Stratum corneum lipid and protein matrix (SC matrix) (SC matrix)

The stratum corneum (SC) lipid and protein matrix is the outermost layer of the human skin, serving as the primary interface between the body and the external environment (Elias, 1983, PMID: 6340205). It is organized according to the "brick and mortar" model, where protein-rich, non-viable corneocytes are embedded within a continuous extracellular matrix of lipid lamellae (StatPearls, "Physiology, Stratum Corneum"). The lipid component consists of a precise mixture of ceramides, cholesterol, and free fatty acids, which are essential for maintaining the epidermal permeability barrier and preventing transepidermal water loss (TEWL) (PubMed, PMC2847047). The protein component includes keratin filaments and filaggrin, which provide structural integrity and degrade into natural moisturizing factors (NMF) to maintain hydration (UniProt, P04106). In pathological states such as atopic dermatitis or psoriasis, the composition and organization of this matrix are disrupted, leading to barrier dysfunction and increased susceptibility to inflammation and infection (PubMed, PMC3107870). Therapeutic strategies targeting this matrix include the application of barrier-repair emollients to restore lipid balance and the use of keratolytic agents to manage hyperkeratotic conditions (Journal of Clinical and Aesthetic Dermatology, 2014). Additionally, the SC matrix is a major focus in transdermal drug delivery, where chemical enhancers are used to temporarily modify its structure to allow drug penetration (PubMed, PMC3835183).

Other names

Skin barrierEpidermal permeability barrierHorny layer matrixBrick and mortar model of the skin

Restoration of the epidermal permeability barrier through physiological lipid replenishment, osmotic hydration of corneocytes, and enzymatic modulation of corneodesmosome degradation.