Salvianolic Acid B Inhibits Growth of Cervical Cancer Cells in vitro via Induction of Apoptosis through the Extrinsic Pathway

In 2014 alone, over 12,000 women are expected to be diagnosed with cervical cancer. Of these women who are diagnosed, about 3,909 will result in death. Despite developments in prevention methods, cervical cancer remains a major health concern for women. Growing evidence suggests that Salvianolic acid B (Sal B), a major component of the Chinese herb Danshen, may inhibit cancer cell growth and help fight against cervical cancer. This study characterizes the potential of Sal B as a cervical cancer drug through in vitro testing on HeLa cells. We hypothesized that application of Sal B to HeLa cells will result in decreased cell viability and increased apoptosis in a dose dependent manner. HeLa cells were treated with varying concentrations of Sal B: 25µM, 50µM, 100µM, and 200µM. Cell viability was determined through colony formation assay, cell death ELISA, and nuclear morphology. An inhibitor study was also conducted for further apoptosis pathway analysis. Colony formation assay demonstrated a significant decrease in cell viability with increasing concentrations of Sal B with 75% viability at 50µM down to 0% viability at 200µM. Cell death ELISA and the analysis of nuclear morphology via Hoechst staining reported significant levels of apoptosis at concentrations equal to 50µM and greater. Furthermore, experiments using caspase inhibitors indicated that Sal B’s apoptotic effects are caspase-8 dependent. In conclusion, our results demonstrate that Sal B inhibits cancer cell growth by a mechanism that involves apoptosis induction through the extrinsic pathway.

A Study of pH Manipulation on Tumor Proliferation and the CTL Response

Adoptive Cell Transfer (ACT) Therapy is a cancer treatment that enhances and utilizes the body’s own immune system. However, this treatment has had limited success in clinical trials. We hypothesized that this is due to the immunosuppressive, acidic microenvironment of cancer tumors. We tested the effects of acidic, neutral, and basic environments in vitro on cytotoxic T lymphocyte (CTL) survival, activation, migration and killing ability and on cancer cell survival. We found that CTLs have most optimum survival, activation, and migration in a neutral environment, while the optimal extracellular conditions for EG-7 lymphoma are slightly acidic and B16-OVA melanoma survives best in physiological conditions. Future research should further study the killing ability of T cells in the three different environments and look to move to in vivo experiments.

Genetic manipulation of Anopheles stephensi immunity to increase plasmodium falciparum salivary gland sporozoite infection levels

Human malaria is responsible for over 700,000 deaths a year. To stay abreast of the threat posed by the parasite, a constant stream of new drugs and vector control methods are required. This study focuses on a vaccine that has the potential to protect against parasite infection, but has been hindered by developmental challenges. In malaria prevention, live, attenuated, aseptic, Plasmodium falciparum sporozoites (PfSPZ) can be administered as a highly protective vaccine. PfSPZ are produced using adult female Anopheles stephensi mosquitoes as bioreactors. Production volume and cost of a PfSPZ vaccine for malaria are expected to be directly correlated with Plasmodium falciparum infection intensity in the salivary glands. The sporogonic development of Plasmodium falciparum in A. stephensi to fully infected salivary gland stage sporozoites is dictated by the activities of several known components of the mosquito’s innate immune system. Here I report on the use of genetic technologies that have been rarely, if ever, used in Anopheles stephensi Sda500 to increase the yield of sporozoites per mosquito and enhance vaccine production. By combining the Gal4/UAS bipartite system with in vivo expression of shRNA gene silencing, activity of the IMD signaling pathway downstream effector LRIM1, an antagonist to Plasmodium development, was reduced in the midgut, fat body, and salivary glands of A. stephensi. In infection studies using P. berghei and P. falciparum these transgenic mosquitoes consistently produced significantly more salivary gland stage sporozoites than wildtype controls, with increases in P. falciparum ranging from 2.5 to 10 fold. Using Plasmodium infection assays and qRT-PCR, two novel findings were identified. First, it was shown that 14 days post Plasmodium infection, transcript abundance of the IMD immune effector genes LRIM1, TEP1 and APL1c are elevated, in the salivary glands of A. stephensi, suggesting the salivary glands may play a role in post midgut defense against the parasite. Second, a non-pathogenic IMD signaling pathway response was observed which could suggest an alternative pathway for IMD activation. The information gained from these studies has significantly increased our knowledge of Plasmodium defense in A. stephensi and moreover could significantly improve vaccine production.

