Luke P. Lee (Advisor)

BPN360: Biomimetic Microfluidic Assembly of Spheroids and Dynamic Perfusion for Anti-Cancer Drug Discovery

Liz Wu
2007

Multicellular tumor spheroids may provide a better model than monolayer culture of in vivo tumors for drug assays. We present a novel microfluidic method for self-assembly of tumor spheroids for these studies. Our device traps cancer cells hydrodynamically and spheroid formation is enhanced by maintaining compact groups of the trapped cells due to continuous perfusion. It was found that spheroid formation speed and size uniformity increased with increased flow rate. A large amount of tumor spheroids (7,500 spheroids per square centimeter) with a narrow size distribution (10 ± 1...

BPN412: Signal Amplifications of SERS by Microfluidic CD-based Preconcentration Methods

Dukhyun Choi
2007

Signal amplifications of surface-enhanced Raman scattering (SERS) by microfluidic compact disk (CD)-based preconcentration method is accomplished for effective label-free bioassays and chemical detections. This is the first demonstration of the SERS-CD platform having capabilities of high-throughput microfluidic multifunctional on-chip biomedical devices. In order to achieve the preconcentration through the accumulation of biomolecules adsorbed on the SERS active site, we inject and dry biomolecular sample solution in the microfluidic channel prior to SERS detection and then repeat...

BPN409: Long-term Cytotoxic Drug Assay via Single-Cell Microfluidic Array

Liz Wu
2007

Understanding cellular dynamics of xenobiotic and ion transport are important for in-vitro drug assay since it is a critical step to estimate the performance, toxin and side effect of new drug candidates. Most current drug assays are based on the average cellular response of large cell populations. In conventional cell culture platforms the mass transport of cell cluster is affected by transport at neighboring cells. In order to study systematically xenobiotic and ion transport, isolated single cells on optofluidic multisensing platform are required. To observe cancer cells under...

BPN384: Single-cell Analysis via Raman Spectroscopy

Adrian Lau
2007

There has been significant interest in applying Raman Spectroscopy on cellular analysis in recent years. Advanced optics has allowed very high resolution Raman signal measurement at the sub-cellular level, fueling the emerging field of Single-cell Raman Spectroscopy. The fact that Raman Spectroscopy/Imaging is in few ways superior to conventional fluorescence techniques enables novel ways of monitoring cell processes. Recently, multiple studies have reported the use of Raman Spectroscopy methods in detecting specific cell behaviors. However, an extensive quantitative study has yet to...

BPN312: High Precision Kinematic Assembly of Soft-State Biofluidic ASICs

Christy Trinkle
2007

Microfluidic chips have made it possible to manipulate biological fluidic samples in increasingly smaller volumes—even enabling multiplexed study of individual cells. Performing biological assays using microfluidic technology not only makes them more portable when compared to their traditional counterparts, but also decreases testing time and cost. These biofluidic circuits vary widely in design and function: multiplexed cell electroporation, on-chip cell culturing, cell-cell communication monitoring, protein crystallization, and small volume sample analysis are only a few examples...

BPN344: Microfluidic Platform for Quantitative Microcirculation Studies in Sickle Cell Disease

Sharon Hsu
2007

Soft Lithography has been pioneered in the past decade as a tool to manipulate cells under well controlled physical and chemical conditions. Despite the vast number of studies applied in various lines of cells, there have been few focusing on the membrane properties of erythrocytes. Here we present a novel and convenient alternative to traditional methods used to obtain physical properties of erythrocytes, and our objective is to establish a standard model for healthy red blood cells and derive clear model for quantification of severity in erythrocyte membrane disorders, with...

BPN398: Single Cell Electroporation Array with OET/PDMS Integration

Hsan-Yin (Tony) Hsu
Yir-Shyuan Liz Wu
2008

Single cell analysis is an important technology for biological and medical research. The precision of manipulating the location of the single cell (relative to the assay sites or other neighboring cells) is a necessary factor. We have previously demonstrated cell manipulation and separation with optoelectronic tweezers (OET), the goal of this project is to integrate this powerful tool with the micrifluidic devices to provide a complete solution for single cell electroporation.

Project end date: 07/30/08

BPN449: Plasmon Engineering the Nanocrescent

Benjamin Ross
2008

We present a systematic numerical study of plasmon resonance in the nanocrescent. We show that by varying the nanocrescent geometry, the plasmon resonance peak can be tuned into the near-infrared and local field enhancement can be increased significantly. Because its wide tunability, high local field enhancement, and geometry which utilizes both a sharp edge and intra-particle coupling, the nanocrescent is a structure well-suited for in vivo biological applications.

Project end date: 08/12/08

BPN340: Single Cell Differential Impedance Spectroscopy Analysis Using High Density Hydrodynamic Cell Trapping Arrays

J. Tanner Nevill
Daniele Malleo
2008

Cells are usually studied in bulk quantities: they are suspended in a cell culture mixture and this suspension is usually analyzed. However, uncertainties and difficulties arise from the study of mixtures and volume fractions: for example it is extremely difficult if not impossible to discover a single cancerous cell in a population of healthy cells. It is immediately obvious that the study of individually-addressed cells can enhance our understanding of their structure and behavior. Here we present a device that allows the trapping, manipulation and simultaneous electrical/optical...

BPN355: Microfluidic Cell Analysis Platform: On Chip Cell Culture and Electrochemical Lysis

J. Tanner Nevill
2008

Cultured cells are used in a variety of contexts ranging from high throughput screening of drugs to systems biology. Microfluidic devices for cell culture studies offer numerous advantages over plate-based cell culture, and because of this, are being increasingly used in laboratory settings.4,5 Microfluidic devices can provide physiologically relevant microenvironments by allowing for constant perfusion and 3D tissue-like structure. Additionally, time and costs are reduced due to decreased reagent volumes and automated handling. Higher surface-to-volume ratios can also offer improved...