HIGHLY-STABILIZED NANOPARTICLES ON POLY-L-LYSINE-COATED OXIDIZED METALS: A VERSATILE PLATFORM WITH ENHANCED ANTIMICROBIAL ACTIVITY.

GHILINI, FIORELA; RODRIGUEZ GONZALEZ, MIRIAM CANDELARIA; MIÑÁN, ALEJANDRO GUILLERMO; PISSINIS, DIEGO EZEQUIEL; CREUS, ALBERTO HERNÁNDEZ; SALVAREZZA, ROBERTO CARLOS; SCHILARDI, PATRICIA LAURA

ACS APPLIED MATERIALS & INTERFACES

AMER CHEMICAL SOC

Año: 2018

1944-8244

The increasing incidence of infections in implantable devices has encouraged the search forbiocompatible antimicrobial surfaces. In order to inhibit the bacterial adhesion andproliferation on biomaterials, several surface functionalization strategies have been developed. However, most of these strategies lead to bacteriostatic effect and only few ofthese are able to reach the bactericidal condition. In this work, bactericidal surfaces weredesigned through the functionalization of titanium surfaces with poly-L-lysine (PLL) asmediator for the incorporation of antimicrobial silver nanoparticles (AgNPs). Thisfunctionalization influences the adsorption of the particles on the substrate impeding theagglomeration observed when bare titanium surfaces are used, leading to a homogeneousdistribution of AgNPs on the surfaces. The antimicrobial activity of this surface has been testedagainst two different strains, namely Staphylococcus aureus and Pseudomonas aeruginosa. Forboth strains and different AgNPs sizes, the surface modified with PLL and AgNPs shows amuch-enhanced antimicrobial activity in comparison with AgNPs deposited on bare titanium.This enhanced antibacterial activity is high enough to reach bactericidal effect, a conditionhard to achieve in antimicrobial surfaces. Importantly, the designed surfaces are able todecrease the bacterial viability more than 5 orders with respect to the initial bacterialinoculum. That means that a relative low load of AgNPs on the PLL-modified titanium surfacesreaches 99.999 % bacterial death after 24 h. The results of the present study are important toavoid infections in indwelling materials, by reinforcing the preventive antibiotic therapy usuallydosed throughout the surgical procedure and during the postoperative period.