Selective delivery of drugs or imaging dyes to tumor is the central challenge for improving existing therapy and diagnosis of cancer. Phage display of random peptides has been used to identify homing peptides that are specific to tumor cells or tumor blood vessels. These homing peptides can be conjugated with imaging agents or therapeutic drugs and may be a promising tool for affinity-based targeted delivery of imaging agents and drugs. This chapter describes the procedures for phage display selection of peptides that selectively bind to bladder tumor cells and home to tumor tissues in vivo. It also describes the application of the tumor-specific peptide to the detection of bladder cancer cells in the patient urine.
