Xia Zhao

Objectives: This study aims to assess the interrater reliability and criterion validity of a three-dimensional (3D) scanning method in evaluating hand volume in patients with stroke. Patients and methods: This observational study was conducted with 20 stroke patients (11 males, 9 females; mean age: 59.5±13.3 years; range, 28 to 74 years) between February 2023 and June 2023. Two trained therapists (Operators A and B) used a hand-held 3D laser scanner to measure bilateral hand volumes sequentially to assess the consistency of measurements between operators. Operator A also used a split cup to measure bilateral hand volumes to assess the accuracy of measurements between 3D scanning and the gold standard water displacement (WD) method. Results: The intraclass correlation coefficient between the two operators was 0.923 (pConclusion: The 3D scanning method has good interrater reliability and criterion validity in the measurement of hand volume of affected and non-affected hands in patients with stroke.

In this study, novel silk (SF)-fibroin based scaffolds were fabricated via 3D printing of a thixotropic SF/hydroxypropyl methyl cellulose (HPMC) hydrogel. Two different concentrations of 3D printed SF/HPMC scaffolds (20 wt% and 30 wt%) were implanted subcutaneously in SD rats for 24 weeks to investigate in vivo degradation and biocompatibility. Scaffold morphology, tissue ingrowth (collagen fibers, blood vessels), and local inflammatory responses were assessed using SEM, histology (HE, Masson staining), immunohistochemistry (CD31, CD68), and RT-qPCR (IL-6, IL-1β, IL-10, TGF-β1 mRNA). Results showed that no purulent secretions were found around the two scaffolds during implantation. Collagen fibers, blood vessels and other tissues could grow into the scaffolds after implantation. The number of collagen fibers and CD31-positive vascular endothelial cells in the 20 wt% SF/HPMC scaffolds were greater than that in the 30 wt% SF/HPMC scaffolds. SEM detection showed the pore structure in the cross section of 20 wt% SF/HPMC scaffolds began to collapse at 12 weeks; No obvious collapse of the pore structure was found in the cross section of the 30 wt% SF/HPMC scaffolds during the period of implantation. Mechanical properties test showed that the compressive modulus of 20 wt% SF/HPMC scaffolds decreased significantly at 12 weeks and was lower than that at the pre-implantation. The mechanical properties of the 30 wt% SF/HPMC scaffolds remained relatively stable, and the mechanical properties were slightly higher at 24 weeks than that before implantation. Both scaffolds did not cause severe inflammatory reactions during the degradation process, and their structures could allow the growth of blood vessels, collagen fibers and other tissues. The degradability was correlated to the concentrations of SF/HPMC and insights gained in this study can serve as a guide to match desired degradation behavior with specific applications for the 3D printed SF/HPMC scaffold.

The functional epithelial regeneration is important for repairing tracheal defects. However, the potential of 3D-printed SF-based scaffolds for tracheal epithelial regeneration is still unknown. In this study, we developed a novel silk fibroin-based scaffold prepared by 3D printing of silk fibroin/hydroxypropyl methyl cellulose (SF/HPMC) thixotropic hydrogel and evaluated the tracheal epithelium proliferation on this scaffold in vitro. Combined with the freeze-dried technology, the 3D-printed SF/HPMC scaffolds had porous structures in the printed bars. After evaluation of their pore sizes, porosities, water contents and mechanical properties, the scaffolds were co-cultured with the normal human bronchial epithelial cell line (BEAS-2B) for seven days. We detected the BEAS-2B cells proliferation on the scaffolds using a CCK-8 assay, determined their mucin secretion and intercellular tight junction formation by immunofluorescence, as well as observed their cell viability and morphology by live/dead staining and scanning electronic microscopy. The results showed that the SF/HPMC scaffolds had good porosity, water content and mechanical properties. In addition, the BEAS-2B cells proliferated well on SF/HPMC scaffolds, during the seven-day co-culture, with high viability, mucin expression, and intercellular tight junction formation. In summary, these results demonstrated that the BEAS-2B cells could attach and proliferate on the 3D-printed SF/HPMC scaffolds, which were expected to have potential for facilitating tracheal epithelial regeneration.

Dry age-related macular degeneration (AMD), a leading cause of blindness in aged population, is directly associated with oxidative stress induced damage of the retinal pigmented epithelial (RPE) cells. In the current study, we investigated the role of AMPK in the protective effect of artemisinin, an FDA approved anti-malarial Chinese herbal drug, on RPE cell line D407, against H₂O₂ induced oxidative stress. Our results showed that artemisinin promoted the survival of D407 cells from H₂O₂. Artemisinin reduced intracellular ROS generation and oxidative stress, decreased LDH release and the loss of mitochondrial membrane potential in D407 cells treated with H₂O₂. Western blotting showed that artemisinin concentration- and time-dependently stimulated the phosphorylation of AMP-activated protein kinase (AMPK) in D407 cells while AMPK inhibitor Compound C or knock-down of AMPK by si-RNA, inhibited the survival protective effect of artemisinin. More importantly, artemisinin produced a similar protective effect in primary cultured retinal pigment cells which was also blocked by inhibitors of AMPK. Taken together, these results suggested that artemisinin promotes survival of human retinal pigment cells against H₂O₂-induced cell death at least in part through enhancing the activation of AMPK. Therefore, artemisinin may be a beneficial therapeutic candidate for the treatment of age-related diseases, including retinal disorders like AMD.

Three-dimensional (3D) printing is a promising technology that can use a patient’s image data to create complex and personalized constructs precisely. It has made great progress over the past few decades and has been widely used in medicine including medical modeling, surgical planning, medical education and training, prosthesis and implants. Three-dimensional (3D) bioprinting is a powerful tool that has the potential to fabricate bioengineered constructs of the desired shape layer-by-layer using computer-aided deposition of living cells and biomaterials. Advances in 3D printed implants and future tissue-engineered constructs will bring great progress to the field of otolaryngology. By integrating 3D printing into tissue engineering and materials, it may be possible for otolaryngologists to implant 3D printed functional grafts into patients for reconstruction of a variety of tissue defects in the foreseeable future. In this review, we will introduce the current state of 3D printing technology and highlight the applications of 3D printed prosthesis and implants, 3D printing technology combined with tissue engineering and future directions of bioprinting in the field of otolaryngology.