Evaluation of Papain–Urea for Enzymatic Debridement of Coagulation Zones Following Ablative Fractional Laser Treatment

Background

Ablative fractional CO₂ laser (10,600 nm) treatment creates an array of microscopic treatment zones composed of an ablation zone (AZ) surrounded by a denatured coagulation zone (CZ). The CZ is believed to play a functional role in skin tightening, posttreatment inflammation, and laser-assisted drug delivery. This study investigates the viability of enzymatic post-processing to remove the CZ without affecting the surrounding tissue.

Methods

Ex vivo skin samples were treated with either control, papain, urea, or papain–urea solutions before being covered with occlusive dressing and incubated at 37°C for 1 h. Tissue viability as well as AZ and CZ geometries were assessed histologically.

Results

Treatment with all three experimental solutions resulted in a decrease in CZ. The largest average reduction in CZ area was observed in the papain–urea group (44%, p < 0.001), followed by the papain (14%, p < 0.001) and urea (11%, p < 0.001) only groups. Only the papain–urea group showed a significant increase in AZ (14%) and changes in lesion geometry.

Conclusion

This exploratory study of enzymatic post-processing with papain–urea highlighted the potential of selectively removing the CZ after treatment with ablative fractional laser therapy. If results can be translated to in vivo studies, these findings could expand the use of high-fluence CO₂ laser therapy with functional implications for lowering posttreatment recovery time, providing clinicians more control over skin tightening, and enabling a broader range of laser-assisted drug delivery.