In biomedicine fields, biofouling can easily occur on devices such as sensors and catheters, causing some iatrogenic infections, which menace the lives and health of patients greatly. Therefore, it is of great significance to solve the problems of bacterial infection on the surfaces of medical devices. In this paper, "selfdefensive" and antifouling zwitterionic hydrogel coatings were prepared by network interpenetration of the hydrogel and the polymeric substrates. The zwitterionic polysulfobetaine methacrylate (PSBMA) hydrogel coatings resisted most of the bacteria to adhere on the substrates. When a few bacteria were lucky to escape the antifouling defense and adhered to the coatings, gentamicin sulfate (GS) would be released under the trigger of a weakly acidic environment caused by bacterial metabolism to kill these bacteria. Simultaneously, the coatings of the bacteria-adhering sites would be degraded by hyaluronidase secreted by these bacteria and peeled off to remove the bacteria and renew the antifouling surfaces. The antifouling properties and mechanism of the self-defensive behavior of the hydrogel coatings on polymeric substrates were investigated. Furthermore, the in vitro and in vivo antibacterial performances, as well as the biocompatibility of the coatings, were demonstrated. The results suggested that the self-defensive antifouling zwitterionic hydrogel coatings hold great potential to be used on the surfaces of polymeric medical devices.
It is well known that superhydrophobic surfaces (SHSs) possess self-cleaning ability, either by impacting or rolling water droplets or by self-propelled jumping condensate. However, contaminants that are present in the air are various. Is it possible that these contaminants can all be removed from SHSs by jumping condensate? In this study, hydrophilic SiO 2 micro-or nanoparticles with diameters larger than, comparable to, and smaller than the width of the nanogaps of the SHS were first filled in the nanogaps or suspended on the nanostructures with the help of ethanol, and the resulting SHS was exposed to condensing water vapor. Direct observation through microscopy showed that jumping condensation was still obvious on the SHS that were capped or filled with micro-or nanoparticles. Scanning electron microscopy (SEM) imaging demonstrated that following jumping condensation, particles that possessed diameters significantly smaller or larger than the width of the nanogaps were both removed from the SHS. However, most particles possessing diameters comparable to the width of the nanogaps remained on the SHS. This confirms for the first time that not all contaminants or dust can be removed from an SHS by self-propelled jumping condensate. Furthermore, the study also simply demonstrates that vapor condensation occurs within the nanogaps of the SHS. This study is helpful in further understanding the mechanism of the selfcleaning caused by jumping condensate and exploring the initial formation of condensate droplets on the SHS.
Long-term recurrent infections are one of the significant reasons why chronic diabetic wounds are difficult to heal, and the treatment of chronic wounds remains a major clinical challenge. In this work, we developed a kind of Janus hydrogel dressing capable of adjusting the complex microenvironment of wounds for promoting the healing of diabetic chronic wounds. The Janus hydrogel dressings are made of zwitterionic polymers and gentamicin sulfate-modified hyaluronic acid (HA-GS). One side of the hydrogel dressings was brushed with chitosan to act as a bridge between wound dressings and wound tissues. Thus, the wound dressings showed Janus properties with an antifouling surface on one side and an adhesive surface on the other, where the antifouling surface of zwitterionic hydrogels can avoid the adhesion of external bacteria, while the adhesive surface helps the dressings to be fixed on the wound. Moreover, the antibiotic GS was connected to HA through Schiff's base, and thus it can be intelligently released in response to the acidic environment of infected wounds to kill the internal bacteria. The Janus hydrogel dressings were carefully characterized and investigated. In vivo results of a diabetic rat infected wound model showed that the Janus hydrogel dressings could effectively inhibit inflammation, accelerate the formation of granulation tissues and collagen deposition, and promote wound healing. Therefore, this multifunctional hydrogel dressing is a promising candidate for chronic wound healing in clinical practice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.