The specific design of a collagen scaffold containing iron oxide nanostructures capped by a TiO2 (anatase) layer is reported. The TiO2 shell is proposed with a dual role: as an innovative and biocompatible cross-linker agent, providing binding sites to the protein moiety, through the well-known TiO2 chemical affinity towards carboxyl groups, and as a protective surface layer from oxidation for the paramagnetic core. Simultaneously, the presence of the nanostructures confers to the collagen gel the sensitivity to an external stimulus, i.e. the application of a magnetic field. The hybrid biomaterial was demonstrated to be healthy and was proposed as a smart scaffold for the on demand release of bioactive compounds. The tunable release upon magnetic field application of a model protein, i.e. myoglobin, was investigated. Myoglobin was loaded in the microporous material and the discharging was induced by consecutive magnet applications, obtaining the release of the protein with a high spatio-temporal and dosage control.
