Water-absorbing, expanded, crosslinked polymers obtainable by. This dispersion composition can achieve the satisfactory stability of the colorant irrespective of the kind of the colorant, and allows the inks to be formulated to have the same composition. Release of the hydrophilic polymer chains exposes the hydrophobic polymers for interaction with outer cell membranes of the target cells to promote fusion of the liposome with the target cells. The third portion is configured to disconnect an electrical connection between the first portion and the second portion when the second portion of the first electrode and the second electrode are short-circuited. When the original paper is copied on a printing paper, an image read from the original paper is printed on a secret image display area, whereas a secret image is printed on a non-secret information display area only when an access operation to the secret image is authenticated. The second connector and the third connector are arranged at the same sides of the LED body and with different polarities.