Sugars polymers isolated from seaweed are used as coatings to protect therapeutic cells. These capsules are capable of protecting and housing cells, which are engineered to be factories of therapeutic protein factories. These particular capsules were recognized by the immune system of the host that they were transplanted into. The immune cells of the host body attacked the capsules and left behind the red stained fibrotic proteins, which coated them. The green and blue spots are cells that did not appreciate the presence of these capsules.