Polymeric Nanoparticles as a Promising Drug Delivery Platform for the Efficacious Delivery of Toll-Like Receptor 7/8 Agonists and IDO-Inhibitor

Abstract The current investigation delineates the poly(lactide-co-glycolic acid) nanoparticles (PLGA NPs) formulation as the drug encapsulating assembly using nanoprecipitation method. Specifically, for the first time, 8-fluorotryptanthrin (Try, an IDO1 inhibitor) and 1-benzyl-2-butyl-1H-imidazo[4,5-c]quinolin-4 amine (BBIQ, a TLR7 agonist) have been encapsulated in the PLGA NPs. BBIQ and Try are the immunomodulating agents which have some shortcomings such as their low solubility and dose-related side effects associated with their systematic administration. To overcome these shortcomings, successful loading of the BBIQ and Try has been done in the polymer-based assembly. To confirm the surfactant coating and drug interaction with the NPs, differential scanning calorimetry and fourier transform infrared spectroscopy have been employed. Physicochemical characterization of the blank and loaded NPs has been done using dynamic light scattering, zeta potential, thermogravimetric analysis a high-resolution transmission electron microscope, atomic force microscopy, and X-ray diffraction analysis. To study the drug release behaviour of the NPs, drug release profiles and kinetic modelling was employed. Thus, co-encapsulation of BBIQ and try within the NPs have proven to be a promising assembly that can be investigated further in cancer vaccines.