Facilitating tissue infiltration and angiogenesis in a tubular collagen scaffold

Abstract

Among different strategies to provide blood supply to tissue-engineered devices and implants, the use of arteriovenous loops and bundles has been proposed. The aim of this study was to compare the vascularization and healing processes that took place in a one-end closed tubular collagen-based scaffold at different implantation sites in mice. These conditions were in the presence or absence of heparin and/or bone marrow cells. By 30 days, very few cell infiltrations were observed in the dorsal subcutaneous and peritoneal implants at any conditions; however, the presence of heparin and bone marrow cells improved cell infiltration toward an inflammatory reaction. The insertion of an arteriovenous bundle into the central cavity of the scaffold resulted in partial wound tissue infiltration in the control scaffolds implanted subcutaneously in the hind limb. In similar conditions, the presence of bone marrow cells and heparin resulted in dense wound tissue with numerous capillaries and a significant amount of newly deposited collagen fibers. The design of a central cavity in a porous scaffold with one closed end may facilitate invasion from the central part of the implant toward the implant wall. In addition, the presence of both a vascular component and stem/progenitor cells may lead to a vascularized implant while limiting the inflammatory reaction.

Influence of Architecture of β-Tricalcium Phosphate Scaffolds on Biological Performance in Repairing Segmental Bone Defects

“…But the use of porous scaffolds as bone substitutes for large segmental bone defect treatment is usually hindered by the limited bone ingrowth, especially in the center region of grafts [19]. On the other hand, tubular design has been proposed in several studies as well, in order to mimic the tubular structure of long bone, with potential efficacy to facilitate bone tissue infiltration and vascularization [20], [21]. However, how the tubular scaffolds compared to porous ones as bone graft substitutes in terms of their osteoconductivity (bone tissue ingrowth) and vascularization during the defect treatment still remains elusive.…”

A cellular delivery system fabricated with autologous BMSCs and collagen scaffold enhances angiogenesis and perfusion in ischemic hind limb

“…A variety of porous naturally derived scaffold or synthetic scaffold have demonstrated potential for therapeutic angiogenesis. A three‐dimensional scaffold acting as a cellular delivery vehicle can facilitate the exchange of oxygen and nutrients for cell growth, differentiation, and tissue functionality 12…”

“…A three-dimensional scaffold acting as a cellular delivery vehicle can facilitate the exchange of oxygen and nutrients for cell growth, differentiation, and tissue functionality. 12 Lyophilized type I collagen can stimulate wound healing by recruiting a number of different cell types (i.e., platelets and macrophages) and proteins (i.e., fibronectin). 13 Platelets and macrophages produce locally acting growth factors that in turn induce fibroblast migration and angiogenesis and increase matrix synthesis.…”

Extra low interstitial titanium based fully porous morphological bone scaffolds manufactured using selective laser melting

“…However, it was found that a sheathed design was unfeasible due to limited vascularisation and the risk of infection due to avascular fluid build-up. In addition, tubular stents proposed in several earlier studies altered the natural loading pattern of the bone anatomical mismatch [69][70][71]. Accordingly, it is evident that stress shielding, osseointegration, and maladapted stress concentration are still a challenging problem for bone scaffolds.…”