Polymer-Based Drug Delivery Systems for Cancer.

The standard treatment for metastatic cancer is generally a combination of chemotherapy, surgery, and radiotherapy. Since there are few specific chemotherapeutics approved by the US Food and Drug Administration, systemic chemotherapy is widely employed in the hopes of destroying rapidly dividing cancer cells before doing irreversible damage to the human body. Because of the nature of traditional chemotherapeutics, systemic treatment is associated with various side effects, such as nausea, dysphoria, vomiting, and pain, and long-term, irreversible damage to major organs, such as the kidney and heart. As life expectancy increases, so has the need for reliable cancer therapy that spares or prevents damage to functional healthy organs. One method is to precisely deliver drugs into specific tumor cells and tissues. Polymers have been characterized as favorable systems to deliver drugs with tunable pharmacokinetics, circulation times, biocompatibility, and biodegradability. Here, various types of polymers, modified as drug delivery systems for targeting cancer, and targeting behaviors of polymer-based carriers will be discussed.