Biocompatibility and Sterilization in 3D Printed Medical Devices

Why Biocompatibility & Sterilizability Are Critical for Medical 3D Printing

As 3D printing becomes more deeply integrated into modern healthcare, it’s opening new doors for personalized care and medical innovation. Patient-specific surgical guides, anatomical models, dental appliances, orthotics, and other devices can now be produced faster and more precisely than ever before. But when these 3D printed parts are intended for use in or near the human body, innovation alone isn’t enough. Safety is non-negotiable. 

To be clinically viable, 3D printed medical parts must meet two critical requirements: biocompatiblity and the ability to be safely sterilized. These aren’t just regulatory hurdles – they're key to making sure a part made from medical-grade 3d printing materials can come into contact with the human body and be used in sterile environments without putting patients at risk.  

This article breaks down what these terms mean in the world of additive manufacturing (AM), how to align with standards like ISO 10993, and why success depends not just on what material you use, but how you use it – from design to delivery.   

What Is Biocompatibility? 

Biocompatibility refers to the ability of a material to perform its intended function without causing harm to the human body. This means it must not trigger cytotoxic (cell-killing), allergic, inflammatory, or immunological responses when in contact with skin, tissue, mucosal membranes, or fluids. 

The global standard used to evaluate biocompatibility is ISO 10993, which outlines various biological risk assessments based on how the material will be used in the body, and for how long. 

Key ISO 10993 Testing Categories Include: 

• Cytotoxicity – Assesses cell damage or death caused by material contact 
• Irritation and Sensitization – Measures skin or mucosal reactivity and allergic potential 
• Systemic Toxicity – Evaluates health effects from exposure throughout the body 
• Hemocompatibility – Determines how blood reacts with the material 
• Pyrogenicity – Tests for the presence of substances that cause fever 
• Implantation Testing – Observes the reaction of tissue over time when the material is implanted 
• USP Class Testing (Class I–VI) – Rates plastic materials for medical use based on their chemical stability and biological performance 

Biocompatibility testing is matched to three key variables: 

1. Contact site (skin, mucosa, bloodstream, tissue, bone) 
2. Contact duration (see below) 
3. Material/device type 

These evaluations are crucial for anyone working with biocompatible 3D printing materials in medical or dental applications, especially for those producing sterile medical parts with additive manufacturing.  

The Overlooked Factor: Post-Processing and Handling 

Even if a material is fully biocompatible off the printer, how it is post-processed, handled, and finished can make or break its medical safety. It is possible—and unfortunately common—for a printed part to lose its biocompatibility due to contamination introduced after printing.  

Post-Processing Risks That Can Compromise Biocompatibility: 

• Contamination from dirty gloves, tools, or surfaces 

• Residues from unapproved solvents, adhesives, polishing agents, or support materials 

• Cross-contact between biocompatible and non-biocompatible parts 

• Improper drying, soaking, or curing procedures that alter surface chemistry 

• Sterilization failure due to unknown additives or material degradation 

Biocompatibility is not guaranteed by the printer or the material—it must be maintained through every step of the process. That’s why working with ISO 13485 compliant providers --   like Stratasys Direct – is crucial to ensuring that each step in the manufacturing process meets the highest regulatory standards.  

What Validated Workflows Look Like: 

A validated post-processing workflow ensures that every step of production, from print to final packaging, preserves the material’s certified biocompatibility. This includes: 

• Using approved support removal techniques (e.g., caustic soda, IPA, or VhP-safe rinses) 

• Controlling environmental exposure (clean surfaces, gloves, PPE) 

• Following regulated sterilization practices that match the material’s specifications 

• Isolating biocompatible jobs from non-biocompatible runs or post-processing spaces 

• Maintaining traceability of each part and the materials used in its production 

• Follow ISO 13485-certified procedures for medical device production 

This ensures 3D printed parts maintain performance and pass quality inspections. These protocols are essential for anyone using additive manufacturing for medical devices.

Key Takeaways: Safe, Sterile, and Biocompatible 3D Printed Devices

Biocompatibility and sterilization are essential pillars of safe medical 3D printing. While selecting a certified material is an important first step, how the part is handled after printing is just as critical. From support removal to sterilization validation, every step in the post-processing workflow must maintain the part’s compliance, integrity, and readiness for clinical use. 

To produce reliable medical devices with 3D printing, manufacturers must: 

• Select tested and certified materials 

• Align designs and materials to intended contact duration and body region 

• Prevent contamination with tight post processing protocols 

• Use appropriate sterilization methods for the chosen material 

• Maintain traceabiity to meet FDA and ISO 13485 requirements. 

 Whether you’re designing surgical tools, dental appliances, or wearable components, successful medical additive manufacturing relies on safety, regulatory discipline, and material knowledge. 

Biocompatible 3D printing isn’t just about what a material can do—it’s about what it should do, and how you ensure it performs as intended every step of the way.