Three-dimensional (3D) bioprinting is an emerging industry that offers the exciting prospect of printing, in 3D, multicellular human organ equivalents (organ equivalent devices or ‘OEDs’) for use in a clinical disease setting.1Sean Murphy & Anthony Atala, 3D Bioprinting of Tissues and Organs, 32 NATURE BIOTECHNOLOGY 773 (2014). Such 3D bioprinting methods rely on computer-aided design (CAD) and computer aided manufacturing (CAM) in order to design, and manufacture OEDs. First, specialized executable CAD software must be created by the CAD developer. This CAD software is then used by the ‘CAD user’ to create a bespoke (patient-specific) 3D CAD model of the patient’s organ that can be used for bioprinting (the ‘CAD print file’); this CAD print file is typically derived from 3D image data obtained from methods such as computed tomography (CT) or magnetic resonance imaging (MRI).2Wei Sun, Binil Starly, Jae Nam & Andrew Darling, Bio-CAD modeling and its applications in computer-aided tissue engineering, 37 COMPUTER-AIDED DESIGN 1097 (2005).
The creation of the CAD print file presents two key technical challenges: (i) replication of intricate organ micro-architecture and (ii) organization of multiple cell types at a resolution that is sufficient to manufacture a fully functional organ.3 A typical human organ consists of multiple cell types, including specific functional, structural, and supportive cells.4 Finally, the CAD print file is used to manufacture the final OED using bioprinting methods. Creating the optimum CAD print file is paramount to successful OED bioprinting, since the design of that file plays a key role in determining the mechanical properties of the OED’s cell scaffold (the structure providing support to 3D bio-printed cells to multiply), cell growth, cell dynamics and differentiation.5 The final use of the CAD software, via the CAD print file, therefore, has an indisputably specific set of characteristics that must be taken into account when assessing the concept of liability during CAD software design and development. While offering enormous benefits, methods of CAD software development may carry generic risks for which liability rests with the developer.6 This is particularly significant for OED manufactures, since OED quality relies heavily, albeit not exclusively, on CAD software quality. In the medical 3D bioprinting field, three theories are, in principle, relevant to the protection of the patient against injuries that are attributable to defective CAD software: (i) medical malpractice (a subset of negligence law),7 (ii) breach of warranty under the Uniform Commercial Code (UCC), 8 and (iii) strict liability. None of these theories, however, adequately address the range of injuries that could potentially arise due to use of defective CAD software. This article will explore these issues in the framework of the ongoing conflict between negligence, breach of warranty, and strict liability. In this context, 3D bioprinting creates the possibility of extending theories of liability;