RESUMO
We developed a very simple, efficient and environment-friendly synthesis method for the manufacturing of high-performance chitosan-capped gold nanoparticles that could be used for biosensing applications. Gold nanoparticles were prepared through the spontaneous reduction of chloroauric acid by chitosan, which was used as both a reducing and a stabilizing agent. The samples were heated to a temperature of 60 °C under ultrasonic conditions. The composite system made of chitosan as a matrix and gold nanoparticles demonstrated a high stability in an aqueous buffer solution. The nanoparticles displayed an enhancement in photonic performance compared with the same property of individual components as a result of surface plasmon resonance at the interface between the structural phases of the hybrid structure. The enhanced photonic reactivity of the hybrid nanostructure may offer new insights for future possible biosensing applications.
RESUMO
Lipid (L-α-phosphatidylcholine) was used in liposome-ketoprofen formulation to obtain vesicles systems characterized by a net positive charge along the liposomal surface. A careful analysis of vesicles formation and systems stability was made. Dynamic stability and specificity of liposomes disruption and prolonged release of ketoprofen was provided by steric effect accomplished on the vesicle surface by chitosan molecules, which were introduced into the system additionally. The retardation effect of the liposomes containing ketoprofen was tested in vitro and in vivo. The studies have shown that the liposomes containing ketoprofen obtained are characterized by a net positive charge and an average diameter of 1,287 nm for dialyzed solutions (pH 7.40). This formulation presents in vivo significant antinociceptive effects starting at 90 min, with a maximum intensity between 2 and 8 h, prolonged more than 10 h, and an analgesic activity within 3-4 h.
