Biofabrication Biofabrication 6 (2014) 035002 (12pp) doi:10.1088/1758-5082/6/3/035002 Usnic acid-loaded biocompatible magnetic PLGA-PVA microsphere thin films fabricated by MAPLE with increased resistance to staphylococcal colonization V Grumezescu 1,2 , A M Holban 3 , A M Grumezescu 1 , G Socol 2 , A Ficai 1 , B S Vasile 1 , R Trusc˘ a 4 , C Bleotu 5 , V Lazar 3 , C M Chifiriuc 3 and G D Mogosanu 6 1 Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Polizu Street no 1-7, 011061 Bucharest, Romania 2 Lasers Department, Plasma and Radiation Physics, National Institute for Lasers, PO Box MG-36, Bucharest-Magurele, Romania 3 Microbiology Immunology Department, Faculty of Biology, University of Bucharest, Aleea Portocalelor 1-3, Sector 5, 77206-Bucharest, Romania 4 Metav SA - CD SA, 31 Rosetti Str., 020015 Bucharest, Romania 5 Stefan S Nicolau Institute of Virology, Bucharest, Romania 6 Department of Pharmacognosy and Phytotherapy, Faculty of Pharmacy, University of Medicine and Pharmacy of Craiova, 2 PetruRares ¸ Street, 200349 Craiova, Romania E-mail: grumezescu@yahoo.com Received 20 January 2014, revised 28 February 2014 Accepted for publication 10 March 2014 Published 11 April 2014 Abstract Due to their persistence and resistance to the current therapeutic approaches, Staphylococcus aureus biofilm-associated infections represent a major cause of morbidity and mortality in the hospital environment. Since (+)-usnic acid (UA), a secondary lichen metabolite, possesses antimicrobial activity against Gram-positive cocci, including S. aureus, the aim of this study was to load magnetic polylactic-co-glycolic acid-polyvinyl alcohol (PLGA-PVA) microspheres with UA, then to obtain thin coatings using matrix-assisted pulsed laser evaporation and to quantitatively assess the capacity of the bio-nano-active modified surface to control biofilm formation by S. aureus, using a culture-based assay. The UA-loaded microspheres inhibited both the initial attachment of S. aureus to the coated surfaces, as well as the development of mature biofilms. In vitro bioevalution tests performed on the fabricated thin films revealed great biocompatibility, which may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to S. aureus colonization and as scaffolds for stem cell cultivation and tissue engineering. Keywords: MAPLE, magnetic PLGA-PVA microspheres, biocompatibility, antibiofilm activity (Some figures may appear in colour only in the online journal) 1. Introduction Despite living in the era of antibiotics, microbial infections represent one of the top public health problems at a global level. Persistent infections, usually caused by resistant pathogens with the ability to grow in biofilms, are very frequent and difficult to treat due to their differing behavior and increased susceptibility to antimicrobial agents [1] of 1758-5082/14/035002+12$33.00 1 © 2014 IOP Publishing Ltd Printed in the UK