Surface hydrophobization of hydrogels via interface dynamics-induced network reconfiguration

Bo Yi; Tianjie Li; Boguang Yang; Sirong Chen; Jianyang Zhao; Pengchao Zhao; Kunyu Zhang; Yi Wang; Zuankai Wang; Liming Bian

doi:10.1038/s41467-023-44646-5

Surface hydrophobization of hydrogels via interface dynamics-induced network reconfiguration

Nat Commun. 2024 Jan 3;15(1):239. doi: 10.1038/s41467-023-44646-5.

Authors

Bo Yi^#^{1

2}, Tianjie Li^#³, Boguang Yang^#⁴, Sirong Chen^{1

2}, Jianyang Zhao^{1

2}, Pengchao Zhao^{1

2

5

6}, Kunyu Zhang^{1

2

5

6}, Yi Wang⁷, Zuankai Wang⁸, Liming Bian^{9

10

11

12}

Affiliations

¹ School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou, 511442, PR China.
² National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, 510006, PR China.
³ Department of Physics, The Chinese University of Hong Kong, Hong Kong, 999077, PR China.
⁴ Department of Orthopaedic and Traumatology, The Chinese University of Hong Kong, Hong Kong, 999077, PR China.
⁵ Guangdong Provincial Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou, 510006, PR China.
⁶ Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou, 510006, PR China.
⁷ Department of Physics, The Chinese University of Hong Kong, Hong Kong, 999077, PR China. yiwang@cuhk.edu.hk.
⁸ Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong, 999077, PR China. zk.wang@polyu.edu.hk.
⁹ School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou, 511442, PR China. bianlm@scut.edu.cn.
¹⁰ National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, 510006, PR China. bianlm@scut.edu.cn.
¹¹ Guangdong Provincial Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou, 510006, PR China. bianlm@scut.edu.cn.
¹² Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou, 510006, PR China. bianlm@scut.edu.cn.

^# Contributed equally.

Abstract

Effective and easy regulation of hydrogel surface properties without changing the overall chemical composition is important for their diverse applications but remains challenging to achieve. We report a generalizable strategy to reconfigure hydrogel surface networks based on hydrogel-substrate interface dynamics for manipulation of hydrogel surface wettability and bioadhesion. We show that the grafting of hydrophobic yet flexible polymeric chains on mold substrates can significantly elevate the content of hydrophobic polymer backbones and reduce the presence of polar groups in hydrogel surface networks, thereby transforming the otherwise hydrophilic hydrogel surface into a hydrophobic surface. Experimental results show that the grafted highly dynamic hydrophobic chains achieved with optimal grafting density, chain length, and chain structure are critical for such substantial hydrogel surface network reconfiguration. Molecular dynamics simulations further reveal the atomistic details of the hydrogel network reconfiguration induced by the dynamic interface interactions. The hydrogels prepared using our strategy show substantially enhanced bioadhesion and transdermal delivery compared with the hydrogels of the same chemical composition but fabricated via the conventional method. Our findings provide important insights into the dynamic hydrogel-substrate interactions and are instrumental to the preparation of hydrogels with custom surface properties.