• Development and evaluation of a quality control system based on transdermal electrical resistance for skin barrier function in vitro.

      Knoth, Katharina; Zäh, Ralf-Kilian; Veldung, Barbara; Burgio, Dominic; Wiegand, Birgit; Smola, Hans; Bock, Udo; Lehr, Claus-Michael; Hittinger, Marius; Groß, Henrik; et al. (Wiley & Sons, 2021-01-06)
      Background: In vitro skin permeation experiments are highly relevant for pharmaceutical, cosmetic, agricultural developments, and regulatory evaluation. A key requirement is the skin barrier integrity, that is accompanied by an intact stratum corneum (SC) which implements high skin quality. A variety of integrity tests are currently available, for example, measurement of transepidermal water loss, monitoring the permeation of tritiated water and the measurement of transdermal electrical resistance (TER). Materials and methods: We aimed for a non-destructive examination of barrier integrity as quality control system, based on TER. Therefore, the in-house developed instrument SkinTER measures electrical resistance on excised human skin samples in a non-invasive and easy-to-use pattern. In this proof of concept study, we compared three human in vitro skin models with focus on their TER and permeation properties. The skin integrity was impaired to mimic conditions of skin during age, lifestyle (eg, shaving) or diseases (eg, obesity, psoriasis, and atopic dermatitis). The OECD permeation marker caffeine was correlated to the corresponding TER value. Results: A correlation between both was obtained by having a Pearson coefficient of -0.830. Hereby, a minimum TER value for intact skin samples of ~1.77 kΩ*cm2 was suggested. Intact samples are significantly different (α = ≤0.05) to their impaired counterparts in flux and TER values. Conclusion: The new SkinTER instrument gives a quick and non-invasive feedback on skin quality before a permeation experiment.
    • Towards More Predictive, Physiological and Animal-free in vitro Models: Advances in Cell and Tissue Culture 2020 Conference Proceedings.

      Singh, Bhumika; Abdelgawad, Mohamed Essameldin; Ali, Zulfiqur; Bailey, Jarrod; Budyn, Elisa; Civita, Prospero; Clift, Martin J D; Connelly, John T; Constant, Samuel; Hittinger, Marius; et al. (Fund for the Replacement of Animals in Medical Experiments (FRAME), 2021-07-06)
      Experimental systems that faithfully replicate human physiology at cellular, tissue and organ level are crucial to the development of efficacious and safe therapies with high success rates and low cost. The development of such systems is challenging and requires skills, expertise and inputs from a diverse range of experts, such as biologists, physicists, engineers, clinicians and regulatory bodies. Kirkstall Limited, a biotechnology company based in York, UK, organised the annual conference, Advances in Cell and Tissue Culture (ACTC), which brought together people having a variety of expertise and interests, to present and discuss the latest developments in the field of cell and tissue culture and in vitro modelling. The conference has also been influential in engaging animal welfare organisations in the promotion of research, collaborative projects and funding opportunities. This report describes the proceedings of the latest ACTC conference, which was held virtually on 30th September and 1st October 2020, and included sessions on in vitro models in the following areas: advanced skin and respiratory models, neurological disease, cancer research, advanced models including 3-D, fluid flow and co-cultures, diabetes and other age-related disorders, and animal-free research. The roundtable session on the second day was very interactive and drew huge interest, with intriguing discussion taking place among all participants on the theme of replacement of animal models of disease.