Polycarbonate Micelles for Cancer Therapy

Volume 6(8) 310-313 (2014) 310 J Cancer Sci Ther ISSN:1948-5956 JCST, an open access journal In cancer therapy a primary goal is to kill cancer cells without damaging normal ones. Following diagnosis, chemotherapy is frequently the method of treatment. Unfortunately, significant challenges associated with conventional chemotherapy limits its efficacy. First, majority of anticancer drugs presently prescribed in chemotherapy are not selective. They kill both cancerous and healthy cells resulting in systemic toxicity and life-threatening side effects. Treatments prescribed for cancer patients typically result in 1 out of 100,000 drug molecules actually reaching the disease target site [1]. Therefore even when chemotherapeutic drugs work in some cancer patients most experience adverse side effects. For instance, patients can suffer a compromised immune system during treatment and become prone to other debilitating diseases. Non-specific anticancer drug distribution also hinders therapeutic strategies employing high doses. Second, most anticancer drugs eventually succumb to multidrug resistance. Some cancer cells at the onset of therapy are intrinsically resistant due to a resistance phenotype. However, majority of cancer cells are initially responsive to chemotherapy and later become unresponsive to similar doses due to acquired resistance following repeated chemotherapy cycles [2]. Once resistance develops, systemic administration of anticancer drugs becomes ineffective. Finally, approximately a third of potent anticancer drugs is highly lipophilic and requires the use of solubilizing agents such as dimethyl sulfoxide (DMSO) and Cremophor® EL to bring them into true solution so they can be administered systemically to be clinically useful. Nonetheless, toxicity of the solubilizing agents hinder application of these anticancer drugs since they can lead to neurotoxicity, cause dose-dependent hemolysis and are harmful to the liver and kidneys [3,4]. Hence, regardless of advances made in drug discovery and therapeutic strategies (e.g., combination therapy), cancer therapy is often associated with unsatisfactory results and the war on cancer must be waged differently to significantly improve the health of cancer patients. Breakthroughs in treating cancer not only require innovative ways of treating cancer but also novel concepts regarding cancer-focused drug delivery.