Related Experiment Video
Updated: Feb 3, 2026

Preparation of Neutrally-charged, pH-responsive Polymeric Nanoparticles for Cytosolic siRNA Delivery
Published on: May 2, 2019
Stabilized calcium phosphate hybrid nanocomposite using a benzoxaborole-containing polymer for pH-responsive siRNA
Quan Zhou1, Yue Wang, Jiajia Xiang
1Center for Bionanoengineering and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China. zhouzx@zju.edu.cn shenyq@zju.edu.cn.
Abstract:
Calcium phosphate (CaP) nanoparticles present a class of promising nonviral gene delivery carriers due to their easy-preparation procedure, low toxicity and high transfection efficiency. PEGylated polyanion block copolymer was widely used to control the CaP crystal growth during CaP co-precipitation with therapeutic genes. However, there also exists a competition between the entrapped gene and polyanion in the system, which results in reduced stability and low gene entrapment efficiency. To solve this problem, herein, we demonstrate a non-anion stabilization strategy using a boroxole-containing block polymer, PEG-b-poly(benzoxaborole) (PEG-PBO), which forms pH-responsive boronic ester bonds with ribose rings of siRNA and also excellently adhers to the hydroxyapatite surface of CaP. The PEG-PBO/siRNA/CaP nanocomposites exhibited high siRNA loading efficiency, low cell cytotoxicity and excellent colloidal stability at neutral pH. The nanocomposites easily entered cancer cells mainly via clathrin-mediated endocytosis and transferred into acidic lysosomes, where the boronic esters broke, nanoparticles dissociated, and siRNA released and escaped from lysosomes. PEG-PBO/siRNA/CaP nanocomposites showed significantly higher gene silencing efficacy than lipofectamine 2000/siRNA lipoplex in multiple cancer cells. Thus, PEG-PBO/siRNA/CaP nanocomposites possess potential for safe and effective siRNA delivery.
More Related Videos
Related Concept Videos
Roles of Electrolytes: Calcium and Phosphate
The calcium concentration in blood plasma is primarily...
siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
Polymers
Hybrid Zones
RNA Stability
Phosphate Buffer
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...

