Cell Micropatterning Using Magnetite Nanoparticles and Magnetic Force

Tissue engineering is a promising technological approach to addressing shortages of organs available for transplantation. Tissue engineering aims to create functional organs by using biomaterials and cells. Artificial tissues can be implanted in patients to recover tissue functions that were lost due to severe injury, disease. However, it is difficult to construct functional organs because tissue-engineered architectures are not entirely similar to the in vivo organs, in which the cells are allocated precisely. Therefore, tissue engineering requires novel technology for allocating cells precisely to fabricating functional tissue architectures. One approach toward creating such a complex organization is the micropatterning of cells. Several cell patterning methods such as microcontact printing or lthography have been developed. However, these methods require cell patterning on specialized surfaces, and fabrication of surfaces is time-consuming. In the present study, we demonstrated cell micropatterning using magnetite nanoparticles and magnetic force, which is a novel technique able to easily allocate cells on arbitrary non-absorbing surface, including biological gels. We previously developed magnetite cationic liposomes (MCLs), which are cationic liposomes containing 10-nm magnetite nanoparticles [1]. MCLs can be taken up easily by target cells. The magnetically labeled cells can be manipulated by means of magnetic force, and we have developed an original tissue engineering methodology using the cells that were magnetically labeled by MCLs and magnetic force and have designated “magnetic force-based tissue engineering” (Mag-TE). With this technique, we fabricated mono-layered cell sheets and multi layered 3D construct without using any artificial polymer scaffolds [2, 3] and tubular constructs [4]. In the present study, we developed a novel methodology of cell patterning by using the Mag-TE technique, which can fabricate several cell patterns easily and rapidly with a high resolution.