Chemotherapeutic agents in general lack specificity because they act on all proliferating cells by inhibiting DNA synthesis or interfering with processes of cell division and metabolism. As a consequence, chemotherapy leads to the damage of healthy cells, especially of the normally dividing cells of the bone marrow, skin, and gastro-intestinal mucosa. In addition, neoplastic cells readily mutate, and many cancers develop resistance to chemotherapeutic agents. The need for improved therapies for the treatment of cancer is still great, and one of the strategies that is currently being investigated to improve patient outcomes is the development of engineered delivery systems that improve the pharmacological characteristics of antineoplastic drugs in vivo. For cancer treatment, specifically, these drug delivery systems aim to increase the therapeutic efficacy of the chemotherapeutic agent while minimizing its interaction with non-pathological sites in the body by modifying its biodistribution and controlling the rate at which the agent is released from the carrier to the systemic circulation or tissues. The design and consequent physiochemical properties of the drug carrier determine the results observed in vivo.
Injectable drug carriers that have been used for the controlled delivery of chemotherapeutic agents include liposomes, micelles, prodrugs, microparticles, and nanoparticles. Numerous biopolymers, both synthetic and natural, have been utilized for drug delivery applications. As for any other device destined for in vivo applications, drug delivery systems must result in low or preferably non-detectable adverse physiological interactions such as immunogenicity and toxicity. Synthetic polymers have a number of benefits compared to natural polymers including high control of polymer properties, such as molecular weight and functionality, and feasible commercial scale production. In addition, although both synthetic and natural polymers may activate the complement system, natural polymers may lead to cellular and humoral immune response as a result of the recognition of foreign organism markers.
The work described in this presentation will include some from our own research lab or targeted delivery of chemotherapeutic and imaging agents as well as work from other labs on targeting to cancer through angiogenesis, using folate receptors and targeting to specific cancer types.