Long-term in vivo performances of polylactide/iron oxide nanoparticles core-shell fibrous nanocomposites as MRI-visible magneto-scaffolds

Construction of bFGF/heparin and Fe3O4 nanoparticles functionalized scaffolds aiming at vascular repair and magnetic resonance imaging monitoring

This work develops a bioactive basic fibroblast growth factor (bFGF)/heparin and Fe3O4 nanoparticles (NPs) trifunctionalized degradable construct with the potential of using as a vascular tissue engineering scaffold with the aim of improving vascular repair and regeneration therapy. The covalent modification of heparin onto the poly(lactic acid) (PLA)-gelatin (Gel)-Fe3O4 (PGF) scaffold improves the hydrophilicity of the scaffold. Furthermore, the electrostatic adsorption of bFGF on heparin allows for a more consistent and prolonged release of bFGF in situ, hence increasing the stability and effectiveness of bFGF around the surrounding vascular tissues. The sustained release of bFGF promotes the M2 macrophage polarization, and adhesion and migration of macrophages and endothelial cells (ECs), providing a stable and favorable microenvironment for vascular regeneration. Furthermore, the covalently modified heparin minimizes platelet adhesion on the scaffold surface, potentially contributing to the long-term patency of the vascular tissue engineering scaffold. Including Fe3O4 NPs in the scaffold delays degradation and provides an in vivo magnetic resonance imaging (MRI) effect to monitor the scaffold's location and in vivo degradation. Furthermore, the mild photothermal effect of Fe3O4 NPs plays a facilitating role in bFGF release, immune modulation, and ECs manipulation, therefore contributary to the vascular tissue reconstruction.

Recent trends in preparation and biomedical applications of iron oxide nanoparticles

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.