Research ArticleBIOMEDICAL ENGINEERING

Nanoparticles that do not adhere to mucus provide uniform and long-lasting drug delivery to airways following inhalation

+ See all authors and affiliations

Science Advances  05 Apr 2017:
Vol. 3, no. 4, e1601556
DOI: 10.1126/sciadv.1601556
  • Fig. 1 Characterization of GRAS-based biodegradable NP.

    Ex vivo stability of NP in BALF at room temperature for 2 or 24 hours, as measured by (A) hydrodynamic diameter and (B) PDI. (C) Transmission electron micrographs of DP/PLGA/F127 and PLGA/F68 NP. Scale bars, 100 nm. (D) Release kinetics of DP from DP/PLGA/F127 and DP/PLGA/F68 NP. Data represent means ± SD. *P < 0.05, **P < 0.01.

  • Fig. 2 The diffusion of biodegradable NP in human CF sputum.

    MPT was performed on NP administered ex vivo in freshly expectorated CF sputum. (A) Representative trajectories of particles. Scale bar, 1 μm. (B) Median MSD at a time scale of 1 s (n = 4). Data represent means ± SEM. *P < 0.05.

  • Fig. 3 The distribution and retention of model PS-based NP in the mouse lungs.

    Airway distribution of (A) 60-, (B) 100-, (C) 300-, and (D) 1000-nm PS and PS-PEG NP at 30 min after administration. PS (green) and PS-PEG (red) NP were coadministered except for 100-nm NP, which were independently dosed to different mice. Cell nuclei were stained blue with 4′,6-diamidino-2-phenylindole (DAPI). The white and yellow arrows indicate PS NP aggregated in the mucus blanket and PS-PEG NP near the surface of epithelium, respectively. Unlike smaller PS-PEG, 1000-nm PS-PEG sparsely distributed throughout the airway similar to PS (red arrows). The retention of PS (white bars) and PS-PEG (gray bars) NP over time is reported as a percentage of the initial deposited dose for (E) 60-, (F) 100-, (G) 300-, and (H) 1000-nm NP (n > 5). Data represent means ± SEM. **P < 0.01.

  • Fig. 4 The distribution and retention of PLGA-based biodegradable NP in the mouse lung.

    Bronchial distribution of (A) PLGA (green) and PLGA-PEG (red) NP and (B) PLGA/F68 (left panel) and PLGA/F127 (right panel) NP at 30 min after administration. Cell nuclei were stained blue with DAPI. The white and yellow arrows indicate PLGA NP aggregated in the mucus blanket and PLGA-PEG NP near the epithelial surface, respectively. (C and D) Tracheal distribution of PLGA (green) and PLGA-PEG (red) NP at 30 min after administration. The yellow dashed box in (C) highlights a submucosal gland covered with PLGA-PEG NP. The white arrows in (C) indicate PLGA NP stuck in the mucus blanket. The same gland can be observed at higher magnification in (D) where the yellow arrow points out deep penetration of PLGA-PEG NP into the gland. (E) The retention of PLGA (white bars) and PLGA-PEG (gray bars) NP over time in BALF. (F) The retention of PLGA and PLGA-PEG NP in the entire lung over time (n = 5). Representative images for PLGA and PLGA-PEG NP exposed lungs over time are shown. The percentage of retention is reported as the percentage of the initial fluorescence (FL) for PLGA (open squares, solid line) and PLGA-PEG (open circles, dotted line) NP. Data represent means ± SEM. *P < 0.05, **P < 0.01.

  • Fig. 5 In vivo anti-inflammatory effects of GRAS-based biodegradable NP carrying DP in the lungs of mice challenged with Pseudomonas aeruginosa LPS.

    Mice were challenged twice with LPS at 0 and 6 hours. At t = 24 hours, LPS-treated mice received DP/PLGA/F127 or DP/PLGA/F68 NP at a dose of 1 mg/kg. Control LPS-treated mice received either carrier-free DP or saline. Mice were sacrificed at 48 hours for BALF analysis. (A) Total inflammatory cell counts. (B) Concentration of TNF-α. Data represent means ± SD. *P < 0.05, **P < 0.01.

