Eur. Phys. J. E (2020) 43: 7
https://doi.org/10.1140/epje/i2020-11931-6

Regular Article

Characterization of zwitterion-modified poly(amidoamine) dendrimers in aqueous solution via a thorough NMR investigation

¹ Department of Interventional and Vascular Surgery, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, 200072, Shanghai, China
² College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 201620, Shanghai, China
³ Department of Physical Chemistry, University of Debrecen, H-4032, Debrecen, Hungary
⁴ CQM - Centro de Química da Madeira, Universidade da Madeira, Campus da Penteada, 9020-105, Funchal, Portugal

^* e-mail: banyai.istvan@science.unideb.hu
^** e-mail: xshi@dhu.edu.cn

Received: 9 November 2019
Accepted: 21 January 2020
Published online: 4 February 2020

Abstract

Zwitterions are a class of unique molecules that can be modified onto nanomaterials to render them with antifouling properties. Here we report a thorough NMR investigation of dendrimers modified with zwitterions in terms of their structure, hydrodynamic size, and diffusion time in aqueous solution. In this present work, poly(amidoamine) (PAMAM) dendrimers of generation 5 (G5) were partially decorated with carboxybetaine acrylamide (CBAA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and 1,3-propane sultone (1,3-PS), respectively with different modification degrees. The formed zwitterion-modified G5 dendrimers were characterized using NMR techniques. We show that the zwitterion modification leads to increased G5 dendrimer size in aqueous solution, suggesting that the modified zwitterions can form a hydration layer on the surface of G5 dendrimers. In addition, the hydrodynamic sizes of G5 dendrimers modified with different zwitterions but with the same degree of surface modification are discrepant depending on the type of zwitterions. The present study provides a new physical insight into the structure of zwitterion-modified G5 dendrimers by NMR techniques, which is beneficial for further design of different biomedical applications.