Superabsorbent crosslinked carboxymethyl cellulose-PEG hydrogel containing a nutgall extract as a broad antimicrobial agent for wound dressing applications

The treatment of chronic wounds encounters major challenges from oxidative stress that results from chronic inflammation and microbial infections. A hydrogel containing an ethanolic extract of Quercus infectoria galls (Qi) Qi ) was developed as a new therapeutic strategy for the treatment of chronically infected wounds. FTIR confirmed the presence of bioactive compounds with 9.42 mg/g gallic acid as revealed by HPLC. Qi hydrogel presented a rough and compact surface with macroporous networks that contributed to an extremely high absorption of wound exudate equivalent to approximately 2300 % of the weight of the hydrogel. The biological activities of Qi hydrogel were compared with those of commercially-available products. According to the kinetic release, the correlation coefficients showed that the hydrogel fitted to the Higuchi model. Qi hydrogel exhibited strong antimicrobial activity against pathogens of clinical importance associated with wound infections. Minimum inhibitory concentrations and minimum bactericidal/fungicidal concentrations ranged from 0.24 to 250 and 3.91 to >250 mg/mL, respectively. In addition, microbial biofilms were significantly inhibited compared with the untreated control (p p < 0.05). At concentrations from 0.78 to 12.5 mg/mL, Qi hydrogel scavenged almost 100 % of DPPH and ABTS radicals and showed a ferric ion reducing power of 443.11 mu M FeSO4/g 4 /g hydrogel by FRAP assay. A biocompatibility assessment of the hydrogel on L929 fibroblast cells confirmed no toxic effects and the hydrogel significantly inhibited lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages (p p < 0.05). The absorbency, permeability, phytochemical compounds and biological activities of Qi hydrogel are suitable properties of a dressing for treating and preventing chronically infected wounds.