Bone marrow-derived mesenchymal stem cells (BMSCs) were seeded in a three-dimensional scaffold of silk fibroin (SF) and chitosan (CS) to repair cartilage defects in the rabbit knee. Totally 54 rabbits were randomly assigned to BMSCs + SF/CS scaffold, SF/CS scaffold and control groups. A cylindrical defect was created at the patellofemoral facet of the right knee of each rabbit and repaired by scaffold respectively. Samples were prepared at 4, 8 and 12 weeks post-surgery for gross observation, hematoxylin-eosin and toluidine blue staining, type II collagen immunohistochemistry, Wakitani histology. The results showed that differentiated BMSCs proliferated well in the scaffold. In the BMSCs + SF/CS scaffold group, the bone defect was nearly repaired, the scaffold was absorbed and immunohistochemistry was positive. In the SF/CS scaffold alone group, fiber-like tissues were observed, the scaffold was nearly degraded and immunohistochemistry was weakly positive. In the control group, the defect was not well repaired and positive immunoreactions were not detected. Modified Wakitani scores were superior in the BMSCs + SF/CS scaffold group compared with those in other groups at 4, 8 and 12 weeks (P < 0.05). A SF/CS scaffold can serve as carrier for stem cells to repair cartilage defects and may be used for cartilage tissue engineering.

Background: One of the main problems associated with the development of osteochondral reparative materials is that the accurate imitation of the structure of the natural osteochondral tissue and fabrication of a suitable scaffold material for osteochondral repair are difficult. The long-term outcomes of single-or bilayered scaffolds are often unsatisfactory because of the absence of a progressive osteochondral structure. Therefore, only scaffolds with gradient pore sizes are suitable for osteochondral repair to achieve better proliferation and differentiation of the stem cells into osteochondral tissues to complete the repair of defects. Methods: A silk fibroin (SF) solution, chitosan (CS) solution, and nano-hydroxyapatite (nHA) suspension were mixed at the same weight fraction to obtain osteochondral scaffolds with gradient pore diameters by centrifugation, freeze-drying, and chemical cross-linking. Results: The scaffolds prepared in this study are confirmed to have a progressive structure starting from the cartilage layer to bone layer, similar to that of the normal osteochondral tissues. The prepared scaffolds are cylindrical in shape and have high internal porosity. The structure consists of regular and highly interconnected pores with a progressively increasing pore distribution as well as a progressively changing pore diameter. The scaffold strongly absorbs water, and has a suitable degradation rate, sufficient space for cell growth and proliferation, and good resistance to compression. Thus, the scaffold can provide sufficient nutrients and space for cell growth, proliferation, and migration. Further, bone marrow mesenchymal stem cells seeded onto the scaffold closely attach to the scaffold and stably grow and proliferate, indicating that the scaffold has good biocompatibility with no cytotoxicity. Conclusion: In brief, the physical properties and biocompatibility of our scaffolds fully comply with the requirements of scaffold materials required for osteochondral tissue engineering, and they are expected to become a new type of scaffolds with gradient pore sizes for osteochondral repair.

No abstract

No abstract

Single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging of the gouty spine is rare. We describe a 66-year-old man who presented with pain and numbness in the right lower leg; he reported a 2-month history of intermittent low back pain. Imaging revealed neoplastic lesions of the spine, which were initially regarded as tumors. Thus, the patient underwent surgical removal of the lumbar lesion. However, the postoperative pathological diagnosis was gout spondylitis. In this report, we show multimodal images of advanced gout spondylitis. The metabolic information provided by SPECT/CT, combined with the microscopic changes in bone structure revealed by dual-source thin-layer CT and the anatomical localization information provided by magnetic resonance imaging, can help clinicians to more fully understand the pathophysiological mechanisms and imaging manifestations of gout from multiple perspectives, thereby reducing the rate of misdiagnosis.

ABSTRACT.A previous experiment demonstrated that fibroin protein and chitosan mixed in proper proportion presented good physical and chemical properties and biological characteristics, which can make up for their respective disadvantages. To observe the growth of bone marrow mesenchymal stem cells (BMSCs) on these fibroin protein/ chitosan 3D scaffolds, induced rabbit BMSCs were seeded on fibroin protein/chitosan scaffolds. The cell adhesion rate was measured, and cell growth was observed under an inverted microscope and a scanning electron microscope. The cell adhesion rate increased with time. The inverted microscope observations showed that the cells on fibroin protein/chitosan scaffolds could not be seen clearly. As time passed, the number of cells around the stent increased and some cells stretched inside the scaffolds. Electron microscopy showed active cell growth and normal proliferation, and the granular and filamentous matrix substances could be seen around cells. The microfilaments of cell and scaffold materials were tightly connected. The cells not only grew on the surface of the adherent material, but also stretched inside of the materials. These results indicated that the fibroin protein/ chitosan mixed scaffolds have good biocompatibility.

We aimed to design an individualized intra-articular stabilization device based on 3D printing technology and investigate the clinical effects of this device for treating traumatic instability of the ulnohumeral joint. This study enrolled nine patients with traumatic instability of the ulnohumeral joint (age: 47.2 ± 1.80   years ) who received treatment between March 2018 and March 2019 in our hospital. All patients underwent a thin-layer computed tomography (CT) scan of the elbow before surgery. The original injury and repair models of the elbow were printed using 3D printing technology based on CT data. An individualized intra-articular stabilization device was designed with a 2.0 mm Kirschner wire based on the repair model. Nine patients agreed to receive surgical treatment for elbow disease and placement of the intra-articular stabilization device. The nine patients underwent open reduction through a posterior median approach, and the intra-articular stabilization device was placed in the elbow. Operation time, intraoperative blood loss, and postoperative complications were recorded and followed up. The device was removed at two postoperative months, and the Mayo score was used to evaluate elbow function. Four months after removing the intra-articular stabilization device, elbow joint function was evaluated again using the Mayo score. The mean operation time was 100.1 ± 8.2   min , and the mean intraoperative blood loss was 35.5 ± 7.1   ml . No complications occurred after operation. Two months after surgery, eight patients received an excellent Mayo score, and one patient received a good Mayo score. Four months after removal of the intra-articular stabilization device, eight patients received an excellent Mayo score, and one patient received a good Mayo score. The individualized intra-articular stabilization device can increase ulnohumeral stability and achieve rapid functional recovery of the elbow.