Definition

A nanoparticle-based formulation consisting of polymeric micelles encapsulating the taxane paclitaxel that are coated with the bladder cancer-targeting ligand PLZ4, a cyclic peptide with amino acid sequence of QDGRMGF, with potential antineoplastic activity. Upon administration of the PLZ4-coated paclitaxel-loaded micelle formulation, the PLZ4 moiety specifically targets and binds to bladder cancer cells while avoiding normal, healthy cells. This specifically delivers paclitaxel to bladder cancer cells and, due to the acidic conditions in the tumor and the pH-responsive nature of the micelles, paclitaxel is released in the tumor environment. Paclitaxel binds to microtubules, promotes microtubule assembly, and prevents depolymerization, thus interfering with normal mitosis. Compared to the administration of paclitaxel alone, this formulation increases the solubility of paclitaxel, enhances its specific retention in cancer tissue, and increases its therapeutic effect, while decreasing its toxicity. In addition, the micelle formulation and the addition of PLZ4 may allow for the delivery of higher doses of paclitaxel to bladder cancer cells while minimizing systemic toxicity.