Fullerene derivatives in photodynamic inactivation of microorganisms

M. B. SPESIA; M. E. MILANESIO; E. N. DURANTINI

Nanostructures for Antimicrobial Therapy, Nanoestructures in Therapeutic Medicine Serie, a volume in Micro and Nano Technologies

Elsevier

Lugar: Amsterdam; Año: 2017; p. 413 - 433

Fullerene derivatives are under intensive investigation for potentialbiomedical applications. These compounds are generally accepted as nanoparticles with several applicationsin medicine. The combination of visible lightabsorption and a long lifetime of triplet excited state allow fullerenes to actas efficient photosensitizers. Also, chemical modifications of the fullerenescan be used to attach functional hydrophilic cationic groups. Interestingresults have been found using amphiphilic cationic fullerenes asphotosensitizers to photoinactivate microorganisms. Under aerobicconditions, the triplet excited state of fullerene can interact with groundstate molecular oxygen to form ROS. This process can occur by energy transferto produce singlet molecular oxygen, O2(1Dg) or by electron transfer to form superoxideanion radical (O2.-). In contrast to 1O2generation, the electron transfer type of reaction is favored in polarsolvents, particularly in the presence of reducing agents, such as NADH. Moreover, fullerenes were attached to light-harvestingantenna structures that increases light absorption and presents high capacityto form photoinduced charge-separated state. Inparticular, cationic fullerenes can selectively bind to microbial cells,inducing an efficient photoinactivation of pathogenic microorganisms.Therefore, functionalized fullerenes are interesting nanostructures withpotential applications as antimicrobial photosensitizing agents.