social cognitions that have been assumed to influence aggression actually forecast change in aggressive habits over time. Participants were 189 3rd- through 7th-grade boys and girls; data on social cognitions and social behaviors were collected in the fall and spring of the school year. Aggression-encouraging cognitions assessed in the fall indeed promoted aggression over the school year, but such developments hinged critically on child sex and on initial (fall) levels of aggression and victimization. Results illustrate the principle that cognitions affect behavioral development mainly when the child's transactions with the social environment support the use of the cognitions as guides for behavior.