Fig. 4. Capillary occlusion and biosafety of microdroplets.

a Two-photon microscopy images taken before (left) and after (right) injection of a 100 μl of microdroplet emulsion. The imaged brain region is indicated. TxRed (607/70 nm filter) and DCM-IR780 (520/50 nm filter) channels are shown in red and green, respectively. The white arrow indicates a microdroplet flowing in the capillary network. Scalebar—50 μm. b Equivalent two-photon images for two regions where microdroplet arrest was observed, indicated with white arrows. Scalebar—50 μm. The experiments were repeated for n = 3 mice to ensure reproducibility. c Relative amounts of microdroplets being arrested in the microvascular network (left) and capillaries being blocked (right) for 8 measurements (black circles) in n = 3 mice. d Blood biochemistry at day 14 following injection of 100 μl of PBS (PBS, blue, n = 4 mice), 100 μl of DCM microdroplets (DCM, red, n = 4 mice), and 100 μl of DCM microdroplets containing IR-780 dye (G3, DCM-IR780, green, n = 4 mice). Individual values (dots) are normalized with the average values for the PBS group, namely 5.45 g/dl total protein, 4.48 g/dl albumin, 0.98 g/dl globulin, 154.75 mmol/dl sodium, 8.28 mmol/dl potassium, 12.53 mg/dl calcium, 14.03 mg/dl phosphate, 107.25 U/l alkaline phosphatase, 30.25 U/l alanine transferase, 15.50 mg/dl blood urea nitrogen. Values for all mice are provided in a Supplementary File. e Weight of the mice for the three groups for different days post injection. Values for all mice are provided in a supplementary file. Day 0 corresponds to the pre-injection time point. Dots correspond to individual measurements. f Blood hematology at three time points (1, 7, and 14 days) for the three groups of mice. WBC white blood cell count, Neu neutrophil count, Lym lymphocyte count, Mon monocyte count, Eos eosinophil count, RBC red blood cell count, HbT hemoglobin, PLT platelet count. Values for all mice are provided in a Supplementary File. Dots represent individual measurements.