In this paper, dextran was modified with hydrophobic cholesteryl hemisuccinate (CHS) to generate amphiphilic dextran-CHS as the colon cancer cell-targeting carrier, a donor-acceptor structure-based PS was then modified with bromine atoms to increase the efficiency, and the PS was encapsulated into dextran-CHS to form NPs to realize selective PDT of colon cells. The gene discussed is LYST; the disease is colonic neoplasm.