Recent Advances in Hydrogel-Mediated Nitric Oxide Delivery Systems Targeted for Wound Healing Applications

Abstract

Despite the noticeable evolution in wound treatment over the centuries, a functional material that promotes correct and swift wound healing is important, considering the relative weight of chronic wounds in healthcare. Difficult to heal in a fashionable time, chronic wounds are more prone to infections and complications thereof. Nitric oxide (NO) has been explored for wound healing applications due to its appealing properties, which in the wound healing context include vasodilation, angiogenesis promotion, cell proliferation, and antimicrobial activity. NO delivery is facilitated by molecules that release NO when prompted, whose stability is ensured using carriers. Hydrogels, popular materials for wound dressings, have been studied as scaffolds for NO storage and delivery, showing promising results such as enhanced wound healing, controlled and sustained NO release, and bactericidal properties. Systems reported so far regarding NO delivery by hydrogels are reviewed.

Polyacrylamide Hydrogel Containing Calendula Extract as a Wound Healing Bandage: In Vivo Test

“…The macrophage is the most important inflammatory cell in this phase and is maintained from the third to the tenth day, along with phagocytes bacteria, debrided foreign bodies and the development of granulation tissue. High phagocytic activity of macrophages was observed after trauma [ 6 ].…”

“…Wound healing for skin wounds is a physiological process that depends on molecular and cellular mechanisms. The process is divided into three phases: the inflammatory, proliferative and remodeling phase [ 3 , 4 , 5 , 6 ]. Acceleration of healing requires the maintenance of wound sterility, pain reduction, elimination of exudate, possibility of gas exchange, ease of handling and reduction in the number of dressing applications [ 7 , 8 ].…”

“…Ideal dressings have the following criteria: providing and maintaining a moist environment, protecting the wound against secondary infections, allowing gas exchange, providing thermal insulation, being free of toxic particles or contaminants, handling excess exudate, being elastic, having a low cost, durability, flexibility and mechanical strength [ 8 , 10 , 11 ]. The main advantage of modern bandages is their ability to retain and build a humid ambient around the injury in order to encourage the cicatrization process [ 6 , 10 , 12 ]. Several skin bandages have been designed using advanced technologies, and are regarded as suitable options, including: fiber bandage wraps, gauze, medical film and hydrogels [ 9 , 10 , 13 , 14 , 15 ].…”

Copper-induced injectable hydrogel with nitric oxide for enhanced immunotherapy by amplifying immunogenic cell death and regulating cancer associated fibroblasts

“…Previous studies including us have developed different kinds of nanoparticles to deliver NO for cancer treatment. However, due to the complex composition of body fluids, NO donor is easily affected by external factors such as metal, pH and temperature, which may have the disadvantages of instability, toxicity, short retention time and low bioavailability [ 39 ]. The injectable, in-situ -forming hydrogels have been widely used to control and sustain release of different bioactive agents, due to their low systemic toxicity and high treatment efficacy.…”

Polymers Enhancing Bioavailability in Drug Delivery

“…The last paper addresses the relevance of treating chronic wounds in view of the significant burden they represent to healthcare systems and their negative impact on patients’ quality of life [ 13 ]. The wound-healing cascade and wound-care strategies, such as debridement and especially wound dressing, are reviewed in detail.…”