Drug delivery systems improving chemical and physical properties of anticancer drugs currently investigated for treatment of solid tumors.

Cancer is the second leading cause of death worldwide. Conventional cancer treatment like chemotherapy do not fulfil the expectations of both patients and physicians and there is a pressing need for a new kind of therapies that will increase drug delivery to the tumor mass. Standard chemotherapy does not show either specific tumor-targeting, or selective mode of action for cancer cells. Moreover, tumor microenvironments additionally disturb drug perfusion and diffusion. Currently approved anticancer drugs have many limitations and therefore special delivery systems improving their chemical and physical properties are beneficial. In the present review paper we discuss various drug delivery systems for solid tumors that are actually at various stages of pre-clinical tests or approved for therapy.