Immuno nanoparticles integrated electrical control of targeted cancer cell development using whole cell bioelectronic device.

Electrical properties of cells determine most of the cellular functions, particularly ones which occur in the cell's membrane. Manipulation of these electrical properties may provide a powerful electrotherapy option for the treatment of cancer as cancerous cells have been shown to be more electronegative than normal proliferating cells. Previously, we used an electrical impedance sensing system (EIS) to explore the responses of cancerous SKOV3 cells and normal HUVEC cells to low intensity (<2 V/cm) AC electric fields, determining that the optimal frequency for SKOV3 proliferation arrest was 200 kHz, without harming the non-cancerous HUVECs. In this study, to determine if these effects are cell type dependant, human breast adenocarcinoma cells (MCF7) were subjected to a range of frequencies (50 kHz-2 MHz) similar to the previously tested SKOV3. For the MCF7, an optimal frequency of 100 kHz was determined using the EIS, indicating a higher sensitivity towards the applied field. Further experiments specifically targeting the two types of cancer cells using HER2 antibody functionalized gold nanoparticles (HER2-AuNPs) were performed to determine if enhanced electric field strength can be induced via the application of nanoparticles, consequently leading to the killing of the cancerous cells without affecting non cancerous HUVECs and MCF10a providing a platform for the development of a non-invasive cancer treatment without any harmful side effects. The EIS was used to monitor the real-time consequences on cellular viability and a noticeable decrease in the growth profile of the MCF7 was observed with the application of the HER2-AuNPs and the electric fields indicating specific inhibitory effects on dividing cells in culture. To further understand the effects of the externally applied field to the cells, an Annexin V/EthD-III assay was performed to determine the cell death mechanism indicating apoptosis. The zeta potential of the SKOV3 and the MCF7 before and after incorporation of the HER2-AuNPs was also obtained indicating a decrease in zeta potential with the incorporation of the nanoparticles. The outcome of this research will improve our fundamental understanding of the behavior of cancer cells and define optimal parameters of electrotherapy for clinical and drug delivery applications.

Facile and rapid generation of 3D chemical gradients within hydrogels for high-throughput drug screening applications.

We propose a novel application of dielectrophoresis (DEP) to make three-dimensional (3D) methacrylated gelatin (GelMA) hydrogels with gradients of micro- and nanoparticles. DEP forces were able to manipulate micro- and nanoparticles of different sizes and materials (i.e., C2C12 myoblasts, polystyrene beads, gold microparticles, and carbon nanotubes) within GelMA hydrogels in a rapid and facile way and create 3D gradients of these particles in a microchamber. Immobilization of drugs, such as fluorescein isothiocyanate-dextran (FITC-dextran) and 6-hydroxydopamine (6-OHDA), on gold microparticles allowed us to investigate the high-throughput release of these drugs from GelMA-gold microparticle gradient systems. The latter gradient constructs were incubated with C2C12 myoblasts for 24h to examine the cell viability through the release of 6-OHDA. The drug was released from the microparticles in a gradient manner, inducing a cell viability gradient. This novel approach to create 3D chemical gradients within hydrogels is scalable to any arbitrary length scale. It is useful for making anisotropic biomimetic materials and high-throughput platforms to investigate cell-microenvironment interactions in a rapid, simple, cost-effective, and reproducible manner.