Enhanced model antigen retention in tissue through topical high-frequency ultrasound treatment.

Reproducible control of tissue delivery and retention of a therapeutic agent facilitates the maximization of the efficacy of pharmacotherapy. Despite the proposal of various chemical and physical methods for modulating drug delivery and retention, the choice of the physical modality for this purpose has been limited in clinical practice. Thus, this study proposes a novel strategy for modulating the retention of a model antigen in tissues by using non-tissue-damaging high-frequency ultrasoundAfter the injection of a fluorescently labeled model antigen, followed by brief treatment with high-frequency ultrasound (5-20 MHz), the clearance of the antigen was monitored using a real-time near-infrared (NIR) fluorescence imaging system in vivo. Further, ultrasound treatment increased tissue retention at the site of model antigen administration. The results suggested that high-frequency ultrasound could change the response to a macromolecule injected into the tissue, such as a vaccine, thereby modulating the immune response. The proposed ultrasound-based technology is translatable to clinical settings and benefits from well-established ultrasound technologies that have been employed in various medical applications for decades. Moreover, this approach can be broadly applied to enhance the therapeutic effects of current and future immune-mediated therapeutic systems.