Carboxymethyl chitosan hydrogel formulations enhance the healing process in experimental partial-thickness (second-degree) burn wound healing

Abstract

Purpose This study aimed to elaborate a hydrogel constituted by carboxymethyl chitosan (CMC), hyaluronic acid (HA) and silver (Ag) and to evaluate its healing effect on partial-thickness burn wounds experimentally induced in rats. Methods CMC was obtained by chitosan reacting with monochloroacetic acid. The carboxymethylation was confirmed by Fourier-transform infrared spectroscopy and hydrogen nuclear magnetic resonance (NMR). Scanning electron microscopy was used to determine the morphologicalcharacteristics of chitosan and CMC. After the experimental burn wound induction, the animals (n = 126) were treated with different CMC formulations, had their occlusive dressings changed daily and were followed through 7, 14 and 30 days. Morphometric, macroscopic and microscopic aspects and collagen quantification were evaluated. Results Significative wound contraction, granulation tissue formation, inflammatory infiltration and collagen fibers deposit throughout different phases of the healing process were observed in the CMC hydrogels treated groups. Conclusions The results showed that, in the initial phase of the healing process, the most adequate product was the CMC/HA/Ag association, while in the other phases the CMC/HA association was the best one to promote the healing of burn wounds.

Fungal Carboxymethyl Chitosan-Impregnated Bacterial Cellulose Hydrogel as Wound-Dressing Agent

“…The first stage of weight loss up to 100 °C is due to retained water dehydration. The second stage of weight loss in the range between 130–230 °C, due to the decomposition of the polymer, and the third stage of thermal decomposition of the polymer structure, might be attributed to weight loss from 250 to 400 °C [ 21 , 23 ]. The difference in the weight loss of the pure BC and CMCS–BC hydrogels for formulations of 0.1CMCS–BC, 0.3CMCS–BC, 0.5CMCS–BC, 0.7CMCS–BC, and 1CMCS–BC % calculated as 8.5, 10.77, 20.9, 18.5, and 16.2% respectively.…”

Hydrogel-based dressings in the treatment of partial thickness experimentally induced burn wounds in rats

“…While Solosite™ treatment induced less fibroblasts than the control and Dersani™, Safgel™ has in its formulation compounds that have the potential to leave the wound bed moist, controlling exudate and favoring ion exchange, oxygenation, and nutrients. It is believed that this effect provided better granulation tissue than Debrigel™ and Solosite™ 13,16,24 . Some studies describe that, after adding hydrogel, silver sulfadiazine provided greater angiogenesis and re-epithelialization in comparison to silver sulfadiazine used alone 18,19,40,43 .…”

“…Regarding the collagen quantification, in the inflammatory phase, the treatment of the wounds should induce greater production of type III collagen. This type of collagen is commonly found in soft tissues, such as blood vessels, dermis and fascia, whereas granulation tissue has the potential to express 30 to 40% of type III collagen, which is considered a more immature collagen tissue, i.e., found at the beginning of the healing process 18,24,33 . The hydrogel-based dressings had the potential to present and activate mechanisms that induced the production of type III collagen fibers 18,24,33 .…”

“…This type of collagen is commonly found in soft tissues, such as blood vessels, dermis and fascia, whereas granulation tissue has the potential to express 30 to 40% of type III collagen, which is considered a more immature collagen tissue, i.e., found at the beginning of the healing process 18,24,33 . The hydrogel-based dressings had the potential to present and activate mechanisms that induced the production of type III collagen fibers 18,24,33 . Thus, at this phase of the healing process, the products with hydrogel induced more collagen fibers than the NaCl 0.9% and silver sulfadiazine control groups.…”

“…The animals in the control groups (G1 -control with NaCl 0.9% -; and G2 -control treated with 1% silver sulfadiazine) received daily occlusive and sterilized dressings. The animals in the silver sulfadiazine group received a uniform and thin layer of the product (1 mm), sufficient to cover the wound bed 24 . The dressings of the animals treated with the products Debrigel™, Safgel™, Dersani Hidrogel™ and Solosite™ were evaluated daily and had the dressings changed every two days, taking into account the specifications of the manufacturers.…”