The Significant Potential of Simonkolleite Powder for Deep Wound Healing under a Moist Environment: In Vivo Histological Evaluation Using a Rat Model

In the present work, simonkolleite powder consisting of Zn-5(OH)(8)Cl-2 center dot H2O composition was proposed as a new candidate material for the healing of deep wounds in a moist environment. The powder was synthesized using a solution process and evaluated for wound-healing effects in rats. The pH value of physiological saline at 37 degrees C using the simonkolleite powder was 7.27, which was the optimal pH value for keratinocyte and fibroblast proliferation (range: 7.2-8.3). The amount of Zn2+ ions sustainably released from simonkolleite powder into physiological saline was 404 mmol/L below cytotoxic ion concentrations (<500 mmol/L), and the rhombohedral simonkolleite was accordingly converted to monoclinic Zn-5(OH)(10)center dot 2H(2)O. To evaluate the wound-healing effect of simonkolleite powder, the powder was applied to a full-thickness surgical wound reaching the subcutaneous tissue in the rat's abdomen. The histological analysis of the skin tissues collected after 1, 2, and 4 weeks found that angiogenesis, collagen deposition, and maturation were notedly accelerated due to the Zn2+ ions released from simonkolleite powder. The simonkolleite regenerated collagen close to autologous skin tissue after 4 weeks. The hair follicles, one of the skin appendages, were observed on the regenerative skin in the simonkolleite group at 4 weeks but not in the control group. Therefore, simonkolleite was hypothesized to stimulate the early regeneration of skin tissue in a moist environment, compared with commercial wound dressing material. These results suggested that simonkolleite could offer great potential as new wound dressing material.