Gene transfection and drug delivery

There are several well-recognized beneficial and/or therapeutic applications of ultrasound (US). Clearly, the long-term use of diagnostic US (DUS) with its numerous and varied applications in a wide range of medical practices has played a major role in evaluative situations. That these DUS applications have not been accompanied by any known adverse “side effects” make its worldwide use even more remarkable and noteworthy. There are also applications of US for therapeutic settings in which tissue heating is required (e.g., sports medicine) to relieve inflammation, or in which destruction of kidney stones (via lithotripsy) is achieved, thereby avoiding surgical intervention and its associated complications. On the horizon, and gaining increasing perspective, are two emerging applications of US; namely, for gene transfection and drug delivery. Application in both of these areas appears to involve similar circumstances, but differs mainly in what is “delivered” into the cell or near the cell by the US application. For gene transfer, the goal is to insert a specific piece of DNA into the cell for incorporation into the cell’s existing genetic machinery; for drug delivery, the goal is to place within the cell, or within the localized environment of a cell, a drug selected to achieve a specific biological response.