On-Cell Surface Cross-Linking of Polymer Molecules by Horseradish Peroxidase Anchored to Cell Membrane for Individual Cell Encapsulation in Hydrogel Sheath.

Hydrogel sheaths were fabricated on the surfaces of individual mammalian cells through the cross-linking of polymer molecules catalyzed by horseradish peroxidase (HRP) in aqueous solution. For confining the progress of the cross-linking only on the cell surface, HRP was anchored to the cell membrane by soaking the cells in the solution containing the HRP conjugated with a biocompatible anchor molecule for cell membrane. The hydrogel sheath of about 1 μm thickness was obtained by soaking the cells with the anchored HRP in aqueous solution containing polymers possessing phenolic hydroxyl (Ph) moieties and H2O2 for 10 min. The hydrogel sheaths could be made from a variety of polymers possessing Ph moieties, for example, derivatives of polysaccharide, protein, and synthetic polymer. Cytocompatibility of the on-cell surface enzymatic hydrogel sheath formation was confirmed from the viability of the enclosed cells (>90%) and subsequent normal growth after removal of the hydrogel sheath.