Magnetic Nanoparticles to Enhance Cell Seeding and Distribution in Tissue Engineering Scaffolds

Abstract

The success of tissue engineering scaffolds is intimately linked with the ability of the seeded cells to adequately distribute and proliferate within the scaffold matrix. In tissue engineering scaffolds, it is difficult to achieve adequate distribution due to the hydrophobic nature of most scaffold materials and poor initial distribution following scaffold seeding. In this study, we investigated the distribution of cells in PLGA salt-leached scaffolds after seeding with magnetic nanoparticle loaded cells with a neodymium magnet placed below. The combined use of magnetic nanoparticle seeded cells and magnetic force was able to not only increase the total number of scaffold adherent cells, but also increase the infiltration and distribution compared with controls. This method to control the distribution of cells may provide a method to increase the functionality of tissue engineering scaffolds.

Harnessing magnetic-mechano actuation in regenerative medicine and tissue engineering

“…Focal adhesion (FA) signalling, actomyosin contraction, stretchactivated ion channels, and nuclear associated proteins [26] are all important for mechanotransduction ( Figure I). Of pivotal importance are integrins, transmembrane heterodimers proteins composed of a and b subunits that physically couple the ECM to the cytoskeleton by linker proteins such as talin and vinculin [27].…”

“…In this technique, cells are labelled with magnetic particles, placed on top of the scaffold, and then driven to invade the scaffold by magnetic forces from below ( Figure 2B). Mag-seeding has proven effective in promoting infiltration and distribution of magnetically labelled fibroblasts in poly(lactic-coglycolic acid) (PLGA), collagen, and polystyrene materials [26][27][28]. This strategy can be used with great precision, enabling distribution of cells with a high degree of spatial resolution.…”

“…Owing to recent progress in nanomedicine and molecular biology, we can begin to understand the signalling pathways involved in mechanotransduction and exploit them with magnetic actuation for a myriad of applications: stem cell differentiation and homing to injury sites, as well as tissue engineering strategies [19][20][21][22][23][24][25]. In tissue engineering, magnetic actuation can allow for better seeding in 3D scaffolds [26][27][28], and can be used in scaffold-free approaches to build tissues bottom-up from mesenchymal stem cells (MSCs) or induced pluripotent stem cells (iPSCs) [29][30][31].…”

Magnetic Nanoparticle-Based Approaches to Locally Target Therapy and Enhance Tissue Regeneration In Vivo

“…Non-magnetic approaches to solve these problems include various dynamic seeding methods and bioreactors [123–125]. These methods may have limitations in that they may either destroy the porous scaffold architecture or fail to produce tissue of adequate thickness [126]. None of the studies cited below directly compared magnetic cell seeding effectiveness with these other approaches.…”

“…The combined use of MNP-seeded cells and magnetic force was shown to increase the infiltration and distribution of cells into PLGA salt-leached scaffolds compared with controls [126]. 3T3 fibroblast cells containing magnetic iron/platinum nanoparticles were seeded along one side of the scaffold.…”