About Our Group:

Our lab is located in the Department of Chemical Engineering and Technology at Tianjin University, China. We are committed to designing and developing functional biomedical polymers based on the concept of bionics for tissue engineering, regenerative medicine, stem cell therapy, life visualization, and electronic skin fields.

The story behind the paper:

Zwitterionic hydrogels exhibit eminent non-fouling and hemocompatibility. Several key challenges hinder their application as coating materials for blood-contacting biomedical devices, including weak mechanical strength and low adhesion to the substrate. But now, Junjie Li, Tianjin University, Tianjin, China, and colleagues have developed poly(carboxybetaine) microgel reinforced poly(sulfobetaine) (pCBM/pSB) zwitterionic hydrogel that acts as an effective anticoagulant coating materials.

“This zwitterionic hydrogel has a unique two phases structure and is stronger than most other zwitterionic hydrogels”, said Prof. Junjie Li at Tianjin University. The sparsely cross-linked pSB network acted as a continuous phase, which restricted deformation by “locking” the entire hydrogel by the electrostatic interactions. The dispersed phase was a double-network microgel composed of interpenetrating pSB and pCB chains. The mechanical and anti-swelling properties of hydrogels were enhanced through the synergistic effect of the two phases.

We employed a simple surface initiation strategy to improve the binding force between pCBM/pSB hydrogels and PVC substrates. When damaged by an external force, the strong binding force enabled energy transfer from the surface to the pCBM/pSB hydrogel, which avoided the separation of the coating from the substrate through its internal energy dissipation mechanism. “This pCBM/pSB hydrogel coating can be easily coated the inner wall of commercial blood circulation PVC tubing, and the thickness of the coating is very thin and uniform and does not affect blood flow”, said Mengmeng Yao, Ph.D., in the Tianjin University and the first author of the study.

We tested the antithrombogenicity properties of the PVC tubing with/without pCBM/pSB hydrogel coating. For this, they used a New Zealand white rabbit veno-venous extracorporeal circuit. They found that the thrombus weight on the pCBM/pSB hydrogel coating was reduced 8 times compared to that on PVC tubing. The pCBM/pSB hydrogel coating shows an ultralow occlusion rate, with a reduction of over 71.8 % of occlusion rate compared with PVC tubing. This long-term durability and strong adhesion zwitterionic hydrogel is a promising candidate to decrease the thrombosis of blood-contacting biomedical devices. Currently, we are moving on toward the development of clinical animal research.

The link for paper in Nature Communications is here: 

https://doi.org/10.1038/s41467-022-33081-7

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