Yao Yu

The limitations of traditional, autologous bone grafts, such as the scarcity of donor material and the risks of secondary surgical trauma, have spurred the development of alternatives for the repair of large bone defects. Bionic bone scaffolds fabricated via fused deposition modeling (FDM)—a three-dimensional (3D) printing technique—are considered promising. While gyroid-structured scaffolds mimic the complex micro-architecture of cancellous bone, their application in FDM 3D printing remains understudied. Furthermore, no consensus has been reached on the ideal pore size for gyroid scaffolds, which is influenced by the infill density. In this study, we fabricated five groups of polycaprolactone/hydroxyapatite (PCL/HA) scaffolds with different infill densities (40%, 45%, 50%, 55%, and 60%) using a solvent-free filament preparation method. Scanning electron microscopy (SEM) observation showed that all scaffolds exhibit an interconnected porous structure. The scaffold with the 55% infill density, featuring a pore size of 465 ± 63 μm, demonstrated optimal hydrophilicity and mechanical properties comparable to natural cancellous bone. In addition, this scaffold supported cellular bridging within its pores and showed the highest alkaline phosphatase (ALP) activity and calcium salt deposition. Our findings offer novel insights into the design of gyroid-like scaffolds and their fabrication via FDM, paving the way for potential clinical applications.

Objective This cohort study aimed to preliminarily explore the effect of midfacial tumor resection procedure with assistance of virtual planning based on CT/MRI multimodal image fusion. Methods For the experimental cohort, patients with midfacial tumors receiving treatment from February 2019 to March 2021 were enrolled. Virtual planning was completed preoperatively based on CT/MRI multimodal image fusion. Tumor resection was performed under virtual planning-based surgical navigation, and intraoperative frozen sections were taken to determine resection margin status. For the control cohort, patients with midfacial tumors treated by the same surgical team were enrolled according to the same criteria. Patients underwent surgery assisted by virtual planning based on single-modality CT images. Resection margin and survival status were compared between groups during follow-up. Results Altogether twenty-nine patients were enrolled. The resection margin status was significantly different between groups at the per-margin level (experimental group: 100% [66/66] negative; control group: 90.9% negative [70/77]; P = 0.014). During follow-up period, two patients in experimental cohort and seven patients in control cohort confirmed local recurrence. Conclusions Patients with midfacial tumor who underwent virtual planning based on CT/MRI multimodal image fusion were more likely to have tumor-free resection margins. The use of the image fusion procedure may improve treatment outcomes in such patients.