Acoustic Cell Patterning-Assisted Digital Light Processing for Bioprinting Anisotropic Tissues

Abstract Bioprinting technology has developed to be a powerful tool for regenerative medicine, tissue engineering, and drug screening. Unlike conventional scaffold fabrication techniques, bioprinting allows for the generation of intricate geometries that closely resemble native tissue architecture. Current various bioprinting techniques include inkjet bioprinting, extrusion-based bioprinting, laser-assisted bioprinting, droplet-based bioprinting, and stereolithography-based bioprinting. However, achieving biomimetic anisotropic characteristics of living tissues remains a significant challenge. To achieve precise control cell alignment and orientation during the bioprinting process, we introduce an acoustic patterning method that can integrate with laser-assisted bioprinting to generate anisotropic-engineered tissues. Here, the bioink consists of the GelMA solution blended with living cells. Our acoustic patterning device comprises pairs of piezoelectric transducers and a Petri dish. Standing acoustic waves generated by transducers manipulate and align cells within the bioink during the time interval of the bioprinting process. Through proof-of-concept experiments, we validated the patterning effects of our acoustic patterning device and the printing ability of our bioprinting platform in terms of printing resolution, three-dimensional (3D) scalability, and anisotropic printing capabilities. The results show this platform successfully produced 3D constructs ranging from millimeter to centimeter scale, including structures such as cones, nerve conduits, and vascular branches. Additionally, we assessed the viability and morphology of NIH 3T3 fibroblast cells within the printed constructs. The results indicated high cell viability and proper cellular extension in the engineered tissues. In conclusion, we anticipate this platform to offer new possibilities for 3D bioprinting applications in regenerative medicine, tissue engineering, and biomedical research.