IIVS Newsletter - December 2021

What's New at IIVS:

Pre-Clinical Efficacy Testing of Skin Care Products

In addition to IIVS’ non-animal safety testing services, we also provide efficacy testing designed to evaluate raw materials and formulations for anti-inflammatory and skin tone modulating properties.

Inflammation is a common effect experienced after encounters with irritating substances, bacterial infection or by those suffering from auto-immune diseases. Compounds such as cannabinol have received significant press lately, being cited as a substance with pronounced anti-inflammatory effects. Testing such compounds with animal models is expensive and time consuming, in addition to being banned in many countries. Fortunately, in vitro models can be an effective tool to accurately evaluate test materials for anti-inflammatory properties.

Our skin tone modulation assay incorporates a 3-D organotypical model expressing a Caucasian, African-American or Asian phototype. The tissues are treated with the experimental material and production of melanin is evaluated after a 7-day exposure course.

Macroscopic examples of melanin production and modulation following treatment of MelanoDerm™ tissues

More information on both assays service can be found at our Efficacy Services page on our website.

IIVS anti-inflammatory and skin tone modulation potential assays can be useful tools in the evaluation of skin care products. Modified in part from: Application of In Vitro Methods in Preclinical Safety Assessment of Skin Care Products

EC3 Prediction Capabilities

Development of the mouse Local Lymph Node Assay (LLNA) was one of the first refinements to animal-based testing for skin sensitization determination. This test was widely viewed to have animal welfare benefits compared to other hazard-based animal tests (e.g., the Guinea Pig Maximization Test). The test also provided a potency determination via the generation of an EC3 value (Effective Concentration required to induce a 3-fold upregulation of lymph node cell proliferation). Safety assessors have used this EC3 value to inform on determining a “Point-of-Departure” concentration for conducting skin sensitization risk assessments. Since the development of the LLNA, several non-animal approaches have been developed and validated to assess skin sensitization potential, including the Direct Peptide Reactivity Assay, KeratinoSens™, human Cell Line Activation Test, and Kinetic Direct Peptide Reactivity Assay. Although recently published OECD guidance permits hazard identification based on a “2 out of 3 approach”, none of these assays or any combination thereof can currently be used to determine a quantitative Point of Departure for use in risk assessment.

Over the last several years, researchers at Givaudan (who developed the KeratinoSens™ assay and Kinetic Direct Peptide Reactivity Assay) have explored linear regression modeling using the results of several of these assays to determine a skin sensitization potency prediction. Results have been highly encouraging, with predicted EC3 values showing excellent correlation with published LLNA EC3 values. Based on Natsch et al. (2015 and 2018) publications, IIVS is now offering predicted EC3 analysis using a combination of in vitro/in chemico assays and the linear regression modeling developed by the team at Givaudan. Please contact clientservices@iivs.org for further information.

New Research on human Precision-Cut Lung Slices

IIVS is pleased to announce the publication of our advanced research into the utility and performance of human Precision-Cut Lung Slices (hPCLS). Within this manuscript, we examine how culture medium and method of culture impact the health and performance of slices in long term culture. We are confident this work will assist in the standardization of the use of this model.

hPCLS offer native architecture of the lung, including respiratory parenchyma, small airways, and immune competent cells involved in inflammatory and sensitization processes.

Click here to read the abstract published in ATLA

PLEASE NOTE:

IIVS will be closed from December 25th until January 2nd. Please arrange for test material shipments to our lab to arrive outside of these dates. We wish you a pleasant holiday season and a healthy and prosperous 2022!

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