The use of ultra-thin films as dressings for cutaneous
wounds could prove advantageous in terms of better conformity to
wound topography and improved vapour transmission. For this purpose, ultra-thin
poly(epsilon-caprolactone) (PCL) films of 5-15 microm thickness were fabricated via a biaxial stretching technique. To evaluate their in vivo biocompatibility and feasibility as an external
wound dressing, PCL films were applied over full and partial-thickness
wounds in rat and pig models. Different groups of PCL films were used: untreated, NaOH-treated, untreated with
fibrin, NaOH-treated with perforations, and NaOH-treated with
fibrin and
S-nitrosoglutathione.
Wounds with no external dressings were used as controls.
Wound contraction rate, histology and biomechanical analyses were carried out.
Wounds re-epithelialized completely at a comparable rate. Formation of a neo-dermal layer and re-epithelialization were observed in all the
wounds. A lower level of
fibrosis was observed when PCL films were used, compared to the control
wounds. Ultimate tensile strength of the regenerated tissue in rats reached 50-60% of that in native rat skin. Results indicated that biaxially-stretched PCL films did not induce inflammatory reactions when used in vivo as a
wound dressing and supported the normal wound healing process in full and partial-thickness
wounds.