Cell-Laden Volumetric Bioprinting: Optical Dose, Cell Shadowing, Gelation, Viability and Construct Fidelity

Volumetric bioprinting forms three-dimensional constructs by delivering many angular light projections into a photosensitive cell-laden volume and solidifying the desired geometry within seconds to tens of seconds. Its speed removes nozzle shear and reduces fabrication time, but it creates a demanding optical-material problem. Cells, proteins and suspended particles can scatter or absorb light; the entire resin volume receives a distributed exposure history; and the printed boundary depends on a nonlinear gelation threshold rather than on a single projected layer. This review focuses on the engineering variables that determine whether a volumetric print is simultaneously geometrically accurate and biologically acceptable. It separates projected optical dose, local accumulated dose, gelation threshold, cell shadowing/scattering, conversion, post-print swelling and viability. A qualification framework is proposed around optical transmission, dose reconstruction, feature fidelity, depth uniformity, cell density and post-print biological function. The central principle is that fast printing does not eliminate dose qualification: it makes three-dimensional dose distribution the primary process variable.

ER-328 · Version 0.5.