Figure 3. Multi-photon microfabricated collagen scaffolds.
(a) Method for multi-photon microfabricating collagen scaffolds by: (i) exposing a fluorescein infused collagen scaffold to the femtosecond laser; (ii) Addition of acetic acid or tris-HCl to dissolve unexposed regions. (b) Fluorescence decay curves showing dissolution and transport away of fluorescently labeled collagen scaffolds during development in (i) acetic acid; (ii) tris-HCl at different laser powers. (c) Arbitrary shapes exposed and developed in collagen. Laser scanning time ~ 5 sec. (i) Single z-slice imaged by 2-photon microscopy. (ii) Isosurface rendering by thresholding voxel dataset obtained from two-photon imaging of collagen scaffold (d) Dependence of collagen shrinkage on (i) collagen scaffold concentration and (ii) exposed laser power and scan speed.