Translational Prospects of Ultrasound-Mediated Tumor Immunotherapy: A Review of Preclinical Advances and Safety Considerations.

Immunotherapy is considered as a promising therapeutic approach for cancer treatment. This therapy focuses on the specificity and memory of the immune system against malignant cells to achieve a sustained cure with minimal toxicity. However, the effectiveness of immunotherapy is often limited by the insufficient delivery and low accumulation of therapeutic molecules in tumors. Ultrasound exposures with the presence of microbubbles can be used as an effective method to greatly increase cell membrane permeability and enhance tissue accessibility to drugs or genes, thereby improving the access of therapeutic molecules into non-permeable tissues and enhancing the therapeutic outcomes. In this review, we discuss challenges in current tumor immunotherapy and feasible approaches that could potentially overcome these obstacles with the help of ultrasound; thereafter, we elaborate on the recent advantages of ultrasound-mediated delivery approach in tumor immunotherapy.