The viscoelastic properties of cell membranes such as cytoskeleton-membrane adhesion, membrane tension, and viscosity all offer valuable insight into fundamental cellular processes such as division, motility, adhesion, and deformability. Cancer cells have significantly increased deformability when compared to their normal counter parts. Erythrocytes circulation life-time is dependent on their ability to deform to pass through narrow passages such as capillaries and spleen. This dissertation examines two different biological systems from a mechanical perspective: Ovarian cancers cells and erythrocyte membrane derived constructs.To perform these studies, I utilize a combined optical tweezers and quantitative phase imaging system to extract and image membrane tethers. From measuring the forces associated with tether extraction, I determine the forces associated with cytoskeleton-membrane adhesion, membrane tension, stiffness, viscosity, and relaxation time constants. By estimating the diameter of membrane tethers, I calculate the bending modulus and tether tension, which are correlated with deformability. In the ovarian cancer cell studies, I investigated and compared viscoelastic properties of a metastatic epithelial ovarian cancer cell line (SKOV3) and normal immortalized ovarian cancer (IOSE364). The results from this study show that SKOV3 cells are less stiff, less viscous, and more deformable than IOSE364 cells. The findings suggest that membrane mechanics play a large role in cancer cell behavior and the cell membrane can also be a target for therapeutics. In the erythrocyte-derived particle studies, I investigate the viscoelastic properties of red blood cells, micron-sized erythrocyte ghosts (µEGs), and micron-sized erythrocyte ghosts loaded with indocyanine green (µNETs). The circulation dynamics and kinetics of micron-sized particles are correlated with their mechanical properties. The results from this study shows that the fabrication of RBCs into EGs drastically decreases the tether stiffness, cytoskeleton membrane adhesion, and increases tether relaxation dynamics, which in turn decreases the deformability compared to red blood cells. The results also show that indocyanine green loading into EGs can restore some mechanical properties similar to red blood cells. The important findings are that the method for preparing erythrocyte membranes as drug delivery construct greatly affects the particles mechanical properties and the cargo loaded into the construct can potentially affect the mechanical properties of the construct.

Coherent Raman Scattering (CRS) microscopy is a technique used to image cells through the use of intrinsic chemical bonds, which allows for label free imaging at video rate speeds. Since the process is coherent the generated signal is orders of magnitude higher than spontaneous Raman microscopy. Many light sources have been developed for CRS microscopy, such as solid state optical parametric oscillators, supercontinuum sources, and fiber lasers. Fiber optical parametric oscillators (FOPOs) are tunable light sources based on the χ⁽³⁾ nonlinearity found in SiO₂. They have the potential to be integrated into compact and robust fiber components. This thesis describes an optimization for output power through tailoring the polarization at the output coupler and characterizes two FOPO systems for their applications in CRS microscopy. Chapter 1 gives a conceptual overview of spontaneous Raman, coherent anti-Stokes Raman scattering (CARS), stimulated Raman scattering (SRS) techniques as well as the pump sources typically used to perform CRS microscopy. Chapter 2 summarizes the physics for understanding FOPO operation. Chapter 3 describes our results for optimizing output power for a Nd:YVO₄ pumped FOPO by using a polarizing beam splitter with polarization dependent components. Chapter 4 illustrates a Ti:Sapphire pumped FOPO and compares its performance with the Nd:YVO₄ system.