Nelson Maria, Li Siwei, Page Samuel J, Shi Xiaomeng, Lee Peter D, Stevens Molly M, Hanna John V, Jones Julian R
Department of Materials, Imperial College London, London SW7 2AZ, UK.
Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
Mater Sci Eng C Mater Biol Appl. 2021 Apr;123:111964. doi: 10.1016/j.msec.2021.111964. Epub 2021 Feb 12.
Inorganic/organic hybrids have co-networks of inorganic and organic components, with the aim of obtaining synergy of the properties of those components. Here, a silica-gelatin sol-gel hybrid "ink" was directly 3D printed to produce 3D grid-like scaffolds, using a coupling agent, 3-glycidyloxypropyl)trimethoxysilane (GPTMS), to form covalent bonds between the silicate and gelatin co-networks. Scaffolds were printed with 1 mm strut separation, but the drying method affected the final architecture and properties. Freeze drying produced <40 μm struts and large ~700 μm channels. Critical point drying enabled strut consolidation, with ~160 μm struts and ~200 μm channels, which improved mechanical properties. This architecture was critical to cellular response: when chondrocytes were seeded on the scaffolds with 200 μm wide pore channels in vitro, collagen Type II matrix was preferentially produced (negligible amount of Type I or X were observed), indicative of hyaline-like cartilaginous matrix formation, but when pore channels were 700 μm wide, Type I collagen was prevalent. This was supported by Sox9 and Aggrecan expression. The scaffolds have potential for regeneration of articular cartilage regeneration, particularly in sports medicine cases.
无机/有机杂化材料具有无机和有机成分的共网络结构，目的是实现这些成分性能的协同作用。在此，使用偶联剂3-缩水甘油氧基丙基三甲氧基硅烷（GPTMS）在硅酸盐和明胶共网络之间形成共价键，将硅胶-明胶溶胶-凝胶杂化“墨水”直接进行3D打印，以生产3D网格状支架。支架打印时支柱间距为1毫米，但干燥方法会影响最终的结构和性能。冷冻干燥产生的支柱小于40微米，通道约700微米大。临界点干燥使支柱固结，支柱约160微米，通道约200微米，从而改善了机械性能。这种结构对细胞反应至关重要：当软骨细胞接种在体外具有200微米宽孔隙通道的支架上时，优先产生II型胶原基质（观察到I型或X型胶原的量可忽略不计），表明形成了类似透明软骨的基质，但当孔隙通道为700微米宽时，I型胶原占主导。这得到了Sox9和聚集蛋白聚糖表达的支持。这些支架具有用于关节软骨再生的潜力，特别是在运动医学病例中。
