ADDRESSING CHALLENGES IN 3D MODELING AND PRINTING FOR VIRTUAL AND RAPID PROTOTYPING OF DEVICES FOR SUBSTITUTIVE MEDICINE AND TISSUE ENGINEERING

Objectives: The increasing demand for the timely availability of biomedical devices in laboratories and clinical practice requires expedited design and development processes through 3D modeling. Simply having a 3D model does not guarantee a functional printed object, because properties such as surface quality, morphological conformity, stability, and biocompatibility must be considered. This study aims to propose a protocol for generating comprehensive 3D models that can be adapted throughout all stages of medical device development, from concept to fabrication to utilization, without compromising the overall design integrity. Methods: Advanced 3D modeling tools were used in the study, such as CAD software PTC Creo release 8, CAE software Comsol Multiphysics, and Zortrax Inkspire 3D printer with basic and medical-grade resins. Focus was on addressing geometric complexity challenges, particularly in rounded areas with merged surfaces, when transferring models between different applications using interchange file formats such as IGES, STEP, and STL. Various medical device models were produced. Particular attention was given to bioreactor design for ovarian tissue culture, which required a thorough investigation of arising specific issues. Results: Modifications were made to geometry to minimize distortions in Multiphysics simulations, with a focus on tissue perfusion with the medium in bioreactors. Adjustments were also made to export and processing parameters for 3D printing, resulting in a set of recommendations for defining a protocol based on best practices. Notably, parameter adjustments were made after measuring the printed part's geometry in the metrology laboratory. Conclusions: Developing a single 3D model meeting the requirements of CAE simulations, 3D printing, and other fabrication techniques is challenging. Even if successfully generated, the model needs to account for way too many factors and variables that influence the final outcome. In such cases, the expertise and capability of the operator play a crucial role in the virtual and real prototyping of custom-made medical devices.