Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: (A) Schematic illustration for constructing PCPP/siRNA nanoparticles via a “synergetic assembly” approach of an electrostatic interaction and borate ester formation-mediated chemical binding. (B) Illustration of the dual pH-responsibility and tumor-targeted siRNA delivery by PCPP. (i) Avoiding “off-target” effect with the protection of PEG corona; (ii) Accumulation of PCPP/siRNA at the tumor site by EPR effect; (iii) Extracellular acidity-activated detachment of PEG-shell and exposure of PBA; (iv) PBA recognition and SA receptor-meditated cellular internalization; (v) Endosomal/lysosomal escape and acidity-triggered disassembly of nanoparticle accompanied by the release of siRNA; (vi) RNAi response induced by siRNA.

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: Binding Assay

Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: Characterization of the PCPP/siRNA nanoparticles. (A) The illustration for constructing PCPP/siRNA nanoparticles (B) Transmission electron microscopy (TEM) images. The scale bar represented 500 nm (a) and 50 nm (b). (C) Particle size distribution (intensity diameter). (D) Zeta potential distribution. (E) Gel electrophoresis assay for PCPP/siRNA binding capacity at different N/P ratios. (F) RNase A protection assay of PCPP/siRNA.

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: Transmission Assay, Electron Microscopy, Zeta Potential Analyzer, Nucleic Acid Electrophoresis, Binding Assay

Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: pH-Responsibility of PCPP and siRNA-loaded nanoparticles. (A) UV-absorption spectra of PCPP at different pHs. (B) The fluorescence of ARS/PEI-PBA in PBS buffer at pH 6.5 was measured in the presence of Neu5Ac at various concentrations. I 0 represents the fluorescence intensity of ARS/PEI-PBA at pH 7.4 without Neu5Ac and I represents the fluorescence intensity of ARS/PEI-PBA at pH 6.5 after adding different concentrations of Neu5Ac. (C) Zeta potentials of PCPP/siRNA and PEI-PBA/siRNA at pH 7.4 and 6.5. (D) Size distribution graph (a) and variation of particle size and PDI (b) at different pH values. (E) Cumulative siRNA release from PCPP/siRNA nanoparticls in different acidic conditions (n=3). The main graph shows the whole release profiles in 48 h, while the small chart in the lower-left corner magnifies the first 6 h portion; (F) Heparin displacement assay for different siRNA-loaded nanoparticles. The main graph shows the stability of nanoparticles challenged with increasing concentrations of heparin, and the small graph within magnifies the low concentrations of heparin (0-5 mg/mL) for easy observation.

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: Fluorescence

Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: (A) Cellular uptake of PCPP/FAM-siRNA nanoparticles at pH 7.4 (red profile) or 6.5 (blue profile) by flow cytometry analysis on 4T1 cells. (B) Luciferase gene silencing of PCPP siLuc nanoparticles on 4T1-Luc cells at different pH values. (n = 3, *** P < 0.001). (C) Intracellular biodistribution of PCPP/FAM-siRNA nanoparticles in 4T1 cells. The DAPI (blue) and LysoTracker® Red DND-99 (red) were used for staining nucleus and endosomes/lysosomes, respectively.

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: Flow Cytometry, Luciferase, Staining

Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: In vitro targeting ability of the nanoparticles. Cellular uptake of naked FAM-siRNA, PEI1.8k/FAM-siRNA and PCPP/FAM-siRNA nanoparticles by CLSM (A) and flow cytometry analysis (B). Representative diagram (B-a) and quantification of the flow cytometry analysis (n = 3) (B-b) is shown. (C) Luciferase gene silencing of different nanoparticles on 4T1-Luc cells. (n = 3). After treatment with sialidase, the cellular uptake of PCPP/Cy3-siRNA in 4T1 cells was analyzed by CLSM (D) and flow cytometry assay (E). To hydrolyze specifically SA, 4T1 cells were pre-treated with sialidase before incubation with PCPP/Cy3-siRNA and then incubated with FITC-MAA (D-a), SNA (D-b) or WGA(D-c) to detect the SA expression on cell surface. Representative flow cytometry analysis showing relatively reduced uptake after treatment with sialidase (E-a), and the mean fluorescence intensity in the cells was then calculated (n = 3) (E-b). (*** P < 0.001).

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: In Vitro, Flow Cytometry, Luciferase, Incubation, Expressing, Fluorescence

Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: (A) Proliferation inhibition assay of siSur-loaded nanoparticles in 4T1 cells (n=6). (B) Representative image of nuclei morphological changes by staining with Hoechst 33258 after cells exposed to PBS, naked siSur, PEI1.8k siSur or PCPP siSur . (C) Quantitative detection of apoptotic 4T1 cells induced by different formulations. (D) Wound healing images after scratch for 24 h and 48 h. Cells with no treatment were used as control. Representative 100× microscopy images of migration (E) and invasion (F) of 4T1 cells after treated with naked siSur (b), PEI1.8k siSur (c) or PCPP siSur (d) in transwell assay. Cells with no treatment were used as control (a). Quantitative cell migration (G) and invasion (H) were evaluated by measuring the dissolved crystal violet in 33% acetic acid at 570 nm. (n = 3, *** P <0.001).

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: Inhibition, Staining, Control, Microscopy, Migration, Transwell Assay

Journal: Theranostics

Article Title: Systemic siRNA Delivery with a Dual pH-Responsive and Tumor-targeted Nanovector for Inhibiting Tumor Growth and Spontaneous Metastasis in Orthotopic Murine Model of Breast Carcinoma

doi: 10.7150/thno.16855

Figure Lengend Snippet: Effects of different siSur-loaded nanoparticles on metastasis burden in 4T1-Luc tumor-bearing mice. (A) Typical bioluminescent images of mice during the treatment with saline, naked siSur, PCPP siN.C , PEI1.8k siSur or PCPP siSur . (B) Quantitative estimation of metastases progression by bioluminescent imaging analysis (n=4, *** P <0.001).

Article Snippet: Our results illustrated that PCPP nanovector could condense siRNA to form stable nanoparticles and facilitate siRNA into target cells to exert RNA interference effects.

Techniques: Saline, Imaging