Nanoparticle-functionalized dressings for the treatment of third-degree skin burns – histopathological and immunohistochemical study

Abstract

Skin burns are one of the most common injuries associated with increased morbidity and mortality, especially in the children and the elderlies. Severe burns, especially, result in a systemic immune and inflammatory response, which may reflect in multiple organ insufficiency, and a fast and effective local restorative process is essential for functionality recovering, as well as for interrupting the generalized systemic response. We have aimed here to assess the effect of different wound dressings in what it regards the morphology and clinical restoration after a skin burn. On a rat animal model, we have evaluated the macroscopic and histopathological features of controlled third degree skin burns in control animals versus treatments with local dressings of silver sulfadiazine (SDA) cream, simple gel (G), gel + silver nanoparticles (AgNPs) (G+NPS), gel + exosomes (G+EXO) and gel + AgNPs + exosomes (Gel+NPS+EXO), at 14 days and, respectively, 21 days after the lesion. Tissue fragments were harvested and processed for histopathology and immunohistochemistry. Immunofluorescence was utilized to evaluate the maturity of underlaying granulation tissue based on double stainings for smooth muscle actin (SMA) and cluster of differentiation 31 (CD31). Our study showed variability in what it regards the vessel density and immunoexpression of SMA between the treatments, and image analysis revealed that most SMA reduction and blood vessel density reduction in the maturing granulation tissue occurred for the G+NPS and G+NPS+EXO treatments. A complete re-epithelization was also observed for the G+NPS+EXO treatment. Overall, our results show that improved topic treatments promote faster re-epithelization and reparation of the dermis after skin burn lesions, providing thus an avenue for new treatments that aim both local recuperation and systemic infection prevention.

Evaluation of the Wound Healing Potential of Cynara humilis Extracts in the Treatment of Skin Burns

“…In contrast, the collagen fibers in the control group were arranged obliquely and loosely. Angiogenesis is one of the most researched processes in a burnt wound [ 41 ].…”

Treatment of skin defects with PRP enriched with hyaluronic acid – histological aspects in rat model

“…Numerous studies have shown that after skin injury, monocytes gather on the wound surface and differentiate into macrophages, which subsequently perform phagocytosis to remove damaged cells and tissues, promote angiogenesis, and skin re-epithelialization. They play a key role in the initiation and resolution of inflammatory responses in both acute and chronic injuries [ 36 , 37 , 38 , 39 , 40 ].…”

Mesenchymal stem cell-derived extracellular vesicles in skin wound healing: roles, opportunities and challenges

“…This action restores the functions of the epidermal permeability barrier by promoting the differentiation of keratinocytes and facilitating the de novo synthesis of ceramides [ 117 ]. EV treatment improved trauma recovery by epidermal stratification after burn injury [ 137 ] and enhanced epidermal re-epithelialization [ 98 ]. Interestingly, EVs reduced the proportion of epidermal stratification and ameliorated skin photodamage in a rat model of photoaged skin [ 119 ].…”

“…The collagenous fibers, fibroblasts, arteries, and nerves that are abundant in the dermis provide strength, nutrition, and sensation to the skin [ 4 , 136 ]. MSC-derived EVs enhance the amount of new dermis at the trauma surface [ 114 , 119 ] and promote granulation tissue maturation and epidermal basement membrane structuring in burn wounds [ 137 ]. This process also inhibits the formation of hyperplastic scars and keloids through the miR-192-5p/interleukin (IL)-17RA/Smad axis and promotes dermal regeneration [ 105 , 114 ].…”