Large-Scale Nanofiber Manufacturing| Hierarchical Biomimetic Electrospun Vascular Grafts forImproved Patency and Regeneration

Professor Wang Yunbing & Associate Researcher Fu Daihua from Sichuan University (AFM): Hierarchical Biomimetic Electrospun Vascular Grafts Achieve Balanced Regeneration

Against the backdrop of rising global cardiovascular disease mortality, the team of Professor Wang Yunbing and Associate Researcher Fu Daihua from Sichuan University innovatively proposed the design concept of "hierarchical biomimesis, balanced regeneration," successfully developing a new generation of small-diameter vascular grafts (SDVGs). This study constructs a three-level biomimetic coordination system of molecule-structure-function, effectively regulating rapid endothelialization and balanced regeneration of smooth muscle tissue. In large animal experiments, the vascular graft showed an endothelial coverage rate exceeding 86% and collagen deposition reaching 78% of natural blood vessels at 12 weeks post-operation, with no obvious signs of calcification or restenosis, fully verifying its superior long-term patency and tissue reconstruction capabilities. Related achievements were published in the internationally renowned journal Advanced Functional Materials.

Coronary artery bypass grafting (CABG) is a critical treatment for cardiovascular diseases, but the application of traditional vascular graft materials in small-diameter vascular grafts (diameter < 6 mm) faces severe challenges. Existing materials easily induce thrombosis, inflammatory responses, and intimal hyperplasia, leading to graft failure. To date, no mature small-diameter vascular graft products have been applied clinically. 

The research team developed a double-layer biomimetic vascular system: 

• the inner dense electrospun structure mimics the natural vascular intima, effectively blocking blood leakage; 

• the outer loose porous structure guides orderly migration and regeneration of smooth muscle cells, promoting vascular wall reconstruction.

A polydopamine (PDA)-copper ion (Cu²⁺)-REDV biomimetic endothelial coating system was further constructed to simulate natural vascular endothelial functions: 

• PDA mimics the endothelial glycocalyx to reduce thrombus risk induced by blood contact, while providing functional groups to chelate Cu²⁺ and endow the graft with anti-inflammatory capabilities; 

• Cu²⁺ catalyzes the release of endogenous RSNO to achieve long-term anticoagulation and vascular protection; 

• REDV peptide promotes rapid adhesion, proliferation, and migration of endothelial cells by specifically binding to α4β1 integrin, accelerating endothelialization.

The dual-layer structure synergizes with the biomimetic coating to achieve a dynamic balance between "promoting regeneration" and "preventing stenosis": 

• the NO-REDV-dense inner layer collaboratively accelerates the formation of a functional endothelial layer, critical for restoring vascular function and maintaining long-term patency. 

• The outer large-pore structure promotes smooth muscle cell migration to support vascular tissue reconstruction; NO regulates smooth muscle cell growth to prevent excessive proliferation and restenosis, achieving balanced smooth muscle regeneration.

Figure 1: Schematic of hierarchical biomimetic SDVG: promoting endothelialization and balanced regeneration.

Figure 2: Beagle dog iliac artery SDVG implantation experiment: evaluation of vascular patency and regeneration.

The study, titled Hierarchical Biomimetic Electrospun Vascular Grafts for Improved Patency and Regeneration, was published in Advanced Functional Materials. The co-first authors are Ph.D. candidate Xiang Zhen from the National Center for Biomedical Materials Engineering Technology Research of Sichuan University and attending physician Xiang Yuwei from West China Hospital of Sichuan University. The corresponding authors are Professor Wang Yunbing and Associate Researcher Fu Daihua from the National Center for Biomedical Materials Engineering Technology Research of Sichuan University. This research was funded by the National Key Research and Development Program (2022YFC2409100), the Innovation Unit of the Chinese Academy of Medical Sciences (CIFMS, 2021-I2M-5-013), the State Key Laboratory of Polymer Materials Engineering (sklpme2024-2-03), and the Fundamental Research Funds for Central Universities (2023SCUH0010).