Compositions of the invention include glycoproteins, such as transferrin, and metal-based coordination complexes, which are preferably chemotherapeutic compounds and more preferably tunable photodynamic compounds. The compositions are useful as in vivo diagnostic agents, and as therapeutic agents for treating or preventing diseases including those that involve hyperproliferating cells in their etiology, such as cancer. Compositions of the invention are further capable of destroying microbial cells, such as bacteria, fungi, and protozoa, and destroying viruses. Treatment methods of the invention can treat conditions throughout the body, including conditions located across the blood-brain barrier, the retina-blood barrier and the blood-cerebrospinal fluid barrier.
