The subject matter disclosed herein relates to compositions that contain a protein cage and a therapeutic agent, such as a photosensitizer. The protein cage is a protein that binds metal ion. The composition can further contain a cell recognition moiety. The methods disclosed are for permeabilizing the endothelial lining of a cancerous tissue or for treating a cancerous tissue to cause therapeutic injury resulting in the reduction of at least one of the surface area, the depth, and the amount of the tissue affected by the cancerous condition, in a subject.
