Fig. 6: Cerebral vessels temperature detection using LIBRA in hypothermia and control mice.

a Schematic of cerebral vessel temperature detection using LIBRA. Mice were treated with intraperitoneal injection of lipopolysaccharide (LPS) to induce hypothermia and then were injected with LIBRA intravenously. Bioimaging at the second and third near-infrared biological windows (NIR-II/III) was performed in LIBRA-injected mice with camera under 808 nm laser excitation. The luminescence intensity ratio of the emissions at 1550 and 980 nm obtained from bioimaging was used to achieve the ratiometric temperature imaging of the mice without LPS injection as control and hypothermia mice after LPS injection. Thermal images of mice’ scalp detected by infrared thermal camera in b control and c hypothermia mice. d Temperature variations of brain tissue and abdomen skin recorded by thermocouple before and during LPS induced hypothermia model. LPS was injected 1.5 h after the temperature recording. Data were presented as mean values based on three biologically independent mice (n = 3). Error bars were defined as standard deviation. e Ratiometric temperature imaging using LIBRA for temperature detection of mice cerebral vessels in control without LPS injection (left) and hypothermia after LPS injection (right). The regions labeled with white boxes in inferior cerebral veins (ICV), superior sagittal sinus (SSS), and the transverse sinus (TS) were used to measure the temperature values. f Statistical histograms of the temperature of mice cerebral vessels including ICV, SSS, and TS in control (denoted as Con ICV, Con SSS, and Con TS) and hypothermia (denoted as Hypo ICV, Hypo SSS, and Hypo TS) groups. Data were presented as mean values based on three biologically independent mice (n = 3). Error bars were defined as standard deviation.