Tag Archive for: medical devices

Assessment of the skin sensitizing potential of pandemic-associated medical devices using the GARDskin Medical Device assay

Joint poster with Essity Hygiene & Health AB,
Presented at the 2021 Eurotox annual meeting

P. Mohlin, A. Forreryd, O. Larne, R.-M. Jenvert, H. Johansson | Essity Hygiene & Health AB, Product Safety, Clinical & Regulatory Affairs, Mölndal, Sweden; SenzaGen AB, 22381 Lund, Sweden

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  • GARDskin is well adapted to risk assess the skin sensitizing potential of medical devices in accordance with ISO 10993.
  • GARDskin Medical Device classified the tested commercially available face masks as non-sensitizers and the nitrile glove as sensitizers.
  • New in vitro technologies, like GARD, is well suited as a routine tool to increase the speed of decision making in extraordinary situations as a pandemic.


The current SARS-CoV-2 pandemic have led to an increased use of medical devices such as face masks and nitrile gloves, within occupational groups of medical care as well as within the general population. Consequently, the incidence reports of adverse effects associated with use of such medical devices have increased manyfold, including reports of allergic skin reactions.

The cause of allergic skin reactions, referred to as Allergic Contact Dermatitis (ACD) is the immunological process known as skin sensitization, which is induced by so-called chemical sensitizers. Assessment of skin sensitizing potential of leachables from medical devices is a part of biocompatibility testing of medical devices and is typically performed by use of the Guinea Pig Maximization Test (GPMT), in accordance with the ISO 10993 series of standards. However, recent developments of in vitro assays for assessment of chemical sensitizers motivates the exploration of such methods in the context of rapid pandemic-associated testing.

The GARDskin assay [1] is a next-generation in vitro assay for hazard assessment of skin sensitizers, currently progressing towards regulatory acceptance. The method evaluates the transcriptional patterns of a genomic biomarker signature in a human dendritic-like cell line following exposure, in order to provide hazard assessments of tested substances. The method has been adapted to testing of solid materials from e.g. medical device products, by application of extraction protocols using polar- and non-polar extraction vehicles, in accordance with ISO 10993-12.

Here, we present results from testing of a commonly used face mask and a nitrile glove in the GARDskin Medical Device assay. Results indicate that the face mask does not leach any compounds with skin sensitizing potential (among four different batches tested), while the nitrile glove was classified as a skin sensitizer. These results harmonize with preexisting experience of similar models of nitril gloves, which are known to be associated with adverse skin reactions, potentially induced by skin sensitization. Furthermore, these results may have implications on the continued use of similar medical devices throughout the pandemic and beyond, as the appropriate application and removal of face masks may indeed benefit from the discontinued simultaneous use of nitrile gloves.

Applicability domain of the GARD™skin Medical Device test for in vitro skin sensitization testing of medical devices

Poster presented at SOT 2021

Joshua Schmidt, Ron Brown and Rose-Marie Jenvert
SenzaGen Inc., Raleigh, NC, USA, Risk Science Consortium LLC, Arnold, MD, USA, SenzaGen AB, Lund, Sweden.

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  • The chemical space of compounds tested in GARD closely approximates the chemical space of compounds known to be released from medical device materials.
  • GARDskin is able to predict the skin sensitization potential of compounds released from medical device materials with a high degree of sensitivity and specificity, including: metals, lipophilic compounds and pre/pro haptens.


Medical device toxicology is undergoing an exciting evolution; transitioning from a process that largely relied on the results of animal testing to evaluate the biological safety of devices in patients to one which is increasingly focused on the use of in vitro methods for the safety assessment of device materials.

Recently, in vitro methods to assess endpoints such as skin irritation and pyrogenicity have been validated and proposed for medical device testing, but a method to assess the potential for device-related skin sensitization to occur has not been sufficiently qualified. A number of in vitro skin sensitization test methods have been shown to have acceptable predictive ability for known skin sensitizers with structures that span a broad range of chemical classes, but the predictive ability of these methods has not been specifically evaluated using compounds typically found in materials used to manufacture medical devices. As a result, the need exists to qualify in vitro methods to assess the skin sensitization of compounds that may be released from medical devices, taking into account the applicability domain of known or potential skin sensitizers, including metals.

To address this challenge, the predictive ability of the GARD assay has been evaluated using a dataset of compounds known to be released from device materials.  Against these data, the assay correctly predicted 19 out of 21 lipophilic and pre-/pro-hapten compounds (90.5% accuracy), with one false positive (95.2% sensitivity) and one false negative (95.2% specificity) being predicted, thus increasing the confidence in use of this in vitro assay to assess the skin sensitization potential of medical devices.  Furthermore, we have also demonstrated that the GARD assay correctly predicts the skin sensitization response of nickel and cobalt salts (sensitizers) and a zinc salt (non-sensitizer). Overall, our data support the use of the GARDskin Medical Device assay as an in vitro alternative for the in vivo methods (e.g., GPMT, LLNA) that are typically used to assess skin sensitization as part of the biological safety assessment of medical devices.

Tag Archive for: medical devices

Webinar: Safety of acrylate monomers, metals, and other materials used in medical device development

Join our upcoming free webinar to explore the effective utilization of in vitro methods for safety assessment of materials during product development of Medical Devices.

We will discuss recent advancements in in vitro methods for assessing the endpoints of skin irritation and skin sensitization. Learn how to integrate these assessments into your product development process as a complement to chemical characterization and cytotoxicity testing.

Discover how this approach can aid in:

Selecting the right material | Developing new materials | Optimizing production | Choosing the appropriate sterilization method

Key takeaways

*Gain insights into the key fundamentals of the biological evaluation of medical devices and the availability of in vitro biocompatibility testing.

*Explore the applicability of the in vitro GARD technology in the assessment of medical devices, supporting both polar and non-polar extraction vehicles (ISO 10993-12).

*Examine user cases illustrating the safety assessment of acrylate monomers, metals, and various materials utilized in medical device development. Learn how these assessments contribute to material selection and production optimization.