Mitochondria-Targeted Fluorescence/Photoacoustic Dual-Modality Imaging Probe Tailored for Visual Precise Diagnosis of Drug-Induced Liver Injury.

The multispectral optoacoustic tomography (MSOT) technique can be used to perform high-resolution molecular imaging under deep tissues, which gives the technology significant prospective for clinical application. Here, we developed a superoxide anion (O2•-)-activated MSOT and fluorescence dual-modality imaging probe (APSA) for early diagnosis of drug-induced liver injury (DILI). APSA can respond quickly to O2•-, resulting in an absorption peak blueshift from 845 to 690 nm, which also leads to the photoacoustic (PA) signal at 690 nm and the fluorescence signal at 748 nm increases linearly with increasing O2•- concentration, which can be utilized to assess the extent of liver damage. The developed MSOT imaging method can eliminate background interference from hematopoietic tissue by collecting the PA signals excited at 680, 690, 740, 760, 800, 845, and 900 nm wavelengths to achieve noninvasive in situ visual diagnosis of DILI. The developed fluorescence imaging method can be used for the imaging of endogenous O2•- in living cells and anatomic diagnosis of liver injury. The developed probe has broad application prospects in the early diagnosis of DILI.

Design and synthesis of a ratiometric photoacoustic imaging probe activated by selenol for visual monitoring of pathological progression of autoimmune hepatitis.

Photoacoustic (PA) imaging with both the high contrast of optical imaging and the high spatial resolution of ultrasound imaging has been regarded as a robust biomedical imaging technique. Autoimmune hepatitis (AIH) is the second largest liver inflammatory disease after viral hepatitis, but its pathogenesis is not fully understood probably due to the lack of an effective in vivo monitoring approach. In this work, an innovative selenol-activated ratiometric PA imaging probe APSel was developed for visual monitoring of pathological progress of AIH. Selenols including selenocysteine (Sec, the major form of Se-containing species in vivo) have been demonstrated to have an effective antioxidant role in inflammation. The reaction of APSel with selenol results in a blue shift of the PA spectrum peak from 860 nm to 690 nm, which enables the ratiometric PA imaging. The APSel probe displays high sensitivity and selectivity to Sec and other selenols. The APSel probe was then employed for ratiometric PA imaging of selenol in cells, and for monitoring the development of AIH in a murine model by tracking the changes of selenol level. The results revealed that the level of selenol was closely correlated with the development of AIH. The proposed APSel, as the first example of a selenol-responsive PA imaging probe, provides a new tool and approach to study and diagnose AIH diseases.

[Fermentation of two insoluble dietary fibers by colonic microflora in vitro].

OBJECTIVE: To investigate the rule of insoluble dietary fiber fermentation in intestinal tract. METHODS: Using destarched wheat bran and sugarcane residue as substrates for the fermentation of colonic microflora in vitro in anaerobic conditions. Samples were collected at 0, 4, 8, 12 and 24 h after fermentation, and the pH value, selective plate colony counts were measured and the content of SCFAs were detected with GC. RESULTS: After fermenting for pH 5.43. The change of colony counts of Bifidobacterium, Lactobacillus, Enterococci, Enterobacter, Bacteroides and total anaerobic bacterium was not significant in two media with different substrates at different fermentation periods. Both destarched wheat bran and sugarcane residue could be utilized by colon microbials to produce SCFAs, most of which was propionate at the amount of 0.58 mg/ml and 0.56 mg/ml respectively. During the fermentation process, lactic acid was accumulated and promptly consumed by colonic microflora. CONCLUSION: Insoluble dietary fiber could be fermented by intestinal microflora. The growth succession of colonic microflora might be varied during fermentation.