Inspired by the Periodontium: A Universal Bacteria-Defensive Hydrogel for Preventing Percutaneous Device-Related Infection

Abstract

Percutaneous device-related infection has greatly shortened the service period of devices and seriously reduced the quality of life of patients. Bacteria are one of the main pathogenic factors and cannot be effectively and conveniently eradicated by traditional strategies (e.g., construct coatings and introduce antibiotics), due to the complex interface among medical devices, surrounding tissue, and colonizing bacteria. Inspired by the periodontium, a universal bacteria-defensive hydrogel adapting to the complicated interface is fabricated by introducing phenol-amine chemistry to a polymeric matrix of N-hydroxyethyl acrylamide (HPC hydrogels). The HPC hydrogels with excellent toughness (2.1 MJ/m3), adhesion (10.2 and 13.2 kPa for pigskin and Ti-6Al-4V alloy, respectively), and antibacterial property (up to 99.9% for both Escherichia coli and Staphylococcus aureus) contributed to the innate microbe barrier via sealing the tissue–device interface and adaptive defense to eradicate bacteria. Meanwhile, bacterial invasion experiments demonstrate HPC hydrogels possess both a bacteria-defensive property (up to 24 h) and cell-protecting function at the same time. Furthermore, the biocompatibility of HPC hydrogels is verified in tests for in vitro cytotoxicity and in vivo irritation. Hence, the designed HPC hydrogels are considered as an emerging and universal candidate for preventing bacterial infection and can protect the deep tissue around a percutaneous device.

Metal‐free Fabrication of Nitrogen‐doped Vertical Graphene on Graphite Felt Electrodes with Enhanced Reaction Kinetics and Mass Transport for High‐performance Redox Flow Batteries

“…The C 1s peaks are deconvoluted into C = C/C‐C (284.4 eV), C‐O/C‐N (285.3 eV), C = N (286.0 eV), and C = O (287.2 eV) bonds and the O 1s peaks are deconvoluted into C‐O (531.8 eV), C = O (533.7 eV) bonds (Figure 3f,g). Additionally, the N 1s spectrum of the NVG@GF (Figure 3h)is deconvoluted into three primary peaks with binding energies of 398.9, 400.0, and 401.0 eV, [ 35,36 ] respectively, corresponding to pyridinic N, pyrrolic N, and graphite N. The content of the N element is up to 2.91at% (Table S1, Supporting Information), specifically, the ratio of pyridinic N, pyrrolic N, and graphite N are 23.88%, 62.36%, and 13.76%, respectively, of which the high‐content of pyridinic N and pyrrolic N are believed to be able to improve the electrochemical activity effectively. [ 37 ] Moreover, the DFT calculations also indicate that the pyridinic N and pyrrolic N sites exhibit strong adsorption of vanadium ions, which can further prove that N‐doped is beneficial to the catalytic activity.…”

Modification mechanism of modified diatomite with flexible amine‐based structure as a filler of epoxy resin and mechanical properties and curing kinetic of composites

“…Consequently, the percentage of the total area of the C spectrum after peak splitting substantially increased. Moreover, the C1 content decreased, whereas the C2 content increased, indicating that a CN bond was generated 31 …”

“…Moreover, the C1 content decreased, whereas the C2 content increased, indicating that a C N bond was generated. 31…”

Sea Cucumber‐Inspired Aerogel for Ultrafast Hemostasis of Open Fracture

“…[ 11,48 ] The CS‐GA contained in GCG‐4H not only has the inherent broad‐spectrum antibacterial properties of chitosan itself, but also contains pyrogallol groups that GA can chelate with Cu 2+ , which enhances the antibacterial property of the aerogel and can effectively deal with the risk of infection in open fractures. [ 18 ] According to the results of plate counting experiments, the aerogel had a surprising inhibitory effect on S. aureus and E. coli , and almost all the bacteria inoculated in the aerogel showed obvious structural damage and death (Figure 6C). Although common clinical commercial hemostatic materials such as medical gauze and gelatin sponge can play a certain role in hemostasis in emergency treatment.…”

“…[ 17 ] The organic component of the composite aerogel is cross‐linked to gelatin and gallic acid‐modified chitosan (CS‐GA), and the pyrogallol groups in CS‐GA not only provide excellent antibacterial properties but also a binding site for metal ions. [ 18 ] In this study, we used metal–polyphenol interactions to bind the pyrogallol groups of CS‐GA to copper ions to achieve a synergistic antibacterial effect in response to the antimicrobial demand of bone trauma during environmental exposure. [ 19 ] At the same time, the aerogel contains a certain inorganic component, nanohydroxyapatite (nHA), which is used to improve the rapid hemostasis efficiency of the aerogel, but also is expected to improve the osteogenic activity of the aerogel for bone regeneration as a traditional bone tissue engineering material.…”