Dextran is a complex branched polysaccharide polymer chain unit of various lengths, from 1000 to 2 000 000 Da. It is a biocompatible material which is widely used in multiple biomedical applications, e.g. coating nanoparticles to prevent the agglomeration and toxicity of magnetic particles. Meanwhile, dextran also possesses the properties of biodegradable and water-soluble. It has been applied to design dextran-coated nanomaterials with specific biological interactions with the complement system.