Evaluation in vitro of epidermal cell keratinization

Defining the identity and the niches of epithelial stem cells with highly pleiotropic multilineage potency in the human thymus

Thymus is necessary for lifelong immunological tolerance and immunity. It displays a distinctive epithelial complexity and undergoes age-dependent atrophy. Nonetheless, it also retains regenerative capacity, which, if harnessed appropriately, might permit rejuvenation of adaptive immunity. By characterizing cortical and medullary compartments in the human thymus at single-cell resolution, in this study we have defined specific epithelial populations, including those that share properties with bona fide stem cells (SCs) of lifelong regenerating epidermis. Thymic epithelial SCs display a distinctive transcriptional profile and phenotypic traits, including pleiotropic multilineage potency, to give rise to several cell types that were not previously considered to have shared origin. Using here identified SC markers, we have defined their cortical and medullary niches and shown that, in vitro, the cells display long-term clonal expansion and self-organizing capacity. These data substantively broaden our knowledge of SC biology and set a stage for tackling thymic atrophy and related disorders.

Sonochemically Prepared BSA Microspheres as Adsorbents for the Removal of Organic Pollutants from Water

This work investigates, for the first time, the application of sonochemically prepared bovine serum albumin (BSA) microspheres (BSAMS) as adsorbents of industrial organic pollutant dyes, such as rhodamine B (RhB), rhodamine 6G (Rh6G), and methylene blue (MB). These dyes also serve as model compounds for other organic pollutants such as bisphenol A and 2-nitrophenol. Adsorption kinetics of the dyes by the BSAMS was studied using pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. It was found that RhB follows PFO, with an adsorption capacity, qe,cal, of 7.9 mg/g, which was closer to the experimental adsorption capacity of qe,exp. of 7.6 mg/g. However, MB and Rh6G were controlled by PSO kinetics, with a qe,cal of 5.6 mg/g for MB and 6.6 mg/g for Rh6G, closer to the experimental adsorption capacity of 5.7 and 6.4 mg/g, respectively. The intraparticle diffusion (ID) model applied to the three dyes indicated multi-linearity with ID as the rate-limiting step in the adsorption process. Furthermore, the adsorption equilibria for each of the organic pollutants were studied through various isotherm models such as Langmuir, Freundlich, Temkin, and Halsey, which indicated physical interaction between the BSAMS and the dye pollutants, thus suggesting the applicability of the BSAMS as pollutant adsorbent materials. It was found that the BSAMS can effectively remove RhB, MB, and Rh6G from wastewater with efficiencies of 95.5, 83.3, and 97.9%, respectively.

The Development and Evaluation of In Vitro Alternative Assays: A Personal Perspective

Over the past 30 years, FRAME has actively participated in the development, evaluation and validation of in vitro alternative methods through the FRAME Alternatives Laboratory (FAL) in the University of Nottingham Medical School. Much has been learned through collaboration with industry (especially the cosmetics industry), other organisations (especially ECVAM), and certain individuals (notably Dr Björn Ekwall), particularly in relation to the need to use human cell cultures and to obtain, wherever possible, high-quality human data for use in in vivo/in vitro comparisons. Reference is made to the author's experience as Director of the FAL, notably in the development of in vitro assays for basal cytotoxicity, phototoxicity and the effects of repeated dosage.