Colloidal stability and “in vitro” antitumor targeting ability of lipid nanocapsules coated by folate–chitosan conjugates

In this study, the synthesis and characterization of lipid nanocapsules coated with folate–chitosan conjugates at varying folate concentrations are reported; these nanocapsules have a potential application as anticancer drug carriers. The main goal of this study was to evaluate (a) the colloidal stability of the particles and (b) their cell targeting. A classical colloidal characterization of the nanocapsules was carried out by analyzing size, electrokinetic charge, and stability in different saline solutions, including cell culture media. At neutral pH, the stability was improved by the presence of folate due to electrical interactions. In addition, folate modulated the hydrophilic/phobic nature of the surface, which became critical to keep the systems stable (or not) under physiological saline conditions due to the action of short-range repulsive hydration forces. The cellular uptake of our nanocapsules was evaluated by working with four tumor cell lines. Both fluorescent analyses with particles colored by Nile Red, and antitumor activity of our systems loaded with docetaxel, demonstrated that the folate-mediated internalization of the particles in the cancer cells was improved when the nanocapsules were coated by folate–chitosan conjugates.