Low generational polyamidoamine dendrimers to enhance the solubility of folic acid: A “dendritic effect” investigation

Low generational (G0–G2, G for generation) polyamidoamine (PAMAM) dendrimers were investigated as enhancers to improve the aqueous solubility of folic acid at pH 11 and pH 5. In these two cases, the solubility of folic acid increases with both the dendrimer concentration and generation. However, the solubilization mechanism is different. The electrostatic interaction between the primary amines of dendrimers and the ionized carboxylic groups of folic acid dominates the dissolution process at pH 11, while the increase of the solubility of folic acid at pH 5 is attributed to the hydrophobic encapsulation inside the dendrimer molecules. In addition, for comparison ethylenediamine was used as a small molecule control to examine the “dendritic effect” in the dendrimer-related solubilization process. Interestingly, PAMAM dendrimers exhibit, at pH 5, a significant superiority over ethylenediamine in enhancing solubility, whereas this “dendritic effect” cannot be observed under the basic condition.

At pH 5, dendrimer exhibits a significant superiority over ethylenediamine in enhancing the solubility of folic acid, whereas the dendritic effect cannot be observed under basic conditions.Figure optionsDownload as PowerPoint slide