Layer-by-layer nanoparticles co-loading gemcitabine and platinum (IV) prodrugs for synergistic combination therapy of lung cancer

Figure 1. Synthesis of CH-Pt and HA-GEM. CH-Pt was synthesized by linking the carboxyl groups of Pt (IV) complex with the amino groups of CH (A); HA-GEM was synthesized by linking the carboxyl groups of HA with the amino groups of GEM (B). Abbreviations: CH, chitosan; Pt, platinum (IV); HA, hyaluronic acid; GEM, gemcitabine.

Figure 2. The 1H-NMR spectra of CH-Pt. Abbreviations: CH, chitosan; Pt, platinum (IV).

Figure 3. The 1H-NMR spectra of HA-GEM. Abbreviations: HA, hyaluronic acid; GEM, gemcitabine.

Figure 4. TEM image of HA-GEM/CH-Pt NPs. Abbreviations: TEM, transmission electron microscopy; HA, hyaluronic acid; GEM, gemcitabine; CH, chitosan; Pt, platinum (IV); NPs, nanoparticles.

Figure 5. The size (A), zeta potential (B), EE (C), and DL (D) of HA-GEM/CH-Pt NPs, HA-GEM/CH NPs, HA/CH-Pt NPs, blank HA/CH NPs and CH-Pt NPs. Note: Data expressed as mean ± SD (n=5). Abbreviations: EE, drug encapsulation efficiency; DL, drug loading efficiency; HA, hyaluronic acid; GEM, gemcitabine; CH, chitosan; Pt, platinum (IV); NPs, nanoparticles.

Figure 6. Serum stability of HA-GEM/CH-Pt NPs, HA-GEM/CH NPs, HA/CH-Pt NPs, blank HA/CH NPs and CH-Pt NPs evaluated by measuring the size (A), PDI (B) and EE (C) of NPs in the presence of FBS. Note: Data expressed as mean ± SD (n=3). Abbreviations: HA, hyaluronic acid; GEM, gemcitabine; CH, chitosan; Pt, platinum (IV); NPs, nanoparticles; PDI, polydispersity; EE, drug encapsulation efficiency; FBS, fetal bovine serum.

Figure 7. In vitro GEM and/or Pt release profiles from HA-GEM/CH-Pt NPs and other NPs. Note: Data expressed as mean ± SD (n=3), *P<0.05. Abbreviations: GEM, gemcitabine; Pt, platinum (IV); HA, hyaluronic acid; CH, chitosan; NPs, nanoparticles.

Figure 8. In vitro cytotoxicity of HA-GEM/CH-Pt NPs and other NPs evaluated in NCl-H460 cells for 72 h (A). CI50 values calculated in HA-GEM/CH-Pt NPs (B). Note: Data expressed as mean ± SD (n=3), *P<0.05. Abbreviations: HA, hyaluronic acid; GEM, gemcitabine; CH, chitosan; Pt, platinum (IV); NPs, nanoparticles; CI, combination index.

Figure 9. In vivo GEM and Pt tissue distribution of drug-loaded NPs and drugs solutions. Note: Data expressed as mean ± SD (n=8), *P<0.05. Abbreviations: GEM, gemcitabine; CH, chitosan; Pt, platinum (IV); NPs, nanoparticles; HA, hyaluronic acid.

Figure 10. In vivo antitumor effect and systemic toxicity conducted in NCl-H460 cells in mouse models. (A) Tumor growth inhibition curves; (B) body weight changes. Note: Data expressed as mean ± SD (n=8), *P<0.05. Abbreviations: HA, hyaluronic acid; GEM, gemcitabine; CH, chitosan; Pt, platinum (IV); NPs, nanoparticles.