Anticancer activity of 9-cis-retinoic acid encapsulated in PEG-coated PLGA-nanoparticles

The use of retinoids in antitumor therapy represents a very promising approach for the treatment of undifferentiated tumors, due to their ability to promote cell differentiation. Among these compounds, 9-cis-retinoic acid (9-cis-RA) is the most active. The therapeutic use of 9-cis-RA is made difficult by the occurrence of several side effects in addition to its photo-degradation following exposition to light or atmospheric oxygen. In this investigation, 9-cis-RA was encapsulated in PEG-coated PLGA nanoparticles to improve both its stability and effectiveness. PEG-coated PLGA nanoparticles showed a mean size of ∼220 nm, a polydispersity index of ∼0.1 and a zeta potential of -12 mV. These parameters were not significantly influenced by the presence of the 9-cis-RA. Encapsulation provided noticeable protection of the 9-cis-RA. In vitro experiments showed that the encapsulated form is more active than the free drug in inducing cell differentiation.