The Cartilage Mystery: Unravelling the Links to Skeletal and Metabolic Comorbidities

骨关节炎（Osteoarthritis， OA）是由关节关节软骨（articular cartilage， AC）退行性变引起的，多年来研究者对其机制的研究主要集中在AC的解剖学特征上，以确定其成分在退行性变中的作用和功能。然而，作为合并症的2型糖尿病（T2DM）患者的OA发病率有所增加。由于遗传、衰老和肥胖等共同的危险因素在这些合并症中表现出来，因此有必要研究这些疾病的退行性机制。本研究旨在利用各种定性和定量表征技术研究OA/T2DM患者AC的结构。AC的变性可以观察到胶原原纤维和蛋白聚糖网络在AC不同区域（浅表、中、深区）排列的变化，这些变化可以用各种技术来表征。利用扫描电子显微镜（SEM）和微计算机断层扫描（micro- ct）分析交流截面的结构变化，可以进行定性表征。同样，可以通过拉曼光谱和x射线能量色散光谱（EDS）来计算AC区蛋白聚糖变化的损失，从而进行定量表征。这些AC的定性和定量特征可以深入了解OA/T2DM的退行性机制。此外，还需要研究交流材料的生物摩擦学特性，以了解其接触界面的摩擦、磨损和润滑行为。这些摩擦学研究将在不同的接触界面（软骨对玻璃，软骨对软骨）上进行，使用不同的润滑剂（滑液，透明质酸，润滑剂等），以了解它们对改变AC摩擦学行为的影响。上述测试将用于牛样品的AC，以及OA/T2DM患者的AC。这些研究将有助于发展OA/T2DM合并症中AC的摩擦学特性。这些研究的结果将用于为OA/T2DM患者开发合适的药物治疗，通过补充润滑剂来减缓AC变性，达到全关节置换术的最终过程。

Osteoarthritis (OA) is caused by the degeneration of articular cartilage (AC) in joints, and researchers have been studying these mechanisms for many years, mainly focusing on the anatomical features of AC to identify the roles and functions of its composition in degeneration. However, there has been an increase in OA rates among patients with Type 2 Diabetes Mellitus (T2DM) as a comorbid disease. Since common risk factors such as genetics, aging, and obesity are exhibited in these comorbidities, there is a need to investigate degenerative mechanisms in these conditions. This study aims to investigate the structure of AC in patients with OA/T2DM using various characterization techniques, both qualitatively and quantitatively. The degeneration of AC can be observed as changes in the arrangement of collagen fibrils and proteoglycan networks in different zones of the AC (superficial, middle, deep zones), and these changes can be characterized using various techniques. The qualitative characterizations can be performed using the scanning electron microscope (SEM) and micro computed tomography (micro-CT) by analysing the structural changes in the AC cross sections. Similarly, the quantitative characterization can be performed by Raman spectroscopy and X-ray energy dispersive spectroscopy (EDS) by calculating the losses of proteoglycan changes in the AC zones. These qualitative and quantitative characterizations of the AC can provide insight into the degenerative mechanism in OA/T2DM conditions. Additionally, the bio-tribological properties of AC needto be investigated to understand its friction, wear, and lubrication behaviours at its contact interfaces. These tribological studies will be performed at different contact interfaces (cartilage on glass, cartilage on cartilage) using different lubricants (synovial fluid, hyaluronic acid, lubricin, etc.) to understand their effects on varying the tribological behaviour of AC. The above-mentioned tests will be performed for the AC of bovine samples, as well as on the AC of OA/T2DM patients. These studies will help in developing the tribological characteristics of AC in OA/T2DM comorbidity conditions. The outcomes of these studies will be used in developing a suitable medical treatment by lubricant supplements for the OA/T2DM patients to slow down the AC degeneration reaching the end process of total joint replacements.