title: pH-sensitive nanocarrier based on gold/silver core-shell nanoparticles decorated multi-walled carbon manotubes for tracing drug release in living cells.
abstract: We fabricate a multifunctional nanocarrier based on multi-walled carbon nanotubes (MWCNTs) decorated with gold/silver core-shell nanoparticles (Au@Ag NPs) and fluorescein isothiocyanate (FITC) for tracking the intracellular drug release process. In the demonstrated nanocarrier, the Au@Ag NPs adsorbed on the surface of MWCNTs were labeled with the pH-dependent SERS reporter 4-Mercaptobenzoic acid (4MBA) for SERS based pH sensing. FITC was conjugated on MWCNTs to provide fluorescence signal for tracing the MWCNTs. Fluorescent doxorubicin (DOX) was used as the model drug which can be loaded onto MWCNTs via π-π stacking and released from the MWCNTs under acidic condition. By detecting the SERS spectrum of 4MBA, the pH value around the nanocarrier could be monitored. Besides, by tracing the fluorescence of FITC and DOX, we can also investigate the drug release process in cells. Experimental results show that the proposed nanocarrier retained a well pH-sensitive performance in living cells, and the DOX detached from MWCNTs inside the lysosomes and entered into the cytoplasm with the MWCNTs being left in lysosomes. To further investigate the drug release dynamics, 2-D color-gradient pH mapping were plotted, which were calculated from the SERS spectra of 4MBA. The detailed release process and carrier distribution have been recorded as environmental pH changes during cell endocytosis. Furthermore, we also confirmed that the proposed nanocarrier has a good biocompatibility. It indicates that the designed nanocarrier have a great potential in intraceable drug delivery, cancer cells imaging and pH monitoring.
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Chen
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China. Electronic address: wangzy@seu.edu.cn.
authors.forename: Zhuyuan
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China.
authors.forename: Shenfei
authors.initials: S
authors.lastname: Zong
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China.
authors.forename: Yizhi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wu
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, China. Electronic address: cyp@seu.edu.cn.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Cui
mesh_terms: D015374:Biosensing Techniques; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000302:isolation & purification* / Q000494:pharmacology; D065546:Drug Liberation; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057145:Nanoshells / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009369:Neoplasms / Q000188:drug therapy*; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D037742:Nanotubes, Carbon; D012834:Silver; D006046:Gold; D004317:Doxorubicin; D016650:Fluorescein-5-isothiocyanate
keywords: Carbon nanotubes; Dox; Fluorescence; SERS; pH sensor