Published online Jan 26, 2020. doi: 10.4252/wjsc.v12.i1.55
Peer-review started: March 8, 2019
First decision: April 16, 2019
Revised: May 13, 2019
Accepted: November 29, 2019
Article in press: November 29, 2019
Published online: January 26, 2020
Critically sized bone defects represent a significant challenge to orthopaedic surgeons worldwide. These defects generally result from severe trauma or resection of a whole large tumour. Autologous bone grafts are the current gold standard for the reconstruction of such defects. However, due to increased patient morbidity and the need for a second operative site, other lines of treatment should be introduced. To find alternative unconventional therapies to manage such defects, bone tissue engineering using a combination of suitable bioactive factors, cells, and biocompatible scaffolds offers a promising new approach for bone regeneration.
To evaluate the healing capacity of platelet-rich fibrin (PRF) membranes seeded with allogeneic mesenchymal bone marrow-derived stem cells (BMSCs) on critically sized mandibular defects in a rat model.
Sixty-three Sprague Dawley rats were subjected to bilateral bone defects of critical size in the mandibles created by a 5-mm diameter trephine bur. Rats were allocated to three equal groups of 21 rats each. Group I bone defects were irrigated with normal saline and designed as negative controls. Defects of group II were grafted with PRF membranes and served as positive controls, while defects of group III were grafted with PRF membranes seeded with allogeneic BMSCs. Seven rats from each group were killed at 1, 2 and 4 wk. The mandibles were dissected and prepared for routine haematoxylin and eosin (HE) staining, Masson's trichrome staining and CD68 immunohistochemical staining.
Four weeks postoperatively, the percentage area of newly formed bone was significantly higher in group III (0.88 ± 0.02) than in groups I (0.02 ± 0.00) and II (0.60 ± 0.02). The amount of granulation tissue formation was lower in group III (0.12 ± 0.02) than in groups I (0.20 ± 0.02) and II (0.40 ± 0.02). The number of inflammatory cells was lower in group III (0.29 ± 0.03) than in groups I (4.82 ± 0.08) and II (3.09 ± 0.07).
Bone regenerative quality of critically sized mandibular bone defects in rats was better promoted by PRF membranes seeded with BMSCs than with PRF membranes alone.
Core tip: Our findings are derived from a rat model for treating critical-sized mandibular bone defects. Defects were grafted with platelet-rich fibrin (PRF) membranes seeded with allogeneic bone marrow-derived stem cells (BMSCs). Our findings confirm the in vivo anti-inflammatory effects of allogenic BMSCs. In addition, BMSCs seeded on the PRF membranes exhibited beneficial syngeneic effects in promoting and accelerating the healing of critically sized mandibular defects. Routine and specific histological and immunohistochemical staining demonstrated for the first time that experimentally treated critically sized mandibular defects with PRF membrane and BMSC combined therapy increased the amount and the rate of the newly formed bone and decreased the amount of granulation tissue with a reduction in the number of inflammatory cell infiltrates.