Thermoresponsive and Self-Healing Hydrogel Based on Chitosan Derivatives and Polyoxometalate as an Antibacterial Coating

Abstract

Hospital-acquired infections are a serious threat to the recovery of patients. To prevent such infections, an antibacterial coating is an effective method to eliminate bacterial colonization on healthcare-related surfaces. Herein, we report an antibacterial hydrogel composed of silver-containing polyoxometalate (AgP5W30 POM) and carboxymethyl chitosan (CMC). The silver ion is encapsulated inside the POM cage and demonstrates long-lasting bacteriostasis after repeated exposure to both Gram-positive and Gram-negative bacteria. The chemical structure of chitosan derivatives, as well as the concentration and pH, is studied to tune the mechanical properties of the hydrogel. The hydrogel undergoes a gel–sol transition above the critical temperature and possesses self-healing ability. This hydrogel can be readily coated on the surface of versatile bulk materials, which is especially convenient for porous objects and resists the growth of Staphylococcus aureus, Escherichia coli, and methicillin-resistant S. aureus (MRSA). In summary, we envision that the AgP5W30-CMC hydrogel has great potential to serve as an antibacterial coating to decrease the prevalence of hospital-acquired infections.

Polyoxometalate‐Containing Supramolecular Gels

“…[125] As a classical matter, silver ion is enwrapped into a POM to form [AgP 5 W 30 O 110 ] 14− (AgP 5 W 30 ), which is further used to combine with chitosan derivatives, generating hydrogels. [126] The chemical substitution of chitosan has obvious influence to the gelation ability, and hydrogel comprising of CMC and AgP 5 W 30 possesses the best mechanical performance, which can be modulated by pH or the concentration of the solution. As shown in Figure 16a, the antibacterial behaviors of the AgP 5 W 30 -CMC hydrogel are evaluated on an agar disk.…”

“…SEM images of S.aureus e) before and f) after its co-cultivation with AgP 5 W 30 -CMC hydrogel. Reproduced with permission [126]. Copyright 2022, The American Chemical Society.…”

“Self-Defensive” Antifouling Zwitterionic Hydrogel Coatings on Polymeric Substrates

“…In the infection process of HAIs, bacteria first attach to the surfaces of the materials in a nonspecific binding manner, continuously secrete the extracellular matrix, form bacterial biofilms on the surfaces, and then multiply. , Antibacterial agents such as antibiotics have been usually used to reduce and eliminate infections, but dense biofilms hindered the penetration of antibiotics, resulting in poor antibacterial effects . In addition, the abuse of antibiotics has caused the emergence of dangerous drug-resistant bacteria, which further threaten human health.…”

Biofunctionalization of 3D Printed Porous Tantalum Using a Vancomycin–Carboxymethyl Chitosan Composite Coating to Improve Osteogenesis and Antibiofilm Properties

“…Carboxymethyl chitosan (CCS) possesses good water solubility. It has a lot of amino, carboxyl, and hydroxyl groups that can provides a convenient condition for further modification. , In addition, the carboxymethyl chitosan film can achieve the controlled release of the loaded substance and has a certain antibacterial ability. , For all these advantages, carboxymethyl chitosan has been widely used as a carrier and medium in the preparation of antibacterial coatings on the surface of biomaterials. In this study, we established a positively charged surface by silane coupling on pTa scaffold, which had been alkali heated, and we further immersed the scaffold alternately in carboxymethyl chitosan solution and vancomycin (first-line medication for methicillin-resistant Staphylococcus aureus (MRSA) infection) solution with opposite charge.…”