Intra-articular injection of ascorbic acid enhances microfracture-mediated cartilage repair.

Previous studies have confirmed that ascorbic acid (AA) can promote cartilage repair and improve cartilage differentiation in bone marrow mesenchymal stem cells. However, the use of microfracture (MFX) combined with AA to repair cartilage damage has not been studied. This study established a rabbit animal model and treated cartilage injury with different concentrations of AA combined with MFX. Macroscopic observations, histological analysis, immunohistochemical analysis and reverse transcription quantitative polymerase chain reaction analysis of TGF-ß, AKT/Nrf2, and VEGF mRNA expression were performed. The results showed that intra-articular injection of AA had a positive effect on cartilage repair mediated by microfractures. Moreover, 10 mg/ml AA was the most effective at promoting cartilage repair mediated by microfractures. Intra-articular injection of AA promoted the synthesis of type II collagen and the formation of glycosaminoglycans by downregulating the mRNA expression of TGF-ß and VEGF. In summary, this study confirmed that AA could promote cartilage repair after MFX surgery.

[Progress and prospect of biological treatment for rotator cuff injury repair].

Objective: To review the research progress in biotherapy of rotator cuff injury in recent years, in order to provide help for clinical decision-making of rotator cuff injury treatment. Methods: The literature related to biotherapy of rotator cuff injury at home and abroad in recent years was widely reviewed, and the mechanism and efficacy of biotherapy for rotator cuff injury were summarized from the aspects of platelet-rich plasma (PRP), growth factors, stem cells, and exosomes. Results: In order to relieve patients' pain, improve upper limb function, and improve quality of life, the treatment of rotator cuff injury experienced an important change from conservative treatment to open surgery to arthroscopic rotator cuff repair. Arthroscopic rotator cuff repair plus a variety of biotherapy methods have become the mainstream of clinical treatment. All kinds of biotherapy methods have ideal mid- and long-term effectiveness in the repair of rotator cuff injury. The biotherapy method to promote the healing of rotator cuff injury is controversial and needs to be further studied. Conclusion: All kinds of biotherapy methods show a good effect on the repair of rotator cuff injury. It will be an important research direction to further develop new biotherapy technology and verify its effectiveness.

HWJMSC-derived extracellular vesicles ameliorate IL-1ß-induced chondrocyte injury through regulation of the BMP2/RUNX2 axis via up-regulation TFRC.

Articular osteochondral injury is a common and frequently occurring disease in orthopedics that is caused by aging, disease, and trauma. The cytokine interleukin-1ß (IL-1ß) is a crucial mediator of the inflammatory response, which exacerbates damage during chronic disease and acute tissue injury. Human Wharton's jelly mesenchymal stem cell (HWJMSC) extracellular vesicles (HWJMSC-EVs) have been shown to promote cartilage regeneration. The study aimed to investigate the influence and mechanisms of HWJMSC-EVs on the viability, apoptosis, and cell cycle of IL-1ß-induced chondrocytes. HWJMSC-EVs were isolated by Ribo™ Exosome Isolation Reagent kit. Nanoparticle tracking analysis was used to determine the size and concentration of HWJMSC-EVs. We characterized HWJMSC-EVs by western blot and transmission electron microscope. The differentiation, viability, and protein level of chondrocytes were measured by Alcian blue staining, Cell Counting Kit-8, and western blot, respectively. Flow cytometer was used to determine apoptosis and cell cycle of chondrocytes. The results showed that HWJMSCs relieved IL-1ß-induced chondrocyte injury by inhibiting apoptosis and elevating viability and cell cycle of chondrocyte, which was reversed with exosome inhibitor (GW4869). HWJMSC-EVs were successfully extracted and proven to be uptake by chondrocytes. HWJMSC-EVs ameliorate IL-1ß-induced chondrocyte injury by inhibiting cell apoptosis and elevating viability and cycle of cell, but these effects were effectively reversed by knockdown of transferrin receptor (TFRC). Notably, using bone morphogenetic protein 2 (BMP2) pathway agonist and inhibitor suggested that HWJMSC-EVs ameliorate IL-1ß-induced chondrocyte injury through activating the BMP2 pathway via up-regulation TFRC. Furthermore, over-expression of runt-related transcription factor 2 (RUNX2) reversed the effects of BMP2 pathway inhibitor promotion of IL-1ß-induced chondrocyte injury. These results suggested that HWJMSC-EVs ameliorate IL-1ß-induced chondrocyte injury by regulating the BMP2/RUNX2 axis via up-regulation TFRC. HWJMSC-EVs may play a new insight for early medical interventions in patients with articular osteochondral injury.

A Target Detection Algorithm for Remote Sensing Images Based on Deep Learning.

In order to improve the accuracy of remote sensing image target detection, this paper proposes a remote sensing image target detection algorithm DFS based on deep learning. Firstly, dimension clustering module, loss function, and sliding window segmentation detection are designed. The data set used in the experiment comes from GoogleEarth, and there are 6 types of objects: airplanes, boats, warehouses, large ships, bridges, and ports. Training set, verification set, and test set contain 73490 images, 22722 images, and 2138 images, respectively. It is assumed that the number of detected positive samples and negative samples is A and B, respectively, and the number of undetected positive samples and negative samples is C and D, respectively. The experimental results show that the precision-recall curve of DFS for six types of targets shows that DFS has the best detection effect for bridges and the worst detection effect for boats. The main reason is that the size of the bridge is relatively large, and it is clearly distinguished from the background in the image, so the detection difficulty is low. However, the target of the boat is very small, and it is easy to be mixed with the background, so it is difficult to detect. The MAP of DFS is improved by 12.82%, the detection accuracy is improved by 13%, and the recall rate is slightly decreased by 1% compared with YOLOv2. According to the number of detection targets, the number of false positives (FPs) of DFS is much less than that of YOLOv2. The false positive rate is greatly reduced. In addition, the average IOU of DFS is 11.84% higher than that of YOLOv2. For small target detection efficiency and large remote sensing image detection, the DFS algorithm has obvious advantages.