New heparinizable modified poly(carbonate urethane) surfaces diminishing bacterial colonization.
Percutaneous devices are extensively used in modern medicine therapies, even in long term applications. Complications from their use, related to bacterial colonization and/or to materials thrombogenicity, may result in a significant morbidity and mortality incidence. In this study, a novel polycarbonate-urethane (PCU), incorporating a tailor-made diamino-diamide-diol (PIME) showing the ability to bind heparin at physiological pH, was compared to commercial medical-grade PCUs (Carbothane and Bionate). Mechanical and thermal properties were evaluated by tensile tests, dynamic mechanical analysis and differential scanning calorimetry. The presence of a low amount of PIME chain extender in Bionate polyurethanes (Bionate-PIME) slightly affects the mechanical properties, remaining however comparable with the medical grade PCUs used for the fabrication of cardiovascular devices. To verify thereof heparin surface adsorbed in disfavouring bacterial colonization, heparinized Bionate-PIME was tested for bacterial adhesion, using Bionate and Carbothane as reference. In vitro bacterial interaction tests were performed with the strains mainly involved in the pathogenesis of device-related infections (S. epidermidis and S. aureus). MTT tests and SEM observations showed a decrease in colonization of the different strains on the heparinized Bionate-PIME surfaces, confirming that preadsorbed heparin plays a role in mediating the biomaterial surface/bacterial cells interactions.
BioMatLab, Bioengineering Department, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy. luigi.denardo@polimi.it
Luigi
L
De Nardo
Silvia
S
Farè
Valentina
V
Di Matteo
Eliana
E
Cipolla
Enrica
E
Saino
Livia
L
Visai
Pietro
P
Speziale
Maria Cristina
MC
Tanzi
D001422:Bacterial Adhesion / Q000187:drug effects*; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D015169:Colony Count, Microbial; D006493:Heparin / Q000737:chemistry*; D008422:Materials Testing; D050296:Microbial Viability / Q000187:drug effects*; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D011076:Polycarboxylate Cement / Q000737:chemistry / Q000494:pharmacology*; D040141:Staphylococcaceae / Q000187:drug effects / Q000254:growth & development; D013499:Surface Properties; D014520:Urethane / Q000737:chemistry / Q000494:pharmacology*
D020099:Coated Materials, Biocompatible; D011076:Polycarboxylate Cement; C005506:polycarbonate; D014520:Urethane; D006493:Heparin