title: Activated human neutrophil response to perfluorocarbon nanobubbles: oxygen-dependent and -independent cytotoxic responses.
abstract: Nanobubbles, a type of nanoparticles with acoustically active properties, are being utilized as diagnostic and therapeutic nanoparticles to better understand, detect, and treat human diseases. The objective of this work was to prepare different nanobubble formulations and investigate their physicochemical characteristics and toxic responses to N-formyl-methionyl-leucyl-phenylalanine (fMLP)-activated human neutrophils. The nanobubbles were prepared using perfluoropentane and coconut oil as the respective core and shell, with soybean phosphatidylcholine (SPC) and/or cationic surfactants as the interfacial layers. The cytotoxic effect of the nanobubbles on neutrophils was determined by extracellular O₂(.)⁻ release, intracellular reactive oxygen species (ROS), lactate dehydrogenase (LDH), and elastase release. Particle sizes of the nanobubbles with different percentages of perfluorocarbon, oil, and surfactants in ranged 186-432 nm. The nanobubbles were demonstrated to inhibit the generation of superoxide and intracellular ROS. The cytotoxicity of nanobubbles may be mainly associated with membrane damage, as indicated by the high LDH leakage. Systems with Forestall (FE), a cationic surfactant, or higher SPC contents exhibited the greatest LDH release by 3-fold compared to the control. The further addition of an oil component reduced the cytotoxicity induced by the nanobubbles. Exposure to most of the nanobubble formulations upregulated elastase release by activated neutrophils. Contrary to this result, stearylamine (SA)-containing systems slightly but significantly suppressed elastase release. FE and SA in a free form caused stronger responses by neutrophils than when they were incorporated into nanobubbles. In summary, exposure to nanobubbles resulted in a formulation-dependent toxicity toward human neutrophils that was associated with both oxygen-dependent and -independent pathways. Clinicians should therefore exercise caution when using nanobubbles in patients for diagnostic and drug targeting aims.
authors: Cellular Pharmacology Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan.
authors: Tsong-Long
authors: TL
authors: Hwang
authors: Chia-Lang
authors: CL
authors: Fang
authors: Saleh A
authors: SA
authors: Al-Suwayeh
authors: Li-Jia
authors: LJ
authors: Yang
authors: Jia-You
authors: JY
authors: Fang
mesh_terms: D000328:Adult; D002470:Cell Survival / Q000187:drug effects; D005466:Fluorocarbons / Q000737:chemistry / Q000633:toxicity; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D018375:Neutrophil Activation / Q000187:drug effects* / Q000276:immunology; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology; D010196:Pancreatic Elastase / Q000097:blood; D010713:Phosphatidylcholines / Q000737:chemistry / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D055815:Young Adult; D010420:Pentanes
chemical_list: D005466:Fluorocarbons; D007770:L-Lactate Dehydrogenase; D009240:N-Formylmethionine Leucyl-Phenylalanine; D010196:Pancreatic Elastase; D010713:Phosphatidylcholines; D017382:Reactive Oxygen Species; D013481:Superoxides; C008806:perfluoropentane; D010420:Pentanes