The Impact of Prolonged Inflammation on Wound Healing

Abstract

The treatment of chronic wounds still challenges modern medicine because of these wounds’ heterogenic pathophysiology. Processes such as inflammation, ischemia and bacterial infection play major roles in the progression of a chronic wound. In recent years, preclinical wound models have been used to understand the underlying processes of chronic wound formation. However, the wound models used to investigate chronic wounds often lack translatability from preclinical models to patients, and often do not take exaggerated inflammation into consideration. Therefore, we aimed to investigate prolonged inflammation in a porcine wound model by using resiquimod, a TLR7 and TLR8 agonist. Pigs received full thickness excisional wounds, where resiquimod was applied daily for 6 days, and untreated wounds served as controls. Dressing change, visual documentation and wound scoring were performed daily. Biopsies were collected for histological as well as gene expression analysis. Resiquimod application on full thickness wounds induced a visible inflammation of wounds, resulting in delayed wound healing compared to non-treated control wounds. Gene expression analysis revealed high levels of IL6, MMP1 and CD68 expression after resiquimod application, and histological analysis showed increased immune cell infiltration. By using resiquimod, we were able to show that prolonged inflammation delayed wound healing, which is often observed in chronic wounds in patients. The model we used shows the importance of inflammation in wound healing and gives an insight into the progression of chronic wounds.

Preparation of Recombinant Human Collagen III Protein Hydrogels with Sustained Release of Extracellular Vesicles for Skin Wound Healing

“…Since 60 μg/mL EVs exhibited a more obvious effect in promoting cell proliferation, this concentration was selected for subsequent cell-function testing. Long-term inflammation plays a major role in defective wound healing and the development of chronic wounds [ 31 ]. M1 phenotype macrophages mainly play a pro-inflammatory role.…”

Ga3+ loaded radiation crosslinked gel-Alg-CMC hydrogels for promoting diabetic wound healing

“…Frequent chronic wounds are often accompanied by microbial infections, and these infections trigger a persistent inflammatory response, 1 which leads to wound deterioration and prolonged separation. 2 Most notably, the biofilm 3,4 that forms on the wound surface prevent the penetration of antibiotics, 5 protects potential microorganisms from treatment, 6 and promotes the development of drug-resistant bacteria, 3 which have been shown to be present in more than 90% of diabetic chronic wounds. 7,8 Therefore, in the case of skin breakage, bacteria are more likely to invade the organism through the wound and there is a great need for a suitable antimicrobial dressing to manage the wound.…”

Microcurrent and Gold Nanoparticles Combined with Hyaluronic Acid Accelerates Wound Healing

“…Currently, the prevalence of non-healing wounds in developed countries is 1 to 2%, and this rate is significantly increased in underdeveloped countries. However, this problem affects the population in general and constitutes a public health problem due to high treatment rates and costs [ 1 , 2 , 3 ]. A wound is any injury that disrupts the structure of living tissue [ 4 ], and skin restoration involves the complex organization of diverse cell types, chemokines, and growth factors [ 5 ].…”