title: Nanoparticle-mediated remote control of enzymatic activity.
abstract: Nanomaterials have found numerous applications as tunable, remotely controlled platforms for drug delivery, hyperthermia cancer treatment, and various other biomedical applications. The basis for the interest lies in their unique properties achieved at the nanoscale that can be accessed via remote stimuli. These properties could then be exploited to simultaneously activate secondary systems that are not remotely actuatable. In this work, iron oxide nanoparticles are encapsulated in a bisacrylamide cross-linked polyacrylamide hydrogel network along with a model dehalogenase enzyme, L-2-HAD(ST). This thermophilic enzyme is activated at elevated temperatures and has been shown to have optimal activity at 70 °C. By exposing the Fe(3)O(4) nanoparticles to a remote stimulus, an alternating magnetic field (AMF), enhanced system heating can be achieved, thus remotely activating the enzyme. The internal heating of the nanocomposite hydrogel network in the AMF results in a 2-fold increase in enzymatic activity as compared to the same hydrogel heated externally in a water bath, suggesting that the internal heating of the nanoparticles is more efficient than the diffusion-limited heating of the water bath. This system may prove useful for remote actuation of biomedical and environmentally relevant enzymes and find applications in a variety of fields.
authors.affiliation: Department of Chemistry, University of Miami, Miami, Florida 33136, USA.
authors.forename: Leslie D
authors.initials: LD
authors.lastname: Knecht
authors.forename: Nur
authors.initials: N
authors.lastname: Ali
authors.forename: Yinan
authors.initials: Y
authors.lastname: Wei
authors.forename: J Zach
authors.initials: JZ
authors.lastname: Hilt
authors.forename: Sylvia
authors.initials: S
authors.lastname: Daunert
mesh_terms: D004789:Enzyme Activation; D006867:Hydrolases / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size
chemical_list: D006867:Hydrolases