Silk fibroin-Pellethane® cardiovascular patches: Effect of silk fibroin concentration on vascular remodeling in rat model

Abstract

Life-threatening cardiovascular anomalies require surgery for structural repair with cardiovascular patches. The biomaterial patch, derived from Bombyx mori silk fibroin (SF), is used as an alternative material due to its excellent tissue affinity and biocompatibility. However, SF lacks the elastomeric characteristics required for a cardiovascular patch. In order to overcome this shortcoming, we combined the thermoplastic polyurethane, Pellethane® (PU) with SF to develop an elastic biocompatible patch. Therefore, the purpose of this study was to investigate the feasibility of the blended SF/PU patch in a vascular model. Additionally, we focused on the effects of different SF concentrations in the SF/PU patch on its biological and physical properties. Three patches of different compositions (SF, SF7PU3 and SF4PU6) were created using an electrospinning method. Each patch type (n = 18) was implanted into rat abdominal aorta and histopathology was assessed at 1, 3, and 6 months post-implantation. The results showed that with increasing SF content the tensile strength and elasticity decreased. Histological evaluation revealed that inflammation gradually decreased in the SF7PU3 and SF patches throughout the study period. At 6 months post-implantation, the SF7PU3 patch demonstrated progressive remodeling, including significantly higher tissue infiltration, elastogenesis and endothelialization compared with SF4PU6. In conclusion, an increase of SF concentration in the SF/PU patch had effects on vascular remodeling and physical properties. Moreover, our blended patch might be an attractive alternative material that could induce the growth of a neo-artery composed of tissue present in native artery.

High-Throughput Preparation of Silk Fibroin Nanofibers by Modified Bubble-Electrospinning

“…Silk fibroin (SF), a kind of natural protein derived from silkworm cocoons, is a widely used as one of the most popular materials for biomedical applications due to its distinct biological properties [ 1 , 2 ], such as good biocompatibility, biodegradability, good cell adhesion and non-toxicity [ 3 , 4 ]. In recent years, many researches have shown that SF biomaterials can be applied widely in tissue engineering scaffolds [ 5 , 6 ], blood vessel tissue engineering [ 7 ], bone tissue engineering [ 8 ], drug delivery systems, and so on [ 9 , 10 , 11 , 12 ]. Through being dissolved and purified, SF obtained from degummed silk can be used to prepare a variety of biomaterials, such as membranes, gels and fibers.…”

Angioplasty Using 4-Hexylresorcinol-Incorporated Silk Vascular Patch in Rat Carotid Defect Model

“…SF was also incorporated into cardiovascular patches purposed for vascular surgery [41,45]. Additionally, an in vivo study confirmed SF to have favorable biological and physical properties, and that it can be effectively used in vessel reconstruction surgery [41].…”

“…Specifically, studies that employed SF as an artificial vessel confirmed it to have excellent hemocompatibility, cell viability, tissue integrity, and mechanical strength [42][43][44]. SF was also incorporated into cardiovascular patches purposed for vascular surgery [41,45]. Additionally, an in vivo study confirmed SF to have favorable biological and physical properties, and that it can be effectively used in vessel reconstruction surgery [41].…”

“…Other reasons for choosing to employ silk as a vascular tissue engineering scaffolding biomaterial are its low thrombotic and immunologic properties and ease of clinical handling [37,38]. In consideration of these properties, silk was processed into various forms of vascular scaffolds, such as tubes, films, and patches [39][40][41]. Specifically, studies that employed SF as an artificial vessel confirmed it to have excellent hemocompatibility, cell viability, tissue integrity, and mechanical strength [42][43][44].…”

“…As an example, silk mat can be easily and economically manufactured by merely peeling the silk cocoon [24], thus making its manufacturing process simpler than that of the SF vascular patch [40]. Furthermore, vascular patch material should have enough mechanical strength to resist suture retention [41]. Thus, in a previous study, silk mat was evaluated as a patch material against collagen and PTFE membranes; the results revealed silk mat to have the highest tensile strength under wet conditions [27].…”