4arm PEG Azide

4-Arm PEG-Azide is a multi-armed PEG derivative with an azide (N3) group at each end of the four arms attached to a pentaerythritol core. Azido groups can be used for coupling to alkynes via click chemistry. Due to the increased number of active end groups, it has a larger molecular weight, so it can carry more drug molecules, and multi-arm PEG derivatives can also modify the surface of biomaterials or form new biomedical materials.