A nanoparticle suitable for delivery of an active agent across the blood-brain barrier is provided. As such, the nanoparticle can target brain tissue so that the active agent can be delivered across the blood-brain barrier to the target brain tissue. The nanoparticle includes a core that includes a core material such as a polymer or inorganic material as well as an active agent； and a shell comprising a membrane derived from a brain metastatic cancer cell, wherein the brain metastatic cancer cell facilitates transport of the nanoparticle across a blood-brain barrier. Also disclosed are methods of forming the nanoparticle and methods of using the nanoparticle.