Image-Guided Precision Manipulation of Cells and Nanoparticles in Microfluidics

Manipulation of single cells and particles is important to biology and nanotechnology. Our electrokinetic (EK) tweezers manipulate objects in simple microfluidic devices using gentle fluid and electric forces under vision-based feedback control. In this dissertation, I detail a user-friendly implementation of EK tweezers that allows users to select, position, and assemble cells and nanoparticles. This EK system was used to measure attachment forces between living breast cancer cells, trap single quantum dots with 45 nm accuracy, build nanophotonic circuits, and scan optical properties of nanowires. With a novel multi-layer microfluidic device, EK was also used to guide single microspheres along complex 3D trajectories. The schemes, software, and methods developed here can be used in many settings to precisely manipulate most visible objects, assemble objects into useful structures, and improve the function of lab-on-a-chip microfluidic systems.

MOLECULAR MASS MANIPULATION ENABLED BY GRAPHENE BASED NANOSTRUCTURES

The surge of interest in graphene, as epitomized by the Nobel Prize in Physics in 2010, is attributed to its extraordinary properties. Graphene is ultrathin, mechanically tough, and has amendable surface chemistry. These features make graphene and graphene based nanostructure an ideal candidate for the use of molecular mass manipulation. The controllable and programmable molecular mass manipulation is crucial in enabling future graphene based applications, however is challenging to achieve. This dissertation studies several aspects in molecular mass manipulation including mass transportation, patterning and storage. For molecular mass transportation, two methods based on carbon nanoscroll are demonstrated to be effective. They are torsional buckling instability assisted transportation and surface energy induced radial shrinkage. To achieve a more controllable transportation, a fundamental law of direction transport of molecular mass by straining basal graphene is studied. For molecular mass patterning, we reveal a barrier effect of line defects in graphene, which can enable molecular confining and patterning in a domain of desirable geometry. Such a strategy makes controllable patterning feasible for various types of molecules. For molecular mass storage, we propose a novel partially hydrogenated bilayer graphene structure which has large capacity for mass uptake. Also the mass release can be achieved by simply stretching the structure. Therefore the mass uptake and release is reversible. This kind of structure is crucial in enabling hydrogen fuel based technology. Lastly, spontaneous nanofluidic channel formation enabled by patterned hydrogenation is studied. This novel strategy enables programmable channel formation with pre-defined complex geometry.

