title: Observation of antibacterial effect of biodegradable polymeric nanoparticles on Staphylococcus epidermidis biofilm using FE-SEM with an ionic liquid.
abstract: We successfully visualized the antibacterial behavior of biodegradable polymeric nanoparticles (NPs) on a biofilm formed by Staphylococcus epidermidis using field emission scanning electron microscopy (FE-SEM). A hydrophilic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), was applied for observation using FE-SEM. The differences in adherence and penetration behavior of three types of NPs were revealed using this method and confocal laser scanning microscopy. Biodegradable poly(dl-lactide-co-glycolide) (PLGA) NPs were prepared by the emulsion solvent diffusion method. In this study, we treated the biofilm with three PLGA NPs: unmodified PLGA, PLGA modified with chitosan (CS) and clarithromycin (CAM)-loaded + CS-modified PLGA. The viability of S. epidermidis cells treated with PLGA NPs was estimated using the LIVE/DEAD BacLight kit to understand the antibacterial ability of each NP sample in a quantitative way. The results confirmed that CAM-loaded + CS-modified PLGA had high antibacterial ability on the biofilm. This novel observation technique would be useful in the development of drug formations and medical agents.
authors.affiliation: School of Pharmacy, Pharmaceutical Engineering, Aichi Gakuin University, 1-100, Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan chisato@dpc.agu.ac.jp.
authors.forename: Chisato
authors.initials: C
authors.lastname: Takahashi
authors.affiliation: School of Pharmacy, Pharmaceutical Engineering, Aichi Gakuin University, 1-100, Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Ogawa
authors.affiliation: School of Pharmacy, Pharmaceutical Engineering, Aichi Gakuin University, 1-100, Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kawashima
authors.affiliation: School of Pharmacy, Pharmaceutical Engineering, Aichi Gakuin University, 1-100, Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yamamoto
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology; D017291:Clarithromycin / Q000737:chemistry / Q000494:pharmacology; D004337:Drug Carriers / Q000494:pharmacology*; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry / Q000494:pharmacology; D011100:Polyglycolic Acid / Q000737:chemistry / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D013212:Staphylococcus epidermidis / Q000187:drug effects*
chemical_list: C419324:1-butyl-3-methylimidazolium tetrafluoroborate; D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D007093:Imidazoles; D052578:Ionic Liquids; D011091:Polyesters; D011108:Polymers; D011100:Polyglycolic Acid; C033616:poly(lactide); D048271:Chitosan; D017291:Clarithromycin
keywords: biofilm; clarithromycin; drug delivery system; electron microscopy; ionic liquid; poly(dl-lactide-co-glycolide)