Low intensity electric field inactivation of Gram-positive and Gram-negative bacteria via metal-free polymeric composite.

The adhesion of pathogenic bacteria in medical implants and surfaces is a health-related problem that requires strong inhibition against bacterial growth and attachment. In this work, we have explored the enhancement in the antibacterial activity of metal free-based composites under external electric field. It affects the oxidation degree of polypyrrole-based electrodes and consequently the antibacterial activity of the material. A conductive layer of carbon nanotubes (graphite) was deposited on porous substrate of polyurethane (sandpaper) and covered by polypyrrole, providing highly conductive electrodes characterized by intrinsic antibacterial activity and reinforced by electro-enhanced effect due to the external electric field. The bacterial inhibition of composites was monitored from counting of viable cells at different voltage/time of treatment and determination of biofilm inhibition on electrodes and reactors. The external voltage on electrodes reduces the threshold time for complete bacterial inactivation of PPy-based composites to values in order of 30 min for Staphylococcus aureus and 60 min for Escherichia coli.

Multifunctional Wearable Electronic Textiles Using Cotton Fibers with Polypyrrole and Carbon Nanotubes.

Multifunctional wearable electronic textiles based on interfacial polymerization of polypyrrole on carbon nanotubes/cotton fibers offer advantages of simple and low-cost materials that incorporate bactericidal, good electrochemical performance, and electrical heating properties. The high conductivity of doped polypyrrole/CNT composite provides textiles that reaches temperature on order of 70 °C with field of 5 V/cm, superior electrochemical performance applied as electrodes of supercapacitor prototypes, reaching capacitance in order of 30 F g-1 and strong bactericidal activity against Staphylococcus aureus. The combination of these properties can be explored in smart devices for heat and microbial treatment on different parts of body, with incorporated storage of energy on textiles.

Antibacterial behavior of polypyrrole: The influence of morphology and additives incorporation.

The antibacterial behavior of polypyrrole (PPy) depends on a diversity of structural parameters such as surface area, aggregation level and additives (metal nanoparticles) incorporation. This paper summarizes the influence of different preparation procedures of PPy on action of resulting antibacterial composite against Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. The bactericidal action has been assigned to morphology (size of polypyrrole nanoparticles). The electrostatic interaction established between polymer nanoparticles and bacteria provokes the bacterial cell death and returns advantages in comparison with conventional composites of polypyrrole decorated with metal nanoparticles.