The study of relationships between pKa value and siRNA delivery efficiency based on tri-block copolymers

Lili Du; Changrong Wang; Lingwei Meng; Qiang Cheng; Junhui Zhou; Xiaoxia Wang; Deyao Zhao; Jianhua Zhang; Liandong Deng; Zicai Liang; Anjie Dong; Huiqing Cao

doi:10.1016/j.biomaterials.2018.05.046

The study of relationships between pKa value and siRNA delivery efficiency based on tri-block copolymers

Biomaterials. 2018 Sep:176:84-93. doi: 10.1016/j.biomaterials.2018.05.046. Epub 2018 May 29.

Authors

Lili Du¹, Changrong Wang², Lingwei Meng³, Qiang Cheng¹, Junhui Zhou², Xiaoxia Wang¹, Deyao Zhao¹, Jianhua Zhang², Liandong Deng², Zicai Liang⁴, Anjie Dong⁵, Huiqing Cao⁶

Affiliations

¹ Laboratory of Nucleic Acid Technology, Institute of Molecular Medicine, Peking University, Beijing, 100871, China.
² Department of Polymer Science and Technology, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, Tianjin University, Tianjin, 300072, China.
³ Laboratory of Nucleic Acid Technology, Institute of Molecular Medicine, Peking University, Beijing, 100871, China; Peking-Tsinghua Center for Life Science, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
⁴ Laboratory of Nucleic Acid Technology, Institute of Molecular Medicine, Peking University, Beijing, 100871, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China.
⁵ Department of Polymer Science and Technology, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, Tianjin University, Tianjin, 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China. Electronic address: ajdong@tju.edu.cn.
⁶ Laboratory of Nucleic Acid Technology, Institute of Molecular Medicine, Peking University, Beijing, 100871, China. Electronic address: caohuiqing@pku.edu.cn.

PMID: 29870899
DOI: 10.1016/j.biomaterials.2018.05.046

Abstract

Tri-block copolymers have exhibited great potentials in small interfering RNA (siRNA) therapeutics. To reveal structure-activity relationships, we here synthesized a series of tri-block copolymers with different hydrophobic segments, PEG-PAMA-P(C6A_x-C7A_y-DPA_z-DBA_m) (EAAS) and PEG-PDAMAEMA-P(C6A_x-C7A_y-DPA_z-DBA_m) (EDAS), termed from EAASa to EAASh and EDASa to EDASh, with pKa ranging from 5.2 to 7.0. Our data showed that the better gene silencing efficiency was located in pKa of 5.8-6.2, which was contributed from higher endosomal escape observed with confocal images and hemolysis assay. EAASc, the leader polymer, showed excellent gene knockdown at w/w ratio of 14.5 on HepG2 (89.94%), MDA-MB-231 (92.45%), 293A (83.06%), and Hela cells (80.27%), all better than lipofectamine 2000. Besides, EAASc mediated effective gene silencing in tumor when performed peritumoral injection. This work found out that polymers with pKa ranging from 5.8 to 6.2 were efficient in siRNA delivery, which provided an optimization strategy for siRNA delivery systems, especially for tri-block copolymers.

Keywords: Gene silencing; Hydrophobic segments; Tri-block copolymer; pKa value; siRNA delivery.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Survival
Endosomes / metabolism
Female
Gene Knockdown Techniques
Gene Silencing
Gene Transfer Techniques
Hep G2 Cells
Heterografts
Humans
Hydrophobic and Hydrophilic Interactions
Injections, Intralesional
Injections, Intravenous
Lipids / chemistry
Mice, Inbred BALB C
Mice, Inbred C57BL
Mice, Nude
Polyethylene Glycols / chemistry
Polymers / chemistry*
Polymethacrylic Acids / chemistry
RNA, Small Interfering / administration & dosage*
RNA, Small Interfering / chemistry
RNA, Small Interfering / metabolism

Substances

Lipids
Lipofectamine
Polymers
Polymethacrylic Acids
RNA, Small Interfering
polymethacrylic acid
Polyethylene Glycols