Engineering clinically relevant volumes of vascularized bone

Abstract

Vascularization remains one of the most important challenges that must be overcome for tissue engineering to be consistently implemented for reconstruction of large volume bone defects. An extensive vascular network is needed for transport of nutrients, waste and progenitor cells required for remodelling and repair. A variety of tissue engineering strategies have been investigated in an attempt to vascularize tissues, including those applying cells, soluble factor delivery strategies, novel design and optimization of bio-active materials, vascular assembly pre-implantation and surgical techniques. However, many of these strategies face substantial barriers that must be overcome prior to their ultimate translation into clinical application. In this review recent progress in engineering vascularized bone will be presented with an emphasis on clinical feasibility.

Effect of prevascularization on in vivo vascularization of poly(propylene fumarate)/fibrin scaffolds

“…HUVECs not only form vascular networks but also promote osteogenesis and proliferation of hMSCs [27–30]. The hMSCs lead to bone formation while acting as trophic mediators for endothelial cells by secreting proangiogenic factors and acting as a scaffold for the formation and stabilization of vascular units [31, 32]. …”

“…Combining these prevascularization strategies with resorbable scaffolding biomaterials could ensure the appropriate size and shape of the forming bone [31]. Poly(propylene fumarate) polymer is a photocrosslinkable, biocompatible and resorbable biomaterial which can be 3-D printed into almost any desirable shape and size and can be rendered with high mechanical strength [33, 34].…”

Characterization and angiogenic potential of xenogeneic bone grafting materials: Role of periodontal ligament cells

“…Often, supraphysiological doses are administered with possible adverse effects 5,7) . Furthermore, recombinant protein costs represent a significant financial burden for the patient 8) . Interestingly, it has been shown that various bone grafting materials, successfully used in clinic, have a high angiogenic potential.…”

Biologically Inspired Smart Release System Based on 3D Bioprinted Perfused Scaffold for Vascularized Tissue Regeneration

“…However, nutrient and waste exchange between individual cells and capillary vessels in bone is limited to distances of 100–300 μm. Therefore, construction of vascularized bone grafts plays a vital role in regenerating and remodeling bone tissue 1. The blood vessels in native bone are critical for transport of oxygen and nutrients to maintain skeletal tissue functions.…”