In degenerative disc disease, an injectable hydrogel can fill a degenerate area completely, reduce the risk of implant migration and subsequent loss of height of the intervertebral disc, and minimise surgical defects. Here, we propose a method of preparing an injectable silk fibroin/polyurethane (SF/PU) composite hydrogel by chemical cross-linking under physiological conditions. Mechanical testing was used to determine the mechanical strength of the hydrogel. The impact of hydrogel height on the biomechanical properties was discussed to estimate the working capacity of the hydrogel for further clinical application. Rheological properties were also examined to assess the practical ability of the hydrogel for clinical application. Hydrogel injection and cell assessment is also of interest for clinical application. An SF/PU composite hydrogel can be injected through a small incision. A cell proliferation assay using bone marrow stromal cells showed positive cell viability and increased proliferation over a seven-day period in culture. Importantly, the hydrogel can be monitored in real-time using X-ray fluoroscopy during and after surgery according to the results of X-ray fluoroscopy examination, and shows good visibility based on X-ray assays. In particular, the hydrogel offers the clinically important advantage of visibility in CT and T2-weighted magnetic resonance imaging. Based on the results of the current study, the SF/AU composite hydrogel may offer several advantages for future application in nucleus pulposus replacement.

In spinal degenerative disease, an injectable liquid hydrogel can fill in defect entirely, lessen the danger of implant relocation and following loss of disc height, minimizing the operative trauma. Here, we propose an injectable in-situ chemically cross-linked hydrogel by a two-component reaction of liquid silk fibroin with liquid polyurethane at physiological temperature conditions. Confined compression tests and fatigue tests were reported to assess physical properties of the hydrogel. Impact of different diameter on the biomechanical behaviours was tested to evaluate the clinical potentiality of the hydrogel for replacing nucleus pulposus. Degradation behaviours in different solutions and animal experiments were also investigated to examine the tissue biocompatibility of the hydrogel. The hydrogel modulus was affected by the hydrogel geometrical (diameter) parameters. SF/PU composite hydrogel can survive a million cycles, unconstrained fatigue resistance. More importantly, in vivo biocompatibility using New Zealand white rabbits, showed good biocompatibility over a three-month period in culture. Particularly, they showed the significant clinical merit of providing stronger axial compressive stiffness on confined compression test. Based on the outcomes of the present research, the SF/PU composite hydrogel may provide significant advantages for use in future clinical application in replacing nucleus pulposus field.

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Background: Three-dimensional (3D) printing involves the layering of seed cells, biologically compatible scaffolds, and biological activity factors to precisely recapitulate a biological tissue. Graphene oxide (GO), a type of micro material, has been utilized as a small molecule-transport vehicle. With the proliferation of GO, the biocompatibility of chondrocytes in a microenvironment constructed by 3D printed scaffolds and GO is innovative. Accordingly, we speculate that, as a type of micro material, GO can be used with 3D scaffolds for a uniform distribution in the cartilage layer. Results: A qualitative analysis of the chondrocyte-proliferation potential revealed that the culture of 3D printing with a 10% GO scaffold was higher than that of the other groups. Meanwhile, the progress of cell apoptosis was activated. Through scanning electron microscopy, immunofluorescence, and in vivo research, we observed that the newborn cartilage matrix extended along the border of the cartilage and scaffold and matured. After an analysis with immunohistochemical staining with aggrecan and collagen I, the cartilage following the 3D-printed scaffold was thinner than that of the 3D-printed GO scaffold. Furthermore, the collagen I of the cartilage expression in treatment with the GO scaffold was significant from week 2 to 6. Conclusions: The findings indicate that a 3D-printed GO scaffold can potentially be utilized for the construction of a cartilage matrix. However, the optimum concentration of GO requires further research and discussion.

SummaryObjectiveTo report the results of the surgical treatment of terrible triad injury with anteromedial coronoid fracture through a combined surgical approach.MethodsThis retrospective study evaluated data from patients who underwent surgery to repair terrible triad injuries and anteromedial coronoid fractures. Surgical treatment involved radial head repair or replacement, medial and lateral collateral ligament repair, and coronoid fracture fixation through combined approaches. Evaluations were performed using the Mayo Elbow Performance Score (MEPS) and anteroposterior and lateral radiographs of the elbow.ResultsTwenty-two patients (15 males, seven females; mean ± SD age, 47.5 ± 11.4 years) were enrolled in this study. Fracture union and concentric reduction of both the ulnotrochlear and radiocapitellar articulations were achieved in all patients. The mean ± SD follow-up was 31.6 ± 11.9 months. The mean ± SD arc of flexion–extension was 110.3° ± 26.3° and arc of forearm rotation was 139.5° ± 17.1°. The mean ± SD MEPS was 88.1 ± 12.2 points, with results classified as excellent in eight elbows, good in ten, and fair in four. Six patients had radiographic signs of post-traumatic arthritis. Three patients required secondary surgeries.ConclusionCombined surgical approaches can be considered for the treatment of terrible triad injuries in association with anteromedial coronoid fractures.