Background: Allografting is currently used in lower limb reconstruction surgery. Demineralised bone matrix (DBM) is more osteoinductive compared with allografts but lacks mechanical strength. Osteogenic protein-1 (OP-1) can improve the osteoinductivity of the allograft, however recent reports indicate significant allograft resorption when it is combined with OP-1. Objectives: Our hypothesis was that hydroxyapatite (HA) with human-mesenchymal stem cells (h-MSCs) and OP-1 (HA+h-MSCs+OP-1) has similar osteoinductive properties to human-DBM+h-MSCs. The objective was to evaluate h-MSC proliferation (by tritiated thymidine incorporation, total DNA Hoechst 33258 and scanning electron microscopy) and osteogenic differentiation (from alkaline phosphatase activity) in human demineralised bone matrix (h-DBM) and HA, with or without OP-1. Results: H-MSC proliferation on HA+OP-1 was significantly higher compared with that on HA at all time points (p < 0.05) and compared with DBM alone [day 1, (198.4 vs 95.4) p = 0.042...

In vitro proliferation and differentiation of human mesenchymal stem cells on hydroxyapatite versus human demineralised bone matrix with and without osteogenic protein-1.

Disclosed herein are compositions and methods of treating osteroporosis, bone fracture, bone loss, and increasing bone density by administration of compounds of formula (I) or compositions comprising a compound of formula (I) and a pharmaceutically acceptable carrier, wherein L1, L2, L4, R1, R4, R5, R6, and s are as defined in the specification.

Difluorolactam compositions for ep4-mediated osteo related diseases and conditions

Grafting based on both autogenous and allogenous human bone is widely used to replace areas of critical loss to induce bone regeneration. Allogenous bones have the advantage of unlimited availability from tissue banks. However, their integration into the remaining bone is limited because they lack osteoinduction and osteogenic properties. Here, we propose to induce the demineralization of the allografts to improve these properties by exposing the organic components. Allografts fragments were demineralized in 10% EDTA at pH 7.2 solution. The influence of the EDTA-DAB and MAB fragments was evaluated with respect to the adhesion, growth and differentiation of MC3′T3-E1 osteoblasts, primary osteoblasts and dental pulp stem cells (DPSC). Histomorphological analyses showed that EDTA-demineralized fragments (EDTA-DAB) maintained a bone architecture and porosity similar to those of the mineralized (MAB) samples. BMP4, osteopontin, and collagen III were also preserved. All the cell types adhered, grew and colonized both the MAB and EDTA-DAB biomaterials after 7, 14 and 21 days. However, the osteoblastic cell lines showed higher viability indexes when they were cultivated on the EDTA-DAB fragments, while the MAB fragments induced higher DPSC viability. The improved osteoinductive potential of the EDTA-DAB bone was confirmed by alkaline phosphatase activity and calcium deposition analyses. This work provides guidance for the choice of the most appropriate allograft to be used in tissue bioengineering and for the transport of specific cell lineages to the surgical site.

In vitro analysis of the influence of mineralized and EDTA-demineralized allogenous bone on the viability and differentiation of osteoblasts and dental pulp stem cells

The sea squirt has a tunic composed of cellulose fibers that are originated from animal cells and form a cellulose membrane that functions as a protective barrier and a skeleton of body. We purified the squirt cellulose membrane (SCM), about 100 μm thickness, from the cystic tunic of Styela clava. The SCM was turned out to be composed of pure native cellulose I in the analyses of X-ray diffraction, attenuated total reflectance Fourier transform-infrared spectroscopy. The inner surface of SCM showed numerous micropores in the meshworks of thin cellulose microfibrils, while the outer surface of SCM showed a few micropores. In order to know the osteoconductive effect of the SCM, it was applied to the perforated rat frontal bone, 8 mm diameter, for 4, 6, 8, 10, 12, and 16 weeks. The mesenchymal cells were tightly adhered to the inner surface of SCM and produced new bone there. The perforations to which the SCM was applied, were completely healed in 10 weeks, while the positive control group applied with the guided tissue regeneration (GTR) material, Bio-Gide® showed incomplete healing until 16 weeks. Immunohistochemistry performed on the experimental group showed that BMP-2 and osteonectin were strongly positive in the early stage of bone healing at 4 weeks, while receptor activator of nuclear factor kappa B ligand (RANKL) became positive at 16 weeks. Particularly, the inner surface of SCM itself was consistently positive for the osteogenic proteins, indicating that the implanted SCM can absorb the osteogenic proteins from the stromal matrix of the host tissue. On the other hands, the positive control group implanted with Bio-Gide® showed relatively weak reaction of the osteogenic proteins in the perforated bone area during the healing period, and the negative control group implanted none showed poor bony regeneration in the perforated wounds. Taken together, the SCM showed an excellent osteoconductive effect in the perforated rat frontal bone, which was quite comparable to the results of Bio-Gide® implantation. Therefore, it is suggested that the SCM be a novel GTR material of a natural source with a strong osteoconductive effect on the injured bone.

Purification of squirt cellulose membrane from the cystic tunic of Styela clava and identification of its osteoconductive effect

Objective An early vascular response for angiogenesis is essential for the normal progression of bone defect healing Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis The aim of this study was to evaluate the effects of a poly (L,D-lactic-co-glycolic acid) (PLGA) membrane with VEGF encapsulated into PLGA microspheres on bone regeneration at bone defects in rat calvaria Study Design Microspheres of PLGA incorporating VEGF 165 (VEGF microspheres) were prepared, and critical-size bone defects were created in rat calvaria The VEGF microspheres, PLGA microspheres, or VEGF microspheres plus PLGA membrane were applied to the defects Bone regeneration was evaluated using image analysis based on soft radiographic and histologic examination Results Mature thick bone regeneration was observed in selected sites at bone defects that had been applied with VEGF microspheres/PLGA membrane compared with those that had been applied with the other treatments Conclusion A combination of VEGF microspheres and a PLGA membrane effectively enhances bone regeneration

Effectable application of vascular endothelial growth factor to critical sized rat calvaria defects.

Demineralized bone matrix (DBM) has been shown to possess osteoinductive capability and one of the specific bone morphogenetic proteins (BMPs) found within DBM that has been attributed with this osteoinductive ability is BMP-7, also known as osteogenic protein-1 (OP-1). The specific aims of this study were (1) to compare the treatment of segmental bone defects with OP-l and DBM in a rat femur model and (2) to determine the effects of the two treatments given at high and low doses via sustained release drug delivery. Animals in Group 1 acted as the control and Group 2 had a created segmental defect with plating and placement of a calcined tricalcium phosphate lysine (TCPL) capsule containing antibiotic (sham). Group 3 and 4 animals had a created segmental defect and received a TCPL carrier containing antibiotic along with DBM or OP-1, respectively. After 4 weeks post-implantation, animals were sacrificed before the retrieval of the bone. The femora were analyzed radiographically and histologically for bone growth. Analysis of the gross specimens showed considerable bone regeneration at low and high doses for both DBM and OP-1 when compared to the shams. At low levels bone regeneration between DBM and OP-1 was very similar. However, at high doses, OP-1 was shown to cause bone overgrowth with a greater curvature and an increased thickness of the distal and proximal ends of the femur. The stained slides showed the defects treated with DBM and OP-1 to be bridged with lamellar and woven bone that was continuous with the original bone. Histologically, the experimental femora demonstrated natural remodeling processes with new osteons and angiogenesis.

Histological and radiographic comparison of allograft substitutes using a continuous delivery model in segmental defects.

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Histological and radiographic comparison of allograft substitutes using a continuous delivery model in segmental defects.