  • Table 1 Physicochemical characterization of PS NP.

    Hydrodynamic diameter and polydispersity index (PDI) were measured by dynamic light scattering (DLS). ζ-potential was measured at pH 7.4 in 10 mM NaCl. Mucus penetration indicates the ability of the NP to penetrate CF sputum, as determined by MPT in our previous work (23, 42, 43) and fig. S3. X, no penetration; O, penetration.

    Nominal size (nm)Particle typeDiameter (nm)PDIζ-Potential (mV)Mucus penetration
    6060-nm PS58 ± 10.12−34 ± 2X
    6060-nm PS-PEG66 ± 30.18−12 ± 1O
    100100-nm PS90 ± 50.06−44 ± 3X
    100100-nm PS-PEG107 ± 30.03−5 ± 1O
    300300-nm PS282 ± 20.04−50 ± 2X
    300300-nm PS-PEG307 ± 90.03−3 ± 1O
    10001000-nm PS1025 ± 130.13−83 ± 4X
    10001000-nm PS-PEG1045 ± 200.11−5 ± 1X
  • Table 2 Physicochemical characterization of biodegradable NP.

    Hydrodynamic diameter and PDI were measured by DLS. ζ-potential was measured at pH 7.4 in 10 mM NaCl. Mucus penetration indicates the ability of the NP to penetrate CF sputum, as determined by MPT in Fig. 2.

    Particle typeDiameter (nm)PDIζ-Potential
    (mV)
    Mucus
    penetration
    PLGA141 ± 150.14−73 ± 4X
    PLGA-PEG128 ± 60.09−6 ± 1O
    PLGA/PF190 ± 70.09−64 ± 2X
    PLGA/F68180 ± 170.09−23 ± 4X
    PLGA/F127200 ± 80.14−8 ± 2O
    DP/PLGA/F68150 ± 100.08−23 ± 1X
    DP/PLGA/
    F127
    260 ± 210.10−4 ± 2O

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/4/e1601556/DC1

    Supplementary Materials and Methods

    fig. S1. Diffusion of 300-nm PS and PS-PEG in human CF sputum.

    fig. S2. Lung histology at 24 hours after administration.

    fig. S3. Safety profile of GRAS-based biodegradable NP.

    movie S1. Diffusion of PLGA NP in freshly collected CF sputum.

    movie S2. Diffusion of PLGA-PEG NP in freshly collected CF sputum.

    movie S3. Diffusion of PLGA/F68 NP in freshly collected CF sputum.

    movie S4. Diffusion of PLGA/F127 NP in freshly collected CF sputum.

    movie S5. Diffusion of 60-nm NP on freshly excised mouse tracheas.

    movie S6. Diffusion of 300-nm NP on freshly excised mouse tracheas.

  • Supplementary Materials

    This PDF file includes:

    • Supplementary Materials and Methods
    • fig. S1. Diffusion of 300-nm PS and PS-PEG in human CF sputum.
    • fig. S2. Lung histology at 24 hours after administration.
    • fig. S3. Safety profile of GRAS-based biodegradable NP.

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • movie S1 (.avi format). Diffusion of PLGA NP in freshly collected CF sputum.
    • movie S2 (.avi format). Diffusion of PLGA-PEG NP in freshly collected CF sputum.
    • movie S3 (.avi format). Diffusion of PLGA/F68 NP in freshly collected CF sputum.
    • movie S4 (.avi format). Diffusion of PLGA/F127 NP in freshly collected CF sputum.
    • movie S5 (.avi format). Diffusion of 60-nm NP on freshly excised mouse tracheas.
    • movie S6 (.avi format). Diffusion of 300-nm NP on freshly excised mouse tracheas.

    Files in this Data Supplement: