Impact of Needle Selection on Survival of Muscle-Derived Cells When Used for Laryngeal Injections

OBJECTIVE: To describe how differing injector needles and delivery vehicles impact Autologous Muscle-Derived Cell (AMDC) viability when used for laryngeal injection. METHODS: In this study, adult porcine muscle tissue was harvested and used to create AMDC populations. While controlling cell concentration (1 × 10(7) cells/ml), AMDCs including Muscle Progenitor Cells (MPCs) or Motor Endplate Expressing Cells (MEEs) were suspended in either phosphate-buffered saline or polymerizable (in-situ scaffold forming) type I oligomeric collagen solution. Cell suspensions were then injected through 23- and 27-gauge needles of different lengths at the same rate (2 ml/min) using a syringe pump. Cell viability was measured immediately after injection and 24- and 48-hours post-injection, and then compared to baseline cell viability prior to injection. RESULTS: The viability of cells post-injection was not impacted by needle length or needle gauge but was significantly impacted by the delivery vehicle. Overall, injection of cells using collagen as a delivery vehicle maintained the highest cell viability. CONCLUSION: Needle gauge, needle length, and delivery vehicle are important factors that can affect the viability of injected cell populations. These factors should be considered and adapted to improve injectable MDC therapy outcomes when used for laryngeal applications.