Abstract: A delivery device for an active agent comprises nanoparticles based on a biopolymer such as starch. The delivery device may also be in the form of an aptamer-biopolymer-active agent conjugate wherein the aptamer targets the device for the treatment of specific disorders. The nanoparticles may be made by applying a high shear force in the presence of a crosslinker. The particles may be predominantly in the range of 50-150 nm and form a colloidal dispersion of crosslinked hydrogel particles in water. The biopolymer may be functionalized. The aptamer may be conjugated directly to the cross-linked biopolymers. The active agent may be a drug useful for the treatment of cancer. The delivery device survives for a period of time in the body sufficient to allow for the sustained release of a drug and for the transportation and uptake of the conjugate into targeted cells. However, the biopolymer is biocompatible and resorbable.