Antibiofilm properties of silver and gold incorporated PU, PCLm, PC and PMMA nanocomposites under two shear conditions

• Published in: PloS one 2013-05, Vol.8 (5), p.e63311
• Main Authors: Sawant, Shilpa N, Selvaraj, Veerapandian, Prabhawathi, Veluchamy, Doble, Mukesh
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibiotics; Bacteria; Bacterial Adhesion - drug effects; Biofilms; Biofilms - drug effects; Biofilms - growth & development; Biology; Biomedical materials; Biotechnology; Caprolactam - chemistry; Caprolactam - pharmacology; Carbohydrates; Colonies; Contact angle; E coli; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - growth & development; Food; Functional groups; Gold; Gold - chemistry; Gold - pharmacology; Infections; Materials Science; Nanocomposites; Nanocomposites - chemistry; Nanoparticles; Nanoparticles - chemistry; Nanotechnology; Personal computers; Polycarbonate; Polycarbonate resins; Polycarbonates; Polycarboxylate Cement - chemistry; Polycarboxylate Cement - pharmacology; Polymers; Polymethyl methacrylate; Polymethyl Methacrylate - chemistry; Polymethyl Methacrylate - pharmacology; Polymethylmethacrylate; Polyurethane; Polyurethane resins; Polyurethanes - chemistry; Polyurethanes - pharmacology; Shear; Silver; Silver - chemistry; Silver - pharmacology; Solid lubricants; Stress, Mechanical; Studies; Swelling; Transplants & implants
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0063311

Silver and gold nanoparticles (of average size ∼20-27 nm) were incorporated in PU (Polyurethane), PCLm (Polycaprolactam), PC (polycarbonate) and PMMA (Polymethylmethaacrylate) by swelling and casting methods under ambient conditions. In the latter method the nanoparticle would be present not only on the surface, but also inside the polymer. These nanoparticles were prepared initially by using a cosolvent, THF. PU and PCLm were dissolved and swollen with THF. PC and PMMA were dissolved in CHCl₃ and here the cosolvent, THF, acted as an intermediate between water and CHCl₃. FTIR indicated that the interaction between the polymer and the nanoparticle was through the functional group in the polymer. The formation of E.coli biofilm on these nanocomposites under low (in a Drip flow biofilm reactor) and high shear (in a Shaker) conditions indicated that the biofilm growth was higher (twice) in the former than in the latter (ratio of shear force = 15). A positive correlation between the contact angle (of the virgin surface) and the number of colonies, carbohydrate and protein attached on it were observed. Ag nanocomposites exhibited better antibiofilm properties than Au. Bacterial attachment was highest on PC and least on PU nanocomposite. Casting method appeared to be better than swelling method in reducing the attachment (by a factor of 2). Composites reduced growth of organisms by six orders of magnitude, and protein and carbohydrate by 2-5 times. This study indicates that these nanocomposites may be suitable for implant applications.