Ultrasonically Powered Implantable Tumor Treating Field (I-TTF) System

An ultrasonically powered, battery-free, implantable Tumor Treating Field (i-TTF) system is presented for localized peritumoral cancer therapy. The system utilizes shape-engineered$\text{BaTiO}_{3}$nanoparticle-based, three-dimensional pyramid receivers, engineered to optimize acoustic-to-electric energy conversion under focused ultrasound. A single pyramid receiver achieves up to fourfold higher efficiency in wireless power transfer compared to a traditional cubic receiver with the same volume. It enables localized, FDA-equivalent electric field ($1-3 \mathrm{V} / \text{cm}$) with improved angular tolerance, overcoming the limitations of the current scalp-array TTF device. The i-TTF system suppresses glioblastoma proliferation in vitro and reduces the Ki-67 proliferation marker in vivo after 3 days of 60 -minute daily stimulation. This platform provides a wireless, battery-free alternative to conventional TTF systems, enabling a potent approach for deep tumor sites with improved field uniformity and safety, while achieving an efficacious anti-mitotic effect.