Abstract Using stereolithography (vat photopolymerisation) to polymerise High Internal Phase Emulsions (PolyHIPEs) is a potent additive manufacturing route to produce materials with a hierarchical porosity. These multiscale porous materials have a microporosity (1–50 μm) dictated by emulsion templating and a macroporosity (100 μm upwards) controlled by additive manufacturing. The interconnected, hierarchical porosity of these structures is particularly desirable in the field of bone tissue engineering as it promotes tissue formation and allows efficient mass transport. However, due to the high light-scattering nature of the HIPEs, the achievable feature resolution is poor in comparison to other photocurable polymers, and they are prone to the formation of a closed porosity ‘skin layer’ at the surface. This study focuses on different methods of both improving the resolution of structures fabricated from HIPEs via stereolithography and minimising skin formation. The inclusion of 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (commercially UV-234 or Tinuvin®234), a UV light-absorber, was found to significantly improve the achievable resolution of PolyHIPE structures fabricated via stereolithography with no cytotoxic effects and reduce the skin formation. Furthermore, in direct comparison with a non-microporous scaffold of the same architecture, the inclusion of a microporosity significantly promoted the proliferation of MLO-A5 murine osteoblasts and permitted superior bone-matrix deposition.

中文翻译：

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PolyHIPE 的基于光的增材制造：控制 3D 细胞培养应用的表面孔隙率

摘要 使用立体光刻（还原光聚合）聚合高内相乳液 (PolyHIPE) 是一种有效的增材制造途径，可生产具有分级孔隙率的材料。这些多尺度多孔材料具有由乳液模板决定的微孔率（1-50 μm）和由增材制造控制的大孔率（100 μm 以上）。这些结构相互连接的分级孔隙率在骨组织工程领域特别受欢迎，因为它促进了组织形成并允许有效的质量传输。然而，由于 HIPE 的高光散射特性，与其他光固化聚合物相比，可实现的特征分辨率较差，并且它们易于在表面形成封闭的孔隙“表层”。这项研究的重点是通过立体光刻提高由 HIPE 制造的结构的分辨率和最小化皮肤形成的不同方法。发现包含 2-(2H-苯并三唑-2-基)-4,6-双(1-甲基-1-苯乙基)苯酚（商业上称为 UV-234 或 Tinuvin®234），一种紫外线吸收剂，显着提高了通过立体光刻制造的 PolyHIPE 结构的可实现分辨率，没有细胞毒性作用并减少皮肤形成。此外，与相同结构的非微孔支架直接比较，微孔的加入显着促进了 MLO-A5 小鼠成骨细胞的增殖，并允许优越的骨基质沉积。发现包含 2-(2H-苯并三唑-2-基)-4,6-双(1-甲基-1-苯乙基)苯酚（商业上称为 UV-234 或 Tinuvin®234），一种紫外线吸收剂，显着提高了通过立体光刻制造的 PolyHIPE 结构的可实现分辨率，没有细胞毒性作用并减少皮肤形成。此外，与相同结构的非微孔支架直接比较，微孔的加入显着促进了 MLO-A5 小鼠成骨细胞的增殖，并允许优越的骨基质沉积。发现包含 2-(2H-苯并三唑-2-基)-4,6-双(1-甲基-1-苯乙基)苯酚（商业上称为 UV-234 或 Tinuvin®234），一种紫外线吸收剂，显着提高了通过立体光刻制造的 PolyHIPE 结构的可实现分辨率，没有细胞毒性作用并减少皮肤形成。此外，与相同结构的非微孔支架直接比较，微孔的加入显着促进了 MLO-A5 小鼠成骨细胞的增殖，并允许优越的骨基质沉积。