Surgical preparation of bone–scaffold interface is critical for bone regeneration inside tissue engineering scaffold

Abstract

The goal of this study was to investigate if the preparation of implantation site affects bone formation inside tissue engineering scaffolds. For this purpose, two different drilling techniques were used to create a hole in distal femurs of rats before the insertion of a bone scaffold: a manually driven wood drill bit and an electrically driven metal drill bit. The size and the position of the hole were identical for the two cases. The bone volume, bone mineral density, and callus formation were assessed noninvasively using micro-CT tomography at several time points after implantation. The formation of bone and soft tissue inside scaffold were evaluated by histology. The bone structure around the holes made by the two techniques was compared ex vivo. The long-term study of bone formation showed that when a wood drill bit was used, the bone formation is accelerated by 3 weeks compared to when a metal drill bit was used. The ex vivo studies suggest that this result is due to the drilling methods differentially affecting the structure of the bone surrounding the generated defects. ß

Prediction of spatio-temporal bone formation in scaffold by diffusion equation

“…It also depends on the ease with which cells and other biological agents diffuse inside the scaffold. The peri-implant osteoinduction coefficient, h, is a property of the surrounding tissue and it depends on the species, age, site of implantation, vascularity of the surrounding tissue, and the quality of the interface between scaffold and bone [13]. The value of the peri-implant osteoinduction coefficient could then varied between different clinical situations.…”

“…In order to satisfy (13) Bi$J 0 ðgÞ ¼ gJ 1 ðgÞ (25) which is satisfied at g i (i ¼ 1,2,3,.). Similarly, satisfying (15) will result in Bi ¼ butanðuÞ (26) which is satisfied at u j (i ¼ 1,2,3,.).…”

“…It involves migration of several cell types [1], proliferation [2], differentiation [3], angiogenesis [4,5], and mineralization [6], as well as the interaction of numerous cytokines and growth factors [7]. Bone formation also depends on the architecture of the scaffold [8], its surface properties [9], the mechanical stimulation [10,11], the implantation site [12], and the boneescaffold interface [13]. Probing the effects of each parameter and their interaction has proven challenging.…”

The Combined Use of Mesenchymal Stromal Cells and Scaffolds for Bone Repair

“…The cutting geometry was found different, and less blood extravasated after metal drilling, suggesting that the cavity formed by the wood drill allowed more growth factors to enter from the hematoma into the scaffold, so fostering bone maturation [114]. In an in vivo study, the effect of two drilling techniques for bone preparation (manual vs electric, and wood vs metal) on the long term bone regeneration was assessed.…”