Increased stem cells delivered using a silk gel/scaffold complex for enhanced bone regeneration

Abstract

The low in vivo survival rate of scaffold-seeded cells is still a challenge in stem cell-based bone regeneration. This study seeks to use a silk hydrogel to deliver more stem cells into a bone defect area and prolong the viability of these cells after implantation. Rat bone marrow stem cells were mingled with silk hydrogels at the concentrations of 1.0 × 105/mL, 1.0 × 106/mL and 1.0 × 107/mL before gelation, added dropwise to a silk scaffold and applied to a rat calvarial defect. A cell tracing experiment was included to observe the preservation of cell viability and function. The results show that the hydrogel with 1.0 × 107/mL stem cells exhibited the best osteogenic effect both in vitro and in vivo. The cell-tracing experiment shows that cells in the 1.0 × 107 group still survive and actively participate in new bone formation 8 weeks after implantation. The strategy of pre-mingling stem cells with the hydrogel had the effect of delivering more stem cells for bone engineering while preserving the viability and functions of these cells in vivo.

The combination of a poly‐caprolactone/nano‐hydroxyapatite honeycomb scaffold and mesenchymal stem cells promotes bone regeneration in rat calvarial defects

“…This complete coverage could be explained by the honeycomb pattern's promotion of extracellular matrix synthesis and upregulation of type II collagen (Eniwumide et al, 2014). Alternatively, it might be due to the high seeding density—a strategy known to have delivered more cells while preserving the latter's viability and functions in vivo (Ding et al, 2017).…”

3D bioactive composite scaffolds for bone tissue engineering

“…Ding et al. adapted a hybrid approach, whereby SF hydrogels were used to deliver rat MSCs to a SF scaffold [380] . In vivo analysis in a calvarial defect found that encapsulated cells were still viable and actively participating in new bone formation 8 weeks after implantation.…”

Evaluation of Neurosecretome from Mesenchymal Stem Cells Encapsulated in Silk Fibroin Hydrogels

“…This is in line with the possibility that MSCs confined in the interior of these hydrogels have cytoskeletal aberrations incompatible with normal growth. In relation to silk, a previous study reported that MSCs survive for up to 10 days in culture when encapsulated in SF hydrogels while they have a moderate proliferation rate 56 . Parallel studies have examined the effect of SF stiffness on MSCs survival, finding that MSCs viability inside SF hydrogels is drastically reduced at polymer concentrations higher than 4–6% 31,32 .…”