Biomedical engineers at Brown University have developed a new instrument that promises advancement in the field of solid organ fabrication on a nano-scale. Currently explored methods of 3D tissue engineering, such as 3D printers, have major drawbacks when it comes to solid organ masses, which need to be continuously perfused (circulated with blood flow). The Bio-Pick, Place, and Perfuse (Bio-P3) is capable of picking up large multicellular parts, moving them to a building area, and placing them at precisely desired locations, while also continuously perfusing the parts and the building area to maintain cell viability and structure.
To construct the multicellular building parts, cells were seeded into non-adhesive micromolds, where they were left to self-assemble into living microtissues. Tissues in the shape of spheroids (1,000 cells), toroids (25,000 cells), and honeycombs (250,000 cells) were constructed. The structures were then removed from the molds and individually picked up and moved by the manually operated Bio-P3, while being perfused by the suction head used for transporting the microtissues. Sixteen toroids and four honeycomb structures were successfully stacked, and, over the next 48 hours, fused to form a single viable tissue. Scaffold-free building parts, as created using this instrument, are a major step forward for large tissue biofabrication. Future studies of this procedure include observing the long-term viability of produced tissues, and automation of the gripping head for more precise placement and speed.
Current methods of tissue engineering such as scaffold-based and cell sheets are limited in their application towards high-density tissue structures. This method of constructing large tissue structures avoids using scaffolding, making it a good candidate for solid organ fabrication. The success of such a device could allow for mass production of replacements for patients in need of donor organs such as livers.
Because the method described has only been tested on a level for proof-of-concept, there are many risks associated with long-term viability of the produced tissue. Currently, these risk remain unknown until further testing. Risks involved with implantation of tissues produced by this device include improper function, degradation, and rejection by the immune system.