title: Novel copper (II) alginate hydrogels and their potential for use as anti-bacterial wound dressings.
abstract: The incorporation of a metal ion, with antimicrobial activity, into an alginate dressing is an attractive approach to minimize infection in a wound. In this work, copper (II) cross-linked alginate hydrogels were successfully prepared using a two-step cross-linking procedure. In the first step, solid alginate films were prepared using a solvent-casting method from soft gels of alginate solutions that had been lightly cross-linked using a copper (II) (Cu(2+)) sulfate solution. In the second step, the films were further cross-linked in a corresponding Cu(2+) sulfate solution using a dipping method to further improve their dimensional stability. Alginate solution (at 2%w/v) and Cu(2+) sulfate solution (at 2%w/v) in acetate buffer at a low pH provided soft films with excellent swelling behavior. An increase in either Cu(2+) ion concentration or cross-linking time led to hydrogels with more densely-cross-linked networks that limited water absorption. The hydrogels clearly showed antibacterial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis and Streptococcus pyogenes, which was proportional to the Cu(2+) ion concentration. Blood coagulation studies showed that the tested copper (II) cross-linked alginate hydrogels had a tendency to coagulate fibrin, and possibly had an effect on pro-thrombotic coagulation and platelet activation. Conclusively, the prepared films are likely candidates as antibacterial wound dressings.
authors.affiliation: The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok 10330, Thailand. The Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Wimonwan
authors.initials: W
authors.lastname: Klinkajon
authors.forename: Pitt
authors.initials: P
authors.lastname: Supaphol
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D047070:Bandages, Hydrocolloid; D001777:Blood Coagulation; D003300:Copper / Q000737:chemistry*; D019327:Copper Sulfate / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D051379:Mice; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013297:Streptococcus pyogenes / Q000187:drug effects; D014945:Wound Healing
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D003432:Cross-Linking Reagents; D006603:Hexuronic Acids; D020100:Hydrogels; D003300:Copper; D020723:Glucuronic Acid; D019327:Copper Sulfate