Oxidative solution polymerization of aniline hydrochloride onto electrospun nanofibers mats of polylactic acid: Preparation method and characterization

Adsorption of methyl orange onto electrospun nanofiber membranes of PLLA coated with pTSA-PANI

This work evaluates the performance of electrospun nanofiber membranes of PLLA coated with p-toluenesulfonic acid doped polyaniline (pTSA-PANI). The adsorption on the prepared membranes of methyl orange (MO), taken as an example of anionic organic dye pollutants, was studied. The effects of different parameters on the adsorption capacity and removal efficiency, such as MO concentration, temperature, adsorbent dosage, pH, and ionic strength of the solution, were investigated. The results indicate the beneficial effect of coating PLLA membranes with pTSA-PANI in promoting the adsorption performance of the membranes. The grounds behind this enhancement are discussed. The adsorption kinetics and adsorption isotherms were performed. DC conductivity and AC impedance measurements of the studied membranes were conducted. The values were correlated to MO concentrations, suggesting the potential capacity of the current membrane to be used as a sensor of MO concentration. Graphical abstract.

Electrospun Conducting and Biocompatible Uniaxial and Core-Shell Fibers Having Poly(lactic acid), Poly(ethylene glycol), and Polyaniline for Cardiac Tissue Engineering

Electroactive and biocompatible fibrous scaffolds have been prepared and characterized using polyaniline (PAni) doped with dodecylbenzenesulfonic acid (DBSA) combined with poly(lactic acid) (PLA) and PLA/poly(ethylene glycol) (PEG) mixtures. The composition of simple and core-shell fibers, which have been obtained by both uniaxial and coaxial electrospinning, respectively, has been corroborated by Fourier-transform infrared and micro-Raman spectroscopies. Morphological studies suggest that the incorporation of PEG enhances the packing of PLA and PAni chains, allowing the regulation of the thickness of the fibers. PAni and PEG affect the thermal and electrical properties of the fibers, both decreasing the glass transition temperature and increasing the electrical conductivity. Interestingly, the incorporation of PEG improves the PAni-containing paths associated with the conduction properties. Although dose response curves evidence the high cytotoxicity of PAni/DBSA, cell adhesion and cell proliferation studies on PLA/PAni fibers show a reduction of such harmful effects as the conducting polymer is mainly retained inside the fibers through favorable PAni···PLA interactions. The incorporation of PEG into uniaxial fibers resulted in an increment of the cell mortality, which has been attributed to its rapid dissolution into the culture medium and the consequent enhancement of PAni release. In opposition, the delivery of PAni decreases and, therefore, the biocompatibility of the fibers increases when a shell coating the PAni-containing system is incorporated through coaxial electrospinning. Finally, morphological and functional studies using cardiac cells indicated that these fibrous scaffolds are suitable for cardiac tissue engineering applications.