Wound-Healing Potential of Cultured Epidermal Sheets Is Unaltered after Lyophilization: A Preclinical Study in Comparison to Cryopreserved CES

Abstract EN

Lyophilized Cultured Epidermal Sheets (L-CES) have been reported to be as effective as the cryopreserved CES (F-CES) in treating skin ulcers.

However, unlike F-CES, no preclinical study assessing wound-healing effects has been conducted for L-CES.

The present study was set out to investigate the microstructure, cytokine profile, and wound-healing effects of L-CES in comparison to those of F-CES.

Keratinocytes were cultured to prepare CES, followed by cryopreservation at −70°C and lyophilization.

Under microscopic observation, intact cells with apparent intracellular junctions were observed in L-CES.

The L-CES, like fresh CES, consisted of three to four well-maintained epidermal layers, as shown by the expression of keratins, involucrin, and p63.

There were no differences in the epidermal layer or protein expression between L-CES and F-CES, and both CES were comparable to fresh CES.

TGF-α, EGF, VEGF, IL-1α, and MMPs were detected in L-CES at levels similar to those in F-CES.

In a mouse study, wounds treated with L-CES or F-CES completely healed at least 4 days faster than untreated wounds.

CES-treated wounds completely healed by day 10, while the untreated wounds did not heal by day 14.

Masson’s trichrome staining showed that collagen deposition in the CES-treated wounds was highly increased in the dermis of the wound center compared to that in the control wounds.

Thus, this study demonstrates that L-CES is as clinically effective as F-CES for wound treatment.