Self-Assembled Vesicle-Carbon Nanotube Conjugate Formation through a Boronate-Diol Covalent Linkage.

Abstract

A vesicle-single walled carbon nanotube (CNT) conjugate was developed by a boronic acid-diol covalent linkage between a self-assembled vesicle and dispersed CNT. Trimesic acid based phenylboronic acid appended triple-tailed amphiphiles (T1 and T1S) were synthesized that formed monolayered vesicles through H-aggregation in DMSO-water (2:1 v/v) and pure water, respectively. Aqueous CNT dispersion was prepared with cholesterol-based glucose-functionalized amphiphile (D1). These two supramolecular self-assemblies were covalently linked by using a boronic acid-diol interaction between a phenylboronic acid based T1S vesicle and 1,2-diol moieties of glucose tethered dispersing agent (D1) to develop a vesicle-CNT conjugate. Lewis acid-base chemistry was exploited to form this boronate-diol adduct between two supramolecular self-assemblies. The formation of vesicles, CNT dispersion, and the vesicle-CNT conjugate was characterized by microscopic and spectroscopic techniques. Anticancer drug doxorubicin was encapsulated within this T1S-vesicle-D1-CNT conjugate with a higher loading capacity compared to the individual cargo carrier (vesicle or CNT). This cytocompatible T1S-vesicle-D1-CNT conjugate successfully delivered loaded doxorubicin within a B16F10 melanoma cell and also exhibited better cellular transportation ability compared to the drug-loaded vesicle or CNT. This was further reflected in an enhanced killing efficiency of the cancer cells by the vesicle-CNT conjugate compared to the drug-loaded vesicle or CNT.