Search

Brain voltage plays a crucial role in indicating internal functions or diseases, and optical voltage imaging has gained intensive attention in recent years. Despite encouraging progress, current implementations encounter limitations pertaining to penetration depth, field of view (FOV), and photostability of indicators. To mitigate these challenges, a robust voltage‐sensitive dye (VSD)‐based whole‐field photoacoustic brain detection (WF‐PABD) platform is proposed, enabling direct evaluation of voltage dynamics across the whole brain, forming as PA‐VSD. WF‐PABD is equipped with a 512‐element ring‐array ultrasound detector capable of 360‐degree scanning, providing a large FOV (≈5 cm), high spatial resolution (≈110 µm), and rapid imaging acquisition. The proposed VSD remained ≈75% photostability after 30 min laser exposure, much greater than most calcium sensors. The optical voltage‐response mechanisms are validated and the capability of PA‐VSD to directly screen seizures is established. It is demonstrated that investigating connectivity among different brain regions allows to identify the precise location of active epileptic foci as well as the electrical conduction pathways and their directionality through fast temporal visualization. In summary, this study not only addresses the need for non‐invasive, high‐resolution, long‐term, and direct monitoring of brain voltage but also empowers exciting venues for PA applications in neuroscience. [ABSTRACT FROM AUTHOR]

Early diagnosis can effectively improve the survival of glioblastoma multiforme (GBM). A specific imaging technique that is simultaneously deep penetrating and sensitive to small tissue changes is desired to identify GBM. Due to its excellent features in signal contrast, detection sensitivity, and none or little attenuation in tissue, magnetic particle imaging (MPI) possesses great potential in cancer diagnosis, especially when the imaging modality is equipped with specifically targeted nanoprobes. However, when gliomas are small, the blood–brain barrier (BBB) is complete and prevents nanoprobes from entering the brain, which negates the theranostic effect. This study proposes a biomimetic nanoplatform that assist the MPI tracers in breaking through the BBB and then demonstrate a targeted and sensitive diagnosis of GBM. Afterward, the photothermal therapy and immune regulation show an excellent therapeutic effect on the GBM. It is experimentally confirmed that the MPI signal does not decay with tissue depth and shows excellent sensitivity for thousands‐cells. Only small animals are conducted in this study due to the limitations of the current commercial MPI scanner, however, this research theoretically enables large animal and human studies, which encourages a promising pathway toward the noninvasive diagnosis of early‐stage GBM in clinics. [ABSTRACT FROM AUTHOR]