Material Selection Techniques for Polymer Hubs of Novel Spinal Stem Cell Introducers using Finite Element and Weighted Property Method

Stem cell studies have progressed significantly in the last decades. Similarly, stem cell therapies have also been applied in clinical settings, includingthe spine. However, stem cells' delivery to the spinal region requires delicate procedures, demanding reliable introducers in addition to the surgeons' psychomotor skills. The introducer is a tubular sleeve to guide a syringe needle to deliver and draw fluids into and from the body, respectively. To date, there is no introducer dedicated to spinal stem cell deliveries. Our group proposed a dedicated introducer for spinal stem cell therapies, which consists of a needle and a hub (a base part of an introducer for gripping and handling). We focused onthe weighting property method (WPM) to select four polymer candidates for the hub:polystyrene, polycarbonate, polypropylene, and polyethylene. Prior to WPM, the mechanical integrity of the hub candidates was analyzed using the finite element method to determine the von Mises Stress (vMS) values. Accordingly, the vMS for each case and the material was compared with the respective tensile strength (TS), thereby vMS:TS ratio (MTR).MTR was included as one of the properties in WPM, in addition to prices, critical radiation doses, hardness, water absorption, and isopropyl alcohol resistance.According to the WPM calculation, polycarbonate received the highest score, thereby recommended for further introducer fabrications.