Penetration of caffeine into two different 3D epidermal models as measured by raman spectroscopy. The model with improved barrier function shows a lower concentration of caffeine at all depths within the epidermis.


Expression of the differentiation marker DSG3 (green) is evident at the cell borders following 5 days of differentiation.

Barrier Function and Differentiation

The development of an effective barrier is the most important result of keratinocyte differentiation.

The newest method for evaluating barrier function is raman spectroscopy. Using this method, the penetration of contrasting hydrophilic and hydrophhobic test compounds can be evaluated in the epidermis at 4 um increments.

In comparison with crude traditional methods, raman spectroscopy is both faster, and also delivers a detailed penetration profile that spans the entire epidermis (see image at left).

Kerationcyte differentiation

To complement an overall functional view of barrier function, it is also possible to evaluate the expression of specific differentiation markers in either 2D or 3D culture.

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