Manzoor Faisal, Golbang Atefeh, Dixon Dorian, Mancuso Elena, Azhar Usaid, Manolakis Ioannis, Crawford Daniel, McIlhagger Alistair, Harkin-Jones Eileen
Department of Mechanical Engineering, School of Engineering, Ulster University, Shore Road, Newtownabbey BT37 0QB, UK.
Nanotechnology and Integrated Bio-Engineering Centre (NIBEC), Ulster University, Shore Road, Newtownabbey BT37 0QB, UK.
Polymers (Basel). 2022 Mar 28;14(7):1376. doi: 10.3390/polym14071376.
In this study, Strontium (Sr) and Zinc (Zn) doped-HA nanoparticles were synthesized and incorporated into polyetheretherketone (PEEK) up to 30 wt.% and processed by a novel approach i.e., fused deposition modelling (FDM) 3D printing for the production of patient specific cranial implants with improved bioactivity and the required mechanical performance. Filaments were produced via extrusion and subsequently 3D-printed using FDM. To further improve the bioactivity of the 3D-printed parts, the samples were dip-coated in polyethylene glycol-DOPA (PEG-DOPA) solution. The printing quality was influenced by filler loading, but was not significantly influenced by the nature of doped-HA. Hence, the printing conditions were optimized for each sample. Micro-CT and Scanning Electron Microscopy (SEM) showed a uniform distribution of bioceramic particles in PEEK. Although agglomeration of particles increased with increase in filler loadings. Differential Scanning Calorimetry (DSC) showed that the melting point and crystallinity of PEEK increased with an increase in doped-HA loading from 343 °C to 355 °C and 27.7% to 34.6%, respectively. Apatite formation was confirmed on the 3D-printed samples after immersion in simulated body fluid (SBF) for 7, 14 and 28 days via SEM, X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The tensile strength and impact strength decreased from 75 MPa to 51 MPa and 14 kJ/m to 4 kJ/m, respectively, while Young's modulus increased with increasing doped-HA content from 2.8 GPa to 4.2 GPa. However, the tensile strengths of composites remained in the range of human cortical bone i.e., ≥50 MPa. In addition, there was a slight increase in mechanical strength after 28 days immersion which was attributed to apatite formation. Water contact angle showed that the hydrophilicity of the samples improved after coating the 3D-printed samples with PEG-DOPA. Hence, based on the results, the 3D-printed PEEK nanocomposites with 20 wt.% doped-HA is selected as the best candidate for the 3D-printing of craniomaxillofacial implants.
在本研究中，合成了锶（Sr）和锌（Zn）掺杂的羟基磷灰石（HA）纳米颗粒，并将其以高达30 wt.% 的比例掺入聚醚醚酮（PEEK）中，采用一种新颖的方法即熔融沉积建模（FDM）3D打印进行加工，以生产具有改善的生物活性和所需机械性能的定制颅骨植入物。通过挤出生产长丝，随后使用FDM进行3D打印。为了进一步提高3D打印部件的生物活性，将样品浸入聚乙二醇 - 多巴胺（PEG - DOPA）溶液中进行浸涂。打印质量受填料含量的影响，但受掺杂HA性质的影响不显著。因此，针对每个样品优化了打印条件。显微CT和扫描电子显微镜（SEM）显示生物陶瓷颗粒在PEEK中分布均匀。尽管随着填料含量的增加颗粒团聚有所增加。差示扫描量热法（DSC）表明，随着掺杂HA含量从343 °C增加到355 °C，PEEK的熔点从27.7%增加到34.6%，结晶度也随之增加。通过SEM、X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）证实，3D打印样品在模拟体液（SBF）中浸泡7、14和28天后形成了磷灰石。拉伸强度和冲击强度分别从75 MPa降至51 MPa和从14 kJ/m降至4 kJ/m，而杨氏模量随着掺杂HA含量的增加从2.8 GPa增加到4.2 GPa。然而，复合材料的拉伸强度仍在人体皮质骨范围内，即≥50 MPa。此外，浸泡28天后机械强度略有增加，这归因于磷灰石的形成。水接触角表明，用PEG - DOPA涂覆3D打印样品后，样品的亲水性得到改善。因此，基于这些结果，选择掺杂20 wt.% HA的3D打印PEEK纳米复合材料作为颅颌面植入物3D打印的最佳候选材料。
