SEMINARS IN BIOMEDICAL ENGINEERING
Laser Guidance-Based Cell Micromanipulation Technique
Bruce Z. Gao, PhD
The fundamental units of an organism are biological cells, which are involved in the development and maintenance of the hierarchical structures of the organism. Communication between neighboring cells, mediated by physical contact and diffusive signaling, regulate normal cellular functions. The functional characteristics of a single cell are determined by its genetic coding as well as its surrounding microenvironment. Due to the extreme complexity of in vivo environments, our understanding of the cellular functions and cell-cell interactions are heavily dependent on cell culture. Numerous studies have demonstrated the importance of cell arrangements for the functions of the cells in culture. To understand the biological mechanisms at cellular level in cell culture, it is necessary to assess the temporospatial interactions of a single cell with its surroundings, including neighboring cells and adjacent extracellular matrix. However, there is no commercially available instrument that can be used to achieve the site- and time-specific placement of an individual cell in a cell culture. There is a critical need to develop a single cell manipulation system for the study of contact and diffusion-mediated communication among neighboring cells. In this talk, I will describe a novel laser cell micromanipulation technique based on the optical force generated by a weakly focused laser beam. In the beam’s focal region, the optical field generates a force with two components: a radial trapping force that draws microparticles, such as cells, into the center of the beam, and an axial pushing force that propels the trapped microparticles along the beam axis and deposits them onto a target surface, a process called laser guidance. Specific cell patterns can be created by moving the target surface relative to the beam axis. I will demonstrate several applications of this technique including 1) alignment of adult myocytes, 2) the formation of a neuronal circuit on microelectrode arrays, and 3) laser guidance based cell detection.
sponsored by
The Laser Microbeam and Medical Program (LAMMP)
a NIH biotechnology resource facility at the Beckman Laser Institute