Ginsenoside Rg1 promotes endothelialization of tissue-engineered blood vessels in transplanted rats

Abstract

Objective To prepare the endothelialization-promoting tissue-engineered blood vessels (TEBVs) with encapsulated Ginsenoside Rg1 (Rg1) to promote endothelialization, and to evaluate its patency and endothelialization after implantation into the rat common carotid artery. Methods CCK-8 assay and flow cytometry were used to detect the effects of Rg1 on the proliferation and apoptosis of endothelial cells (ECs) after 48 hours' treatment, and the optimal dose of the agent was also determined. ECs was divided into control group, Rg1 treatment group (15.63 μmol/L Rg1), and Rg1+XL184 (15.63 μmol/L Rg1+0.5 μg/mL XL184, VEGFR2 inhibitor) treatment group. Cell proliferation and wound healing of ECs were examined after the treatment for 48 h. Chitosan coated Rg1-(2-hydroxypropyl)-cyclodextrin particles (Rg1-HGC/CS NPs, abbreviated as NPs) were prepared and modified to the lumen of blood vessels (after decellularization and collagen treatment), and then Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM) were used to detect these obtained samples. ECs were co-cultured with acellular vessels and TEBVs for 48 h to observe the biocompatibility. For in vivo study, the acellular vessels were divided into collagen group (collagen treatment), blank CS group (collagen and chitosan treatment), and NPs group (modified with NPs). Then these vessel samples were transplanted into the left common carotid artery of SD rats respectively. Ultrasound and micro-CT scanning were performed to observe the vascular patency in 30 and 90 d after transplantation. HE and Masson staining and immunofluorescence assay for CD31 and vWF were used to observe the endothelialization in each group in 90 d after transplantation. Results Rg1 promoted the proliferation and migration of ECs via VEGFR2 (P < 0.05), and showed no significant effect on apoptosis. The prepared NPs were about 130 nm in diameter and uniform in shape (PDI < 0.3), and could be successfully modified to the lumen of blood vessels. The co-cultured study showed that endothelialization-promoting TEBVs displayed better biocompatibility for favorable of cell adhesion and growth. In 30 and 90 d after transplantation, radiological studies displayed that the NPs-treated vessels showed better vascular patency than the other groups. HE and Masson staining indicated that in 90 d after transplantation, the collagen and blank CS groups had blood vessels deformed, without normal structures and blocked due to the thrombosis and collagen fibrosis, while the NPs group had intact blood vessels and better patency. Immunofluorescence assay for CD31 and vWF showed that the lumen in the vessles from the NPs group had ECs well-covered, suggesting better endothelialization when compared with other groups. Conclusion Endothelialization-promoting TEBVs shows better promoting effect on endothelialization, and is helpful in maintenance of long-term patency of blood vessels after transplantation.

Keywords

• tissue-engineered blood vessels
• endothelial cells
• ginsenoside rg1
• endothelialization