Targeted drug delivery is an integral part of treatment for a myriad of diseases. Drug delivery projects in the Putnam lab focus on two main areas: cancer and the brain. P-glycoprotein (P-gp) receptors help cells pump out unwanted, potentially hazardous molecules from the brain to protect it. However, in cancer, this process allows the cancerous tissue to avoid accumulation of chemotherapeutics, and thus cell death. These types of cancer are termed ‘chemotherapeutic resistant’ cancers that are not easily treated. Blocking P-gp receptors, however, would allow drug delivery to these cancers without the drugs being removed, increasing their effectivity. Brain delivery can also benefit from blocking these receptors, as, if drugs can make it through the blood-brain barrier (BBB), they are immediately removed through P-gp. Co-delivery of a BBB-targeting agent, drug, and P-gp inhibitor could greatly benefit treatment of brain diseases in future.