Electrospinning lecithin-polycaprolactone scaffolds with gold nanoparticles for osteoarthritis prevention

Abstract

The human body has articular cartilage covering the ends of the bones to act as a shock absorber and aid in movement. In a disease state, this articular cartilage breaks down causing pain, swelling, and stiffness. With time, the cartilage continues to wear down, and bone on bone interactions occur. This disease is osteoarthritis (OA), and it is the most prevalent joint degenerative disease, affecting approximately 27 million Americans. OA cannot be reversed, so treatment methodologies are mostly palliative, which only provides temporary pain relief, or alternatively are very invasive, requiring total knee replacement. To help mitigate the progression of OA, a hydrophilic, immunomodulatory membrane was developed, which would be placed over the articulating surface to prevent further degeneration of osteoarthritic cartilage. The electrospun membrane is composed of 20 nm gold nanoparticles, soy lecithin, and the polymer polycaprolactone (PCL). Soy lecithin and PCL solutions were electrospun to develop a unique nonwoven mat for OA. The electrospinning parameters were optimized to achieve different solution ratios for the best fiber formation. Different concentrations of lecithin and PCL were used: the amount of solute needed was 40% (w/v) and the amount of lecithin mixed with PCL was 40% (40:40), and 50% (w/v) solute needed with 50% soy lecithin with PCL (50:50). 20 nm gold nanoparticles were then introduced at 1%, 5%, and 10% (v/v) to modulate the inflammatory response. The chemical composition of the scaffolds was analyzed via Fourier Transform Infrared Spectroscopy (FTIR), and the thermal properties were investigated using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) to determine stability and percent of materials. Contact Angle Measurements were taken to observe the hydrophilicity of the scaffolds. Neutron Activation Analysis (NAA) was performed to quantify the gold nanoparticles present in the mats. Scanning Electron Microscopy (SEM) was conducted to determine fiber formation as well as nanoparticle presence. To characterize the biocompatibility and cytotoxicity of the mats, WST-1 and ROS assays were performed using L929 murine fibroblast cells. It is expected that lecithin and gold will be homogeneously integrated with the PCL and that the mechanical properties will be strong enough to withstand the microenvironment of the knee. This study demonstrated that it is possible to successfully electrospin lecithin and polycaprolactone nanofibrous scaffolds with various polymerized solution concentrations with and without gold nanoparticles. It was hypothesized that the electrospun lecithin/PCL/nanoparticle scaffold would promote hydrophilicity while maintaining strength and flexibility, thereby prolonging mechanical stability in cartilage