A Multiphysics Model for Bone Repair Using Magnetic Scaffolds for Targeted Drug Delivery

Magnetic bone substitutes are multifunctional nanocomposite biomaterials designed to serve as an in-situ attraction platform for magnetic carriers of growth factors. The morphological and functional properties of these biomaterials were characterized so far, but very little is known on the treatment dynamics, and the latter cannot be designed from an engineering point of view. For the first time, this work deals with the mathematical modeling of the use of magnetic scaffolds and functionalized nanoparticles to evaluate the enhancement of osteogenesis and bone repair. The non-linear magnetization of the scaffolds is considered to simulate the attraction and transport of magnetic nanoparticles. Different biomaterials and drug carriers from the literature are analyzed. The drug release via RF-heating is modeled considering the multiphysics nature of the phenomena. The physiological process of bone healing is reproduced using nine non-linear equations. The influence of the delivered growth factor on osteogenesis is assessed and quantified in silico, while compared to numerical simulations of intravenous injection of growth factor and to its release from the biomaterial. The exploitation of magnetic carriers of biomolecules with magnetic scaffolds allows to produce a more homogeneous and uniform distribution of mature bone, overcoming the limitation of traditional drug delivery techniques.