Table 5.

Proliferation and differentiation capacity of the epidermal layer was modulated in the tri-layer constructs. The metabolic activity and differentiation capacity of the epidermal region of the tri-layer constructs were studied using immunohistochemical staining for keratin 10, an epidermal differentiation marker. BrdU incorporation was used to document epidermal proliferation. The expression of keratin 10 confirmed the differentiation capacity of the epidermal layers. Unexpectedly, there was higher expression of keratin 10 at earlier time points, and reduced keratin 10 expression at later time points, with similar results for BrdU incorporation. These unexpected results point to the formation of a more biologically relevant epidermal layer.

	Epidermal Marker
	Keratin 10	BrdU
Day5	+++	++
Day9	+++	++
Day11	+	+
Day13	+	+
Day15	+	+
Day18	+	+

(–) means no protein detected, (+/−) means borderline detection, (+) means low protein level, (++) means moderate protein level, and (+++) means high protein level. Levels are representative of n=2 per group.