Effect of Targeted Cytokine Inhibition on Progression of Post-Traumatic Osteoarthritis Following Intra-Articular Fracture

Synovial Fluid Immune Cell Composition Following Intraarticular Fracture May Contribute to Posttraumatic Osteoarthritis

Intra-articular ankle fracture (IAF) often leads to post-traumatic osteoarthritis (PTOA), resulting in significant long-term morbidity. While previous research has focused on the inflammatory cytokines and matrix metalloproteinases within the synovial fluid fracture hematoma (SFFH), the immune cell populations within SFFH that contribute to PTOA development remain underexplored. This study aimed to characterize the immune cell populations in SFFH to better understand their role in the inflammatory response and potential for inducing lasting cartilage damage. Twenty-four patients with IAF underwent surgical ankle aspiration to collect SFFH, which was analyzed using polychromatic flow cytometry. The analysis revealed that 72.8% of the CD45+ cells were lymphocytes, predominantly CD3+ T cells (76.5%), with 42.1% being CD4+ and 39.2% CD8+ T cells. Additionally, monocytes accounted for 21.2% of CD45+ cells, with small populations of natural killer cells and myeloid-derived suppressor cells also present. These findings emphasize the predominance of T cells, particularly CD4+ subsets, in the immune response following IAF. Understanding these dynamics is essential for developing targeted interventions to prevent PTOA. Future research should focus on elucidating the specific roles of these immune cell populations in PTOA progression and exploring potential therapeutic strategies.

Traumatic inflammatory response: pathophysiological role and clinical value of cytokines

Severe trauma is an intractable problem in healthcare. Patients have a widespread immune system response that is complex and vital to survival. Excessive inflammatory response is the main cause of poor prognosis and poor therapeutic effect of medications in trauma patients. Cytokines are signaling proteins that play critical roles in the body's response to injuries, which could amplify or suppress immune responses. Studies have demonstrated that cytokines are closely related to the severity of injuries and prognosis of trauma patients and help present cytokine-based diagnosis and treatment plans for trauma patients. In this review, we introduce the pathophysiological mechanisms of a traumatic inflammatory response and the role of cytokines in trauma patients. Furthermore, we discuss the potential of cytokine-based diagnosis and therapy for post-traumatic inflammatory response, although further clarification to elucidate the underlying mechanisms of cytokines following trauma is warranted.

Three-Dimensional Bioprinting: A Comprehensive Review for Applications in Tissue Engineering and Regenerative Medicine

Since three-dimensional (3D) bioprinting has emerged, it has continuously to evolved as a revolutionary technology in surgery, offering new paradigms for reconstructive and regenerative medical applications. This review highlights the integration of 3D printing, specifically bioprinting, across several surgical disciplines over the last five years. The methods employed encompass a review of recent literature focusing on innovations and applications of 3D-bioprinted tissues and/or organs. The findings reveal significant advances in the creation of complex, customized, multi-tissue constructs that mimic natural tissue characteristics, which are crucial for surgical interventions and patient-specific treatments. Despite the technological advances, the paper introduces and discusses several challenges that remain, such as the vascularization of bioprinted tissues, integration with the host tissue, and the long-term viability of bioprinted organs. The review concludes that while 3D bioprinting holds substantial promise for transforming surgical practices and enhancing patient outcomes, ongoing research, development, and a clear regulatory framework are essential to fully realize potential future clinical applications.

Covalent Conjugation of Small Molecule Inhibitors and Growth Factors to a Silk Fibroin-Derived Bioink to Develop Phenotypically Stable 3D Bioprinted Cartilage

Implantation of a phenotypically stable cartilage graft could represent a viable approach for repairing osteoarthritic (OA) cartilage lesions. In the present study, we investigated the effects of modulating the bone morphogenetic protein (BMP), transforming growth factor beta (TGFβ), and interleukin-1 (IL-1) signaling cascades in human bone marrow stromal cell (hBMSC)-encapsulated silk fibroin gelatin (SF-G) bioink. The selected small molecules LDN193189, TGFβ3, and IL1 receptor antagonist (IL1Ra) are covalently conjugated to SF-G biomaterial to ensure sustained release, increased bioavailability, and printability, confirmed by ATR-FTIR, release kinetics, and rheological analyses. The 3D bioprinted constructs with chondrogenically differentiated hBMSCs were incubated in an OA-inducing medium for 14 days and assessed through a detailed qPCR, immunofluorescence, and biochemical analyses. Despite substantial heterogeneity in the observations among the donors, the IL1Ra molecule illustrated the maximum efficiency in enhancing the expression of articular cartilage components, reducing the expression of hypertrophic markers (re-validated by the GeneMANIA tool), as well as reducing the production of inflammatory molecules by the hBMSCs. Therefore, this study demonstrated a novel strategy to develop a chemically decorated, printable and biomimetic SF-G bioink to produce hyaline cartilage grafts resistant to acquiring OA traits that can be used for the treatment of degenerated cartilage lesions.