Silk fibroin scaffolds loaded with angiogenic genes in adenovirus vectors for tissue regeneration

Abstract

Vascularization remains a critical challenge in dermal tissue regeneration. In this study, a vascular endothelial growth factor (VEGF165) and angiopoietin‐1 (Ang‐1) dual gene coexpression vector that encoded green fluorescent protein (GFP) was constructed from an arginine–glycine–aspartic acid‐modified adenovirus. Silk fibroin (SF) scaffolds loaded with adenovirus vectors were fabricated by freeze‐drying method. In vitro, the human endothelial‐derived cell line EA.hy926 was infected with adenovirus vectors and then expressed GFP, secreted VEGF165 and Ang‐1, and promoted cell proliferation effectively. The VEGF165 and Ang‐1 genes loaded in the SF scaffolds significantly promoted the formation of abundant microvascular networks in the chick embryo chorioallantoic membrane. In vivo, angiogenic genes loaded in the scaffolds promoted vascularization and collagen deposition in scaffolds, thus effectively accelerating dermal tissue regeneration in a dorsal full‐thickness skin defect wound model in Sprague–Dawley rats. In conclusion, SF scaffolds loaded with arginine–glycine–aspartic acid‐modified adenovirus vectors encoding VEGF165 and Ang‐1 could stimulate the formation of vascular networks through the effective expression of target genes in vascular endothelial cells, thereby accelerating the regeneration of dermal tissue.

Angiogenic property of silk fibroin scaffolds with adipose-derived stem cells on chick chorioallantoic membrane

“…Our finding is consistent with a previously published report [40]. In that study, several blood vessels were seen underneath the freezedried SF scaffolds after 4 days of implantation on the CAM [40]. Their finding also suggested the angiogenic capability of the SF scaffolds, although a sham control was not included.…”

“…We believe that the filter paper is biologically inert, as they have been used as a negative control in various angiogenic molecule-delivery experiments [30,38,39]. Our finding is consistent with a previously published report [40]. In that study, several blood vessels were seen underneath the freezedried SF scaffolds after 4 days of implantation on the CAM [40].…”

“…The scaffolds made from PET alone resulted in less blood vessel density compared to the SF-PET scaffolds after 4 days of incubation [41]. Both mentioned works reported the angiogenic induction by the modified SF scaffolds after 4 days of implantation on the CAM while our SF-hADSC scaffolds induced the angiogenesis within 3 days after implantation [40,41]. This means that our SF scaffolds with the hADSCs promote the angiogenesis earlier than other modifications.…”

“…This means that the SF-hADSC scaffolds took only 3 days while the SF scaffolds alone took 6 days. A previous study conducted using adenovirus vector-modified SF scaffolds (SF-Ad scaffolds) containing angiogenic genes showed that the SF-Ad scaffolds promoted the microvascular network formation 4 days after implantation onto E8 CAM [40]. Another study was done by implanting SF-monofilament of polyethylene terephthalate (SF-PET) and monofilament of polyethylene terephthalate (PET) textile scaffolds in E10 embryos [41].…”

Research progress of natural silk fibroin and the application for drug delivery in chemotherapies

“…The results have found that: 1) the use of fibroin nanoparticles as a non-toxic, biocompatible delivery carrier to enhance the feasibility of tumor treatment effects that have a little inhibitory effect on normal cells; 2) the fibroin can be prepared with other materials into a composite carrier (such as: cellulose acetate, gold and silver nanoparticles, adenovirus, gelatin, etc. ), among them, the scaffold of silk fibroin loaded with amino acid modified adenovirus can stimulate the formation of vascular network and thus accelerate the regeneration of dermal tissue, and the composite nanofibers made of silk fibres have a high inhibitory effect on tumor cells ( Wang et al, 2019c ); 3) the surface of silk fibroin can be properly modified to meet different needs. For example, the sustained-release behavior of adriamycin can be enhanced by modifying the surface of silk fibroin with Tween 80 as surfactant; 4) silk fibroin can be prepared into nanocarriers with stimulation response, which can be triggered by the changes of pH value, ultraviolet, near infrared, ultrasonic and magnetic field, to accurately release the drug at the tumor site and enhance the curative effect; 5) the composite nanoparticles prepared from silk fibroin can also significantly improve the tumor inhibition effect through the combination of photothermal therapy (PTT)/tumor-specific photodynamic therapy (PDT)/chemotherapy, with minimal systemic toxicity or adverse reactions; 6) the combination with specifically targeted ligands (such as antibody, growth factor, transferrin, polypeptide, polysaccharide, etc.)…”