Nanomagnetic approaches for vascular healing and cardiac regeneration

Boris Polyak

Department of Surgery, Drexel University College of Medicine, Philadelphia, USA

Magnetic nanoparticles and various magnet systems have been used in a range of applications aimed to achieve localized delivery of therapy and tissue regeneration. For local delivery of therapy, magnetic carriers associated with drugs, nucleic acids or loaded within cells are directed or guided by magnetic forces towards certain biological targets. The magnetic delivery of therapeutic agents results in the concentration of the therapy at the target site, consequently improving therapy delivery efficiency while reducing or eliminating the systemic therapy side effects. For tissue regeneration, magnetic nanomaterials are used in remotely controlled actuation for the release of bioactive molecules or mechanical conditioning of cells to generate tissue constructs for restorative tissue support or reconstruction. Mechanical conditioning of cells and tissue constructs is an important factor in determining the properties of the tissue being produced. This conditioning is particularly relevant to the generation of vascularized cardiac muscle, where mechanical stress activates mechano-sensitive receptors, triggering biochemical pathways that promote the production of functional tissue. This talk will present two applications where the magnetic approach has the potential to enable tissue restoration or support. One example will present an innovative method that takes advantage of magnetic nanoparticles and intravascular steel stents to deliver endothelial cells to the blood vessels with the ultimate aim to repair the injured artery. Another study will present a novel strategy for creating a vascularised and functional tissue graft by combining the use of a macroporous alginate scaffold impregnated with magnetically responsive nanoparticles in combination with non-invasive magneto-mechanical stimulation. While a distinct mechanism underlines the strategies described in each example, both cases demonstrate versatile capabilities of magnetic systems for regenerative applications.