Prabhakaran Molamma P, Venugopal J, Ramakrishna S
Nanoscience and Nanotechnology Initiative, Division of Bioengineering, National University of Singapore, Singapore 117576, Singapore.
Acta Biomater. 2009 Oct;5(8):2884-93. doi: 10.1016/j.actbio.2009.05.007. Epub 2009 May 15.
The current challenge in bone tissue engineering is to fabricate a bioartificial bone graft mimicking the extracellular matrix (ECM) with effective bone mineralization, resulting in the regeneration of fractured or diseased bones. Biocomposite polymeric nanofibers containing nanohydroxyapatite (HA) fabricated by electrospinning could be promising scaffolds for bone tissue engineering. Nanofibrous scaffolds of poly-l-lactide (PLLA, 860+/-110 nm), PLLA/HA (845+/-140 nm) and PLLA/collagen/HA (310+/-125 nm) were fabricated, and the morphology, chemical and mechanical characterization of the nanofibers were evaluated using scanning electron microscopy, Fourier transform infrared spectroscopy and tensile testing, respectively. The in vitro biocompatibility of different nanofibrous scaffolds was also assessed by growing human fetal osteoblasts (hFOB), and investigating the proliferation, alkaline phosphatase activity (ALP) and mineralization of cells on different nanofibrous scaffolds. Osteoblasts were found to adhere and grow actively on PLLA/collagen/HA nanofibers with enhanced mineral deposition of 57% higher than the PLLA/HA nanofibers. The synergistic effect of the presence of an ECM protein, collagen and HA in PLLA/collagen/HA nanofibers provided cell recognition sites together with apatite for cell proliferation and osteoconduction necessary for mineralization and bone formation. The results of our study showed that the biocomposite PLLA/collagen/HA nanofibrous scaffold could be a potential substrate for the proliferation and mineralization of osteoblasts, enhancing bone regeneration.
骨组织工程当前面临的挑战是制造一种能模拟细胞外基质(ECM)且具有有效骨矿化能力的生物人工骨移植物,从而实现骨折或患病骨骼的再生。通过静电纺丝制备的含有纳米羟基磷灰石(HA)的生物复合聚合物纳米纤维有望成为骨组织工程的支架材料。制备了聚-L-乳酸(PLLA,860±110纳米)、PLLA/HA(845±140纳米)和PLLA/胶原蛋白/HA(310±125纳米)的纳米纤维支架,并分别使用扫描电子显微镜、傅里叶变换红外光谱和拉伸试验对纳米纤维的形态、化学和力学特性进行了评估。还通过培养人胎儿成骨细胞(hFOB)并研究不同纳米纤维支架上细胞的增殖、碱性磷酸酶活性(ALP)和矿化情况,评估了不同纳米纤维支架的体外生物相容性。结果发现,成骨细胞能在PLLA/胶原蛋白/HA纳米纤维上积极黏附并生长,其矿物质沉积增强,比PLLA/HA纳米纤维高57%。PLLA/胶原蛋白/HA纳米纤维中细胞外基质蛋白、胶原蛋白和HA的协同作用提供了细胞识别位点以及磷灰石,以促进细胞增殖以及矿化和骨形成所需的骨传导。我们的研究结果表明,生物复合PLLA/胶原蛋白/HA纳米纤维支架可能是成骨细胞增殖和矿化的潜在基质,可促进骨再生。