WIn the area of drug delivery, we focus on design of polymers for controlled delivery of therapeutic agents. One interest of ours is in designing pH-sensitive delivery systems whereby delivery of a therapeutic is facilitated by reduction in pH such as is observed in the tumor interstitium or in the endosome. Recently, we developed catechol-containing polymers for pH dependent delivery of the approved anticancer drug bortezomib (Velcade®). Velcade is a small molecule proteasome inhibitor that contains a boronic acid functional group. We formed polymer complexes between catechol polymers and Velcade, which exhibited pH dependent release of Velcade due to the pH sensitivity of the complex between catechol and boronic acid (Figure). This approach has the potential to aid in more effective delivery of the drug to tumor tissue and to reduce side effects associated with systemic exposure.