Near-Infrared Photodynamic Therapy with π-Extended Porphyrins.

Photodynamic therapy has several benefits over chemotherapy and radiotherapy in the treatment of localized tumors such as a high selectivity, low side effects and immune stimulatory properties [1]. Due to the fast spread of multi-resistant microorganisms that represent a threat to public health, antimicrobial photodynamic therapy (a-PDT) is also experiencing renewed interest [2]. A major strength of a-PDT is the absence of bacterial resistance to the treatment and its effectiveness on resistant strains [3]. Nevertheless, treatments based on PDT have severallimitations related to the photosensitizer properties, selectivity, light delivery and tissue oxygenation. Regarding these issues, our group has developed photosensitizers for PDT, a-PDT and theranostic applications that can be excited in the optical therapeutic window for deeper treatment with less photodamage. They are based on porphyrins with an extended π-conjugated system for one or two-photon excitation in the near infrared (Figure 1) [4]. For a-PDT, a porphyrin connected to an antimicrobial peptide was recently synthesized to target and kill bacteria upon near-infrared excitation and its photodynamic disinfection capacity will be discussed [5]. [ABSTRACT FROM AUTHOR]