Channeled β‐TCP Scaffolds Promoted Vascularization and Bone Augmentation in Mandible of Beagle Dogs

Abstract

A major hindrance to successful alveolar bone augmentation and ridge preservation using synthetic scaffolds is insufficient vascularization in the implanted bone grafts. The slow ingrowth of host vasculature from the bone bed of alveolar bone to the top of the implanted bone grafts leads to limited bone formation in the upper layers of the implanted grafts, which hinders the subsequent implantation of titanium dental implants. In this study, macroporous beta‐tricalcium phosphate (β‐TCP) scaffolds with multiple vertical hollow channels are fabricated that play a similar role as blood vessels for nutrient diffusion and cell migration. The results show that the hollow channels accelerate the degradation rate of the β‐TCP scaffolds and the in vitro release of a bone forming peptide‐1, which significantly promote proliferation and osteogenesis of human bone mesenchymal stem cells on the channeled scaffolds, compared to nonchanneled scaffolds in vitro. More volume of newly formed bone tissues with more blood vessels are augmented in the channeled scaffolds when implanted in mandibular bone defects of beagle dogs. Channeled scaffolds significantly promote new bone formation and augment the height of the mandible. These findings indicate channeled scaffolds facilitate vascularization and bone formation and have great potential for vascularized bone augmentation.

The synergistic effect of bone forming peptide‐1 and endothelial progenitor cells to promote vascularization of tissue engineered bone

“…The combination of these proangiogenic growth factors with bioceramic scaffolds to enhance the vascularization of engineered bone grafts has been introduced, such as silica‐calcium phosphate nanocomposite combined with BMP‐2 to repair bone defects, and high vascularization were observed in the regenerated bone, however, these growth factors were either too expensive or unstable to administrate in vivo which limited their application . BFP‐1 was reported to have the potential of increasing VEGF receptor expression in endothelial cells and of enhancing the vascularization subsequently . Additionally, BFP‐1 was easy to synthesize at lower cost .…”

“…However, these growth factors are either too expensive to acquire or too poor to sustain in vivo due to the fast clearance. Recently, a peptide called bone forming peptide‐1 (BFP‐1) which derived from the immature region of bone morphogenetic protein‐7, has been reported to enhance vascularization through upregulating the expression level of VEGF receptor in endothelial cells …”

“…Recently, a peptide called bone forming peptide-1 (BFP-1) which derived from the immature region of bone morphogenetic protein-7, has been reported to enhance vascularization through upregulating the expression level of VEGF receptor in endothelial cells. 18 Therefore, in our current study, we added EPCs onto the BFP-1 laden beta-tricalcium phosphate (b-TCP) scaffolds to construct a vascularized bone grafts, we hypothesized that the combination of BFP-1 and EPCs will synergistically and vigorously enhance the vascular formation in engineered bone constructs and promote the integration of grafts with host tissue. We first investigated the angiogenic effects of BFP-1 on rabbit peripheral blood derived EPCs, and fabricated the EPCs-laden b-TCP/BFP-1 constructs, then implanted the engineered bone constructs into femur shaft segmental bone defects of rabbits to evaluate the vascularization and osteogenesis efficacy of the constructs.…”

3D Bioprinting of Artificial Tissues: Construction of Biomimetic Microstructures

“…Vascular networks play important role in supplying cells/tissues with essential oxygen and nutrients. Many strategies have been developed to build vascular networks in tissue engineering including cell‐based, growth factor‐based, scaffold‐based, and AV loop model methods. More details about these approaches can be found in previous reviews .…”

Modification of honeycomb bioceramic scaffolds for bone regeneration under the condition of excessive bone resorption

“…It is generally regarded that the minimum pore size of 100 μm supports bone ingrowth, and the size >300 μm is more beneficial for vascularization . Many studies demonstrated that the channel‐like pores facilitated fast vascularization and cell growth, thus conducing to better new bone regeneration . Previously, we originally fabricated honeycomb β‐TCP scaffolds through an extrusion method featuring high production.…”