Application of Bone Morphogenetic Protein 7 Enhanced the Osteogenic Differentiation and Mineralization of Bone Marrow-Derived Stem Cells Cultured on Deproteinized Bovine Bone

The growth of bone morphogenetic protein 7 (BMP-7) has been applied for tissue regeneration due to its osteoinductive properties. The aim of this research is to analyze the enhancing effects of BMP-7 on the osteogenic differentiation and mineralization of human bone marrow-derived stem cells cultured on the bovine bone particle. After the stem cells were loaded onto the bone graft material, their morphology was observed on day 7. Viability assays based on the application of fluorescent stains were used for qualitative analyses. Alkaline phosphatase activity assays and Alizarin red staining were used for the assessment of osteogenic differentiation on days 7 and 14. Next-generation mRNA sequencing was applied to evaluate global gene expression. Gene ontology and pathway analysis was used to propose the underlying mechanism. Fibroblast-like morphology was attained with the stem cells. The cells were shown to be firmly attached to the bone particle. Most of the stem cells produced an intense green fluorescence. The relative cellular viability assay values for BMP-7 groups at 0, 10, and 100 ng/mL on day 7 were 0.295 ± 0.003, 0.250 ± 0.002, and 0.240 ± 0.003, respectively (p < 0.05). Alkaline phosphatase activity was significantly higher in BMP-7 groups at concentration of 100 ng/mL compared to the control on days 7 and 14 (p < 0.05). The results of the mineralization assay showed significantly higher values for BMP-7 groups at 100 ng/mL concentration when compared with the control (p < 0.05). The expression of RUNX2 was increased with application of BMP-7 and mitogen-activated protein kinase pathway was associated with the target genes. Overall, this study shows that in vitro application of BMP-7 increases alkaline phosphorylase activity and mineralization of stem cells culture on deproteinized bovine bone mineral. The study suggests that combining stem cells with osteoinductive growth factors with scaffolds can have synergy effects on osteogenic differentiation.

Collagenated Porcine Heterologous Bone Grafts: Histomorphometric Evaluation of Bone Formation Using Different Physical Forms in a Rabbit Cancellous Bone Model

Collagenated porcine-derived bone graft materials exhibit osteoconductive properties and the development of different formulations intends to enhance bone regeneration. This study aims to evaluate bone healing in a rabbit cancellous bone defect in response to grafting with different physicochemical forms of heterologous porcine bone. Twenty-six adult male New Zealand White rabbits received two critical size femoral bone defects per animal (n = 52), each randomly assigned to one of the five tested materials (Apatos, Gen-Os, mp3, Putty, and Gel 40). Animals were sacrificed at 15- and 30-days post-surgery. Qualitative and quantitative (new bone, particle and connective tissue percentages) histological analyses were performed. Histomorphometry showed statistically significant differences in all evaluated parameters between mp3 and both Putty and Gel 40 groups, regardless of the timepoint (p < 0.05). Moreover, statistical differences were observed between Apatos and both Putty (p = 0.014) and Gel 40 (p = 0.007) groups, at 30 days, in regard to particle percentage. Within each group, regarding new bone formation, mp3 showed significant differences (p = 0.028) between 15 (40.93 ± 3.49%) and 30 (52.49 ± 11.04%) days. Additionally, intragroup analysis concerning the percentage of particles revealed a significant reduction in particle occupied area from 15 to 30 days in mp3 and Gen-Os groups (p = 0.009). All mp3, Gen-Os and Apatos exhibited promising results in terms of new bone formation, thus presenting suitable alternatives to be used in bone regeneration.

Comparison of the Bone Harvesting Capacity of an Intraoral Bone Harvesting Device and Three Different Implant Drills

The aim of the present study was to compare bone-collecting capacity of bone harvesting device and minimally irrigated low-speed drilling using three implant systems. One bone harvesting device and three commercially available drill systems were compared using the osteotomies on bovine rib bones. The amount of the collected bone particle and particle size (<500 μm: small, 500–1000 μm: medium, and >1000 μm: large) were measured. Total wet (1.535±0.232 mL) and dry volume (1.147±0.425 mL) of the bone particles from bone harvesting device were significantly greater than three drill systems (wet volume: 1.225±0.187–1.27±0.29 mL and dry volume: 0.688±0.163–0.74±0.311 mL) (P<0.05). In all groups, the amount of large sized particles in wet and dry state was the greatest compared to that of medium and small particles. The dry weight of the bone particles showed the same tendency to volumetric measurement. In conclusion, total bone particles and large sized particles (>1000 μm) were harvested significantly greater by bone harvesting device than minimally irrigated low-speed drilling. The composition of particle size in all harvesting methods was similar to each other.

Effects of Micron Fish Bone with Different Particle Size on the Properties of Silver Carp(Hypophthalmichthys molitrix)Surimi Gels

Qualities of silver carp surimi (SCS) gels incorporated with micron fish bone of different particle size (22 to 0.12 μm) were evaluated. Textural values, whiteness, and water holding capacity of the SCS gels with setting significantly increased (P<0.05) as the micron fish bone particle size decreased. As the particle size decreased, more calcium ion was apparently released from the fish bone (P<0.05). Consequently the released calcium ion increased the activity of endogenous transglutaminase (TGase) and resulted in the formation of more myosin heavy chain (MHC) cross-links in the SCS gel with setting. Fish bone with particle size below 0.48 μm was steadily trapped in the three-dimensional SCS gel network without disrupting the matrices. Results indicated that size reduction of the incorporated micron fish bone improved qualities of the SCS gel with setting by the means of releasing more calcium ion and maintaining better gel matrices.