Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah, USA.
Division of Plastic Surgery, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, USA.
J Biomed Mater Res A. 2024 Mar;112(3):473-483. doi: 10.1002/jbm.a.37645. Epub 2023 Nov 14.
Hydroxyapatite (HA) is commonly used as a bone substitute material, but it lacks mechanical strength when compared to native bone tissues. To improve the efficacy of HA as a bone substitute by improving the mechanical strength and cell growth attributes, porous composite scaffolds of HA and titania (HA-TiO ) were fabricated through a freeze-casting process. Three different compositions by weight percent, 25-75 HA-TiO , 50-50 HA-TiO , and 75-25 HA-TiO , were custom-made for testing. After sintering at 1250°C, these composite scaffolds exhibited improved mechanical properties compared to porous HA scaffolds. Substrate mixing was observed, which helped reduce crystal size and introduced new phases such as β-TCP and CaTiO , which also led to improved mechanical properties. The composition of 50-50 HA-TiO had the highest ultimate compressive strength of 3.12 ± 0.36 MPa and elastic modulus 63.29 ± 28.75 MPa. Human osteoblast cell proliferation assay also increased on all three different compositions when compared to porous HA at 14 days. These results highlight the potential of freeze casting composites for the fabrication of bone substitutes, which provide enhanced mechanical strength and biocompatibility while maintaining porosity.
羟基磷灰石（HA）通常被用作骨替代材料，但与天然骨组织相比，其机械强度不足。为了通过提高机械强度和细胞生长特性来提高 HA 作为骨替代物的疗效，通过冷冻铸造工艺制备了 HA 和二氧化钛（HA-TiO）的多孔复合支架。通过重量百分比定制了三种不同的组成，即 25-75 HA-TiO、50-50 HA-TiO 和 75-25 HA-TiO，用于测试。在 1250°C 烧结后，与多孔 HA 支架相比，这些复合支架表现出改善的机械性能。观察到基质混合，这有助于减小晶体尺寸并引入新相，如β-TCP 和 CaTiO，这也导致机械性能提高。50-50 HA-TiO 的组成具有最高的抗压强度 3.12±0.36 MPa 和弹性模量 63.29±28.75 MPa。与多孔 HA 相比，人成骨细胞增殖试验在 14 天时也在所有三种不同的组成上增加。这些结果突出了冷冻铸造复合材料在骨替代物制造中的潜力，它们在保持多孔性的同时提供了增强的机械强度和生物相容性。
