Optothermal systems for cellular manipulation and tissue culture

Abstract

Two novel optothermal microfluidic systems capable of facilitating tissue cell culture were developed and tested. Both systems feature optical-based heating that is used to trigger thermal effects. The first system involves a mechanism for cell isolation and culture. Cells are suspended in a thermoresponsive hydrogel solution, and optical patterns are utilized to heat the solution, producing localized hydrogel formation around cells of interest. The hydrogel traps only the desired cells in place, while also serving as a biocompatible scaffold for supporting the cultivation of cells in 3D. This is demonstrated with the trapping of MDCK II and HeLa cells. The light intensity from the optically induced hydrogel formation does not significantly affect cell viability. The second system utilizes optically actuated bubbles in oil as microrobots. Simulations of the thermocapillary fluid flow within the oil phase are used to illustrate the mechanisms driving the bubble actuation. Parallel manipulation of sub-millimeter objects including glass beads and hydrogel beads was demonstrated. These capabilities show the potential for using the bubble microrobots in a broader range of biomedical or other microassembly applications, including the assembly of cell-laden scaffolds for tissue culture.