Zhao Ying&#x27;s research while affiliated with National Center for Nanoscience and Technology and other places

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Bifunctional Therapeutic Peptide Assembled Nanoparticles Exerting Improved Activities of Tumor Vessel Normalization and Immune Checkpoint Inhibition

Characterization of DPPA and FD nanoparticles. a) TEM images of DPPA and FD nanoparticles before and after incubation with the legumain enzyme; scale bar = 100 nm. b,c) Corresponding size distribution and zeta potential of nanoformulations detected by DLS. Data are shown as the mean ± SD (n = 3). d) Enzyme responsiveness of FD peptide was monitored using MALDI‐TOF mass spectrometry.

In vitro functional characterization of FD and DPPA nanoparticles and other formulations. a) Cell viability of 4T1 cells and HUVECs that were treated with DPPA nanoparticles, FD nanoparticles, DPPA peptide, and FSEC peptide for 24 and 48 h (n = 3). b,c) Analyzing the antiangiogenic function of FD nanoparticles by transwell cell migration assay. Percentage of migrated HUVECs in a transwell assay after 8 h of incubation with the legumain enzyme indicated effects of FSEC peptide sequence after cleavage from FD nanoparticles. (Scale bar = 40 µm.) d,e) Capillary tube formation of HUVECs after incubation with FD nanoparticles in the absence and presence of the legumain enzyme. Percentages of inhibition were quantified using image analysis software. f) The binding efficiency of DPPA toward PD‐L1 was evaluated by flow cytometry. PE‐labeled anti‐PD‐L1 antibody was incubated with 4T1 cells in the presence or absence of DPPA peptide sequence.

In vivo evaluation of designed sequences effect on the normalization of tumor vessel structures, leakiness, and hypoxia. a) FSEC peptide sequence act as a specific VEGF receptor antagonist and promotes vessel normalization through inhibition of angiogenesis. Double immunofluorescence staining of pericytes (anti‐αSMA antibody, green) and endothelial cells (anti‐CD31 antibody, red) visualized the regained vascular organizations in groups that have been treated by FSEC peptide sequence and in particular by FD nanoparticles. b) Vascular maturity was calculated through the ratio of pericytes coverage to endothelial cells. c) Changes in vascular leakage were evaluated by FITC–dextran in vivo 14 days after treatment with peptide sequences. Scale bars = 100 µm. d) Relative vessel leakiness. e) The modified Miles assay was used to assess vascular permeability in the tumor. Evans blue dye concentration shows significantly decreased vessel leakiness after the treatment of mice using FD nanoparticles. f) Confocal microscopy images of vessels perfused with FITC–lectin. Perfusion of vessels after normalization was increased meaningfully in FD nanoparticle treated group. Treatment with other sequences cannot normalize vessels, which represent dilation and leaked structure similar to untreated tumors. Scale bar = 100 µm. g) Relative vessel perfusion intensity. h) Immunohistochemical staining for HIF1α in tumor tissues of treatment groups. Hypoxic areas significantly decreased in groups treated by the FSEC peptide sequence or FD nanoparticles compared to other control groups. i) Decreased expression levels of HIF1α in the tumors after treatment by FSEC peptide sequences and FD nanoparticles indicate better tissue oxygenation and less hypoxic effect as a consequence of vessel normalization. Scale bar = 50 µm. The experiments were repeated three times.

In vivo immunomodulatory effects of nanoformulations. a) Immunohistochemistry images of CD8⁺ T cells infiltration into the tumors (red arrows) treated with peptide nanoparticles. b,c) Quantification of NK cells and CD8⁺ T cells in tumor tissues using flow cytometry. High infiltration of these cells after treatment by FD nanoparticles indicated the effectiveness of combined vascular normalization and immunotherapy. d,e) Concentrations of IFN‐γ and interleukin‐2 (IL‐2) were detected by an ELISA kit.

Tumor accumulation and biodistribution of peptide nanoparticles. a) In vivo evidence of tumor accumulation of FD nanoparticles 8 and 24 h after tail injection. b) Ex vivo fluorescence imaging of free Cy5.5 and Cy5.5‐labeled FD nanoparticles biodistribution in heart, liver, spleen, lung, kidney, and tumor 24 h postintravenous injection. c) Blood clearance and d) tumor growth curves of 4T1‐implanted tumors in BALB/c mice that were treated by FD nanoparticles alone or through the combinational chemotherapy with DOX. e) Picture of the dissected tumors of the mice 14 days after tumor inoculation.

May 2021

81 Reads

25 Citations

Advanced Healthcare Materials

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adhm202100051-sup-0001-suppmat (1).pdf

The effectiveness of cancer immunotherapy is impaired by the dysfunctional vasculature of tumors. Created hypoxia zones and limited delivery of cytotoxic immune cells help to have immune resistance in tumor tissue. Structural and functional normalization of abnormal tumor vasculature provide vessels for more perfusion efficiency and drug delivery that result in alleviating the hypoxia in the tumor site and increasing infiltration of antitumor T cells. Taking advantage of peptide amphiphiles, herein, a novel peptide amphiphile nanoparticle composed of an antiangiogenic peptide (FSEC) and an immune checkpoint blocking peptide (DPPA) is designed and characterized. FSEC peptide is known to be involved in vessel normalization of tumors in vivo. DPPA is an inhibitory peptide of the PD‐1/PD‐L1 immune checkpoint pathway. The peptide amphiphile nanoparticle sets out to test whether simultaneous modulation of tumor vasculature and immune systems in the tumor microenvironment has a synergistic effect on tumor suppression. Increased intratumoral infiltration of immune cells following vascular normalization, and simultaneously blocking the immune checkpoint function of PD‐L1 reactivates effective immune responses to the tumors. In summary, the current study provides a new perspective on the regulation of tumor vessel normalization and immunotherapy based on functional peptide nanoparticles as nanomedicine for improved therapeutic purposes.

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Data

May 2021

25 Reads

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Normalization of tumor blood vessels, a regulation factor in tumor microenvironment and immune system function

Poster

October 2020

56 Reads

Amplified Cycle of Vessel Normalization and Immune System activation to Regulate Tumor Microenvironment for Cancer Immunotherapy

[...]

Guangjun Nie

Poster

August 2019

84 Reads

Bifunctional Therapeutic Peptide Assembled Nanoparticles Exerting Improved Activities of Tumor Vessel Normalization and Immune Checkpoint Inhibition

Chen Li

[...]

Guangjun Nie

... The fundamental reason for the low accumulation of drugs within the tumor is the insufficient blood perfusion within the tumor interior [11]. Studies have revealed that the local capillary venous pressure within tumors is approximately 20 mm Hg, while the interstitial pressure ranges from 20 to 130 mm Hg [12]. ...
Reference:
Achieving deep intratumoral penetration and multimodal combined therapy for tumor through algal photosynthesis

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May 2021

Advanced Healthcare Materials

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