Bone Healing in Critical-Size Defects Treated With Immediate Transplant of Fragmented Autogenous White Adipose Tissue

Abstract

This study analyzed the influence of fragmented autogenous white subcutaneous adipose tissue (WSAT) on bone healing in critical-size defects created in rabbit calvaria. A 15-mm diameter defect was created in the calvaria of 42 rabbits, which were treated with 86 mm3 WSAT grafts or filled only with blood clots (control). Animals were euthanized at 7, 15, and 40 days postsurgery (n = 7), and the data were analyzed using histomorphometry and immunohistochemistry using the anti-CD34 and bone morphogenetic protein-2 (BMP2) antibodies. The calvaria treated with only blood clots demonstrated positivity to CD34 concentrated in endothelial cells, whereas the BMP2 were restricted to the borders of the defects. In contrast, the group treated with WSAT revealed fatty cells exhibiting positivity to BMP2 both in membrane and cytoplasm and intense quantities of stromal spindle cells that exhibited positivity to CD34 simultaneously to BMP2; these results together coincided with a larger bone matrix deposited in all postsurgery periods analyzed. These results revealed that the WSAT may be an alternative to craniofacial bone reconstruction because the adipose tissue exhibited prominent immunoexpression of BMP2, which was coexpressed with stromal CD34+ cells, indicating the plasticity of CD34+ stem cells into osteoblasts, and in the adipocytes, facts that suggest bone tissue development through cellular transdifferentiation from adipocytes.

Critical size defects for bone regeneration experiments in rabbit calvariae: systematic review and quality evaluation using ARRIVE guidelines

“…; Gomes et al. ; Oliveira et al. ). Rectangular defects Defects of 15 × 13 mm are critical up to 12 weeks (Clokie et al.…”

Bone grafting materials in critical defects in rabbit calvariae. A systematic review and quality evaluation using ARRIVE guidelines

“…Studies performed in rabbit calvariae have found that defects of over 15 mm can be considered critical (Hollinger et al 1989;Hollinger & Kleinschmidt 1990;Schmitz & Hollinger, 1996). The present review found that 15 mm defects were frequently used in the studies included (Kleinschmidt et al 1993;Clokie et al 2002;Kroese-Deutmanx et al 2006;Hadad et al 2006;Nagata et al 2009;Di Bella et al 2008;Humber et al 2010;Ma et al 2010;Dumas et al 2012;Gomes et al 2012;Kim et al 2012;Oliveira et al 2013), but some used smaller defects (Wong & Rabie 1999;Pripatnanont et al 2007;Moxham et al 2007;Pripatnanont et al 2009;Borie et al 2011;Lin et al 2013;Calvo-Guirado et al 2014;Cabrejos Azama et al (2014).…”

The influence of the protein Wnt10b as a marker of bone repair of critical size defects fille with autogenous adipose tissue graft: A study in rabbit calvaria

“…In this regard, the autogenous adipose tissue can theoretically serve as an important and abundant source of multipotent adult stem cells, since it contains approximately 100 times more stem cells than the bone marrow do, with suitable properties for tissue engineering and tissue regeneration with orthopedic purposes 19 . Moreover, new findings show that subcutaneous adipose tissue and bone marrow tissue share the same stem cell phenotype.…”