Cell-by-cell construction of living tissue by ambient laser transfer

In order to fabricate and interface biological systems for next generation applications such as biosensors, protein recognition microarrays, and engineered tissues, it is imperative to have a method of accurately and rapidly depositing different active biomaterials in patterns or layered structures. Ideally, the biomaterial structures would also be compatible with many different substrates including technologically relevant platforms such as electronic circuits, microfluidic devices, or even living tissue. We have developed a technique termed matrix assisted pulsed laser evaporation direct write (MAPLE DW), that is able to form patterns and three-dimensional structures of numerous biologically active species ranging from protein solutions to living cells. Specifically, we have shown that MAPLE DW is capable of forming mesoscopic patterns of many components needed to construct complex 3D tissue such as living mammalian cells (mouse pluripotent, human osteoblast, rat cardiac), numerous active proteins, extracellular matrix materials, and semi-rigid scaffold materials. This manuscript presents experimental results on our stepwise efforts to fabricate living tissue constructs. We first demonstrate the ability to form 2D microarrays from active proteins and living cells. We then discuss our efforts to begin 3D printing of both living cells and scaffold materials.