Open-source extrusion 3D bioprinters: Trends and recommendations

Three-dimensional (3D) extrusion bioprinting, an additive manufacturing process that hybridizes traditional thermoplastic 3D printing technology with the latest developments in tissue engineering, is a promising tool for engineering lab-scale tissues and organs for drug screening, pathological modeling, and transplantation. The technology has been proven to be reliable, high-throughput, and capable of printing complex physiological structures at relevant scales. Commercially available 3D extrusion bioprinters can manipulate a broad range of soft materials with sub-millimeter resolution. However, these bioprinters are expensive and typically contain proprietary software, impeding the customization of bioprinters to lab-specific applications. In response, researchers have recently manufactured and published open-source 3D extrusion bioprinters converted from thermoplastic printers. This review compares and evaluates currently available open-source 3D extrusion bioprinters, including their total cost, features, and necessary technical experience to fabricate in most academic labs. Current open-source slicing software is detailed, and guidelines are offered to ensure this technology continues contributing to the democratization of additive manufacturing technology. These comparisons and recommendations will allow researchers to choose an open-source printer that best suits their laboratory's 3D bioprinting needs and will highlight the need to iterate and improve published designs.