Flow modeling in a novel non-perfusion conical bioreactor

We have developed a bioreactor vessel design which has the advantage of simplicity and ease of assembly and disassembly, and with the appropriately determined flow rate, even allows for a scaffold to be suspended freely regardless of its weight. This article reports our experimental and numerical investicagions to evaluate the performance of a newly developed non perfusion conical bioreactor by visualizing the flow through scaffolds with 45 degrees and 90 degrees fiber lay down patterns. The experiments were conducted at the Reynolds numbers (Re) 121, 170 and 218 based on the local velocity and width of scaffolds. The flow fields were captured using short-time exposures of 60 mu m particles suspended in the bioreactor and illuminated using a thin laser sheet. The effects of scaffold fiber lay down patter and Reynolds number were obtained and correspondingly fluid dynamics (CFD) software package. The objectives of this article are twofold: to investigate the hyposthesis that there may be an insufficient exchange of medium within the interior of the scaffold when using our non-perfusion bioreactor, and second, to compare the flows within and around scaffolds of 45 degrees and 90 degrees fiber lay down patterns. It was therefore shown that fluidic transport could be achieved within scaffolds with our bioreactor design, being a non-perfusion vessel. Fluid velocities were generally same of the same or one order lower in magnitude as compared to the inlet flow velocity. Additionally, the 90 degrees fiber lay down patterns scaffold was found to allow for slightly higher fluid velocities within, as compared to the 45 degrees fiber lay down pattern scaffold. This was due to the architecture and pore arrangement of the 90 degrees fiber lay down pattern scaffold, which allows for fluid to flow directly through (channel-like flow).