Targeted Delivery of a Mannose-Conjugated BODIPY Photosensitizer by Nanomicelles for Photodynamic Breast Cancer Therapy

The targeted delivery of a photosensitizer (PS) with appropriate carriers represents an attractive means of selectively delivering cargo to target tissues or subcellular compartments for photodynamic therapy (PDT). Herein, a three-arm distyryl BODIPY derivative conjugated with mannose units (denoted by BTM) that can co-assemble with Tween 80 to form nanomicelles (BTM-NMs) for targeted PDT is reported. MDA-MB-231 breast cancer cells recognized and specifically internalized BTM-NMs via mannose-receptor-mediated endocytosis with preferential accumulation in the lysosomes. These NMs could disassemble in cell lysosomes and subsequently induce highly efficient singlet oxygen (1O2) generation upon light irradiation. 1O2 disrupted the lysosomal membrane and promoted the escape of BTM from the lysosome into the cytoplasm, thereby resulting in the efficient and selective killing of cancer cells through PDT. This study may provide a new strategy for designing targeted PDT systems to fight cancer.