Novel thiol-dendrimer nanocarriers for the delivery of antiviral, antifungal and anticancer drugs

Abstract

In the recent years the interest in bioadhesion has been inspired by the development of novel bioadhesive polymers for mucosal delivery. In the process of developing novel bioadhesive polymers, the concept of thiol bearing polymers the so called thiomers has evolved. The thiomers so far reported have one sulfahydral group per mole of polymer. Hence in the present study we are aiming on the preparation and characterization of thiolated dendrimers with anionic (Generation 3.5) and cationic (Generation 4.0) type dendrimers. The ligands selected are cysteamine for anionic type dendrimer and 2-iminothiolane for cationic dendrimers. The prepared thiolated dendrimers were loaded /conjugated with drugs and further were evaluated for their mucoadhesive behavior by applying to the different mucus lining organs such as ocular, oral and nasal. The acyclovir was physically loaded into the cysteamine conjugated PAMAM dendrimer (Generation 3.5), the drug amphoterecin B was chemically conjugated with the cysteamine conjugated PAMAM dendrimer (Generation 3.5) and the drug paclitaxel was conjugated with 2-iminothiolane conjugated dendrimer (Generation 4.0). The prepared thiolated dendrimers and drug loaded/conjugated thiolated dendrimers were duly characterized for free thiol/disulfide content, stability of the thiol moieties, drug content, in vitro release and in vitro mucoadhesion.