Biomedical evaluation of a novel nitrogen oxides releasing wound dressing

Abstract

Chronic wounds are a major cause for both suffering and economical losses. Management of chronic non-healing wounds requires multipronged approach. They are polymicrobial and agonizing for the patient due to associated pain. Moist dressing providing antimicrobial action is a highly desirable chronic wound management option. Here we report a hydrogel based dressing that possesses the antimicrobial properties of acidified sodium nitrite and the homeostatic property of a hydrogel. The dressing was developed by combining citric acid cross-linked cotton gauze and sodium nitrite loaded gelatin. The cotton gauze was cross-linked with citric acid by pad-dry-curing in presence of nano-titania catalyst. The cotton gauze-gelatin hydrogel combination was gamma-irradiated and freeze-dried. At the time of application, the freeze-dried dressing is wetted by sodium nitrite solution. The dressing has a fluid uptake ability of 90 % (w/v) and the water vapour evaporation rate was estimated to be 2,809 ± 20 g/m(2)/day. The dressing showed significant antimicrobial activity against both planktonic and biofilm forms and was effective during consecutive re-uses. Cytotoxicity study showed inhibition of fibroblasts, but to a lesser extent than clinically administered concentrations of antiseptic like povidone iodine. Storage at 37 °C over a 3 month period resulted in no significant loss of its antimicrobial activity.

Antimicrobial strategies centered around reactive oxygen species – bactericidal antibiotics, photodynamic therapy, and beyond

“…Dave et al . () developed a hydrogel‐based dressing containing citric acid cross‐linked cotton gauze and sodium nitrite loaded gelatin. The dressing showed significant antimicrobial activity against both planktonic and biofilm forms and was effective during consecutive reuses.…”

Nitric Oxide Therapy for Diabetic Wound Healing

“…This facile generation of NO allows for localized treatment, with salts like sodium nitrite easily incorporated into creams and ointments. While nitrite applied by itself to a wound would interact with basal acidic species to produce NO, it is most effective to provide acidic coreactants to assure complete conversion of nitrite to NO . Two creams combined on the skin, one incorporating sodium nitrite and the other an acidic agent, usually citric or ascorbic acid, will immediately generate NO.…”

A high efficacy antimicrobial acrylate based hydrogels with incorporated copper for wound healing application

“…The fluid loss can be compensated by absorption of exudates from the wound into the dressing, for example during the early stage of exudating of a wound. On the contrary, if the dressing has to be used on dry wounds, then it should be wetted at regular intervals by normal saline or sterile water [40].…”