Hydrogel materials are widely used due to the outstanding biocompatibility. However, the micro-nano fabrication biomaterials such as small diameter artificial blood vessels, flexible biomaterials microdevices, minimally invasive tissue adhesion agents, and organ and tissue engineering stents, are still facing a challenge of higher precision. It is urgent to develop new hydrogel materials with fine 3D geometry to meet the future development of biomedical fields.

Prof. ZHENG Meiling’s team from the Technical Institute of Physics and Chemistry of the Chinese Academy and Sciences developed a biocompatible hydrogel photoresist. In the new strategy, vinyl ester hyaluronic acid (HAVE) is monomer, cyclopentanone-based material is initiator, and DL-Dithiothreitol (DTT) is thiol-ene click chemical cross-linker. The proposed two-photon polymerization (TPP) of HAVE photoresist strategy leads to a 22 nm resolution.

The work is published in ACS Applied Materials & Interfaces on May. 23^th 2023.

In this study, researchers have comprehensively investigated the TPP of HAVE hydrogel photoresists, and achieved the feature size of 22 nm. The photoresist formulation was optimized and the biocompatibility of 3D hydrogel cell scaffolds was explored. The influence of the focus position on the laser threshold was also comprehensively studied. Furthermore, the biocompatible 3D hydrogel scaffold structures have been fabricated. The protocol proposed in this study is promising for creating complex biocompatible 3D hydrogel structures and exploring the potential applications in microenvironment regulation, tissue engineering, biomedicine, and biomimetic science.

This work is supported by the National Key R&D Program, the Natural Science Foundation of China, and the International Partnership Program of Chinese Academy of Sciences. 

Figure. Schematic illustration of TPP of HAVE 3D hydrogel structures （Image by ZHENG et. al.）

https://doi.org/10.1021/acsami.3c04346