Assessment of Silver Nanoparticles for Burn Injury Healing in Rats

The present research aims to assess the histological and clinical effects of applying silver nanoparticles (AgNPs) to rats with superficial second-degree burns. A total of 20 male Wistar rats weighing (240 ± 20 gm) have been used, and they were split in a random way into two equal groups: the G1/control group, which received no treatment, and the rest, while the G2/silver group (AgNPs) received treatment with topical application of AgNPs for consequent 7 days. Following general anesthesia, a stainless-steel bar was placed in a boiling water for 15 minutes, creating one circle site on the animal's body to cause second-degree superficial burns. Histological and clinical assessments regarding the wound healing were conducted. According to macroscopic findings, group2(G2) experienced a substantial (p ≤ 0.05) increase in wound contraction compared to G1 in the two groups. Microscopic cells in group1(G1), at day 7, demonstrate the existence of a thick crust over the skin's surface and a sparse amount of stratum basale hyperplasia, along with inflammatory cell infiltration and profuse collagen in the dermis as in addition to hemorrhage and profuse irregular thick collagen. On the fourteenth day, there was a broad incision, sloughing of the epidermal layers, infiltration of the inflammatory cells, and profuse collagen. Mild hyperplasia regarding the epidermal layers in surrounding area, along with the existence of granulation tissue that is characterized through the fibrosis with a thick collagen network, growth of new blood vessels, infiltration of inflammatory cells, primarily macrophages, and fibroblast proliferation. At 21, the epidermal layers reveal incomplete hyperplasia, a narrow incision with profuse granulation tissue, profuse fibrosis with few collagens, and significant infiltration of the inflammatory cells, primarily lymphocytes and macrophages. Stratum basale had undergone certain stratum basale hyperplasia, the epidermal layer has entirely shed, and G2 at seven days exhibits a crusty layer above skin's surface. The tissue is infiltrated by inflammatory cells, notably lymphocytes and macrophages, although little granulation tissue is produced. At 14 days, there is a purulent discharge and a thick crust above the skin's surface, and the stratum basale has only incompletely and mildly hyperplized. Hemorrhage, the appearance of granulation tissue, and the creation of a new B.V. are also present, as well as an infiltration of inflammatory cells, primarily lymphocytes and macrophages, a thin collagen network, and fibroblast growth in the dermis. The epidermal layer had completely epithelized and developed a keratinized layer following 21 days. The growth of new blood vessels, RBCs, hair follicles, a thin collagen network, and fibroblast proliferation are also present, along with abundant and frequent fibrosis. The use of AgNP in treating rats with superficial 2nd-degree burns was observed to enhance the healing process and speed up proliferation, wound contraction, and complete healing in less time.