We report the loading efficacy of folic acid (FA) by polyamidoamine (PAMAM-G3 and PAMAM-G4) nanoparticles in aqueous solution at physiological pH. Thermodynamic parameters ΔH = -47.57 (kJ Mol-1), ΔS = -122.78 (J Mol-1, K-1) and ΔG = -10.96 (kJ Mol-1) showed FA-PAMAM bindings occur via H-bonding and van der Waals contacts. The stability of acid-PAMAM conjugate increased as polymer size increased. The acid loading efficacy was 40 to 50%. TEM images exhibited major polymer morphological changes upon acid encapsulation. PAMAM dendrimers are capable of FA delivery in vitro.
Keywords: TEM; conjugation; dendrimer; folic acid; loading efficacy; modeling; thermodynamic.