In Situ 3D Label-Free Contactless Bioprinting of Cells through Diamagnetophoresis

Using whole blood, we demonstrate the first realization of a novel macroscale, contactless, label-free method to print in situ three-dimensional (3D) cell assemblies of different morphologies and sizes. This novel bioprinting method does not use nozzles that can contaminate the cell suspension, or to which cells can adhere. Instead, we utilize the intrinsic diamagnetic properties of whole blood cells to magnetically manipulate them in situ in a nontoxic paramagnetic medium, creating (a) rectangular bar, (b) three-pointed star, and (c) spheroids of varying sizes. We envision the technique to be transferable to other cell lines, with potential applications in tissue engineering and drug screening.