title: Environment-responsive aza-BODIPY dyes quenching in water as potential probes to visualize the in vivo fate of lipid-based nanocarriers.
abstract: Environment-responsive near-infrared (NIR) aza-BODIPY dyes capable of fluorescence quenching in water were explored to visualize the in vivo fate of model lipid-based nanocarriers, solid lipid nanoparticles (SLNs). The water-quenching effect of the dyes was confirmed to be sensitive and remained stable for at least 24h. In vitro lipolysis measured by fluorescence quenching completed within 20min, which was in correlation with alkaline compensation results. In vivo live imaging indicated predominant digestion of SLNs within 2h and complete digestion within 4h, which correlated well to in vitro data. Rekindling of quenched dyes by mixed micelles was observed in vitro, but not in vivo. In sharp contrast, SLNs encapsulating another NIR dye DiR showed persistent fluorescence both in vitro and in vivo despite significant lipolysis. It was envisaged that water-quenching fluorescence dyes can be used as probes to monitor the in vivo fate of lipid-based nanocarriers.
  
  
  BACKGROUND
  Lipid-based drug delivery systems can provide an excellent nanocarrier platform for the delivery of poorly water-soluble drugs. Nonetheless, the mechanism of oral absorption and subsequent kinetics is poorly understood. In this article, the authors studied the novel use of near-infrared (NIR) aza-BODIPY dyes to visualize the fate of these lipid-based nanocarriers. The positive finding means that this approach may be useful for in-vivo monitoring of lipid-based nanocarriers.
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Xiongwei
authors.initials: X
authors.lastname: Hu
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yu
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Yunchang
authors.initials: Y
authors.lastname: Xie
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Haisheng
authors.initials: H
authors.lastname: He
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Qi
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Dong
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China; Key Laboratory for Special Functional Materials of the Ministry of Education, Henan University, Kaifeng, China. Electronic address: zhaoweili@fudan.edu.cn.
authors.forename: Weili
authors.initials: W
authors.lastname: Zhao
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China. Electronic address: wuwei@shmu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000737:chemistry*; D004337:Drug Carriers / Q000032:analysis* / Q000493:pharmacokinetics; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D008055:Lipids / Q000032:analysis* / Q000493:pharmacokinetics; D008819:Mice, Nude; D053758:Nanoparticles / Q000032:analysis*; D061848:Optical Imaging; D014867:Water / Q000737:chemistry
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D004337:Drug Carriers; D005456:Fluorescent Dyes; D008055:Lipids; D014867:Water
keywords: BODIPY; Drug delivery; In vivo fate; Lipid-based nanocarriers; Water-quenching