The use of ultrasound for drug delivery

Ultrasound has been in use for the last three decades as a modality for dia gnostic imaging in medicine. Recent studies have shown that nonthermal ultr asound energy could be applied for targeting or controlling drug release. T his new concept of therapeutic ultrasound combined with drugs has induced i nterest in various medical fields. Enhanced effects of thrombolytic agents such as urokinase and TPA with acoustic energy have been demonstrated. Ultr asound transducer-tipped catheters are being developed for treatment of car diovascular diseases. Other devices with ultrasound transducers implanted i n transdermal drug patches are also being evaluated for possible delivery o f insulin through the shin. Echo contrast microbubbles could also be used t o carry and release genes to various tissues and lesions. Chemical activati on of drugs by ultrasound energy for treatment of cancers is another new fi eld recently termed "sonodynamic therapy." Various examples of ultrasound a pplication, are under investigation that could lead to revolutionary drug d elivery systems of the future.