Cell patterning and cell manipulation are for better control and understanding, and their application in practical biomedicine. In this regard, nanobiotechnologists have developed and implemented new methods to immobilize cells on substrates in a controlled manner, so-called cell patterning. Cell patterning and cell manipulation currently represent fundamental steps for conducting drug testing experiments as well as conducting basic research in the field of biology. Among them, magnetic manipulation refers to the manipulation of cells using permanent magnets or electromagnets. Since cells often lack paramagnetism or diamagnetism, immunomagnetic beads are used for cell surface labeling. Surface-modified magnetic beads can adhere to the cell surface through the specific binding of antibodies to antigens.
Magnetic forces and magnetic biomaterials can not only guide cells for tissue engineering applications that require complex and functional tissues. The 3D magnetic bioprinting system can also be used to remove uterine rings from patient cells. In this system the cells are magnetized with biocompatible gold nanoparticles, iron oxide and polylysine, but these do not change the behavior of the cells. After the magnetization procedure, the resuspended cells were placed under a 384-well plate on a magnet to form a tight ring structure in each well. This fast mode was used to study the contractility of different inhibitors simultaneously. In addition, the need for single-cell studies of membrane function, interactions with new drugs, detection and classification, and other biological applications are driving the development of magnetic single-cell arrays.
Fig.1 Phase-microscope images of cell patterns created by magnetic forces.
For single-cell studies, we use magnetic manipulation to form patterns with complex structures and to precisely locate individual cells on large arrays. To manipulate cells, we magnetically and specifically label cells using immunomagnetic labeling and magnetic in situ hybridization strategies to localize labeled single cells into the target space. Additionally, we offer combined systems of magnetic and microfluidic systems. We enhanced the immunomagnetic separation of cells by embedding paramagnetic structures within microfluidic channels. Compared to channels without magnetic structures, this approach will greatly improve the trapping efficiency. The layout of the magnetic structures and the location of the external magnets will together determine the spatial distribution of the captured cells.
For bacterial research, we offer magnetic arrays suitable for bacterial patterns. We magnetically label bacteria by immunomagnetic in situ hybridization to improve specificity and ensure bacterial immobilization, suitable for further study of bacteria.
In tissue engineering, we can facilitate three-dimensionally controlled seeding of cells by magnetic guidance. We provide magnetic scaffolds with short-scale strong magnetic gradients capable of orienting and trapping magnetized cells on selected sides of the scaffold fibers. Such localized magnetic patterns provide a convenient route to construct 3D cellular architectures with microscale texture control.