Amniotic membrane as a biological dressing in infected wound healing in rabbits

Abstract

PURPOSE:To investigate amniotic membrane as a biological dressing in infected wound healing in rabbits. METHODS:The use of preserved amniotic membranes (AMs) was examined using 15 rabbits with experimentally induced wound infections on their backs. Healing was histologically evaluated during different phases including inflammation, granulation, epithelialization, and fibroplasia. The animals were distributed into three groups for histological study at seven, 14, 21, and 28 days postwound induction. Group A did not receive treatment: the wound was left exposed and dry; Group B received a daily exposure treatment with collagenase; and Group C received one AM, which also remained exposed. RESULTS:A marked reduction of the inflammatory phase was observed in Group C at 21 days, and the granulation phase of this healing increased at 14 days. Epithelialization was similar among the three groups, and fibroplasia was more pronounced in Group C at 14 days. Furthermore, gradual collagen organization also began for the animals in Group B at 14 days. CONCLUSION:The amniotic membrane did not significantly alter the inflammation, epithelialization, or fibroplasia phases but did increase angiogenesis up to Day 14 compared with the dry dressing and collagenase treatments.

Effects of the application of the amniotic membrane in the healing process of skin wounds in rats

“…It should be emphasized that the use of the HAM has a long history in the treatment of wounds because since the first half of the last century, researchers have been studying its use in the reconstitution of tissue lesions, especially of the skin. In addition, it has been used in ophthalmology and in burns [5][6][7] .…”

“…antigenicity, antimicrobial action, and ability to decrease exudates and adhesions, accelerate epithelization, reduce local pain, and act as a substrate for tissue growth [5][6][7][8] .…”

“…Pre-clinical studies have employed the HAM successfully and showed that its use can accelerate the regeneration of various tissues 5,10,11 . However, only a limited number of studies have investigated its application as biological dressings.…”

“…The HAM has the ability to stimulate skin repair and synthesize essential growth factors and cytokines that promote cell migration, proliferation, and metabolic activity in the cells and tissues [21][22] . It is evident that the repair process had an early initiation in the wounds protected compared with that in the fully exposed wounds because the membrane acts as a biological bandage protecting the injured tissues; this favors local hydration and avoids contamination by microorganisms and contaminated materials 5 .…”

“…Duarte et al 5 reported that in the wound healing process of rats treated with the HAM, a predominance of mature collagen fibers was observed. Vascular formation was more significant in the animals that received the HAM, indicating that even its conservation at lower temperatures does not inactivate proangiogenic substances previously identified in the cryopreserved membrane 26 .…”