dGEMRIC and CECT Comparison of Cationic and Anionic Contrast Agents in Cadaveric Human Metacarpal Cartilage.

Magnetic resonance imaging (MRI) and computed tomography (CT) are widely used to image cartilage and their diagnostic capability is enhanced in the presence of contrast agents. The aim of the study is to directly compare the performance between commercial anionic MRI (Gd(DTPA), Gd2-) and CT (Ioxaglate, Iox1-) contrast agents with novel cationic MRI (Gd(DTPA)Lys , Gd4+) and CT (CA4+) contrast agents for assessment of cartilage mechanical and biochemical properties using the ex vivo human osteoarthritis metacarpal cartilage model. First, indentation testing was conducted to obtain the compressive modulus of the human fifth metacarpals.

A Synthetic Bottle-brush Polyelectrolyte Reduces Friction and Wear of Intact and Previously Worn Cartilage.

A poly(7-oxanorbornene-2-carboxylate) polymer containing pendent triethyleneglycol (TEG) chains of 2.8 MDa ("2.8M TEG") was synthesized and evaluated for long-term lubrication and wear reduction of ex vivo bovine cartilage as well as for synovitis in rats and dogs after intra-articular administration.

A synthetic polymeric biolubricant imparts chondroprotection in a rat meniscal tear model.

Intra-articular injection of hyaluronic acid (HA) is used to treat osteoarthritis (OA) as a viscosupplement, yet it only provides short-term benefit because HA is cleaved by hyaluronidase and cleared out of the joint after several days. Therefore, we developed a new polymer biolubricant based on poly-oxanorbornane carboxylate to enhance joint lubrication for a prolonged time. Rheological and biotribological studies of the biolubricant reveal viscoelastic properties and coefficient of friction equivalent and superior to that of healthy synovial fluid, respectively.

Assessing Cartilage Biomechanical Properties: Techniques for Evaluating the Functional Performance of Cartilage in Health and Disease.

Osteoarthritis (OA) affects millions of people and results in weakened hyaline cartilage due to overloading. During joint articulation, hyaline cartilage must withstand high loads while maintaining low friction to prevent wear and tissue loss. Thus, cartilage compressive stiffness and the coefficient of friction are important indicators of the tissue's functional performance.

Contrast-enhanced CT imaging as a non-destructive tool for ex vivo examination of the biochemical content and structure of the human meniscus.

The biochemical and histopathological techniques used to investigate meniscal content and structure are destructive and time-consuming. Therefore, this study evaluated whether contrast-enhanced computed tomography (CECT) attenuation and contrast agent flux using the iodinated contrast agents CA4+ and ioxaglate correlate with the glycosaminoglycan (GAG) content/distribution and water content in human menisci. The optimal ioxaglate and CA4+ contrast agent concentrations for mapping meniscal GAG distribution were qualitatively determined by comparison of CECT color maps with Safranin-O stained histological sections.

Contrast-enhanced CT using a cationic contrast agent enables non-destructive assessment of the biochemical and biomechanical properties of mouse tibial plateau cartilage.

Mouse models of osteoarthritis (OA) are commonly used to study the disease's pathogenesis and efficacy of potential treatments. However, measuring the biochemical and mechanical properties of articular cartilage in these models currently requires destructive and time-consuming histology and mechanical testing. Therefore, we examined the feasibility of using contrast-enhanced CT (CECT) to rapidly and non-destructively image and assess the glycosaminoglycan (GAG) content.

Effect of mechanical convection on the partitioning of an anionic iodinated contrast agent in intact patellar cartilage.

To determine if mechanical convection accelerates partitioning of an anionic contrast agent into cartilage while maintaining its ability to reflect the glycosaminoglycan (GAG) content in contrast-enhanced computed tomography (CECT) of cartilage. Bovine patellae (N = 4) were immersed in iothalamate and serially imaged over 24 h of passive diffusion at 34°C. Following saline washing for 14 h, each patella was serially imaged over 2.

A large-molecular-weight polyanion, synthesized via ring-opening metathesis polymerization, as a lubricant for human articular cartilage.

A large-molecular-weight polyanion is found to possess lubricating properties for cartilage. The polyanion, sodium poly(7-oxanorbornene-2-carboxylate), is synthesized by ring-opening metathesis polymerization of methyl 5-oxanorbornene-2-carboxylate. When dissolved in aqueous solution and applied to the surface of human cartilage it reduces the friction at the interface and acts as a lubricant.