Hixon Katherine R, Melvin Alexa M, Lin Alexander Y, Hall Andrew F, Sell Scott A
1 Department of Biomedical Engineering, Saint Louis University, St. Louis, MO, USA.
2 Department of Surgery, Saint Louis University, St. Louis, MO, USA.
J Biomater Appl. 2017 Nov;32(5):598-611. doi: 10.1177/0885328217734824. Epub 2017 Oct 5.
Bone defects are extremely common in children with cleft-craniofacial conditions, especially those with alveolar cleft defects and cranial defects. This study used patient-specific 3D-printed molds derived from computed tomography and cryogel scaffold fabrication as a proof of concept for the creation of site-specific implants for bone reconstruction. Cryogel scaffolds are unique tissue-engineered constructs formed at sub-zero temperatures. When thawed, the resulting structure is macroporous, sponge-like, and mechanically durable. Due to these unique properties, cryogels have excellent potential for the treatment of patient-specific bone defects; however, there is little literature on their use in cleft-craniofacial defects. While 3D-printing technology currently lacks the spatial resolution to print the microstructure necessary for bone regeneration, it can be used to create site-specific molds. Thus, it is ideal to integrate these techniques for the fabrication of scaffolds with patient-specific geometry. Overall, all cryogels possessed appropriate geometry to allow for cell infiltration after 28 days. Additionally, suitable mechanical durability was demonstrated where, despite mold geometry, all cryogels could be compressed without exhibiting crack propagation. Such a patient-specific scaffold would be ideal in pediatric cleft-craniofacial defects, as these are complex 3D defects and children have less donor bone availability.
骨缺损在患有颅面裂疾病的儿童中极为常见，尤其是那些患有牙槽裂缺损和颅骨缺损的儿童。本研究使用源自计算机断层扫描的患者特异性3D打印模具和冷冻凝胶支架制造，作为创建用于骨重建的位点特异性植入物的概念验证。冷冻凝胶支架是在零下温度下形成的独特的组织工程构建体。解冻后，所得结构为大孔状、海绵状且机械耐用。由于这些独特特性，冷冻凝胶在治疗患者特异性骨缺损方面具有巨大潜力；然而，关于其在颅面裂缺损中的应用的文献很少。虽然3D打印技术目前缺乏打印骨再生所需微观结构的空间分辨率，但它可用于创建位点特异性模具。因此，将这些技术整合用于制造具有患者特异性几何形状的支架是理想的。总体而言，所有冷冻凝胶在28天后都具有允许细胞浸润的合适几何形状。此外，还展示了合适的机械耐用性，即尽管模具几何形状不同，但所有冷冻凝胶都可以被压缩而不出现裂纹扩展。这种患者特异性支架在小儿颅面裂缺损中是理想的，因为这些是复杂的3D缺损且儿童可用的供体骨较少。
