Biocompatibility Testing Program for Class III Medical Device
The Challenge
A medical device company was developing a next-generation implantable cardiac monitor with a novel polymer housing material. As a Class III device requiring Premarket Approval (PMA), the FDA mandated a comprehensive biological evaluation per ISO 10993 standards. The novel polymer had no predicate device history, requiring the full battery of biocompatibility tests rather than an abbreviated program. The device would be implanted subcutaneously for up to 3 years, classifying it as a permanent implant with prolonged tissue contact — the most stringent biocompatibility category. The client needed a single laboratory capable of executing the complete testing program to ensure consistency across all studies.
Our Solution
Meramec designed an integrated ISO 10993 biocompatibility program encompassing all required endpoints for a permanent implant device. The program included: ISO 10993-5 cytotoxicity assessment using L929 mouse fibroblasts with both direct contact and extract methods; ISO 10993-10 sensitization study using the murine Local Lymph Node Assay (LLNA) in CBA/J mice; ISO 10993-10 intracutaneous irritation study in New Zealand White rabbits; ISO 10993-11 acute systemic toxicity in mice via IV, IP, and oral routes; ISO 10993-3 genotoxicity battery including Ames test, in vitro chromosomal aberration assay, and in vivo mouse micronucleus test; ISO 10993-6 implantation study in rats with 4-week and 26-week evaluation periods including quantitative histomorphometry; ISO 10993-11 subchronic systemic toxicity 90-day study in rats. Extract preparation followed ISO 10993-12 using clinically relevant conditions. All studies were conducted under GLP with full traceability.
The Results
All biocompatibility endpoints met or exceeded acceptance criteria across the complete test battery. The cytotoxicity assay showed no evidence of cellular toxicity. Sensitization and irritation studies were negative. Acute and subchronic systemic toxicity studies revealed no treatment-related adverse effects. The genotoxicity battery was negative across all three assays. The 26-week implantation study demonstrated excellent tissue compatibility with minimal fibrous encapsulation and no chronic inflammatory response. The integrated data package, including detailed pathology reports and statistical analyses, was accepted by FDA as part of the PMA submission without any deficiency letters related to biological safety evaluation. The device received PMA approval and is now commercially available in the US market.