Photodynamic therapy (PDT) is a well-established clinical treatment modality for various diseases, including cancer. It involves the topical or systemic administration of a photosensitizer, followed by selective irradiation of the target lesion with a specific wavelength of non-ionizing light, which triggers oxidative photodamage and subsequent death of the targeted cells. Due to this two-step therapeutic process, PDT is a safe and minimally-invasive therapy. Nevertheless, classical non-targeted photosensitizers lack sufficient tumor selectivity and are taken up in the neighboring normal tissues, resulting in undesirable adverse effects. To overcome this obstacle, diverse tumor-targeting approaches have been developed. In this article, we discuss the current strategies and rationale regarding tumor-targeted PDT.
Keywords: Drug delivery; photodynamic therapy; photosensitizer; review; tumor targeting.