Stem cell tracking with optically active nanoparticles Hossein Khadem

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

Outline Damaged Tissue Stem cell injection Delivery path

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

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)

Stem Cell Self-renewal Symmetric division Parent Daughters

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

Stem-Cell-Based Therapy

Necessity of Tracking 1- Monitoring the delivery path

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

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

Embedding Methods Endocytosis through incubation Cell External object Release

Embedding Methods Receptor-Mediated Endocytosis

Embedding Methods Microinjection

Embedding Methods Electroporation cuvette Electrodes

Embedding Methods Electroporation By voltage applying + -

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

Imaging Methods Fluorescence Imaging Quantum Dots

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

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

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

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

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

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

Imaging Methods Fluorescence Imaging Gold Nanoparticles

Imaging Methods Fluorescence Imaging Gold Nanoparticles Dark field microscopy

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)

Imaging Methods Photoacoustic Imaging

Imaging Methods Photoacoustic Imaging

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

Imaging Methods Raman Imaging Raman Reporters SWNT Labeling

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

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

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

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