A novel 3D printing method for cell alignment and differentiation

The application of bioprinting allows precision deposition of biological materials for bioengineering applications. Here we propose a 2 stage methodology for bioprinting using a back pressure-driven, automated robotic dispensing system. This apparatus can prepare topographic guidance features for cell orientation and then bioprint cells directly onto them. Topographic guidance features generate cues that influence adhered cell morphology and phenotype. The robotic dispensing system was modified to include a sharpened stylus that etched on a polystyrene surface. The same computer-aided design (CAD) software was used for both precision control of etching and bioink deposition. Various etched groove patterns such as linear, concentric circles, and sinusoidal wave patterns were possible. Fibroblasts and mesenchymal stem cells (MSC) were able to sense the grooves, as shown by their elongation and orientation in the direction of the features. The orientated MSCs displayed indications of lineage commitment as detected by fluorescence-activated cell sorting (FACS) analysis. A 2% gelatin bioink was then used to dispense cells onto the etched features using identical, programmed co-ordinates. The bioink allows the cells to contact sense the pattern while containing their deposition within the printed pattern.