THE USE OF COMPUTATIONAL FLUID DYNAMICS IN THE OPTIMIZATION OF AIR-IMPEDANCE ELECTROSPUN STRUCTURES FOR TISSUE ENGINEERING

Electrospinning is a viable method for dermal tissue engineering scaffold fabrication. Grafts using air-impedance electrospinning possess the ability to significantly increase cellular infiltration. However, current air-impedance methods lack precise control over flow properties through the collecting mandrel and are unable to accurately control fiber deposition in an organized and well-distributed manner. This study focusses on the use of computational fluid dynamics (CFD) and its application to air-impedance structures to optimize the deposition of the resulting dermal graft. Air-impedance structures were created from a range of air pressures to determine the optimal pressure for fiber collection. Initial results showed a pressure of 11 psi (1.3 scfm), which led to increased cellular penetration, but created uneven structures. This inlet flow rate was implemented as the primary boundary condition for CFD simulations. CFD software was used to gather data on fluid flow characteristics for a variety of mandrel geometries. Results showed that a mandrel with increased length and offset pore geometry provided the highest uniformity of flow along the length of the model over the other mandrel lengths, geometries, and pore alignments based largely on pressure and velocity analysis. This mandrel was manufactured and used for validation of CFD data via scaffold analysis and cellular infiltration studies. Scaffold characterization confirmed a significant advantage in the creation of structures fabricated with the optimized air-impedance mandrel by effectively doubling the efficiency of production via larger usable scaffold area. The results indicate that CFD validation is a valuable technique to optimize air impedance scaffolds in silico and has proven to be a useful tool in the fabrication of tissue engineering scaffolds.