Construction of magnetic nanochains to achieve magnetic energy coupling in scaffold

Abstract

Background Fe3O4 nanoparticles are highly desired for constructing endogenous magnetic microenvironment in scaffold to accelerate bone regeneration due to their superior magnetism. However, their random arrangement easily leads to mutual consumption of magnetic poles, thereby weakening the magnetic stimulation effect. Methods In this study, magnetic nanochains are synthesized by magnetic-field-guided interface co-assembly of Fe3O4 nanoparticles. In detail, multiple Fe3O4 nanoparticles are aligned along the direction of magnetic force lines and are connected in series to form nanochain structures under an external magnetic field. Subsequently, the nanochain structures are covered and fixed by depositing a thin layer of silica (SiO2), and consequently forming linear magnetic nanochains (Fe3O4@SiO2). The Fe3O4@SiO2 nanochains are then incorporated into poly l-lactic acid (PLLA) scaffold prepared by selective laser sintering technology. Results The results show that the Fe3O4@SiO2 nanochains with unique core–shell structure are successfully constructed. Meanwhile, the orderly assembly of nanoparticles in the Fe3O4@SiO2 nanochains enable to form magnetic energy coupling and obtain a highly magnetic micro-field. The in vitro tests indicate that the PLLA/Fe3O4@SiO2 scaffolds exhibit superior capacity in enhancing cell activity, improving osteogenesis-related gene expressions, and inducing cell mineralization compared with PLLA and PLLA/Fe3O4 scaffolds. Conclusion In short, the Fe3O4@SiO2 nanochains endow scaffolds with good magnetism and cytocompatibility, which have great potential in accelerating bone repair.

Photothermal and Photodynamic Effects of g-C3N4 Nanosheet/Bi2S3 Nanorod Composites with Antibacterial Activity for Tracheal Injury Repair

“…The scaffold not only needs a good antibacterial property but also should possess excellent tracheal regeneration function when it is applied to repair tracheal defects. − The proliferation and live/dead staining of mBMSCs after coculturing with the composite scaffolds under 808 nm NIR light irradiation for 15 min were employed to evaluate the effect of heating and ROS on the cells surrounding the scaffold. As shown in Figure a, on the first day of culture, the number of mBMSCs for the ZnCN-Bi 2 S 3 /PLLA group was lower than that of the PLLA group under NIR light irradiation for 15 min, and more dead cells cultured on the ZnCN-Bi 2 S 3 /PLLA with NIR light irradiation were observed than for the PLLA group under 808 nm NIR light irradiation, indicating that the heating and ROS produced by the photothermal and photodynamic effects could hurt normal cells in some scaffolds.…”

Fe3O4‐nanoparticle‐functionalized 3D‐printed injectable microgel

“…52,53 The magnetic Fe 3 O 4 nanoparticles can construct an endogenous magnetic microenvironment to mediate the osteogenic differentiation of stem cells via magnetic stimuli because of the diamagnetism of cell membranes. 10 However, the delivery of Fe 3 O 4 nanoparticles is still a problem on account of the aggregation. The incorporation of microgels and Fe 3 O 4 nanoparticles is anticipated to realize controllable release of Fe 3 O 4 nanoparticles.…”

“…In recent years, many studies have demonstrated that superparamagnetic Fe 3 O 4 nanoparticles can activate the receptor on the cell (such as ISCA1 or GPCRs) whether there is an applied magnetic field 6,7 . And then a series of signaling pathways will be modulated to enhance osteogenic differentiation 5,8–10 . Wang et al found that Fe 3 O 4 can upregulate long noncoding RNA INZEB2 (an essential factor for maintaining osteogenesis) and activate the classical mitogen‐activated protein kinase signal pathway, showing great potential in bone tissue regeneration 11,12 .…”

“…6,7 And then a series of signaling pathways will be modulated to enhance osteogenic differentiation. 5,[8][9][10] Wang et al found that Fe 3 O 4 can upregulate long noncoding RNA INZEB2 (an essential factor for maintaining osteogenesis) and activate the classical mitogen-activated protein kinase signal pathway, showing great potential in bone tissue regeneration. 11,12 However, there are still some limitations for their widespread application, such as easy aggregation, the leakage of nanoparticles, and the risk of blood capillary obstruction.…”

Structural and Functional Adaptive Artificial Bone: Materials, Fabrications, and Properties

“…Biometals, including stainless steel and titanium alloy, possess distinguished mechanical properties and plastic toughness, and they can cause some complications and the release of toxic metal ions easily, and so on. [13][14][15][16][17] Bioceramics, including hydroxyapatite (HAP) and tricalcium phosphate (TCP), have great bioactivity, biocompatibility, and bone conductivity, but the major issue is their poor strength and low toughness. [18][19][20] Biopolymers, including poly (L-lactide) (PLLA) and poly (ε-caprolactone) (PCL), possess good biosafety, biodegradability, and formability, but their strength is insufficient, and their degradation products are acidic, easily resulting in aseptic inflammatory reaction.…”