The SOUND project followed a multidisciplinary approach combining nanotechnology, biotechnology and neuroscience to develop the technological components required for a biomimetic platform for targeted brain delivery. During the project, the research strategy evolved towards the independent development and validation of each component of the system, enabling substantial scientific progress despite the technical challenges associated with the complete integration of the platform.
A major achievement was the establishment of M13 bacteriophages as biomimetic vectors for brain delivery. Comprehensive protocols for bacteriophage production, purification and quality control were developed, together with advanced biological validation workflows. The interaction of bacteriophages with cells was systematically investigated, demonstrating excellent biocompatibility, efficient cellular uptake and intracellular trafficking. Furthermore, bacteriophages successfully crossed both 2D and 3D in vitro blood-brain barrier models while preserving their structural integrity and biological functionality, highlighting their potential as delivery vectors for central nervous system applications.
Significant advances were also achieved in the development of the nanomaterial component of the platform. A reproducible synthesis protocol for monodisperse P3HT nanoparticles below 100 nm was established, overcoming an important technological limitation. In addition, a new bioorthogonal functionalisation strategy based on clickable azide-functionalised P3HT nanoparticles was developed, enabling efficient antibody conjugation while preserving nanoparticle stability and biological activity. These results provide a versatile platform for the future functionalisation of semiconducting nanoparticles with targeting biomolecules.
To better understand bio–nano interactions, bacteriophage assembly with gold nanoparticles was investigated as a model system. The study demonstrated the spontaneous formation of stable hybrid nanostructures while preserving bacteriophage morphology, infectivity and biological functionality, providing valuable insights into the future integration of biological vectors with functional nanomaterials.
The project also established advanced experimental workflows for evaluating neuronal compatibility. Primary neuronal cultures and electrophysiological protocols were successfully implemented, demonstrating that bacteriophages do not alter intrinsic neuronal membrane properties or neuronal excitability. This finding supports their use as safe biological targeting vectors for future neuromodulation applications.
Overall, although the complete ultrasound-responsive Ph-US-P3HT platform could not be assembled within the duration of the fellowship, the project successfully established its key technological and biological building blocks. The work generated two peer-reviewed scientific publications, several proof-of-concept results and robust experimental methodologies that significantly reduce the technological risks associated with the future development of multifunctional biomimetic platforms for targeted brain delivery.
