Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, Tomsk 634050, Russia.
Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow 119234, Russia.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):56555-56579. doi: 10.1021/acsami.4c06835. Epub 2024 Oct 8.
Millions of people worldwide suffer from musculoskeletal damage, thus using the largest proportion of rehabilitation services. The limited self-regenerative capacity of bone and cartilage tissues necessitates the development of functional biomaterials. Magnetoactive materials are a promising solution due to clinical safety and deep tissue penetration of magnetic fields (MFs) without attenuation and tissue heating. Herein, electrospun microfibrous scaffolds were developed based on piezoelectric poly(3-hydroxybutyrate) (PHB) and composite magnetic nanofillers [magnetite with graphene oxide (GO) or reduced GO]. The scaffolds' morphology, structure, mechanical properties, surface potential, and piezoelectric response were systematically investigated. Furthermore, a complex mechanism of enzymatic biodegradation of these scaffolds is proposed that involves (i) a release of polymer crystallites, (ii) crystallization of the amorphous phase, and (iii) dissolution of the amorphous phase. Incorporation of FeO, FeO-GO, or FeO-rGO accelerated the biodegradation of PHB scaffolds owing to pores on the surface of composite fibers and the enlarged content of polymer amorphous phase in the composite scaffolds. Six-month biodegradation caused a reduction in surface potential (1.5-fold) and in a vertical piezoresponse (3.5-fold) of the FeO-GO scaffold because of a decrease in the PHB β-phase content. assays in the absence of an MF showed a significantly more pronounced mesenchymal stem cell proliferation on composite magnetic scaffolds compared to the neat scaffold, whereas in an MF (68 mT, 0.67 Hz), cell proliferation was not statistically significantly different when all the studied scaffolds were compared. The PHB/FeO-GO scaffold was implanted into femur bone defects in rats, resulting in successful bone repair after nonperiodic magnetic stimulation (200 mT, 0.04 Hz) owing to a synergetic influence of increased surface roughness, the presence of hydrophilic groups near the surface, and magnetoelectric and magnetomechanical effects of the material.
全世界数以百万计的人患有肌肉骨骼损伤，因此使用了最大比例的康复服务。骨骼和软骨组织的自我再生能力有限，这就需要开发功能性生物材料。由于磁场（MFs）的临床安全性和深部组织穿透性，而没有衰减和组织加热，磁活性材料是一种很有前途的解决方案。在此，基于压电聚（3-羟基丁酸酯）（PHB）和复合磁性纳米填料[具有氧化石墨烯（GO）或还原 GO 的磁铁矿]开发了电纺微纤维支架。系统研究了支架的形态、结构、力学性能、表面电位和压电响应。此外，提出了这些支架酶促生物降解的复杂机制，涉及（i）聚合物晶相的释放，（ii）无定形相的结晶和（iii）无定形相的溶解。由于复合纤维表面的孔和复合支架中聚合物无定形相的含量增加，FeO、FeO-GO 或 FeO-rGO 的掺入加速了 PHB 支架的生物降解。由于 PHB β 相含量的降低，6 个月的生物降解导致 FeO-GO 支架的表面电位（降低 1.5 倍）和垂直压电阻抗（降低 3.5 倍）降低。在没有 MF 的情况下进行的测试表明，与纯支架相比，复合磁性支架上间充质干细胞的增殖明显更为显著，而在 MF（68 mT，0.67 Hz）中，当比较所有研究的支架时，细胞增殖没有统计学上的显著差异。将 PHB/FeO-GO 支架植入大鼠股骨缺损中，由于材料的协同影响，即表面粗糙度增加、表面附近存在亲水性基团以及材料的磁电和磁机械效应，在非周期性磁刺激（200 mT，0.04 Hz）后成功修复了骨骼。
