Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA.
Acta Biomater. 2010 Aug;6(8):3004-12. doi: 10.1016/j.actbio.2010.01.045. Epub 2010 Feb 6.
In a previous study, a three-dimensional nanofibrous spiral scaffold for bone tissue engineering was developed, which showed enhanced human osteoblast cell attachment, proliferation and differentiation compared with traditional cylinder scaffolds, owing to the incorporation of spiral structures and nanofiber. However, the application of these scaffolds to bone tissue engineering was limited by their weak mechanical strength. This limitation triggered the design for novel structured scaffolds with reinforced physical characteristics. In this study, spiral polycaprolactone (PCL) nanofibrous scaffolds were inserted into poly(lactide-co-glycolide) (PLGA) microsphere sintered tubular scaffolds to form integrated scaffolds to provide mechanical properties and bioactivity appropriate for bone tissue engineering. Four experiment groups were designed: PLGA cylinder scaffold; PLGA tubular scaffold; PLGA tubular scaffold with PCL spiral structured inner core; PLGA tubular scaffold with PCL nanofiber containing spiral structured inner core. The morphology, porosity and mechanical properties of the scaffolds were characterized. Furthermore, human osteoblastic cells were seeded on these scaffolds, and the cell attachment, proliferation, differentiation and mineralized matrix deposition on the scaffolds were evaluated. The integrated scaffolds had Young's modulus 250-300 MPa, and compressive strength 8-11 MPa under uniaxial compression. With the addition of an inner highly porous insert to the tubular shell, human osteoblast cells seeded on the integrated scaffolds showed slightly higher cell proliferation, 20-25% more alkaline phosphatase expression and twofold higher calcium deposition than those on the cylinder and tubular scaffolds. Furthermore, compared with sintered PLGA cylinder scaffolds, the integrated scaffolds allowed better cellular infiltration Therefore, this design demonstrates great potential for integrated scaffolds in bone tissue engineering applications.
在之前的研究中，开发了一种用于骨组织工程的三维纳米纤维螺旋支架，与传统的圆柱支架相比，由于螺旋结构和纳米纤维的加入，该支架显示出增强的人成骨细胞附着、增殖和分化。然而，这些支架在骨组织工程中的应用受到其机械强度较弱的限制。这一限制促使设计出具有增强物理特性的新型结构支架。在这项研究中，螺旋聚己内酯（PCL）纳米纤维支架被插入聚（乳酸-共-乙醇酸）（PLGA）微球烧结管状支架中，形成集成支架，为骨组织工程提供适当的机械性能和生物活性。设计了四个实验组：PLGA 圆柱支架；PLGA 管状支架；PLGA 管状支架内有 PCL 螺旋结构内芯；PLGA 管状支架内有含有 PCL 螺旋结构内芯的纳米纤维。对支架的形态、孔隙率和机械性能进行了表征。此外，将人成骨细胞接种到这些支架上，评估细胞在支架上的附着、增殖、分化和矿化基质沉积。集成支架的杨氏模量为 250-300MPa，在单轴压缩下的抗压强度为 8-11MPa。在管状壳内加入高度多孔的内插物后，接种在集成支架上的人成骨细胞的增殖率略高，碱性磷酸酶表达增加 20-25%，钙沉积增加两倍，高于圆柱和管状支架。此外，与烧结的 PLGA 圆柱支架相比，集成支架允许更好的细胞渗透。因此，这种设计在骨组织工程应用中具有很大的潜力。
