Characterization of folic acid-PAMAM conjugates: drug loading efficacy and dendrimer morphology

Abstract

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:

• folic acid
• dendrimer
• conjugation
• loading efficacy
• thermodynamic
• TEM
• modeling