3D printed autoclavable biocompatible biodegradable bioreactor vessels with integrated sparger made from poly-lactic acid

Abstract

3D printing has become widespread for the manufacture of parts in various industries and enabled radically new designs. This trend has not spread to bioprocess development yet, due to a lack of material suitable for the current workflow, including sterilization by autoclaving. This work demonstrates that commercially available heat temperature stable poly-lactic acid (PLA) can be used to easily manufacture novel bioreactor vessels with included features like harvest tubes and 3D printed spargers. Temperature responsiveness was tested for PLA, temperature stable PLA (PLA-HP) and glass for temperatures relevant for insect and mammalian cell culture, including temperature shifts within the process. Stability at 27 °C and 37 °C as well as temperature shifts to 22 °C and 32 °C showed acceptable performance with slightly higher temperature overshoot for 3D printed vessels. A stable temperature is reached after 2 h for PLA, 3 h for PLA-HP and 1 h for glass reactors. Temperature can be maintained with a fluctuation of 0.1 °C for all materials. A 3D printed sparger design directly integrated into the vessel wall and bottom was tested under three different conditions (0.3 SLPH and 27 °C, 3 SLPH and 37 °C and 13 SLPH and 37 °C). The 3D printed sparger showed a better kLa than the L-Sparger with more pronounced differences for higher flowrates. An insect cell culture run in the novel vessel exhibited the same growth behavior as that in standard glass vessels, reaching the same maximum cell concentration. Being 3D printed from biodegradable materials, these bioreactors offer design flexibility for novel bioreactor formats. Additionally, their autoclavability allows seamless integration into standard workflows.