Fully Human Skin Model (FDM)
The full thickness fibroblast-derived matrix (FDM) model provides you with a healthy, living human epidermis and dermis of full human origin. Biomimiq’s FDM can be used for many research and screening purposes requiring the full functionality of human skin, including dermal skin conditions, epidermal-dermal interactions, skin aging and long-term efficacy studies. In addition, Biomimiq’s FDM can be customized to answer your specific research questions. For example, FDMs can be generated with specific epidermal keratinocytes and dermal fibroblasts of your choice.
Dermal and epidermal cell types
The fibroblast-derived matrix (FDM) skin model is generated by culturing primary normal human epidermal keratinocytes air-exposed on a primary human fibroblast-derived dermal matrix. The resulting skin model is of full human origin and has superior resemblance to native skin. Also, a variety of epidermal and dermal cells can be cultured in the FDM to study a specific functional human skin response.
Normalized stratification and proliferation
Like healthy human skin, the epidermis of Biomimiq’s FDM models consists of about seven epidermal cell layers. The FDM epidermis displays normal stratification into a basal layer (stratum basale), spinous layer (stratum spinosum), granular layer (stratum granulosum) and outer corneal layer (stratum corneum). Proliferation rates in Biomimiq’s fibroblast-derived matrix (FDM) models are normalized in vitro: approximately 10-15% of the basal epidermal cells are in a proliferative state.
Fibroblast-derived matrix (FDM) models are cultured in vitro with a normal epidermal differentiation pattern. Basal epithelial markers (e.g. keratin 15) are restricted to the basal layer of the epidermis. Early differentiation (e.g. keratin 10) is restricted to the suprabasal layers, whereas terminal differentiation (e.g. loricrin, involucrin) is found exclusively in the subcorneal granular layers of the epidermis. Epidermal activation and stress-related proteins (e.g. keratin 17) are not present in FDMs, reflecting their normalized and non-activated
state in vitro.
Fibroblast-derived matrix (FDM) models represent the human skin to the fullest, including functional basement membrane proteins (e.g. laminin 332, collagen type VII). Also on the ultrastructural level, the basement membrane of FDM models resembles that of native human skin. Transmission electron microscopy recordings reveal that the human fibroblasts in FDM models synthesize new collagen fibers and that the dermal–epidermal junctions exhibit a continuous basement membrane with lamina lucida, lamina densa, regular hemidesmosomes and anchoring fibers.
Healthy fibroblast-derived matrix (FDM) models can be cultured air-exposed for up to 20 weeks. This distinguishes Biomimiq’s FDM models from other healthy full thickness models commercially available. The epidermis of FDM models stabilizes at 5 viable cell layers from the 13th week of air-exposed culture, whereas general healthy full thickness models (FTMs) cannot be cultured air-exposed as a viable skin in vitro beyond 8 weeks. After 6 weeks, epidermal proliferation of FDMs stabilizes at 5% of basal cells. Application of compounds or treatments can be initiated during any culture phase relevant to the compound or treatment, including the entire air-exposed culture phase up to 20
weeks, enabling long-term studies.