RESUMO
In this paper, we present the facile preparation of polyaniline (PANI) hollow spheres by using a silane coupling agent, N-[3-(trimethoxysilyl) propyl]aniline (PAPTMS), as a precursor. The PANI hollow spheres exhibit tunable shell thickness. PAPTMS was used to prepare aniline-modified silica microparticles, ~550 nm in diameter, by the Stöber process. PANI-coated silica core-shell microcapsules (SiO(2)@PANI) were subsequently obtained by performing chemically oxidative polymerization of a specific aniline monomer loading in the presence of the core-shell particles. PANI hollow spheres with tunable PANI shell thicknesses were eventually obtained by immersing the as-prepared core-shell particles in 5 wt% HF aqueous solutions to simultaneously remove the silica cores and further dope the PANI shells. The as-prepared core-shell particles and PANI hollow spheres were characterized using Fourier-transform infrared (FTIR) and (29)Si nuclear magnetic resonance (NMR) spectroscopies. The surface morphologies of the core-shell particles and PANI hollow spheres were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrical conductivities and optical absorption spectra of the as-prepared core-shell microparticles and the PANI hollow spheres were measured using the standard four-point probe method and ultraviolet-visual (UV-Vis) absorption spectroscopy, respectively.
RESUMO
In this manuscript, neat electrospun poly(o-methoxyaniline) (POMA) fibers were applied for the first time in the growth of neural stem cells. POMA was synthesized by chemical oxidative polymerization, followed by dissolving in tetrahydrofuran/dimethylformamide to prepare electrospinning solution. Subsequently, the solution was electrospun to produce polymeric fibers. The structure, transparency and morphology of as-prepared POMA fibers were characterized by Fourier transform infrared spectroscopy, UV-visible spectroscopy and scanning electron microscopy, respectively. It was found to have no adverse effects on the long-term proliferation of the neural stem cells (NSCs), retain the ability to self-renew, and exhibit multipotentiality. Studies on cell-fiber interactions were carried out by culturing NSCs on the POMA substrate and assessing their growth, cell viability, and differentiation. Results of cell viability assay, immunofluorescence staining, quantitative real-time reverse transcription-PCR and calcium image studies confirmed that POMA electrospun fibers not only showed better NSCs attachment, but also enhanced and accelerated differentiation.