Protein microswimmers capable of delivering cells for tissue engineering applications

Despite biomimetic artificial tissues having the potential to greatly contribute to regenerative medicine and drug screening, technologies for constructing functional tissue architectures in a sophisticated manner have not yet been fully developed. Here, a novel approach for tissue construction using an intelligent microswimmer capable of delivering cells is presented. The body of the swimmer was fabricated using serum albumin and magnetic nanoparticles, and cell membrane anchoring reagents were bound to its surface. This magnetically propelled protein swimmer could capture intact cells, transport them towards target destinations, and release them at target sites in a controllable manner without causing any damage to the cells. Protein swimmers were employed to perform various tasks, including single-cell manipulation, cell delivery to the side wall of an enclosed space, the creation of cellular patterns with the desired shapes and timings, and the fabrication of cellular constructs composed of multiple cell types. Protein swimmers allowed us to deliver a specific number of intact cells to a desired target positions, both on the substrate and inside an enclosed space, with various shapes and timings. Our approach will provide new avenues for the development of more flexible and dynamic tissue constructions.