Poly(propyleneimine) Dendrimers as pH-Sensitive Controlled-Release Systems

摘要: Molecular composites were prepared by solubilizing pyrene in di- aminobutane poly(propyleneimine) den- drimers having 32 or 64 primary amine end groups (DAB-32 DAB-64). The dendrimer - binding constants determined as Kpy/DAB-32a 16 725 200m ˇ1 and Kpy/DAB-64a 33 858 663m fluorescence spec- troscopy. Fluorescence studies also employed to probe the release of from interior dendrimers a function pH. When pH value system was decreased 11 addition HCl, inten- sity found increase approximately tenfold at 2 4. In addition, 2, ratio first third vibrational peak (I1/I3) increased 0.9, typical for solvated solution, 1.60, characteristic water. Pyrene con- firmed quenching when sodium iodide added, since NaI does not affect emission dendrim- er-solubilized pyrene. Finally, fluores- cence used locate solubilization sites within microcavities. These are close core dendrimer, near tertiary amino which responsible dendrimer-bound