Title: 3D printing in biotechnology: Supply chain independent single-use plasticware for cell culture

Abstract

The current shortages in single use (SU) supply chains show how dependent both industry and academia are from only a few vendors worldwide. This is severely hindering fundamental research and process development for the COVID pandemic response and will do so in future. With 3D printing technology we can manufacture SU equipment on demand and on site. In this study we investigated different commercially available low-cost materials and their compatibility for cell culture. We identified poly lactic acid (PLA) as perfect candidate for 3D printed parts for cell culture applications. The worldwide supply chain issues for SU shaking flasks and bioreactors prompted us to develop 3D printed counterparts to maintain our HEK293 cell culture intended for bionanoparticle production. The shaking flasks were designed in Autodesk inventor 3D CAD. Materials tested represent the market of different 3D printing technologies and low-cost materials, ranging from UV-polymerizing resin printers to thermoplastic printers. The different materials were tested with HEK293 cells under standard conditions. Cell growth and viability were monitored daily. Our tests showed that only PLA has the same growth behavior as the commercially available SU flasks. We suspect that volatile organic compounds (VOC) inhibit cell growth for resin-based materials and have a toxic effect on the cell culture. We were able to show that heat treatment to reduce the VOC concentration was of partial success (data not shown). Moreover, we present the application for insect cells intended for virus like particle production and show the potential uses of customized equipment such as custom made bioreactors with geometries that are not possible to achieve with any other methodology than 3D printing. While 3D printed SU ware is very unlikely to be universally adopted as a full replacement for all SU-labware, it could be of interest to low income countries, given the sharp decrease in prices of 3D printers in recent years and low costs of PLA filament (~15 €/kg equivalent to ~33 $/lb).