In-situ immobilization and excitation of cells in hydrogel

2PP-DLW is transferred to the fabrication of three-dimensional hydrogel microstructures. A highly biocompatible cell environment is created from a PEG-based compound with living cells and bacteria incorporated into the prepolymer. A variety of extremely flexible and fast cell immobilization approaches was demonstrated employing a completely non-invasive and contactless method. Hydrogels formed strong bonds to the plasma membrane of yeast cells, as well as Escherichia coli bacteria. After developing a functional work flow for a cell environments, diverse types of cell immobilization structures were successfully implemented. Additionally waveguides were developed for excitation and probing of fluorescent stained yeast cells enabling complex light based networks in-situ fabrication at arbitrary sites. Ongoing experiments include in-vivo injection and polymerization of BSA compounds in living zebra fish embryos.

Figure 4: Left: Cell (1) is immobilized by connection to the pillar, while a second drifting cell (2) is thus ’leashed’ to cell (1). Polymerized hydrogel str is highly flexible and does not break, even upon strong flexion and torsion. Middle: Multiple hydrogel waveguides attached to a 488 nm SMF for cell excitation. Right: GFP stained yeast cell cluster immobilized and excited by a hydrogel waveguide. The fluorescent signal from the cell membrane is clearly observable (inset).