Neutrophils are involved in early bone formation during midpalatal expansion

Stretched Vascular Endothelial Cells Polarized Neutrophils to N2 Type via TRPC1-IL13-STAT3 Axis

OBJECTIVE

VECs play a crucial role in regulating the function of neutrophils, which is essential for immune responses and inflammation. As stretch-sensitive cells, VECs sense mechanical stretch through surface mechanoreceptors, converting external mechanical stimuli into biochemical signals. This study aimed to explore the molecular mechanisms underlying the regulation of neutrophil behavior by stretched VECs.

MATERIALS AND METHODS

The key cytokine-inducing neutrophil N2 polarization in the conditioned medium from stretched vascular endothelial cells (CM-stretch) was validated through multifactorial matrix and flow cytometry. Additionally, the molecular mechanism underlying the response of vascular endothelial cells to stretch was systematically verified through layer-by-layer analysis using WB.

RESULTS

IL13, not IL4, was ultimately identified as a key cytokine-inducing neutrophil N2 polarization in CM-stretch. Inhibition of the transient receptor potential channel (TRPC1) and siRNA-mediated knockdown of TRPC1 both significantly decreased IL13 production. Furthermore, neutralizing IL13 in the CM-stretch or inhibiting STAT3 phosphorylation inhibited neutrophil N2 polarization, as evidenced by reduced CD206 and VEGFA expression.

CONCLUSIONS

These results demonstrate that stretched VECs initiate a signaling cascade that induces neutrophil N2 polarization through the TRPC1-IL13-STAT3 axis, suggesting that mechanical stretching of VECs could shift neutrophil function from a pro-inflammatory to a more regulatory and healing role.

Dual-functional Hydroxyapatite scaffolds for bone regeneration and precision drug delivery

Addressing infected bone defects remains a significant challenge in orthopedics, requiring effective infection control and bone defect repair. A promising therapeutic approach involves the development of dual-functional engineered biomaterials with drug delivery systems that combine antibacterial properties with osteogenesis promotion. The Hydroxyapatite composite scaffolds offer a one-stage treatment, eliminating the need for multiple surgeries and thereby streamlining the process and reducing treatment time. This review delves into the impaired bone repair mechanisms within pathogen-infected and inflamed microenvironments, providing a theoretical foundation for treating infectious bone defects. Additionally, it explores composite scaffolds made of antibacterial and osteogenic materials, along with advanced drug delivery systems that possess both antibacterial and bone-regenerative properties. By offering a comprehensive understanding of the microenvironment of infectious bone defects and innovative design strategies for dual-function scaffolds, this review presents significant advancements in treatment methods for infectious bone defects. Continued research and clinical validation are essential to refine these innovations, ensuring biocompatibility and safety, achieving controlled release and stability, and developing scalable manufacturing processes for widespread clinical application.

Bridging the Gap in Understanding Bone Metastasis: A Multifaceted Perspective

The treatment of patients with advanced cancer poses clinical problems due to the complications that arise as the disease progresses. Bone metastases are a common problem that cancer patients may face, and currently, there are no effective drugs to treat these individuals. Prostate, breast, and lung cancers often spread to the bone, causing significant and disabling health conditions. The bone is a highly active and dynamic tissue and is considered a favorable environment for the growth of cancer. The role of osteoblasts and osteoclasts in the process of bone remodeling and the way in which their interactions change during the progression of metastasis is critical to understanding the pathophysiology of this disease. These interactions create a self-perpetuating loop that stimulates the growth of metastatic cells in the bone. The metabolic reprogramming of both cancer cells and cells in the bone microenvironment has serious implications for the development and progression of metastasis. Insight into the process of bone remodeling and the systemic elements that regulate this process, as well as the cellular changes that occur during the progression of bone metastases, is critical to the discovery of a cure for this disease. It is crucial to explore different therapeutic options that focus specifically on malignancy in the bone microenvironment in order to effectively treat this disease. This review will focus on the bone remodeling process and the effects of metabolic disorders as well as systemic factors like hormones and cytokines on the development of bone metastases. We will also examine the various therapeutic alternatives available today and the upcoming advances in novel treatments.