Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Telangana, India.
Department of Material Science and engineering, Indian Institute of Technology Hyderabad, Telangana, India.
J Tissue Eng Regen Med. 2018 Apr;12(4):e2073-e2084. doi: 10.1002/term.2640. Epub 2018 Feb 11.
Considering the complex hierarchical structure of bone, biomimicking the micro and nano level features should be an integral part of scaffold fabrication for successful bone regeneration. We aim to biomimic the microstructure and nanostructure of bone and study the effect of physical cues on cell alignment, proliferation, and differentiation. To achieve this, we have divided the scaffolds into groups: electrospun SU-8 nanofibers, electrospun SU-8 nanofibers with UV treatment, and micropatterned (20 μm sized ridges and grooves) SU-8 nanofibers by photolithography with UV treatment. Two types of culture conditions were applied: with and without osteoinduction medium. In vitro cell proliferation assays, protein estimation, alkaline phosphatase osteodifferentiation assay, live dead assay, and cell alignment studies were performed on these micropatterned nanofiber domains. Our findings show that patterned surface induced an early osteodifferentiation of mesenchymal stem cells even in absence of osteoinduction medium. An interesting similarity with the helicoidal plywood model of the bone was observed. The cells showed layering and rotation along the patterns with time. This resembles the in vivo anisotropic multilamellar bone tissue architecture thus, closely mimicking the subcellular features of bone. This might serve as a smart biomaterial surface for mesenchymal stem cell differentiation in therapeutics where the addition of external chemical factors is a challenge.
考虑到骨的复杂层次结构，仿生微纳结构应该是骨再生成功的支架制造的一个组成部分。我们旨在仿生骨的微观和纳米结构，并研究物理线索对细胞取向、增殖和分化的影响。为此，我们将支架分为三组：电纺 SU-8 纳米纤维、电纺 SU-8 纳米纤维经紫外处理、通过光刻和紫外处理的微图案化（20 µm 大小的脊和槽）SU-8 纳米纤维。应用了两种培养条件：有和没有成骨诱导培养基。对这些微图案化纳米纤维区域进行了体外细胞增殖试验、蛋白质估计、碱性磷酸酶成骨分化试验、死活试验和细胞取向研究。我们的研究结果表明，即使没有成骨诱导培养基，图案化表面也能诱导间充质干细胞的早期成骨分化。观察到与骨的螺旋胶合板模型的有趣相似性。随着时间的推移，细胞沿着图案分层和旋转。这类似于体内各向异性的多层骨组织结构，因此，紧密模仿骨的亚细胞特征。对于治疗中添加外部化学因素是一个挑战的间充质干细胞分化，这可能是一种智能生物材料表面。
