Implantable microdevices for treating brain tumors

Despite extensive research investment, malignant brain tumors continue to be associated with significant morbidity and mortality. Implantable microdevices placed directly in the central nervous system (CNS) represent a promising area of investigation in neuro-oncology. In this review, we provide an overview of the control mechanisms, release kinetics, outcomes, strengths, and limitations of implantable microdevices in clinical and laboratory studies. Eight implantable microdevices that delivered various compounds, including chemotherapy, immunotherapy, and nitric oxide, were identified. Device control functions varied from no control after implantation to active coordination of the release of multiple drugs at different rates. We find that, although the devices can reliably deliver therapeutic compounds to the tumor site, their efficacy in terms of prolonging survival and achieving durable remission remains modest. Our findings reveal a critical narrative that emphasizes the unsolved barriers impeding clinical success of implantable microdevices in neuro-oncology.