MANIPULATION OF IONS, ELECTRONS, AND PHOTONS IN 2D MATERIALS BY ION INTERCALATION

2D materials have attracted tremendous attention due to their unique physical and chemical properties since the discovery of graphene. Despite these intrinsic properties, various modification methods have been applied to 2D materials that yield even more exciting results. Among all modification methods, the intercalation of 2D materials provides the highest possible doping and/or phase change to the pristine 2D materials. This doping effect highly modifies 2D materials, with extraordinary electrical transport as well as optical, thermal, magnetic, and catalytic properties, which are advantageous for optoelectronics, superconductors, thermoelectronics, catalysis and energy storage applications. To study the property changes of 2D materials, we designed and built a planar nanobattery that allows electrochemical ion intercalation in 2D materials. More importantly, this planar nanobattery enables characterization of electrical, optical and structural properties of 2D materials in situ and real time upon ion intercalation. With this device, we successfully intercalated Li-ions into few layer graphene (FLG) and ultrathin graphite, heavily dopes the graphene to 0.6 x 10^15 /cm2, which simultaneously increased its conductivity and transmittance in the visible range. The intercalated LiC6 single crystallite achieved extraordinary optoelectronic properties, in which an eight-layered Li intercalated FLG achieved transmittance of 91.7% (at 550 nm) and sheet resistance of 3 ohm/sq. We extend the research to obtain scalable, printable graphene based transparent conductors with ion intercalation. Surfactant free, printed reduced graphene oxide transparent conductor thin film with Na-ion intercalation is obtained with transmittance of 79% and sheet resistance of 300 ohm/sq (at 550 nm). The figure of merit is calculated as the best pure rGO based transparent conductors. We further improved the tunability of the reduced graphene oxide film by using two layers of CNT films to sandwich it. The tunable range of rGO film is demonstrated from 0.9 um to 10 um in wavelength. Other ions such as K-ion is also studied of its intercalation chemistry and optical properties in graphitic materials. We also used the in situ characterization tools to understand the fundamental properties and improve the performance of battery electrode materials. We investigated the Na-ion interaction with rGO by in situ Transmission electron microscopy (TEM). For the first time, we observed reversible Na metal cluster (with diameter larger than 10 nm) deposition on rGO surface, which we evidenced with atom-resolved HRTEM image of Na metal and electron diffraction pattern. This discovery leads to a porous reduced graphene oxide sodium ion battery anode with record high reversible specific capacity around 450 mAh/g at 25mA/g, a high rate performance of 200 mAh/g at 250 mA/g, and stable cycling performance up to 750 cycles. In addition, direct observation of irreversible formation of Na2O on rGO unveils the origin of commonly observed low 1st Columbic Efficiency of rGO containing electrodes. Another example for in situ characterization for battery electrode is using the planar nanobattery for 2D MoS2 crystallite. Planar nanobattery allows the intrinsic electrical conductivity measurement with single crystalline 2D battery electrode upon ion intercalation and deintercalation process, which is lacking in conventional battery characterization techniques. We discovered that with a “rapid-charging” process at the first cycle, the lithiated MoS2 undergoes a drastic resistance decrease, which in a regular lithiation process, the resistance always increases after lithiation at its final stage. This discovery leads to a 2- fold increase in specific capacity with with rapid first lithiated MoS2 composite electrode material, compare with the regular first lithiated MoS2 composite electrode material, at current density of 250 mA/g.

CERVIXCHECK: A SPIRITUALLY-BASED SMS TEXT MESSAGING PILOT INTERVENTION TO INCREASE CERVICAL CANCER AWARENESS AND PAP TEST SCREENING INTENTION AMONG AFRICAN AMERICAN WOMEN

African American women account for a disproportionate burden of cervical cancer incidence and mortality rate when compared to non-Hispanic White women. Cervical cancer is one of the most preventable types of cancer, and women can be screened for it with a routine Pap test. Given that religion occupies an essential place in African American lives, framing health messages with important spiritual themes and delivering them through a popular communication delivery channel may allow for a more culturally-relevant and accessible technology-based approach to promoting cervical cancer educational content to African American women. Using community-engaged research as a framework, the purpose of this multiple methods study was to develop, pilot test, and evaluate the feasibility, acceptability, and initial efficacy of a spiritually-based SMS text messaging intervention to increase cervical cancer awareness and Pap test screening intention among African American women. The study recruited church-attending African American women ages 21-65 and was conducted in three phases. Phases 1 and 2 consisted of a series of focus group discussions (n=15), cognitive response interviews (n=8), and initial usability testing that were conducted to inform the intervention development and modifications. Phase 3 utilized a non-experimental one-group pretest-posttest design to pilot test the 16-day text messaging intervention (n=52). Of the individuals enrolled, forty-six completed the posttest (retention rate=88%). Findings provided evidence for the early feasibility, high acceptability, and some initial efficacy of the CervixCheck intervention. There were significant pre-post increases observed for knowledge about cervical cancer and the Pap test (p = .001) and subjective norms (p = .006). Additionally, results post-intervention revealed that 83% of participants reported being either “satisfied” or “very satisfied” with the program and 85% found the text messages either “useful” or “very useful”. 85% of the participants also indicated that they would “likely” or “very likely” share the information they learned from the intervention with the women around them, with 39% indicating that they had already shared some of the information they received with others they knew. A spiritually-based SMS text messaging intervention could be a culturally appropriate and cost-effective method of promoting cervical cancer early detection information to African American women.