Papers by Keyword: Demineralized Bone Matrix

Abstract: Ideal bone graft must possess the desirable trait such as osteoconductive, osteoinductive and osteogenesis. Demineralized Bone Matrix (DBM) provides both osteoconductive and osteoinductive trait. Referring to the tissue engineering principle, the addition of mesenchymal stem cell would add the osteogenic trait to this procedure. The design of this study is experimental using Bovine DBM. Bone Marrow Mesenchymal Stem Cell (BMSCs) and Adipose Mesenchymal Stem Cells (ASCs) were taken from New Zealand white rabbit. There are two groups of treatment, divided into DBM implanted with BMSCs and DBM implanted with ASCs. Each BMSCs and ASCs groups is incubated in the normal and osteogenic culture plate. Evaluation is performed by counting the osteoblast and immunohistochemistry stain using Alkaline Phosphate and Osteocalcin. After 4 weeks of incubation, we found that the osteoblast count in BMSCs groups is higher compared to the ASCs groups in both culture condition (p<0.01) along with Alkaline Phosphate staining (p<0.05), while the Osteocalcin staining showed insignificant differences (p>0.05). This study revealed that xenogenic bovine DBM can act as the potential osteoinductive scaffold for the MSCs to differentiate. The tissue engineering application by combining MSCs and Bovine DBM can be considered as an alternative in managing bone defect cases.

Abstract: A new class of osteoconductive and osteoinductive combination biomaterials composed of calcium phosphate cement (CPC), demineralized bone matrix (DBM) and a water-soluble viscosity modifier were prepared and characterized in-vitro and in-vivo. In previous studies, a range of combinations formulations were tested in order to compare their performance characteristic. In-vitro characterization results show that the mechanical strength is decreased when the amount of DBM increases. However, DBM does not affect the CPC’s ability to set hard and convert to nanocrystalline apatitic calcium phosphate, which shares the chemical structure of natural bone as seen in x-ray diffraction. It is known that the DBM alone is osteoinductive. In-vivo osteoinductivity testing of the formulations in an intramuscular, athymic rat model demonstrated that the combination material is also osteoinductive. Two formulations were chosen for in-vivo efficacy testing based on the results of in-vitro and in-vivo characterization. These formulations were studied using rabbit critical-sized femoral core defect model. The formulations were composed of DBM with particle sizes of 250 to 710 μm, carboxymethyl-cellulose (CMC) as the viscosity modifier and weight percent compositions of 50% DBM/ 45% CPC/ 5% CMC and 60% DBM/ 30% CPC/ 10% CMC. Bone integration and healing was graded at 6, 12, and 24 weeks. The two formulations were compared to the gold standard autograft at 12 weeks and to an empty defect as the negative control at 24 weeks. Based on micro-computed topography (μCT), both formulations allowed for continuity of bone throughout the defect region at all time points. No differences in dense area fraction were seen between two formulations at 6 weeks (p = 0.8661). There was no significant statistical difference between the two formulations and autograft at 12 weeks (p = 0.2467). At 24 weeks, both formulations had significantly higher dense area fractions than empty controls (p = 0.0001). Histologically, the biology of the treatment areas appeared to have returned to normal by 24 weeks with CPC appearing to be the principal osteogenic inducer. In conclusion, these combinations of CPC and DBM offers significant advantages (handling, mechanical properties and osteoinductivity) over current DBM products and can be an effective alternative to autograft in healing of bone defects.

Abstract: Mesenchymal stem cells are multipotential cells capable of differentiating into osteoblasts, chondrocytes, adipocytes, tenocytes, and myoblasts. Wharton’s jelly consists of stem cells that are a rich source of primitive multipotent mesenchymal cells. Demineralized bone matrix (DBM) has been widely utilized as a biomaterial to promote new bone formation. We isolate and characterize umbilical cord Wharton’s Jelly-derived mesenchymal stem (UCMS) cells derived from Wharton’s jelly and examine the biological activity of DBM in this cell line. Osteoblast differentiation of the UCMS cells was determined using alkaline phosphatase (ALP) activity assay. To examine differential gene expression during osteogenic differentiation, total RNA was isolated from UCMS cells in the absence or presence of DBM on day7 and analyzed using osteogenesis cDNA gene array. The selected genes were verified using reverse transcriptase-polymerase chain reaction (RT-PCR) analyses. Wharton’s jelly derived cells could differentiate along an osteogenic lineage after treatment of DBM. The ALP activity assay showed that human UCMS cells could differentiate into osteogenic lineage. Gene expression of human UCMS cells treated with DBM for 7 days was analyzed by using cDNA array and RT-PCR analyses. We found that expression of RUNX2 and SMAD2 was upregulated whereas SMAD7 expression was downregulated as confirmed by RT-PCR. UCMS cells from a Wharton’s jelly of human umbilical cord could express osteogenesis genes for treatment with DBM. Wharton’s jelly from umbilical cord is a new source of mesenchymal stem cells that are readily available for application to bone tissue engineering.

Abstract: Human demineralized bone matrix (DBM) containing bone morphogenetic proteins (BMPs) is naturally biocompatible and can be remodeled by patients’ own bone. The major shortcoming of many of the currently used DBM gel formulations is that they have a tendency to flow, particularly if there is continuous bleeding at the application site. In this study, the physicochemical properties of human DBM were examined to improve the efficiency of DBM formulations. DBM remarkably showed higher water absorption than nondemineralized bone powder after 150 min. Hydroxyl groups in DBM appeared in fourier transform infrared analysis, although hydroxyl band in nondemineralized bone powder was not observed. The results suggested that hydrogels such as CMC, hyaluronic acid, or poloxamer as carriers can be applied for injectable DBM products, such as gel or putty types.

Abstract: In this study, we developed an injectable carrier for demineralized bone matrix (DBM) which consists of chitosan and glycerol phosphate (GP). The phase transition behaviors of chitosan and GP solution characterized as a function of temperature. The chitosan and GP solutions were shown to form a sol at room temperature, and the chitosan solution with 10-20 wt% concentrations were found to undergo sol-to-gel phase transitions as the temperature was increased. In situ gel forming implant in vivo was successfully fabricated by simple subcutaneous injection of chitosan and GP solutions with demineralized bone matrix (DBM). von Kossa images of the gel implant formed from solution with DBM revealed the presence of mineral deposits.

Abstract: The aim of this report was to investigate the behavior of human mesenchymal stem cells (hMSCs) when cultured on different porous 3D scaffolds, having natural or synthetic origination. Natural scaffolds were obtained by hand made processing of human bone tissue (allograft), because its well known osteoconductive features, using different procedures to eliminate the donor cellular phase. Cancellous bone was frozen, heated or demineralized before being loaded with hMSCs. Among the variety of synthetic materials, biodegradable polymeric spongy matrices were chosen and comparatively tested as scaffolds for hMSCs growth.