Biodegradable Acoustic Targeting (BATUS) system enhances gene delivery, silences PD-L1, and prolongs survival in GBM mice.

Glioblastoma (GBM) remains one of the most aggressive and challenging brain malignancies, primarily due to the formidable blood-brain barrier (BBB). This physiological barrier severely restricts the delivery of therapeutic agents, including advanced gene therapies, to tumor sites. Current standard-of-care treatments often struggle to achieve pharmacologically relevant concentrations within the tumor, leading to poor prognosis and limited survival benefits. A critical unmet need exists for innovative strategies that can safely and effectively bypass the BBB to enable targeted delivery of potent therapeutics, such as immunomodulatory gene therapies, directly to GBM cells.

Researchers developed Biodegradable Acoustic Targeting for Ultrasound-Supported Gene Therapy (BATUS), a modular platform designed for safe, repeated, and targeted gene delivery to the brain. The system integrates an implantable, fully biodegradable glycine-based ultrasound (US) transducer, surgically placed via craniotomy for precise BBB opening. This was combined with customizable tLyp1-functionalized liposomal gene carriers. As a proof-of-concept, BATUS delivered PD-L1-targeting siRNA. In vitro evaluations confirmed efficient siRNA entrapment, stability, and specific cellular uptake. In vivo studies were conducted in orthotopic GL261 GBM mouse models to assess enhanced BBB permeability, PD-L1 silencing, tumor growth, and overall survival, alongside a comprehensive safety profile.

The BATUS system demonstrated significant efficacy in preclinical models. In vitro studies confirmed efficient siRNA entrapment within the liposomes, maintaining stability and exhibiting specific cellular uptake. In vivo experiments in orthotopic GL261 GBM mouse models revealed enhanced BBB permeability, facilitating improved delivery of the gene carriers to the brain tumor. This led to significant PD-L1 silencing within the tumor microenvironment, a crucial target for immunotherapy.

Crucially, BATUS resulted in reduced tumor growth and prolonged survival in the treated animal models, directly addressing the core challenges of GBM therapy. Furthermore, the system exhibited a favorable safety profile, with no detectable local or systemic toxicity observed in the animal models, highlighting its potential for clinical translation. The modular design allows for easy adaptation of targeting ligands and genetic cargo.