Antibacterial Strategies: Photodynamic and Photothermal Treatments Based on Carbon-Based Materials

The problem of bacterial resistance is based on the abuse of antibiotics such as trimethoprim, fluoroquinolones, chloramphenicol, and some carbapenems. For this reason, conventional treatments to treat diseases caused by bacteria have become ineffective. Therefore, developing new therapies with multifunctional materials to combat bacteria is mandatory. In this context, photodynamic treatment (PDT) and photothermal treatment (PTT) have been proposed to combat bacteria. These light-stimulated treatments are minimally invasive and have a low incidence of side effects. In addition, they are simple, fast, and profitable. The antibacterial effect of PDT, PTT, or synchronic PDT/PTT arises from the generation of reactive oxygen species (ROS) and heat caused by a photoactivated specific photosensitizer (PS) and photothermal agents (PTAs), respectively. The effectiveness of photoinduced treatment depends, among other parameters, on the nature and concentration of the PS/PTAs, light dose, and irradiation wavelength. PS/PTAs based on carbon-based materials (CBMs), such as graphene oxide, reduced graphene oxide, carbon dots, and carbon nanotubes as antibacterial agents, will be discussed in this chapter. These CBMs have emerged as excellent antibacterial alternatives due to their excellent physicochemical properties, biocompatibility, low toxicity in the dark, specificity, and excellent response to light. Moreover, several composites and hybrids employing polymers, metal oxides, and metals have been tested to enhance the antibacterial activity of the CBMs.