Tang Shuo, Liao Xiang, Shi Bo, Qu Yanzhen, Huang Zeyu, Lin Qiang, Guo Xiaodong, Pei Fuxing
Department of Orthopaedics, West China Hospital, Sichuan University, Chengdu, China.
Department of Pain Medicine, Shenzhen Nanshan Hospital, Shenzhen, China.
PLoS One. 2014 Sep 12;9(9):e107517. doi: 10.1371/journal.pone.0107517. eCollection 2014.
Neural stem cells (NSCs) have emerged as a potential source for cell replacement therapy following spinal cord injury (SCI). However, poor survival and low neuronal differentiation remain major obstacles to the use of NSCs. Biomaterials with neurotrophic factors are promising strategies for promoting the proliferation and differentiation of NSCs. Silk fibroin (SF) matrices were demonstrated to successfully deliver growth factors and preserve their potency. In this study, by incorporating NT-3 into a SF coating, we successfully developed NT-3-immobilized scaffolds (membranes and conduits). Sustained release of bioactive NT-3 from the conduits for up to 8 weeks was achieved. Cell viability was confirmed using live/dead staining after 14 days in culture. The efficacy of the immobilized NT-3 was confirmed by assessing NSC neuronal differentiation in vitro. NSC neuronal differentiation was 55.2 ± 4.1% on the NT-3-immobilized membranes, which was significantly higher than that on the NT-3 free membrane. Furthermore, 8 weeks after the NSCs were seeded into conduits and implanted in rats with a transected SCI, the conduit+NT-3+NSCs group achieved higher NSC survival (75.8 ± 15.1%) and neuronal differentiation (21.5 ± 5.2%) compared with the conduit+NSCs group. The animals that received the conduit+NT-3+NSCs treatment also showed improved functional outcomes, as well as increased axonal regeneration. These results indicate the feasibility of fabricating NT-3-immobilized scaffolds using the adsorption of NT-3/SF coating method, as well as the potential of these scaffolds to induce SCI repair by promoting survival and neuronal differentiation of transplanted NSCs.
神经干细胞(NSCs)已成为脊髓损伤(SCI)后细胞替代治疗的潜在细胞来源。然而,低存活率和低神经元分化率仍然是使用神经干细胞的主要障碍。含有神经营养因子的生物材料是促进神经干细胞增殖和分化的有前景的策略。丝素蛋白(SF)基质已被证明能成功递送生长因子并保持其活性。在本研究中,通过将神经营养因子-3(NT-3)掺入丝素蛋白涂层中,我们成功开发了固定有NT-3的支架(膜和导管)。实现了生物活性NT-3从导管中持续释放长达8周。培养14天后,使用活/死染色法确认细胞活力。通过评估神经干细胞在体外的神经元分化来确认固定化NT-3的功效。在固定有NT-3的膜上,神经干细胞的神经元分化率为55.2±4.1%,显著高于无NT-3的膜。此外,将神经干细胞接种到导管中并植入SCI横断大鼠体内8周后,与导管+神经干细胞组相比,导管+NT-3+神经干细胞组实现了更高的神经干细胞存活率(75.8±15.1%)和神经元分化率(21.5±5.2%)。接受导管+NT-3+神经干细胞治疗的动物还表现出功能结果改善以及轴突再生增加。这些结果表明使用NT-3/丝素蛋白涂层吸附法制备固定有NT-3的支架的可行性,以及这些支架通过促进移植神经干细胞的存活和神经元分化来诱导SCI修复的潜力。