Rutgers scientists have engineered PEG hydrogels that can biodegrade - they provide novel drug delivery capabilities relative to standard PEG technologies. The technology utilizes soluble, biodegradable PEG molecules which are cross-linked in the presence of drug agents. The resulting hydrogels serve as standard depots for sustained release of the drug and then fully degrade; eliminating the need for surgical removal. Importantly, these gels can also be designed to covalently link the agent so that drug release can occur via controlled degradation in addition to passive diffusion. Selective derivatization of PEG can provide tailored degradation times for a variety of applications. Further, controlled degradation is designed to be independent of any other chemical groups in the hydrogel or in the drug due to selected reactive groups. By providing novel degradable features that do not require surgical removal, this technology represents an important advance in PEG-based implants and delivery systems.