Epidermis equivalents capable of pigmentation include cells derived from the differentiation of matrix cells; reconstructed skins comprised thereof, optionally containing hair follicles, are useful for evaluating the effect of topical cosmetic, pharmaceutical or dermatological products and may also be used for the preparation of grafts suited to be transplanted on mammals, more particularly on human patients such as victims of third-degree burns.

Some embodiments are directed to an in vitro skin, in particular animal skin, including, mammalian and/or human skin, equivalent, and to the use thereof. In particular, the subject matter of some embodiments includes the use of a skin equivalent as a laboratory tool and/or in a method for testing cosmetic and/or dermatological compounds.

The present invention relates to a method for producing a dermal or skin or epidermal equivalent on a two-layer substrate comprising a layer of at least 200 nm in thickness and having a porosity less than or equal to 5 ?m formed by electrospinning of a composition comprising at least one polymer, and a layer of at least 20 ?m in thickness and having a porosity greater than or equal to 20 ?m formed by electrowriting of a composition comprising at least one polymer. The application also relates to the skin or dermal or epidermal equivalent that can be obtained with said method, the use of a dermal equivalent or a skin equivalent or an epidermal equivalent for screening compounds and finally the use thereof in wound dressing or for skin grafts.

The invention provides a micro-organ composite which comprises a core group of cells and an outer layer of cells, wherein the cells of the core group are mesenchymal cells and the cells of the outer layer are epithelial cells or wherein the cells of the core group are epithelial cells and the cells of the outer layer are mesenchymal cells, and wherein the core group of cells is at least partially encapsulated by the outer layer of cells.

Disclosed herein are methods of differentiating human neural progenitor cells to nociceptor-like cells. Also disclosed are methods of making an innervated skin-like construct using nociceptor-like cells differentiated from human neural progenitor cells. Also disclosed are engineered constructs for screening potentially therapeutic compounds that include a skin-like construct and nociceptor-like cells differentiated from human neural progenitor cells. Also disclosed is a method of screening potential therapies.

The provided is a skin damage organoid model and a drug screening method using the same, which utilize a technology of producing an air-liquid interface skin organoid forming skin cells, appendages, nerve cells, and fat cells in a structure similar to actual skin, and creates damaged skin by irradiating the skin organoid with UV rays that mimic UV rays reaching the actual Earth surface. Since the skin damage organoid model is irradiated with solar light-mimicking UV rays, including 94.5% UV-A and 5.5% UV-B, the skin barrier is damaged and the activity of a support protein degradation enzyme is increased, degradation of collagen is promoted, and the secretion of pro-inflammatory cytokines is increased, which mimic the characteristics of skin damaged by UV rays well, this model can be effectively used as a model of UV-induced damage and aging, and is expected to be a useful technology for screening potential therapeutic drugs.

Disclosed are bioprinted, three-dimensional, biological skin tissues comprising: a dermal layer comprising dermal fibroblasts; and an epidermal layer comprising keratinocytes, the epidermal layer in contact with the dermal layer to form the three-dimensional, engineered, biological skin tissue. Also disclosed are arrays of engineered skin tissues and methods of making engineered skin tissues.