Human dermis separation via ultra-short pulsed laser plasma-mediated ablation

Abstract

In vitro layer separation of human dermal tissues via laser plasma-mediated ablation was successfully conducted for the first time. The ablation of wet dermis was generated using a 900 fs ultra-short pulsed laser with the wavelength centred at 1552 nm. The ablation and separation results were imaged and measured by scanning electron microscopy. The dermis ablation threshold was determined as 9.65 ± 1.21 J cm−2 and the incubation factor was found as 0.46 ± 0.03. Histological examinations were performed to find proper laser parameters for dermis ablation and separation with minimal thermal damage. No thermal damage was found in the single line ablation results when the pulse overlap rate was not over 5 pulses µm−1. Even in the multi-line ablation, thermal damage was insignificant and the lateral damage zone was generally within 5 µm in the results with 100 continuously repeated line scans. The separation of a whole piece of wet dermal tissue into two thin layers was presented. Several separation tests with different layer thicknesses from 200 to 600 µm were completed. The unevenness of the separated layers was generally under 10%. The cohesion and morphology of the separated tissue layers were not altered.