the present invention relates to a biodegradable hydrogel comprising bonds which are hydrolyzable under physiological conditions . more particularly , the hydrogel consists of two interpenetrating polymer networks interconnected to one another through hydrolyzable spacers . in addition , the invention relates to a method for the preparation of a hydrogel , wherein macromolecules , e . g ., polymers which contain bonds which are hydrolyzable under physiological conditions , are cross - linked in an aqueous solution .