Investigation on some physicochemical properties of guest-conjugated and -incorporated hybrid organic/inorganic linear-dendritic nanocarriers

Abstract

Benzyl alcohol, as a model compound in conjugation, and 1-(2-pyridylazo)-2-naphtol (PAN), as a lipophilic dye molecule in encapsulation, were exploited using linear-dendritic ABA amphiphilic triblock copolymers, which is known as "hybrid macromolecules", containing silicon atoms by two methods. In the first route, benzyl alcohol was attached to the Si-Cl peripheral groups of the hybrid in different generations to synthesize host-benzyl alcohol conjugates. In the second procedure, PAN as the guest molecule was incorporated into different generations of the synthesized hybrid. Binding capacity and incorporation content (IC) of different generations of the hybrid were investigated using conventional methods such as nuclear magnetic resonance and UV-vis spectroscopy. It was observed that the IC, hydrolytic behavior and the release rate from the prepared micellar structures can be tuned by either external parameters such as pH or internal parameters such as hydrophilic/lipophilic ratio by developing generations. Dynamic light scattering and transmission electron microscopy experiments depicted diameter of the prepared nanocarriers between 100 to 250 nm. The release of guest molecules from the carriers was evaluated at pH 1, 7.4 and 10. Briefly, the prepared micelles can play a role as carrier with tunable release rate without sacrificing their micellar stability.