Nanobubbles: Fundamentals and recent drug delivery applications

The emerging branch in pharmaceutical sciences known as pharmaceutical nanotechnology presents new tools, opportunities and scope, which are expected to have significant applications, in disease diagnostics and therapeutics. There is a growing interest in nanobubble (NB) technology because of its wide range of potential applications in theranostics and targeted drug delivery including anticancer drug delivery, antibiotic delivery, gene delivery etc. Nanobubbles could offer several features in anticancer drug delivery, improving cellular uptake of chemotherapy drugs into cancer cell lines. Nanobubbles opened a new field of ultrasound imaging and were used as a diagnostic method. Generally, the delivery of drugs to organs and tissues is affected by two main ultrasound effects including the cavitation and sonoporation effects. This review describes the history of nanobubble, nomenclature, stability of nanobubble, physicochemical properties, characterization of nanobubble, method of preparation and applications. This article aims at highlighting the most recent and promising research trends including oxygen nanobubble, silica nanobubble and pluronicnanobubble and enlist the various drug delivery approaches involving the application of nanobubbles.