Eslami Hossein, Azimi Lisar Hamidreza, Jafarzadeh Kashi Tahereh Sadat, Tahriri Mohammadreza, Ansari Mojtaba, Rafiei Tohid, Bastami Farshid, Shahin-Shamsabadi Alireza, Mashhadi Abbas Fatemeh, Tayebi Lobat
Department of Biomedical Engineering, University of Meybod, Yazd, Iran.
Department of Oral and Maxillofacial Surgery, School of Dentistry, Shahed University, Tehran, Iran.
Biologicals. 2018 May;53:51-62. doi: 10.1016/j.biologicals.2018.02.004. Epub 2018 Mar 2.
The aim of this study was to synthesize and characterize novel three-dimensional porous scaffolds made of poly (lactic-co-glycolic acid)/TiO nanotube (TNT) composite microspheres for bone tissue engineering applications. The incorporation of TNT greatly increases mechanical properties of PLGA/TNT microsphere-sintered scaffold. The experimental results exhibit that the PLGA/0.5 wt% TNT scaffold sintered at 100 °C for 3 h showed the best mechanical properties and a proper pore structure for tissue engineering. Biodegradation test ascertained that the weight of both PLGA and PLGA/PLGA/0.5 wt% TiO nanotube composites slightly reduced during the first 4 weeks following immersion in SBF solution. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and alkaline phosphatase activity (ALP activity) results represent increased cell viability for PLGA/0.5%TNT composite scaffold in comparison to the control group. In vivo studies show the amount of bone formation for PLGA/TNT was approximately twice of pure PLGA. Vivid histologic images of the newly generated bone on the implants further supported our test results. Eventually, a mathematical model showed that both PLGA and PLGA/TNT scaffolds' mechanical properties follow an exponential trend with time as their degradation occurs. By a three-dimensional finite element model, a more monotonous distribution of stress was present in the scaffold due to the presence of TNT with a reduction in maximum stress on bone.
本研究的目的是合成并表征由聚（乳酸-乙醇酸共聚物）/二氧化钛纳米管（TNT）复合微球制成的新型三维多孔支架，用于骨组织工程应用。TNT的加入大大提高了PLGA/TNT微球烧结支架的力学性能。实验结果表明，在100℃下烧结3小时的PLGA/0.5 wt% TNT支架具有最佳的力学性能和适合组织工程的孔隙结构。生物降解试验确定，在浸入模拟体液（SBF）溶液后的前4周内，PLGA和PLGA/0.5 wt% TiO纳米管复合材料的重量均略有降低。此外，3-（4,5-二甲基噻唑-2-基）-2,5-二苯基-2H-四唑溴盐（MTT）试验和碱性磷酸酶活性（ALP活性）结果表明，与对照组相比，PLGA/0.5%TNT复合支架的细胞活力有所提高。体内研究表明，PLGA/TNT的骨形成量约为纯PLGA的两倍。植入物上新生成骨的清晰组织学图像进一步支持了我们的测试结果。最终，一个数学模型表明，随着PLGA和PLGA/TNT支架的降解，它们的力学性能随时间呈指数趋势变化。通过三维有限元模型，由于TNT的存在，支架内应力分布更加均匀，骨上的最大应力降低。
