Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan.
Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
Int J Nanomedicine. 2019 Sep 19;14:7683-7694. doi: 10.2147/IJN.S217416. eCollection 2019.
Nerve regeneration is important for the treatment of degenerative diseases and neurons injured by accidents. Nerve growth factor (NGF) has been previously conjugated to materials for promotion of neurogenesis.
Photoreactive gelatin was prepared by chemical coupling of gelatin with azidobenzoic acid (P-gel), and then NGF was immobilized on substrates in the presence or absence of micropatterned photomasks. UV irradiation induced crosslinking reactions of P-gel with itself, NGF, and the plate for immobilization.
By adjustment of the P-gel concentration, the nanometer-order height of micropatterns was controlled. NGF was quantitatively immobilized with increasing amounts of P-gel. Immobilized NGF induced neurite outgrowth of PC12 cells, a cell line derived from a pheochromocytoma of the rat adrenal medulla, at the same level as soluble NGF. The immobilized NGF showed higher thermal stability than the soluble NGF and was repeatedly used without loss of biological activity. The 3D structure (height of the formed micropattern) regulated the behavior of neurite guidance. As a result, the orientation of neurites was regulated by the stripe pattern width.
The micropattern-immobilized NGF nanolayer biochemically and topologically regulated neurite formation.
神经再生对于退行性疾病和事故损伤神经元的治疗很重要。神经生长因子（NGF）已被用于与材料结合以促进神经发生。
通过将明胶与叠氮苯甲酸（P-gel）进行化学偶联制备光反应性明胶，然后在有无微图案光掩模的情况下将 NGF 固定在基底上。UV 照射诱导 P-gel 与自身、NGF 和固定板的交联反应。
通过调整 P-gel 浓度，可以控制微图案的纳米级高度。NGF 可以定量地与 P-gel 一起固定。固定化的 NGF 诱导源自大鼠肾上腺髓质嗜铬细胞瘤的 PC12 细胞的突起生长，与可溶性 NGF 达到相同水平。固定化的 NGF 表现出比可溶性 NGF 更高的热稳定性，并且可以在没有生物活性损失的情况下重复使用。3D 结构（形成的微图案的高度）调节了突起引导的行为。结果，突起的取向通过条纹图案的宽度来调节。
微图案固定化的 NGF 纳米层在生化和拓扑结构上调节了突起的形成。
