Preparation of folate-conjugated starch nanoparticles and its application to tumor-targeted drug delivery vector

Anion starch nanoparticles (StNP) were prepared in water-in-oil microemulsion. Folate modified with PEG was conjugated to the surface of StNP to obtain the folate-conjugated starch nanoparticles (FA-PEG/StNP). The average diameter of FA-PEG/StNP determined by AFM and Zeta-Sizer apparatus was about 130 nm. Doxorubicin (DOX)-loaded FA-PEG/StNP was obtained via infiltrating combination. The result of UV spectrophotometer showed that the saturation concentration of DOX-loaded FA-PEG/StNP was 28 mu g/mg, which was effective for the controlled release of anticancer drug DOX. The cell experiments showed that the L-c50 of DOX-loaded FA-PEG/StNP and DOX-loaded StNP was higher than that of DOX, which indicates that FA-PEG/StNP and StNP can decrease the toxicity of DOX; while the lethal rate of DOX-loaded FA-PEG/StNP was 3 times that of DOX-loaded StNP with the same quantity of DOX, which indicates that FA in FA-PEG/StNP is effective for improving the targeting function of nanoparticles, thus enhancing the inhibition effect of anticancer drug to cancer cell. This work demonstrates that the FA-PEG/StNP system is a potentially useful system for the targeted delivery of anticancer drug DOX.