Biocompatibility assessment of nerve vessel retractors


The company markets a range of nerve vessel retractors (NVRs), differing only in external colour, for use during surgical procedures. Biocompatibility data were limited to the raw material, a silicone polymer, with no such information on the pigments.


A medical device manufacturer.

Project goals

Bibra was asked to evaluate the cytotoxicity, skin irritation and skin sensitisation potential of the whole devices, in line with ISO 10993 guidance, as part of a regulatory submission.


Bibra summarised the available biocompatibility insights from the reported conclusions of the previously conducted studies (full study reports were not provided) and supplementary literature searches were conducted to identify any additional relevant information on the cytotoxicity, skin irritation or skin sensitisation of the base polymer. Additional literature searches for the key endpoints were conducted on the coloured materials.

Project outcome

The NVR constituents were concluded to lack any significant potential to cause skin irritation or skin sensitisation reactions in patients. No concern was identified in regard to cytotoxicity, based on the identified data and, for the pigments, following a consideration of the composition and manufacturing of the NVRs. As such, a good biocompatibility was demonstrated with regards to the key endpoints under consideration.

Bibra project team

Daniel Threlfall

Pete Watts


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