a Center for Integrative Nanotechnology Sciences , University of Arkansas at Little Rock , Little Rock , AR , USA.
b Department of Large Animal Clinical Sciences, College of Veterinary Medicine , University of Tennessee , Knoxville , TN , USA.
J Biomater Sci Polym Ed. 2018 Aug;29(12):1426-1443. doi: 10.1080/09205063.2018.1464264. Epub 2018 May 2.
A wide variety of biomaterials are utilized in tissue engineering to promote cell proliferations in vitro or tissue growth in vivo. The combination of cells, extracellular matrices, and biocompatible materials may make it possible to grow functional living tissues ranging from bone to nerve cells. In bone regeneration, polymeric scaffolds can be enhanced by the addition of bioactive materials. To this end, this study designed several ratios of polyurethane (PU) and nano-hydroxyapatite (nHA) composites (PU-nHA ratios: 100/0, 90/10, 80/20, 70/30, 60/40 w/w). The physical and mechanical properties of these composites and their relative cellular compatibility in vitro were determined. The chemical composition and crystallinity of the composites were confirmed using X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analyses. Atomic force microscopy, nano-indentation, and contact angle measurements were used to evaluate surface properties. The results showed a significant increase in surface roughness and a decrease in contact angle when the nHA concentration increased above 20%, resulting in a significant increase in hydrophilicity. These surface property changes influenced cellular behavior when MC 3T3-E1 cells were seeded on the composites. All composites were cytocompatible. There was a linear increase in cell proliferation on the 80/20 and 70/30 composites only, whereas subjective evaluation demonstrated noticeable clusters or nodules of cells (considered hallmarks of osteogenic differentiation) in the absence of any osteogenic inducers only on the 90/10 and 80/20 composites. Cellular data suggests that the 80/20 composite was an optimal environment for cell adhesion, proliferation, and, potentially, osteogenic differentiation in vitro.
生物材料在组织工程中被广泛应用，以促进细胞在体外增殖或组织在体内生长。细胞、细胞外基质和生物相容性材料的结合可能使我们有可能生长出从骨骼到神经细胞等功能活性组织。在骨再生中，可通过添加生物活性材料来增强聚合物支架。为此，本研究设计了几种聚氨酯（PU）和纳米羟基磷灰石（nHA）复合材料（PU-nHA 比：100/0、90/10、80/20、70/30、60/40 w/w）。测定了这些复合材料的物理力学性能及其体外相对细胞相容性。采用 X 射线衍射、X 射线光电子能谱和热重分析对复合材料的化学组成和结晶度进行了确认。原子力显微镜、纳米压痕和接触角测量用于评估表面性能。结果表明，当 nHA 浓度增加到 20%以上时，表面粗糙度显著增加，接触角显著降低，亲水性显著提高。这些表面性质的变化影响了 MC3T3-E1 细胞在复合材料上的细胞行为。所有复合材料均具有细胞相容性。只有在 80/20 和 70/30 复合材料上，细胞增殖呈线性增加，而在没有任何成骨诱导剂的情况下，仅在 90/10 和 80/20 复合材料上，细胞表现出明显的细胞簇或结节（被认为是成骨分化的标志）。细胞数据表明，80/20 复合材料是体外细胞黏附、增殖和潜在成骨分化的最佳环境。
