Targeting Tumor Cells through Chitosan-Folate Modified Microcapsules Loaded with Camptothecin

Poly(vinyl alcohol) microcapsules have been tailored as carriers to deliver camptothecin, an anticancer drug poorly soluble in water. The capsules have been reacted with a chitosan–folate complex in order to selectively target cancer cells overexpressing the folic acid receptor. Microcapsules decorated with the chitosan–folate complex have been characterized in their uptake and release of camptothecin, following the absorption band at λ = 370 nm diagnostic of the drug molecule. The selectivity of chitosan–folate microcapsules in targeting cancer cells has been demonstrated by fluorescence microscopy using HeLa cells, overexpressing the folate receptor and NIH3t3 fibroblasts as a negative control. The chitosan–folate microcapsules loaded with camptothecin significantly reduce the proliferation of HeLa tumor cells, while they have a negligible effect on fibroblasts. This work demonstrates that the chitosan–folate microcapsules represent a promising system to selectively target hydrophobic drugs, such as camptothecin, to tumor cells.