“Building-block crosslinking” micelles for enhancing cellular transfection of biocompatible polycations

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  • ReceivedMar 26, 2020
  • AcceptedApr 21, 2020
  • PublishedJul 22, 2020



the National Natural Science Foundation of China(81903556)

the Natural Science Fund for Colleges and Universities in Jiangsu Province(19KJB350004)

and the National Health and Medical Research Council(NHMRC)


This work was supported by the National Natural Science Foundation of China (81903556), and the Natural Science Fund for Colleges and Universities in Jiangsu Province (19KJB350004). Dr. Liu T was supported by the National Health and Medical Research Council (NHMRC) Early Career Fellowship (1112258) of Australia.

Interest statement

The authors declare that they have no conflict of interest.

Contributions statement

Wu P and Wang K were responsible for the study design; Wang K and Ding D conceived the project and acted as project leader; Wu P and Yin S performed the actuation experiments; Wu P and Yin S were responsible for the manuscript writing; Wu P and Liu T were responsible for the data analyses. All the authors commented and revised the manuscript.

Author information

Pengkai Wu received his PhD degree from China Pharmaceutical University with Prof. Oupický in 2019. He also conducted his work at the University of Nebraska Medical Center as a postdoctoral fellow. His research interests mainly focus on the delivery of drug/siRNA and drug/miRNA combinations in the treatment of liver diseases.

Dan Ding received his PhD degree from Nanjing University in 2010. After a postdoctoral training in the National University of Singapore, he joined Nankai University, where he is currently a professor in the College of Life Sciences. He also conducted his work in The Hong Kong University of Science and Technology as a visiting scholar. His current research focuses on the design and synthesis of smart/functional molecular imaging probes and exploration of their biomedical applications.

Kaikai Wang received his PhD degree in pharmacy with Prof. Yiqiao Hu and Prof. Jinhui Wu from Nanjing University in 2015. He joined China Pharmaceutical University as a postdoc in Prof. Oupický’s group in 2015. He is now working as an associate professor in Nantong University. His research currently focuses on the development of multifunctional formulations based on novel polymers and proteins for photodynamic and photothermal therapy applications.

Supplementary data

Supplymentary information

Supporting data are available in the online version of the paper.


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  • Figure 1

    Structures of PEI-X monomers and crosslinked PEI-X-SS-X-PEI copolymers.

  • Figure 2

    Transfection efficiency of the polyplexes. The cell uptake (a) and gene silencing ability (b) of PEI monomers. *P<0.05 and **P<0.01 vs. PEI 1.8k group. (c) Cell viability of all the tested siRNA polyplexes in CHO cells. EGFP gene silencing efficacy was determined by flow cytometry (d) and confocal microscopy (e) in CHO-EGFP cells. Scale bar=400 μm. *P<0.05 vs. PEI 25k group; # P<0.05 vs. Ch-SS-Ch group. The results are shown as mean±standard deviation (SD) (n=3).

  • Figure 3

    Luciferase reporter gene silencing. Transfection efficacy of siLuc polyplexes in B16F10.Luc, 4T1.Luc and 231.Luc cells at different w/w ratios. * P<0.05 vs. PEI 25k group; # P<0.05 vs. Ch-SS-Ch group. The results are shown as mean±SD (n=3).

  • Figure 4

    Cellular uptake and intracellular trafficking of Ch-SS-F-SS-PBA/siRNA polyplexes in B16F10 cells. (a) Intracellular distribution and trafficking of Ch-SS-F-SS-PBA/siRNA polyplexes by confocal microscopy after 4 h of incubation. Scale bar=20 μm. (b) Cellular uptake of Ch-SS-F-SS-PBA/siRNA polyplexes by flow cytometry after 4 h of incubation. * P<0.05 vs. PEI 25k group; # P<0.05 vs. Ch-SS-Ch group.

  • Figure 5

    (a) Fluorescence images of EGFP protein expression on CHO-EGFP cells after different treatments in the presence of 10%, 20%, and 30% FBS detected by fluorescence microscopy. Scale bar=400 μm. Effect of different treatments on the transfection activity in CHO-EGFP (b), B16F10.Luc (c), 4T1.Luc (d) and MDA-MB-231.Luc (e) cells in the presence of 10%, 20%, and 30% FBS. * P<0.05 vs. PEI 25k group; # P<0.05 vs. Ch-SS-Ch group. All results are shown as mean±SD (n=3).

  • Figure 6

    (a) Bioluminescence images of mice with B16F10.Luc tumors before and after gene silencing. (b) Quantification of Luc expression from the whole-body images. (c) Ex vivo analysis of the Luc activity in the isolated tumor tissues. All Luc silencing data are shown as mean% Luc expression relative to vehicle±SD (n=3). * P<0.05 vs. PEI 25k group; # P<0.05 vs. Ch-SS-Ch group.


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