Smart delivery systems are nanoscopic structures containing entrapped guests, e.g., drugs, that can be released in specific locations. Janus-type Au/mesoporous silica (MS) nanoparticles have been designed with a gate on the MS side of the nanoparticle that is controlled by two enzyme effectors, glucose oxidase and esterase, attached to Au on the other face.

Ramón Martínez-Máñez, Universitat Politècnica de València, Spain, Reynaldo Villalonga, Complutense University of Madrid, Spain, José M. Pingarrón, Complutense University of Madrid, and colleagues designed the gate to open selectively through an enzyme-catalyzed reaction in the presence of either D-glucose or ethyl butyrate, or both substrates. Thus, release of the guest cargo is controlled by an enzymatic logical OR operator.

Nanoparticles loaded with an anti-cancer drug were successfully tested with HeLa cancer cells.

• Toward the Design of Smart Delivery Systems Controlled by Integrated Enzyme-Based Biocomputing Ensembles,
  P. Díez, A. Sánchez, M. Gamella, P. Martínez-Ruíz, E. Aznar, C. de la Torre, J. R. Murguía, R. Martínez-Máñez, R. Villalonga, J. M. Pingarrón,
  J. Am. Chem. Soc. 2014.
  DOI: 10.1021/ja503578b