title: Spectroscopic and calorimetric studies of formation of the supramolecular complexes of PAMAM G5-NH₂ and G5-OH dendrimers with 5-fluorouracil in aqueous solution.
abstract: The results of spectroscopic measurements (increase in solubility, equilibrium dialysis, (1)H NMR titration) and calorimetric measurements (isothermal titration ITC) indicate exothermic (ΔH<0) and spontaneous (ΔG < 0) combination of an antitumor drug, 5-fluorouracil, by both cationic PAMAM G5-NH2 dendrimer and its hydroxyl analog PAMAM G5-OH in aqueous solutions at room temperature. PAMAM G5-NH2 dendrimer combines about 70 molecules of the drug with equilibrium constant K ≅ 300, which is accompanied by an increase in the system order (ΔS < 0). Hydroxyl dendrimer, PAMAM G5-OH, combines about 14 molecules of 5-fluorouracil with equilibrium constant K ≅ 100. This process is accompanied by an increase in the system disorder (ΔS > 0).
authors.affiliation: Unit of Biophysical Chemistry, Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 165, 90-236 Lodz, Poland. Electronic address: adam.buczkowski@chemia.uni.lodz.pl.
authors.forename: Adam
authors.initials: A
authors.lastname: Buczkowski
authors.affiliation: Unit of Biophysical Chemistry, Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 165, 90-236 Lodz, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Olesinski
authors.affiliation: Molecular Spectroscopy Laboratory, Faculty of Chemistry, University of Lodz, Tamka 12, 91-403 Lodz, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Zbicinska
authors.affiliation: Department of Inorganic and Analytical Chemistry, Faculty of Chemistry, University of Lodz, Tamka 12, 91-403 Lodz, Poland.
authors.forename: Pawel
authors.initials: P
authors.lastname: Urbaniak
authors.affiliation: Unit of Biophysical Chemistry, Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 165, 90-236 Lodz, Poland.
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Palecz
mesh_terms: D002151:Calorimetry / Q000379:methods; D002626:Chemistry, Pharmaceutical / Q000379:methods; D050091:Dendrimers / Q000737:chemistry*; D005472:Fluorouracil / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D019999:Pharmaceutical Solutions / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry*
chemical_list: D050091:Dendrimers; C104700:PAMAM Starburst; D019999:Pharmaceutical Solutions; D014867:Water; D005472:Fluorouracil
keywords: 5-Fluorouracil; Dendrimer; Equilibrium dialysis; Isothermal titration calorimetry; PAMAM G5-NH(2); PAMAM G5-OH