1. Wang, W. , Vellaisamy, K. , Li, G. , Wu, C. , Ko, C. N. , Leung, C. H
Wang, W., Vellaisamy, K., Li, G., Wu, C., Ko, C. N., Leung, C. H., & Ma, D. L. (2017). Development of a long-lived luminescence probe for visualizing β-galactosidase in ovarian carcinoma cells. Analytical Chemistry, 89(21),
Jingtao Zhang

2. Introduction Ovarian cancer: 161,000 death
The seventh-most common cancer
Physical examination
Blood test
Ultrasound
Rossing, M. A., Wicklund, K. G., Cushing-Haugen, K. L., & Weiss, N. S. (2010). Predictive value of symptoms for early detection of ovarian cancer. Journal of the National Cancer Institute, 102(4),
Ovarian cancer's early stages (I/II) are difficult to diagnose because most symptoms are nonspecific and thus of little use in diagnosis; as a result, it is rarely diagnosed until it spreads and advances to later stages (III/IV).

3. Background -------Screening CA125
Β-Gal
(High sensitivity)
Low specificity
Worse specificity
May not increase at early stage[1]
strong and positive correlations
CA125
is a protein as a biomarker for some cancers.
It may also be elevated in other cancers, including endometrial cancer, fallopian tube cancer, lung cancer, breast cancer and gastrointestinal cancer.
Β-Gal
is a glycoside hydrolase enzyme that catalyzes the hydrolysis of β-galactosides.
Chatterjee, S. K., Bhattacharya, M., & Barlow, J. J. (1979). Glycosyltransferase and glycosidase activities in ovarian cancer patients. Cancer research, 39(6 Part 1),

4. Background Background ------- β-Gal Colorimetric assays,
β-Gal has also been demonstrated as an important
biomarker for cell senescence and primary ovarian cancer.
Therefore, methods for the sensitive detection
of β-gal could aid in the monitoring of ovarian cancer
development.
Colorimetric assays,
Immunostaining assays,
Histochemical methods.
Low sensitivity,
Tedious sample preparation,
High cost.

5. Background -------Luminescence imaging
Tung, C. H., Zeng, Q., Shah, K., Kim, D. E., Schellingerhout, D., & Weissleder, R. (2004). In vivo imaging of β-galactosidase activity using far red fluorescent switch. Cancer research, 64(5),
Kamiya, M., Asanuma, D., Kuranaga, E., Takeishi, A., Sakabe, M., Miura, M., ... & Urano, Y. (2011). β-Galactosidase fluorescence probe with improved cellular accumulation based on a spirocyclized rhodol scaffold. Journal of the American Chemical Society, 133(33),
Sakabe, M., Asanuma, D., Kamiya, M., Iwatate, R. J., Hanaoka, K., Terai, T., ... & Urano, Y. (2012). Rational design of highly sensitive fluorescence probes for protease and glycosidase based on precisely controlled spirocyclization. Journal of the American Chemical Society, 135(1),

6. Background Fluorescent probes are limited by
Luminescence imaging
Fluorescent probes are limited by
the high endogenous fluorescence of biological samples.
Asanuma, D., Sakabe, M., Kamiya, M., Yamamoto, K., Hiratake, J., & Ogawa, M., et al. (2015). Sensitive β-galactosidase-targeting fluorescence probe for visualizing small peritoneal metastatic tumours in vivo. Nature Communications, 6, 6463.

7. Background Background -------phosphorescence
limit interference between excitation and emission

8. Results & Discussion -------characterization Structural Confirmation
Stability Exam
Luminescent Spectra(TRES)
High-resolution Mass Spectra
Confocal

9. Results & Discussion
Stability
large Stokes shift

10. Results & Discussion Results & Discussion -------Spectra
selectivity of complex 1 for β-gal
To obtain the optimal performance of the probe

11. Results & Discussion Results & Discussion -------TRES
A good linear relationship

12. Results & Discussion
High-resolution Mass
Results & Discussion

13. Results & Discussion Results & Discussion MLCT -------Mechanism3
MLCT
Complex 2 is nonemissive due to nonradiative interactions with the solvent leading to luminescence quenching. However, β-gal
cleaves the galactose moiety of complex 1 to generate the dealkylated product 2, which binds to β-gal. Upon binding to β-gal, the complex is protected from the bulk solvent and hence becomes emissive via the triplet metal-to-ligand charge-transfer (3MLCT) excited state.
synthetically prepared complex 2 showed little luminescence

14. Results & Discussion Results & Discussion -------Mechanism
Typical pathways for cyclo-metalated Ir (III) complexes photochemistry
You, Y., & Nam, W. (2012). Photofunctional triplet excited states of cyclometalated Ir (III) complexes: beyond electroluminescence. Chemical Society Reviews, 41(21),

15. Results & Discussion
Confocal
Results & Discussion

16. Conclusion -------Innovation
1. First phosphorescent probe for ovarian cancer;
2. Good compatibility with reasonable stability in PBS;
3. Sensitivity
Asanuma, D., Sakabe, M., Kamiya, M., Yamamoto, K., Hiratake, J., Ogawa, M., ... & Urano, Y. (2015). Sensitive β-galactosidase-targeting fluorescence probe for visualizing small peritoneal metastatic tumours in vivo. Nature communications, 6.

17. Conclusion Conclusion -------Shortcomings BT474
Maximum Excitation Wavelength

18. Conclusion -------Shortcomings
They did not preclude the possibility that complex 2 may also bind to other proteins.

19. Question?