Poly(ethylene glycol) (PEG) is by far the most well-known synthetic biocompatible polymer for its widespread use in the food, cosmetics, and biomedical applications. However, its limited functionality combined with its challenging synthetic nature often poses challenges for advanced material design and synthesis. Recently, new functional monomers based polyglycerols and their derivatives are emerging as alternatives for next-generation biocompatible polymers with controlled functionalities and architectures. The present talk will cover the design and the synthesis of well-defined stimuli-responsive polyethers such as pH-, and redox-stimuli for biocompatible and biodegradable smart drug delivery systems. Furthermore, our recent effort in the development of novel functional epoxide monomers with multifunctionality will be highlighted