Transcrystalline growth of PLLA on carbon fiber grafted with nano-SiO
            <sub>2</sub>
            towards boosting interfacial bonding in bone scaffold

Chen

et al. 2022

Biomater Res

Self Cite

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.

Section: Resultsmentioning

confidence: 66%

Construction of magnetic nanochains to achieve magnetic energy coupling in scaffold

Chen

et al. 2022

Biomater Res

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“…In the FTIR spectrum (Fig. 3g), the absorption peak at 1076 cm − 1 in Fe 3 O 4 @SiO 2 was adscripted to Si-O bond while the peak at 592 cm − 1 was attributed to Fe-O bond [29][30][31], which further con rmed that the coreshell structure of Fe 3 O 4 @SiO 2 nanochains.…”

Section: Fe 3 O 4 @Sio 2 Nanochainsmentioning

confidence: 72%

Construction of Magnetic Nanochains to Achieve Magnetic Energy Coupling in Scaffold

Chen

et al. 2022

Preprint

Self Cite

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.

“…42 Specifically, during the cooling process, the nanoparticles with a large specific surface area and high surface activity could act as nucleating sites to induce the ordered arrangement of polymer chain under a higher temperature. 43,44 Furthermore, it was found that the sintering window, defined as the difference between the melting temperature and crystallization temperature, was enlarged with the introduction of nanoparticles. It had been reported that the larger the sintering window, the more conducive to processing.…”

Section: Resultsmentioning

confidence: 99%

Sr²⁺ Sustained Release System Augments Bioactivity of Polymer Scaffold

Wang

ACS Appl. Polym. Mater.

et al. 2022

Self Cite

Strontium ion (Sr 2+ ) enabled us to endow polymer bone scaffolds with bioactivity owing to its excellent osteoinductive capacity. Nevertheless, the burst release of Sr 2+ hindered its further application. Herein, strontium substituted hydroxyapatite (SrHA) was constructed to achieve a sustained release system. Specifically, Sr 2+ could substitute Ca 2+ in a HA lattice framework through ion exchange due to their similar ion radius. The ionic bond formed by Sr 2+ and surrounding ions could prevent the rapid escape of Sr 2+ and thereby achieve the sustained release of Sr 2+ . Subsequently, SrHA was introduced into the poly-L-lactic (PLLA) scaffold fabricated by selective laser sintering. Results demonstrated that PLLA/SrHA scaffolds presented a sustained Sr 2+ release with a cumulative concentration of 5.6 mg/L over 28 days. The released Sr 2+ significantly promoted the cell proliferation and differentiation. Furthermore, the tensile and compressive strengths of PLLA/ SrHA scaffolds were also greatly enhanced in comparison with that of PLLA scaffolds. These positive findings demonstrated that PLLA/SrHA scaffolds had considerable potential for bone repair.