Phototoxicity free quantum dot-based niosome formulation for controlled drug release and its monitoring

Abstract

A novel niosomes-based system composed of Hypromellose (HPMC) functionalized fluorescent, biocompatible ZnS: Mn quantum dots (QDs), and anti-HIV drug Tenofovir disoproxil fumarate (TDF) was designed. An appropriate ratio of surfactant Sorbitan Monostearate (SPAN-60) and cholesterol was used to obtain an optimal entrapment efficiency. Initially, after observing the successful interaction of HPMC with SPAN-60, the noisome formulation including (QDs+drug) and HPMC-coated QDs was synthesized by a wet chemical route and characterized by X-ray diffraction (XRD), Transmission electron microscope (TEM) and Selected Electron Diffraction (SAED). Secondly, (QDs+drug) loaded niosome formulations were studied by varying the ratio of SPAN-60 and cholesterol. Multiple studies were done to characterize the shape, size, viscosity, colloidal stability, and entrapment efficiency of (QDs+drug) loaded niosomes. Lastly, pH-dependent (QDs+drug) release profiles were studied by a spectroscopic technique considering the pH of the human gastrointestinal region to obtain the formulation stability of (QDs+drug) release from the niosome vesicles. These studies also include pH-dependent photostability measurements based on laser-induced multiphoton excitation technique in the Infrared region. The multiphoton time-resolved studies were completed to avoid the UV induced phototoxicity in the drug delivery modules. Current studies on the formulation of niosomes-based (QDs+drug) system laid a foundation to make a complete phototoxicity free system for tracking controlled drug release and its imaging.