Delemeester Mitchell, Pawelec Kendell M, Hix Jeremy M L, Siegenthaler James R, Lissy Micah, Douek Philippe, Houmeau Angèle, Si-Mohamed Salim, Shapiro Erik M
bioRxiv. 2024 Mar 1:2024.02.26.582070. doi: 10.1101/2024.02.26.582070.
3D printed biomaterial implants are revolutionizing personalized medicine for tissue repair, especially in orthopedics. In this study, a radiopaque Bi O doped polycaprolactone ( ) composite is developed and implemented to enable the use of diagnostic X-ray technologies, especially photon counting X-ray computed tomography ( ), for comprehensive in vivo device monitoring. PCL filament with homogeneous Bi O nanoparticle ( ) dispersion (0.8 to 11.7 wt%) are first fabricated. Tissue engineered scaffolds ( ) are then 3D printed with the composite filament, optimizing printing parameters for small feature size and severely overhung geometries. These composite TES are characterized via micro-computed tomography ( ), tensile testing, and a cytocompatibility study, with Bi O mass fractions as low as 2 wt% providing excellent radiographic distinguishability, improved tensile properties, and equivalent cytocompatibility of neat PCL. The excellent radiographic distinguishability is validated in situ by imaging 4 and 7 wt% TES in a mouse model with µCT, showing excellent agreement with in vitro measurements. Subsequently, CT image-derived swine menisci are 3D printed with composite filament and re-implanted in their corresponding swine legs . Re-imaging the swine legs via clinical CT allows facile identification of device location and alignment. Finally, the emergent technology of PCCT unambiguously distinguishes implanted menisci in situ.
3D打印生物材料植入物正在彻底改变用于组织修复的个性化医疗，尤其是在骨科领域。在本研究中，开发并应用了一种不透射线的Bi₂O₃掺杂聚己内酯（PCL）复合材料，以实现利用诊断性X射线技术，特别是光子计数X射线计算机断层扫描（PCCT），对体内装置进行全面监测。首先制备了具有均匀Bi₂O₃纳米颗粒（NP）分散体（0.8至11.7 wt%）的PCL长丝。然后用该复合长丝3D打印组织工程支架（TES），针对小特征尺寸和严重悬垂几何形状优化打印参数。通过微计算机断层扫描（µCT）、拉伸测试和细胞相容性研究对这些复合TES进行表征，Bi₂O₃质量分数低至2 wt%时即可提供出色的射线可分辨性、改善的拉伸性能以及与纯PCL相当的细胞相容性。通过在小鼠模型中用µCT对4 wt%和7 wt%的TES进行成像，原位验证了出色的射线可分辨性，结果显示与体外测量结果高度吻合。随后，用复合长丝3D打印CT图像衍生的猪半月板，并将其重新植入相应的猪腿中。通过临床CT对猪腿进行重新成像，可以轻松识别装置的位置和对齐情况。最后，PCCT这项新兴技术能够在原位明确区分植入的半月板。
