Assessment of activated porous granules on implant fixation and early bone formation in sheep

Abstract

SummaryBackground/ObjectiveDespite recent progress in regeneration medicine, the repair of large bone defects due to trauma, inflammation and tumor surgery remains a major clinical challenge. This study was designed to produce large amounts of viable bone graft materials in a novel perfusion bioreactor to promote bone formation.MethodsCylindrical defects were created bilaterally in the distal femurs of sheep, and titanium implants were inserted. The concentric gap around the implants was randomly filled either with allograft, granules, granules with bone marrow aspirate (BMA) or bioreactor activated granule (BAG). The viable BAG consisted of autologous bone marrow stromal cells (BMSCs) seeded upon porous scaffold granules incubated in a 3D perfusion bioreactor for 2 weeks prior to surgery. 6 weeks after, the bone formation and early implant fixation were assessed by means of micro-CT, histomorphometry, and mechanical test.ResultsMicroarchitectural analysis revealed that bone volume fraction and trabecular thickness in the allograft were not statistically different than those (combination of new bone and residue of granule) in the other 3 groups. The structure of the allograft group was typically plate-like, while the other 3 groups were combination of plate and rod. Histomorphometry showed that allograft induced significantly more bone and less fibrous tissue in the concentric gap than the other 3 granule groups, while the bone ingrowth to implant porous surface was not different. No significant differences among the groups were found regarding early implant mechanical fixation.ConclusionIn conclusion, despite nice bone formation and implant fixation in all groups, bioreactor activated graft material did not convincingly induce early implant fixation similar to allograft, and neither bioreactor nor by adding BMA credited additional benefit for bone formation in this model.

Titanium Nanobowl-Based Nest-Like Nanofiber Structure Prepared at Room Temperature and Pressure Promotes Osseointegration of Beagle Implants

“…There are various methods for surface modification of titanium, such as grit blasting ( Qingge Wang et al, 2020 ), acid etching ( Han et al, 2019 ; Nobre et al, 2020 ), electrochemical anodic oxidation ( Cho et al, 2015 ), hydrothermal method ( Vishnu et al, 2019 ), sol-gel ( Xue et al, 2020 ), and plasma spraying ( Ding et al, 2016 ), which can lead to different micro- and nanostructures on the surface of the titanium. Two or more methods can also be combined to make special structures on the surface of the titanium.…”

Translational study of orthopaedic biomaterials and devices

“…Owing to its amphiphilic characteristic, this composite can be supplemented with small hydrophobic molecules or biologics, for example to provide controlled release of both rhBMP-2 and dexamethasone for improved osteoinductivity. Similar efforts have been made by Ding’s group, who developed and tested bone graft materials in a novel perfusion bioreactor to promote bone formation [11] .…”

Biofunctionalization with a TGFβ-1 Inhibitor Peptide in the Osseointegration of Synthetic Bone Grafts: An In Vivo Study in Beagle Dogs

“…No standardized, objective, and systematic measurement has been proposed to date to assess the bone tissues in living contact with the biomaterial fragment’s surface. Alt et al [52] and Ding et al [53] propose that the histomorphometric analysis be made with histological images, but different parameters and regions of interest (ROIs) are proposed. Our analysis was made also on the whole perimeter of the alveolar defect as represented in a stitched complete image of the mandible.…”