What are the best practices for ensuring biocompatibility in 3D printed implants?

1 Choose biocompatible materials

The first step to ensure biocompatibility is to choose materials that are suitable for 3D printing and for the intended application of the implant. The materials should have adequate mechanical properties, such as strength, stiffness, and elasticity, to match the native tissue and withstand the physiological loads. They should also have good biodegradability, bioactivity, and biostability, to promote tissue regeneration and prevent degradation or toxicity. Some of the most commonly used biocompatible materials for 3D printing are metals, ceramics, polymers, and composites, each with their own advantages and limitations.

3 Select appropriate fabrication method

The third step to ensure biocompatibility is to select an appropriate fabrication method, based on the material and the design of the implant. The fabrication method should be able to produce the desired geometry, resolution, and accuracy of the implant, without compromising the material properties or introducing defects or contaminants. Some of the most widely used fabrication methods for 3D printing are fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography (SLA), and direct metal laser sintering (DMLS), each with their own pros and cons.

4 Perform adequate post-processing

The fourth step to ensure biocompatibility is to perform adequate post-processing, after the implant is 3D printed. The post-processing should aim to improve the quality, performance, and safety of the implant, by removing any excess material, support structures, or residual stresses. The post-processing should also modify the surface characteristics, such as roughness, chemistry, and topography, to enhance the biocompatibility of the implant. Some of the common post-processing techniques are polishing, cleaning, sterilizing, coating, and functionalizing, depending on the material and the application of the implant.

5 Evaluate biocompatibility in vitro and in vivo

The final step to ensure biocompatibility is to evaluate the implant in vitro and in vivo, before and after implantation. The evaluation should assess the biological response of the implant, such as cytotoxicity, inflammation, infection, immunogenicity, and integration, using relevant cell cultures, animal models, and human subjects. The evaluation should also monitor the mechanical performance of the implant, such as fatigue, fracture, wear, and corrosion, using appropriate testing methods and instruments. The evaluation should follow the established guidelines and standards, such as ISO 10993 and ASTM F75, to ensure the reliability and validity of the results.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?