Vacuum microcasting of 2-methacryloyloxyethyl phosphorylcholine polymer for stable cell patterning

Biomimetic polymers with phosphorylcholine groups as biomaterials for medical devices

Biomimetic molecular designs can yield superior biomaterials. Polymers with a phosphorylcholine group, a polar group of phospholipid molecules, are particularly interesting. A methacrylate monomer, 2-methacryloyloxyethyl phosphorylcholine (MPC), was developed using efficient synthetic reactions and purification techniques. This process has been applied in industrial production to supply MPC globally. Polymers with various structures can be readily synthesized using MPC and their properties have been studied. The MPC polymer surface has a highly hydrated structure in biological conditions, leading to the prevention of adsorption of proteins and lipid molecules, adhesion of cells, and inhibition of bacterial adhesion and biofilm formation. Additionally, it provides an extremely lubricious surface. MPC polymers are used in various applications and can be stably immobilized on material surfaces such as metals and ceramics and polymers such as elastomers. They are also stable under sterilization and in vivo conditions. This makes them ideal for application in the surface treatment of various medical devices, including artificial organs, implanted in humans.

Novel Quick Cell Patterning Using Light-Responsive Gas-Generating Polymer and Fluorescence Microscope

Conventional cell patterning methods are mainly based on hydrophilic/hydrophobic differences or chemical coating for cell adhesion/non-adhesion with wavering strength as it varies with the substrate surface conditions, including the cell type and the extracellular matrix components (ECMs) coating; thus, the versatility and stability of cell patterning methods must be improved. In this study, we propose a new cell patterning method using a light-responsive gas-generating polymer (LGP) and a conventional fluorescence microscope. Herein, cells and cellular tissues are easily released from the substrate surface by the nitrogen gas bubbles generated from LGP by the excitation light for fluorescence observation without harming the cells. The LGP-implanted chip was fabricated by packing LGP into a polystyrene (PS) microarray chip with a concave pattern. HeLa cells were spread on the LGP-implanted chips coated with three different ECMs (fibronectin, collagen, and poly-D-lysine), and all HeLa cells on the three LGP patterns were released. The pattern error between the LGP pattern and the remaining HeLa cells was 8.81 ± 4.24 μm, less than single-cell size. In addition, the LGP-implanted chip method can be applied to millimeter-scale patterns, with less than 30 s required for cell patterning. Therefore, the proposed method is a simple and rapid cell patterning method with high cell patterning accuracy of less than the cell size error, high scalability, versatility, and stability unaffected by the cell type or the ECM coating.