title: A blue fluorescent labeling technique utilizing micro- and nanoparticles for tracking in LIVE/DEAD® stained pathogenic biofilms of Staphylococcus aureus and Burkholderia cepacia.
abstract: Strategies that target and treat biofilms are widely applied to bacterial cultures using popular live/dead staining techniques with mostly red or green fluorescent markers (eg, with SYTO(®) 9, propidium iodide, fluorescein). Therefore, visualizing drugs or micro- and nanoparticulate delivery systems to analyze their distribution and effects in biofilms requires a third fluorescent dye that does not interfere with the properties of the live/dead markers. The present study establishes and evaluates a model for tracking polymeric particles in fluorescently stained biological material. To this end, poly(D,L-lactide-co-glycolide) (PLGA)-based micro- and nanoparticles were used as well-established model systems, which, because of their favorable safety profiles, are expected to play important future roles with regard to drug delivery via inhalation. PLGA was covalently and stably labeled with 7-amino-4-methyl-3-coumarinylacetic acid (AMCA), after which blue fluorescent poly(ethylene glycol)-block-PLGA (PEG-PLGA) particles were prepared using a mixture of fluorescent AMCA-PLGA and PEG-PLGA. Because chitosan is known to reduce negative surface charge, blue fluorescent PEG-PLGA-particles with chitosan were also prepared. These micro- and nanoparticles were physicochemically characterized and could be clearly distinguished from live/dead stained bacteria in biofilms using confocal laser scanning microscopy.
authors.affiliation: Center for Infectious Diseases and Infection's Control, Jena University Hospital, Jena, Germany; Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Klinger-Strobel
authors.affiliation: Department of Pharmaceutical Technology, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Ernst
authors.affiliation: Department of Internal Medicine IV, Jena University Hospital, Jena, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lautenschläger
authors.affiliation: Center for Infectious Diseases and Infection's Control, Jena University Hospital, Jena, Germany; Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
authors.forename: Mathias W
authors.initials: MW
authors.lastname: Pletz
authors.affiliation: Department of Pharmaceutical Technology, Friedrich Schiller University Jena, Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Fischer
authors.affiliation: Center for Infectious Diseases and Infection's Control, Jena University Hospital, Jena, Germany; Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
authors.forename: Oliwia
authors.initials: O
authors.lastname: Makarewicz
mesh_terms: D000085:Acetates / Q000737:chemistry; D018441:Biofilms; D016956:Burkholderia cepacia; D048271:Chitosan / Q000737:chemistry; D003374:Coumarins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D018613:Microscopy, Confocal / Q000379:methods; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011419:Propidium / Q000737:chemistry; D013211:Staphylococcus aureus
chemical_list: C000610434:7-amino-4-methyl-3-coumarinylacetic acid; D000085:Acetates; D003374:Coumarins; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011091:Polyesters; C103389:SYTO 9; C000589473:polyethylene glycol-poly(lactide-co-glycolide); D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011419:Propidium; D011092:Polyethylene Glycols; D048271:Chitosan
keywords: 7-amino-4-methyl-3-coumarinylacetic acid; PEG; PLGA; chitosan; confocal laser scanning microscopy; cystic fibrosis; hydrodynamic diameter