An anti-infection and biodegradable TFRD-loaded porous scaffold promotes bone regeneration in segmental bone defects: experimental studies.

BACKGROUND: Addressing segmental bone defects remains a complex task in orthopedics, and recent advancements have led to the development of novel drugs to enhance the bone regeneration. However, long-term oral administration can lead to malnutrition and poor patient compliance. Scaffolds loaded with medication are extensively employed to facilitate the restoration of bone defects. METHODS: Inspired by the local application of total flavonoids of Rhizoma Drynariae (TFRD) in the treatment of fracture, a novel 3D-printed HA/CMCS/PDA/TFRD scaffold with anti-infection, biodegradable and induced angiogenesis was designed, and to explore its preclinical value in segmental bone defect of tibia. RESULTS: The scaffold exhibited good degradation and drug release performance. In vitro, the scaffold extract promoted osteogenesis by enhancing bone-related gene/protein expression and mineral deposition in BMSCs. It also stimulated endothelial cell migration and promoted angiogenesis through the upregulation of specific genes and proteins associated with cell migration and tube formation. This may be attributed to the activation of the PI3k/AKT/HIF-1α pathway, facilitating the processes of osteogenesis and angiogenesis. Furthermore, the HA/CMCS/PDA/TFRD scaffold was demonstrated to alleviate infection, enhance angiogenesis, promote bone regeneration, and increase the maximum failure force of new formed bone in a rat model of segmental bone defects. CONCLUSION: Porous scaffolds loaded with TFRD can reduce infection, be biodegradable, and induce angiogenesis, presenting a novel approach for addressing tibial segmental bone defects.

Fixators dynamization for delayed union and non-union of femur and tibial fractures: a review of techniques, timing and influence factors.

The optimal balance between mechanical environment and biological factors is crucial for successful bone healing, as they synergistically affect bone development. Any imbalance between these factors can lead to impaired bone healing, resulting in delayed union or non-union. To address this bone healing disorder, clinicians have adopted a technique known as "dynamization" which involves modifying the stiffness properties of the fixator. This technique facilitates the establishment of a favorable mechanical and biological environment by changing a rigid fixator to a more flexible one that promotes bone healing. However, the dynamization of fixators is selective for certain types of non-union and can result in complications or failure to heal if applied to inappropriate non-unions. This review aims to summarize the indications for dynamization, as well as introduce a novel dynamic locking plate and various techniques for dynamization of fixators (intramedullary nails, steel plates, external fixators) in femur and tibial fractures. Additionally, Factors associated with the effectiveness of dynamization are explored in response to the variation in dynamization success rates seen in clinical studies.

Use of network pharmacology and molecular docking to explore the mechanism of action of curcuma in the treatment of osteosarcoma.

Curcuma has been used as an adjuvant treatment for osteosarcoma (OS) due to its anticancer compounds. However, the underlying mechanism remains unclear. Therefore, this study aimed to explore the mechanism of action of curcuma in the treatment of OS using network pharmacology and molecular docking. In this study, anticancer compounds were obtained from relevant literature, and curcuma-related targets and OS treatment targets were obtained from public databases. Protein‒protein interaction networks were constructed to screen out the hub genes using the STRING database and Cytoscape software. Cluster analysis of the protein modules was then performed using the Cytoscape MCODE plugin. Furthermore, Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed for common targets among curcuma targets and OS-related targets using the DAVID database. Finally, molecular docking was performed, and the results were verified by Auto dock Tool and PyMOL software. Our research identified 11 potential active compounds, 141 potential therapeutic targets and 14 hub genes for curcuma. AKT1, TNF, STAT3, EGFR, and HSP90AA1 were the key targets closely related to the PI3K/Akt signaling pathways, HIF-1 signaling pathways, ErbB signaling pathways, and FOXO signaling pathways, which are involved in angiogenesis, cancer cell proliferation, metastasis, invasion, and chemotherapy resistance in the microenvironment of OS. Molecular docking suggested that the core compound had a strong affinity for key targets, with a binding energy of less than - 5 kJ/mol. The study showed that curcuma-mediated treatment of OS was a complex process involving multiple compounds, targets, and pathways. This study will enhance the understanding of how curcuma affects the proliferation and invasion of OS cells and reveal the potential molecular mechanism underlying the effect of curcuma on OS lung metastasis and chemotherapy resistance.

Total flavonoids of Rhizoma drynariae promote angiogenesis and osteogenesis in bone defects.

Bone defects are difficult to heal, which conveys a heavy burden to patients' lives and their economy. The total flavonoids of Rhizoma drynariae (TFRD) can promote the osteogenesis of distraction osteogenesis. However, the dose effect is not clear, the treatment period is short, and the quality of bone formation is poor. In our study, we observed the long-term effects and dose effects of TFRD on bone defects, verified the main ingredients of TFRD in combination with network pharmacology for the first time, explored its potential mechanism, and verified these findings. We found that TFRD management for 12 weeks regulated osteogenesis and angiogenesis in rats with 4-mm tibial bone defects through the PI3K/AKT/HIF-1α/VEGF signaling pathway, especially at high doses (135 mg kg-1  d-1 ). The vascularization effect of TFRD in promoting human umbilical vein endothelial cells was inhibited by PI3K inhibitors. These results provide a reference for the clinical application of TFRD.

Comparison of Cement Leakage Rate and Severity After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures Using Front-Opening Versus Side-Opening Cannulas.

The authors assessed the occurrence and severity of cement leakage (CL) following percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs) performed using front-opening cannulas (FOCs) vs side-opening cannulas (SOCs). This retrospective cohort study included 811 patients with single-level OVCFs who underwent PVP between March 2016 and September 2018. The 264 patients who met the inclusion criteria were divided into two groups according to whether the procedure was performed using a FOC (n=128) or a SOC (n=136). Visual analog scale score, Oswestry Disability Index, local kyphotic angle, vertebral height, amount of bone cement injected, and rate of CL were compared between the groups. Types of CL were classified according to postoperative computed tomography. The CL types were further classified according to severity (mild and severe). Visual analog scale score, Oswestry Disability Index, local kyphotic angle, and vertebral height were all significantly improved after surgery. The total incidence of CL was significantly higher for FOCs than for SOCs (P=.001). Similarly, the occurrence of the CL subtypes was significantly higher for FOCs than for SOCs (B type, P=.033; C type, P=.01; and S type, P=.015). Analysis of CL type severity revealed that the rates of severe D type (intradiskal leakage category of the C type) and severe S type were significantly lower for SOCs than for FOCs (P=.001), while the incidence of severe B type leaks was not significantly different between the groups (P=.443). Percutaneous vertebroplasty performed using SOCs decreases the incidence and severity of D type and S type CL compared with FOCs. Secondary classification of CL could help physicians better understand the severity of leakage and select a more appropriate surgical approach to reduce CL. [Orthopedics. 2021;44(3):134-140.].