5 Hydrogel for medical purposes; hydrogel for use in medical procedures; in situ polymerizing hydrogel-based preparations for medical purposes; implantable surgical materials, namely, pliable, synthetic hydrogel; kits comprised of a pre-filled applicator of hydrogel precursors for medical purposes; kits for use in medical and surgical procedures comprised of hydrogel precursors that react to form a hydrogel when combined with each other and also including applicators therefore; medical devices sold filled with polymer precursors that, when combined, form an in situ polymerizing hydrogel material; medical instrument in the nature of an applicator sold filled with medical hydrogel precursors for delivering and applying hydrogels in medical and surgical procedures; medical polymer precursors for use in medical procedures; medical preparations in the nature of precursor polymers sold as a component of in situ polymerizing hydrogels for use in medical and surgical procedures; synthetic sealant preparations for medical purposes; polymer precursors that, when combined, form an in situ polymerizing hydrogel used in surgical procedures; surgical devices and instruments, sold filled with surgical hydrogel preparations, for delivering and applying such surgical hydrogels; and syringes sold filled with medical hydrogel-based materials