Accelerated repair of cortical bone defects using a synthetic extracellular matrix to deliver human demineralized bone matrix

To improve ostegenic healing efficiency by demineralized bone matrix, we evaluated the ectopic bone formation induced by variously demineralized allogenic cortical bone matrices at subcutaneous and muscular sites in rats. The rat tubular cortical bone matrices were demineralized in heated 0.6N HCl at 60 °C for 5 and 20 mins, respectively, using a controlledheat ultrasonic cleaner and implanted in rat dorsal subcutaneous pouches and thigh muscles for 1-3 weeks. The influence of the demineralized condition of bone matrix on cellular proliferation and osteogenic differentiation was also evaluated in vitro by MTT assay and ALP staining. The cortical matrices were completely demineralized within 20 mins by sonication and heating of diluted 0.6 N HCl. The sonicated bone matrices in heated acidic solution at 60 °C revealed no adverse immunogenic and inflammatory response in vivo regardless of demineralized condition. Cellular proliferation and osteoblastic differentiation was facilitated by more fully demineralized. Ectopic bone formation was induced only by demineralized bone matrices and were more favorable in fully demineralized matrices. The ectopic bone induction was more favorably in subcutaneous pouches than in muscular tissue. These findings suggest that a fully demineralized cortical bone matrix maximizes osteogenic repair by exposing more bioactive molecules which in turn induce chondro- and osteognic differentiation of mesenchymal cells around the implanted matrices, and that the sonication of diluted 0.6 N HCl heated at 60 ° C is a rapid and effective method for sterile demineralized graft preparation.

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Evaluation of Mesenchymal Stem Cell Sheets Overexpressing BMP-7 in Canine Critical-Sized Bone Defects

International Journal of Molecular Sciences ◽

10.3390/ijms19072073 ◽

2018 ◽

Vol 19 (7) ◽

pp. 2073 ◽

Cited By ~ 5

Author(s):

Yongsun Kim ◽

Byung-Jae Kang ◽

Wan Kim ◽

Hui-suk Yun ◽

Oh-kyeong Kweon

Keyword(s):

Bone Defect ◽

Therapeutic Potential ◽

Demineralized Bone Matrix ◽

Bone Matrix ◽

Bone Defects ◽

Trophic Factors ◽

Gene Expressions ◽

Cell Sheets ◽

Demineralized Bone

The aim of this study was to investigate the in vitro osteogenic capacity of bone morphogenetic protein 7 (BMP-7) overexpressing adipose-derived (Ad-) mesenchymal stem cells (MSCs) sheets (BMP-7-CS). In addition, BMP-7-CS were transplanted into critical-sized bone defects and osteogenesis was assessed. BMP-7 gene expressing lentivirus particles were transduced into Ad-MSCs. BMP-7, at the mRNA and protein level, was up-regulated in BMP-7-MSCs compared to expression in Ad-MSCs. Osteogenic and vascular-related gene expressions were up-regulated in BMP-7-CS compared to Ad-MSCs and Ad-MSC sheets. In a segmental bone-defect model, newly formed bone and neovascularization were enhanced with BMP-7-CS, or with a combination of BMP-7-CS and demineralized bone matrix (DBM), compared to those in control groups. These results demonstrate that lentiviral-mediated gene transfer of BMP-7 into Ad-MSCs allows for stable BMP-7 production. BMP-7-CS displayed higher osteogenic capacity than Ad-MSCs and Ad-MSC sheets. In addition, BMP-7-CS combined with demineralized bone matrix (DBM) stimulated new bone and blood vessel formation in a canine critical-sized bone defect. The BMP-7-CS not only provides BMP-7 producing MSCs but also produce osteogenic and vascular trophic factors. Thus, BMP-7-CS and DBM have therapeutic potential for the treatment of critical-sized bone defects and could be used to further enhance clinical outcomes during bone-defect treatment.

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