1. Stem cell tracking with optically active nanoparticles Hossein Khadem

2. Contents Outline Stem Cells Stem-Cell-Based Therapy Necessity of Tracking Embedding Methods Imaging Methods

3. Outline Damaged Tissue Stem cell injection Delivery path

4. Outline Contrast agents Embedding Fluorescence imaging Photoacoustic imaging Raman imaging Surface-enhanced Raman spectroscopy (SERS) imaging Laser

5. Stem Cell Introduction Stem cells are undifferentiated biological cells that can differentiate into specialized cells and can divide to produce more stem cells. The unique properties of all stem cells: 1.Being unspecialized 2.Capability of giving rise to specialized cell types 3.Capability of dividing and renewing themselves for long periods(self-renewal)

6. Stem Cell Self-renewal Symmetric division Parent Daughters

7. Stem Cell Self-renewal Asymmetric division Parent Differentiation Back-up Daughter Differentiation Back-up Daughter

8. Stem-Cell-Based Therapy

10. Necessity of Tracking 1- Monitoring the delivery path

11. Necessity of Tracking 1- Monitoring the delivery path 2- Monitoring the functions and processes Differentiation Proliferation Migration Necrosis or apoptosis

12. Embedding Methods Introduction endocytosis through incubation receptor-mediated uptake lipid-based transduction microinjection electroporation peptide-mediated delivery

13. Embedding Methods Endocytosis through incubation Cell External object Release

14. Embedding Methods Receptor-Mediated Endocytosis

15. Embedding Methods Microinjection

16. Embedding Methods Electroporation cuvette Electrodes

17. Embedding Methods Electroporation By voltage applying + -

18. Imaging Methods Intriduction Fluorescence Imaging Photoacoustic Imaging Raman or Surfece-Enhanced Raman Spectroscopy

19. Imaging Methods Fluorescence Imaging Quantum Dots

20. Imaging Methods Fluorescence Imaging Quantum Dots High fluorescence Q.Y of QDs~0.85 Q.Y of dyes~0.9

21. Imaging Methods Fluorescence Imaging Quantum Dots High fluorescence High extinction coefficients Tunable emissions sharp emission bandwidths good photostability Extinction coefficient of solar cell dyes ~ 50 cm -1 M -1

22. Imaging Methods Fluorescence Imaging Quantum Dots High fluorescence High extinction coefficients Tunable emissions sharp emission bandwidths

23. Imaging Methods Fluorescence Imaging Quantum Dots High fluorescence High extinction coefficients Tunable emissions Sharp emission bandwidths Good photostability

24. Imaging Methods Fluorescence Imaging Quantum Dots High fluorescence High extinction coefficients Tunable emissions Sharp emission bandwidths Good photostability Cytotoxicity

25. Imaging Methods Fluorescence Imaging Dye-doped Nanoparticles Shell: silica, polymer(polystyrene ) Core: fluorescent dyes C-dots IRIS dots Polymeric NPs

26. Imaging Methods Fluorescence Imaging Gold Nanoparticles

27. Imaging Methods Fluorescence Imaging Gold Nanoparticles Dark field microscopy

28. Imaging Methods Fluorescence Imaging Upconversion Nanoparticles higher sensitivity (lack of autofluorescence background) less toxic components (in comparison to QDs) high penetration depths (excitation with NIR light) good photostability (no photobleaching)

29. Imaging Methods Photoacoustic Imaging

30. Imaging Methods Photoacoustic Imaging

31. Imaging Methods Raman Imaging Is not affected by the presence of water Molecular information(finger print) Noninvasiveness Accessibility approximately 12-14 orders of magnitude weaker than fluorescence

32. Imaging Methods Raman Imaging Raman Reporters SWNT Labeling

33. Imaging Methods SERS Imaging Surface-Enhanced Raman Spectroscopy(SERS) Imaging In presence of metallic nanoparticles(often noble metallic NPs; Au,Ag,…)

34. Imaging Methods SERS Imaging Surface-Enhanced Raman Spectroscopy(SERS) Imaging

35. Imaging Methods SERS Imaging Surface-Enhanced Raman Spectroscopy(SERS) Imaging

36. Thank You!