Three-Dimensional Hybrid Mesoporous Scaffolds for Simvastatin Sustained Delivery with in Vitro Cell Compatibility

The development of scaffolds with suitable physicochemical and mechanical properties allowing for the structural regeneration of injured bone and recovery of the natural biological functionality is still a challenge in the tissue engineering field. Nanostructured materials with added theranostic abilities, together with an interconnected hierarchy of pores, offer the possibility to provide a new generation of bone implants. In this work, scaffolds with highly porous and resistant three-dimensional structures have been successfully developed by homogeneously embedding mesoporous silica nanostructures in a bioactive matrix of chitosan/kappa-carrageenan. Moreover, magnetite (Fe3O4) nanoparticles were also added to the mesoporous scaffold to include additional magnetic functionalities for diagnostic or therapeutic actions. The complete physicochemical characterization shows mesoporous materials with a wide range of interconnected pores, remarkable surface roughness, and large effective surface area, suitable for cell adhesion. In accordance to these properties, a simvastatin loading and release assay showed high loading capacities and sustained release over a long period of time. Together with a suitable resistance against degradation and biocompatible performance assessed by cell viability assays, these scaffolds show interesting features for delivering drugs with activity in bone regeneration processes.