The present invention relates to a particular class of biodegradable linkers, ensuring transiently stable conjugation of building blocks and/or bioactive compounds into drug delivery systems (DDS), such as DDS based on polymeric micelles or hydrogels. In addition, the present invention relates to compounds, comprising said linkers, such compounds preferably being prodrugs. Further, the invention is directed to the use of said linkers, and especially said biodegradable linkers, in a drug delivery system. Moreover, the invention relates to controlled release system comprising a polymer matrix, capable of releasing an active ingredient, wherein the active ingredient is covalently linked to the polymer molecules of the polymer matrix through said linkers, as well as to a method of synthesizing these linkers and preparing such controlled release systems.
