Novel pH sensitive nanocarriers for in situ release of anticancer drugs.

In the last decades, amphiphilic self-assembling block copolymers have been studied as carriers for hydrophobic anticancer drugs. Incorporation of drugs into polymeric micelles offer a variety of advantages such as increased stability and improved solubility. However, often polymeric micelles are devoid of site selectivity. To overcome this limitation, targeting approaches have been developed [1]. A “Smart materials” that respond with sharp physical and morphological alterations to the microenvironmental conditions have been designed for selective drug delivery. Responsive systems that exploipit the peculiar features of tumor tissues, namely low extracellular pH, altered redox potential and enzymatic pool, high temperature, have been sucecsfuly investigated. In the present work, pH-responsive polymeric materials featuring ionizable groups as pendant units have been developed to produce stimuli sensitive colloidal drug carriers. The polymers have been designed to undergo pH depndent hydrophilic/hydrophobic switching [2]. The polymer assembled in micelles potentially able to release tamoxifen in the tumor, thus combining the EPR effect and the pH response to improve the site selectivity of the anticancer therapy [3].