RETRACTED ARTICLE: A pH/enzyme dual responsive PMB spatiotemporal release hydrogel promoting chronic wound repair

Abstract

Suppressing persistent multidrug-resistant (MDR) bacterial infections and excessive inflammation is the key for treating chronic wounds. Therefore, developing a microenvironment-responsive material with good biodegradability, drug-loading, anti-infection, and anti-inflammatory properties is desired to boost the chronic wounds healing process; however, using ordinary assembly remains a defect. Herein, we propose a pH/enzyme dual-responsive polymyxin B (PMB) spatiotemporal-release hydrogel (GelMA/OSSA/PMB), namely, the amount of OSSA and PMB released from GelMA/OSSA/PMB was closely related the wound pH and the enzyme concentration changing. The GelMA/OSSA/PMB showed better biosafety than equivalent free PMB, owing to the controlled release of PMB, which helped kill planktonic bacteria and inhibit biofilm activity in vitro. In addition, the GelMA/OSSA/PMB exhibited excellent antibacterial and anti-inflammatory properties. A MDR Pseudomonas aeruginosa caused infection was effectively resolved by the GelMA/OSSA/PMB hydrogel in vivo, thereby significantly boosting wound closure during the inflammatory phase. Furthermore, GelMA/OSSA/PMB accelerated the sequential phases of wound repair.

Recent advances of hydrogels as smart dressings for diabetic wounds

“…The released PMB binds to the outer membrane of bacteria, ultimately leading to cell death by increasing membrane permeability, which helps inhibit biofilm activity in vitro and promotes diabetic wound healing. 121 Similarly, Zhang and colleagues prepared a pH/glucose-responsive hydrogel for delivering tetracycline using benzeneboric acid groups. 122 To reduce the emergence of resistant bacteria, adding inorganic metal antibiotics and natural extracts to hydrogels is also a common strategy.…”

Hydrogel-based dressings designed to facilitate wound healing

“…162,163 Although insufficient wound inflammation is not commonly observed, excessive inflammation is nearly ubiquitous in chronic wounds, impeding the normal tissue repair of the wound. 164 Consequently, addressing excessive inflammation is crucial for facilitating the wound healing process. As a result, extensive research has been conducted by investigators in the field of anti-inflammatory hydrogels, yielding significant achievements.…”

Recent advances on 3D‐bioprinted gelatin methacrylate hydrogels for tissue engineering in wound healing: A review of current applications and future prospects

“…35 Silver nanoparticles destroy bacteria and accelerate wound healing, which is why they were studied at Jahan's lab. 19 The pH and enzyme-responsive hydrogel for regulated polymyxin B release, developed by Dong et al, promotes healing throughout the inflammatory phase, 36 making it a useful tool in the therapy of chronic wounds. [37][38][39] The angiogenesis and immunological modulation facilitated by Yan et al's surfactinenhanced hydrogel accelerated wound healing in diabetic rats.…”