PDF(Pubmed)
Abstract：
Scaffolds for the filling and regeneration of osteochondral defects are a current challenge in the biomaterials field, and solutions with greater functionality are still being sought. The novel approach of this work was to obtain scaffolds with biologically active additives possessing microstructural, permeability, and mechanical properties, mimicking the complexity of natural cartilage. Four types of scaffolds with a gelatin/alginate matrix modified with hydroxyapatite were obtained, and the relationship between the modifiers and substrate properties was evaluated. They differed in the type of second modifier used, which was hydrated MgCl2 in two proportions, ZnO, and nanohydroxyapatite. The samples were obtained by freeze-drying by using two-stage freezing. Based on microstructural observations combined with X-ray microanalysis, the microstructure of the samples and the elemental content were assessed. Permeability and mechanical tests were also performed. The scaffolds exhibited a network of interconnected pores and complex microarchitecture, with lower porosity at the surface (15 ± 7 to 29 ± 6%) and higher porosity at the center (67 ± 8 to 75 ± 8%). The additives had varying effects on the pore sizes and permeabilities of the samples. ZnO yielded the most permeable scaffolds (5.92 × 10-11 m2), whereas nanohydroxyapatite yielded the scaffold with the lowest permeability (1.18 × 10-11 m2), values within the range reported for trabecular bone. The magnesium content had no statistically significant effect on the permeability. The best mechanical parameters were obtained for ZnO samples and those containing hydrated MgCl2. The scaffold\'s properties meet the criteria for filling osteochondral defects. The developed scaffolds follow a biomimetic approach in terms of hierarchical microarchitecture and mechanical parameters as well as chemical composition. The obtained composite materials have the potential as biomimetic scaffolds for the regeneration of osteochondral defects.
摘要：
骨软骨缺损的填充和再生支架是当前生物材料领域的挑战。和具有更大功能的解决方案仍在寻求。这项工作的新方法是获得具有微结构的生物活性添加剂的支架，渗透性,和机械性能，模仿天然软骨的复杂性。获得了四种类型的支架，该支架具有羟基磷灰石修饰的明胶/藻酸盐基质，并评估了改性剂与基材性能之间的关系。它们使用的第二种改性剂的类型不同，它是两个比例的水合MgCl2，ZnO,和纳米羟基磷灰石。通过使用两阶段冷冻的冷冻干燥获得样品。根据微观结构观察结合X射线微观分析，评估样品的微观结构和元素含量。还进行了渗透性和机械测试。支架表现出相互连接的孔和复杂的微观结构的网络，表面孔隙率较低（15±7至29±6％），中心孔隙率较高（67±8至75±8％）。添加剂对样品的孔径和渗透性具有不同的影响。ZnO产生了最可渗透的支架(5.92×10-11m2)，而纳米羟基磷灰石产生的支架具有最低的渗透性（1.18×10-11m2），小梁骨报告范围内的值。镁含量对渗透率没有统计学意义。对于ZnO样品和含有水合MgCl2的样品，获得了最佳的力学参数。支架的性能符合骨软骨缺损的填充标准。所开发的支架在分层微结构和机械参数以及化学组成方面遵循仿生方法。所获得的复合材料具有作为骨软骨缺损再生的仿生支架的潜力。
