Investigation of an injectable gold nanoparticle extracellular matrix.

This study investigates a method to tackle post-traumatic osteoarthritis, a degenerative disease that erodes joint cartilage and initiates a specific cell death process in cartilage cells. Researchers developed an injectable scaffold made of the extracellular matrix (ECM), gold nanoparticles, and supplemented with curcumin and hyaluronic acid. Their findings suggest this injectable may help reduce inflammation and cell death.

Methodology

• The process began with the decellularization and homogenization of the extracellular matrix (ECM) derived from pig diaphragm. This involves removing all cellular materials, to leave behind a network of proteins for structural support.
• Gold nanoparticles (AuNP) of 20 nm in size were then conjugated, or chemically bonded, to the ECM. This step was followed by mixing with medicinal compounds curcumin and hyaluronic acid.
• The research team used injection force testing, scanning electron microscopy and energy-dispersive X-ray spectroscopy for characterizing the physically altered ECM scaffolds. These techniques helped establish a link connecting the structural and compositional makeup of the scaffolds.
• The biocompatibility of these structures was evaluated through tests involving L929 murine fibroblasts, equine synovial fibroblasts, and human cartilage cells. It was crucial to determine whether the modified ECM could interact effectively with these cells without causing harm.

Findings

• The study successfully demonstrated that the conjugation of 20 nm AuNPs to the ECM was possible without significantly changing the physical properties of the ECM, as evinced by the low injection force.
• Furthermore, the conjugate appeared biocompatible with a tendency to reduce intracellular reactive oxygen species (ROS) – chemically reactive molecules that can lead to cellular damage.
• The material also seemed to protect against the death of cartilage cells when stimulated with IL-1β, a known inducer of a specific cell death process called apoptosis.
• Altogether, it was concluded that an injectable AuNP-ECM could potentially combat inflammation and apoptosis, implying its possible utility in treating disorders like post-traumatic osteoarthritis.