Figures & data
Figure 1 The gelatinase-stimuli strategy enhanced nanoparticles interactions with cancer cells in the tumor tissues. After release from tumor capillaries, the PEG-Pep conjugates were cleaved by gelatinases, which were specifically secreted in the tumor microenvironment. The remained PCL blocks aggregated and the PEG-uncoated PCL nanoparticles interacted efficiently with cancer cells, resulting in fast drug release and effective therapeutics.
Abbreviations: PEG, poly(ethylene glycol); PCL, poly(ɛ-caprolactone); Pep, peptide.
Figure 2 The gelatinase-stimuli characterization of PEG-Pep-PCL nanoparticles. (A) SEM images of PEG-Pep-PCL nanoparticles in response to gelatinases (a) PEG-Pep-PCL, (b) PEG-Pep-PCL co-incubation with gelatinases. (B) In vitro release of DOC from the nanoparticles in the presence of gelatinases. (C) The cellular uptake of coumarin-6-loaded PEG-PCL and PEG-Pep-PCL nanoparticles in two kinds of cancer cells, which express different gelatinases levels (LOVO cells expressed relatively high gelatinases compared with LLC cells).
Abbreviations: DOC, docetaxel; LLC, Lewis lung carcinoma; PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide; SEM, scanning electron microscope.
Figure 3 The in vitro H22 cellular uptake studies of nanoparticles. (A) Confocal microscopy images of H22 cells after incubation with coumarin-6-loaded Rhodamine-B labeled PEG-PCL and Rhodamine-B labeled PEG-Pep-PCL nanoparticles. (B) The uptake efficiencies of coumarin-6-loaded PEG-PCL and PEG-Pep-PCL nanoparticles at different time points.
Notes: **P < 0.01; ****P < 0.0001.
Abbreviations: PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide.
Figure 4 In vivo NIRF images of H22 tumor bearing mice following intravenous administration of NIR-797 labeled DOC-NPs and DOC-TNPs during 72 hours. The tumors were marked by arrows.
Abbreviations: DOC-NP, docetaxel-loaded nanoparticle; DOC-TNP, tumor-targeted docetaxel-loaded nanoparticle; NIR, near-infrared; NIRF, near-infrared fluorescent.
Figure 5 In vivo antitumor effects of different groups. (A) The tumor growth curves of H22 tumor-bearing mice that received different treatments. The same DOC dose (10 mg/kg) was given by intravenous injection on days 1, 7 and 13 (marked by arrows). For Taxotere®, DOC-NPs and DOC-TNPs. **P < 0.01 versus Taxotere® treated group or DOC-NPs group. (B) H&E stained slices of tumors from mice on the day 21 at the end of treatment with saline (a), empty PEG-PCL nanoparticles (b), empty PEG-Pep- PCL nanoparticles (c), Taxotere® (d) (10 mg/kg), DOC-NPs (e) (10 mg/kg DOC equal), DOC-TNPs (f) (10 mg/kg DOC equal) (×40).
Abbreviations: DOC, docetaxel; DOC-NPs, docetaxel-loaded nanoparticles; DOC-TNPs, tumor-targeted docetaxel-loaded nanoparticles; H&E, hematoxylin and eosin; PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide.
Figure 6 PET/CT images of mice administered 100 μCi of 18F-FDG and scanned 30 minutes post injection. From up to down, CT, PET and fusion views. (A) Taxotere® (10 mg/kg DOC equal). (B) DOC-NPs (10 mg/kg DOC equal). (C) DOC-TNPs (10 mg/kg DOC equal).
Abbreviations: CT, computed tomography; DOC, docetaxel; DOC-NPs, docetaxel-loaded nanoparticles; DOC-TNPs, tumor-targeted docetaxel-loaded nanoparticles; PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide; PET, positron emission tomography.
Figure S1 Synthesis scheme of PEG-Pep-PCL copolymers.
Abbreviations: PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide.
Figure S2 1H nuclear magnetic resonance spectra (300 MHz, 25°C) of polymers in CDCl3: (A) PEG-Pep-PCL copolymers; (B) PEG-PCL copolymers.
Note: The insert in (A) shows the proton signal from methyl groups in peptide (0.816–1.032 ppm), thus indicating portions of peptide were successfully conjugated into the copolymers.
Abbreviations: PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide.
Table S1 Characterization of the DOC-TNPs and DOC-NPs
Figure S3 In vitro DOC release of DOC-TNPs and DOC-NPs in phosphate buffered saline.
Abbreviations: DOC, docetaxel; DOC-NPs, docetaxel-loaded nanoparticles; DOC-TNPs, tumor-targeted docetaxel-loaded nanoparticles; PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide.
Figure S4 Detection of gelatinases by gelatin zymography, which can quantitatively measure the activity of gelatinases (MMP2/9). Following the Coomassie blue staining, gelatinases activity is detected as a white zone on black background and quantified by densitometry. (A) Scanning images of the gelatin zymography for LLC and LOVO cancer cells. (B) The expressions of LLC and LOVO cells for MMP-2 and MMP-9 by a semi-quantitative technique.
Abbreviations: LLC, Lewis lung carcinoma; MMP, matrix metalloproteases.
Figure S5 (A) Gelatin zymography of the gelatinases (MMP2/9) expression by in H22 cells. (B) Immunohistochemical analysis of the gelatinases (MMP2/9) expression in H22 tumours (×100).
Abbreviation: MMP, matrix metalloproteases.
Figure S6 (A) Body weight curves of each group during the whole experiment. (B) Blood chemistry ALT and AST test was performed on Day 21 after initiation of the treatment. (C) Blood chemistry BUN and Cr test was performed on Day 21 after initiation of the treatment. (D) Abnormal damage was not observed in the H&E stained sections of main organs (×40). The result was consistent with the normal hepatic enzyme levels measured in the blood test (a) saline; (b) empty PEG-PCL nanoparticles; (c) empty PEG-Pep-PCL nanoparticles; (d) Taxotere®; (e) DOC-NPs; (f) Doc-TNPs.
Abbreviations: ALT, alamine aminotransferase; AST, aspartate aminotransferase; BUN, blood urea nitrogen; Cr, creatinine; DOC-NP, docetaxel-loaded nanoparticle; DOC-TNP, tumor-targeted docetaxel-loaded nanoparticle; H&E, hematoxylin and eosin; PCL, poly(ɛ-caprolactone); PEG, poly(ethylene glycol); Pep, peptide.
