Cytotoxicity

Medical devices must be designed in such a way that they do not have any adverse or undesirable effects on the user. The EN ISO 10993 series of standards describes biological assessment and testing as part of a risk management system. Cytotoxicity testing is an important test point for all medical devices that come into direct contact with the body. 

In accordance with the standard, UFAG Laboratorien AG is investigating whether extracts from medical devices adversely affect mammalian cells in vitro. The cellular viability and morphology of the cells are determined microscopically and by photometric measurement of the cellular metabolic processes. 

The test in accordance with EN ISO 10993-5 provides meaningful information for product development and the selection of suitable materials as well as for batch release. 

We are a GMP-certified, ISO 17025 accredited Swiss contract laboratory with many years of experience in the testing of medical devices. The cytotoxicity tests carried out at UFAG Laboratorien AG are accredited by the SAS. 

Read on to see which points you need to observe, or alternatively you can contact us.

How are extracts prepared?

TThe extracts are prepared according to the intended use of the product at a defined temperature using cell culture medium or another extraction agent. 

The extraction conditions are always selected in consultation with the client in order to obtain meaningful results that are appropriate for the intended use of the medical device. 

How will analysis be performed?

Active cultures of living mammalian cells (e.g. mouse fibroblasts) are incubated with the (medical) product extract and analysed microscopically for changes in cell morphology after 24 and/or 72 hours. In parallel, changes in cell viability are measured, for example via the chemical reaction of a tetrazolium salt to a formazan dye. 

Evaluation of the analysis

The cytotoxicity of a (medical) product is determined according to the morphological grade and cell viability. 

Cell morphology is classified by a grading system from 0-4. A cell morphology grade of ≤ 2 means that the (medical) product is not cytotoxic, while grades ≥ 3 indicate cytotoxic properties.
In addition, the cytotoxicity of a (medical) product is determined on the basis of cell viability, whereby various commercial cell viability assays can be used (e.g. XTT assay). If the viability of the cells drops to <70% compared to untreated cells, it can be assumed that the product being examined has cytotoxic properties.

Our services in detail:

• Consultation on cytotoxicity testing
• Cytotoxicity testing
• Autres prestations selon cahier des charges ou sur demande.