Magnetically Actuated Microscaffold with Controllable Magnetization and Morphology for Regeneration of Osteochondral Tissue

Abstract

Magnetic microscaffolds capable of targeted cell delivery have been developed for tissue regeneration. However, the microscaffolds developed so far with similar morphologies have limitations for applications to osteochondral disease, which requires simultaneous treatment of the cartilage and subchondral bone. This study proposes magnetically actuated microscaffolds tailored to the cartilage and subchondral bone for osteochondral tissue regeneration, named magnetically actuated microscaffolds for cartilage regeneration (MAM-CR) and for subchondral bone regeneration (MAM-SBR). The morphologies of the microscaffolds were controlled using a double emulsion and microfluidic flow. In addition, due to their different sizes, MAM-CR and MAM-SBR have different magnetizations because of the different amounts of magnetic nanoparticles attached to their surfaces. In terms of biocompatibility, both microscaffolds were shown to grow cells without toxicity as potential cell carriers. In magnetic actuation tests of the microscaffolds, the relatively larger MAM-SBR moved faster than the MAM-CR under the same magnetic field strength. In a feasibility test, the magnetic targeting of the microscaffolds in 3D knee cartilage phantoms showed that the MAM-SBR and MAM-CR were sequentially moved to the target sites. Thus, the proposed magnetically actuated microscaffolds provide noninvasive treatment for osteochondral tissue disease.

Stimuli-responsive microcarriers and their application in tissue repair: A review of magnetic and electroactive microcarrier

“…For osteochondral defects, Lee et al [ 38 ] used the microfluidic method to prepare PLGA microcarriers, and obtained 250–350 μm and 750–850 μm microspheres by controlling the flow rate of the oil and water phase. The different surface area could adjust the adhesion amount of MNPs.…”

Effect of Polydispersity on the Structural and Magnetic Properties of a Magnetopolymer Composite

“…The dependence of the MPC’s properties on the structuring features of the magnetic filler has been demonstrated in experimental works [ 9 , 16 , 17 , 18 , 19 ]. To predict the magnetic properties of an MPC, theories have been developed for various cases of the magnetic filler’s orientation texturing: the easy magnetization axes are aligned parallel to each other [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], orientation texturing is absent [ 27 , 29 , 30 , 31 ], and the orientation of the easy magnetization axes is formed under the influence of a constant magnetic field [ 32 , 33 , 34 ].…”