Recent advances and challenges in silk fibroin-based small-caliber vascular grafts: A review

Cardiovascular diseases are a major cause of morbidity and mortality globally. Currently, commercial synthetic vascular grafts have limited clinical use in small-caliber (<6 mm) vessels due to their propensity to induce thrombosis formation and restenosis after implantation. These high-frequency complications can be thoroughly resolved through the modification of the inner surface for endothelialization or in situ regeneration of defective vessels, in order to restore the balance of the coagulation system. Thus, there is an urgent need for small-caliber vascular grafts to modify their inner surface or replace these materials with bioactive and degradable biopolymers. Bombyx mori silk fibroin (SF) is a fascinating degradable biomaterial that has been continuously developed in the field of vascular tissue engineering over the past 30 years. In vitro and in vivo studies have confirmed that SF exhibits excellent mechanical properties, hemocompatibility, cell compatibility, and low immunogenicity. Herein, the review critically summarized recent advances in SF-based small-caliber vascular grafts, focusing on the biological performance, design strategies, and preclinical outcomes. We further discussed the existing challenges for clinical translation, expecting to provide valuable strategies for the construction of small-caliber vascular grafts to eliminate complications.