Delemeester Mitchell, Pawelec Kendell M, Hix Jeremy M L, Siegenthaler James R, Lissy Micah, Douek Philippe, Houmeau Angèle, Si-Mohamed Salim, Shapiro Erik M
Department of Radiology, Michigan State University, East Lansing, MI 48824, USA.
Department of Chemical Eng & Materials Science, Michigan State University, East Lansing, MI 48824, USA.
Adv Funct Mater. 2024 Oct 29;34(44). doi: 10.1002/adfm.202404860. Epub 2024 May 17.
3D printed biomaterial implants are revolutionizing personalized medicine for tissue repair, especially in orthopedics. In this study, a radiopaque bismuth oxide (BiO) doped polycaprolactone (PCL) composite is developed and implemented to enable the use of diagnostic X-ray technologies, especially spectral photon counting X-ray computed tomography (SPCCT), for comprehensive tissue engineering scaffold (TES) monitoring. PCL filament with homogeneous BiO nanoparticle (NP) dispersion (0.8 to 11.7 wt%) are first fabricated. TES are then 3D printed with the composite filament, optimizing printing parameters for small features and severely overhung geometries. These composite TES are characterized via micro-computed tomography (μCT), tensile testing, and a cytocompatibility study, with 2 wt% BiO NPs providing improved tensile properties, equivalent cytocompatibility to neat PCL, and excellent radiographic distinguishability. Radiographic performance is validated in situ by imaging 4 and 7 wt% BiO doped PCL 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 corresponding swine legs ex vivo. Re-imaging the swine legs via clinical CT allows facile identification of device location and alignment. Finally, the emergent technology of SPCCT unambiguously distinguishes the implanted meniscus in situ via means of color K-edge imaging.
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，开发并应用了一种含不透射线氧化铋（BiO）的聚己内酯（PCL）复合材料，以实现利用诊断性X射线技术，特别是光谱光子计数X射线计算机断层扫描（SPCCT），对组织工程支架（TES）进行全面监测。首先制备了BiO纳米颗粒（NP）均匀分散（0.8至11.7 wt%）的PCL长丝。然后用复合长丝3D打印TES，针对小特征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）、拉伸试验和细胞相容性研究对这些复合TES进行表征，含2 wt% BiO NPs的复合TES具有改善的拉伸性能、与纯PCL相当的细胞相容性以及出色的射线可分辨性。通过在小鼠模型中用μCT对含4 wt%和7 wt% BiO的PCL TES进行成像，对射线照相性能进行了原位验证，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进行离体研究。通过临床CT对猪腿进行再次成像，可以轻松识别装置的位置和对齐情况。最后，新兴的SPCCT技术通过彩色K边成像能够在原位明确区分植入的半月板。
