Ortholab, Department of Surgical Sciences-Orthopaedics, Uppsala University, Sweden; Biomaterial Systems, Department of Materials Science and Engineering, Uppsala University, Sweden.
Ortholab, Department of Surgical Sciences-Orthopaedics, Uppsala University, Sweden.
Mater Sci Eng C Mater Biol Appl. 2021 Jun;125:112091. doi: 10.1016/j.msec.2021.112091. Epub 2021 Apr 1.
Additive manufacturing (AM) has revolutionized the design of regenerative scaffolds for orthopaedic applications, enabling customizable geometric designs and material compositions that mimic bone. However, the available evidence is contradictory with respect to which geometric designs and material compositions are optimal. There is a lack of studies that systematically compare different pore sizes and geometries in conjunction with the presence or absence of calcium phosphates. We therefore evaluated the physicochemical and biological properties of additively manufactured scaffolds based on polylactic acid (PLA) in combination with hydroxyapatite (HA). HA was either incorporated in the polymeric matrix or introduced as a coating, yielding 15 and 2% wt., respectively. Pore sizes of the scaffolds varied between 200 and 450 μm and were shaped either triangularly or hexagonally. All scaffolds supported the adhesion, proliferation and differentiation of both primary mouse osteoblasts and osteosarcoma cells up to four weeks, with only small differences in the production of alkaline phosphatase (ALP) between cells grown on different pore geometries and material compositions. However, mineralization of the PLA scaffolds was substantially enhanced in the presence of HA, either embedded in the PLA matrix or as a coating at the surface level, and by larger hexagonal pores. In conclusion, customized HA/PLA composite porous scaffolds intended for the repair of critical size bone defects were obtained by a cost-effective AM method. Our findings indicate that the analysis of osteoblast adhesion and differentiation on experimental scaffolds alone is inconclusive without the assessment of mineralization, and the effects of geometry and composition on bone matrix deposition must be carefully considered in order to understand the regenerative potential of experimental scaffolds.
增材制造（AM）彻底改变了骨科应用中再生支架的设计，可以定制出模仿骨骼的几何设计和材料组成。然而，关于哪种几何设计和材料组成是最佳的，现有的证据相互矛盾。缺乏系统比较不同孔径和几何形状以及是否存在磷酸钙的研究。因此，我们评估了基于聚乳酸（PLA）与羟基磷灰石（HA）结合的增材制造支架的理化和生物学特性。HA 要么掺入聚合物基质中，要么作为涂层引入，分别达到 15%和 2%wt。支架的孔径在 200 和 450μm 之间变化，形状为三角形或六边形。所有支架均支持原代小鼠成骨细胞和骨肉瘤细胞的粘附、增殖和分化，长达四周，细胞在不同孔径和材料组成上的碱性磷酸酶（ALP）产量仅略有差异。然而，在 HA 存在的情况下，PLA 支架的矿化得到了极大的增强，HA 要么嵌入 PLA 基质中，要么作为表面涂层，且较大的六边形孔增强效果更明显。总之，通过经济高效的 AM 方法获得了用于修复临界尺寸骨缺损的定制化 HA/PLA 复合多孔支架。我们的研究结果表明，如果不评估矿化，仅分析成骨细胞在实验支架上的粘附和分化，结果是不确定的，并且必须仔细考虑几何形状和组成对骨基质沉积的影响，以便了解实验支架的再生潜力。
