Fig. 2

US/PA imaging data of a mouse brain treated with the PFCnDs-based intracerebral delivery approach. All images have a coronal orientation and are viewed in the caudal direction. In vivo, transcranial US/PA imaging was performed four hours after nanodroplet delivery without removing the skull or scalp. (A, B) US/PA images, acquired at PA imaging wavelengths of 760 nm and 1064 nm (color bars). Thresholding was applied to remove signals from endogenous chromophores. US imaging (grayscale) generated an anatomical map of the head, skull, and brain. US/PA images of the head show 760 nm and 1064 nm signals localized toward the treated (right) side of the head. (C) US B-mode image, acquired after laser-activation of PFCnDs-760. The image shows a bright, echogenic region on the treated side of the head (circled). (D) Time-series US intensity signals, during the application of 760 nm wavelength laser stimulation. The PFCnDs-760 and background signals were acquired as a mean of the pixels of regions on the treated (right) and untreated (left) sides of the brain, respectively. The PFCnDs-760 signal increased in response to laser stimulation, while the background signal remained constant. (E) PFCnDs-760-detected image acquired using PFCnD-mediated CEUS imaging and a PFPnD detection algorithm. The algorithm highlighted US B-mode image pixels (yellow) based on their response to laser stimulation. The PFCnDs-760-detected is overlaid on the US B-mode image. The PFCnDs-760-detected signal was localized to the treated side of the brain. (F) A merged view image of all measured signals. The image shows an overlapping distribution of PA, US, and PFCnDs-760-detected signals