The slow release of BMP-7 at a low dose accelerates dental implant healing in an osteopenic environment

The aim of the present study was to investigate in vivo whether bone morphogenetic protein-7 (BMP-7) was able to promote and accelerate dental implant healing at a low dose in an osteopenic environment by using a delayed drug-release system. Skeletally mature Chinese goats, having physiologically osteopenic (osteoporotic-like) facial bones, served as an animal model. Dental implants were provided with a delayed-release drug-delivery system and BMP-7 was applied at three different dosages. The implants, inserted into healed extraction sockets, were removed 1, 2 and 3 weeks after surgery. Quantification of osseointegration and formation of new bone in the peri- implant space were measured histomorphometrically. Data revealed no evidence of any adverse drug effect at or near the implantation sites. After the first postoperative week, bone neoformation was minimal; after the second week, peri-implant bone formation appeared, particularly in the groups with low dosages of BMP-7. After 3 weeks, new-bone volume was the largest in the group with the lowest (near-physiological) dosage of BMP-7, also showing the highest efficacy of BMP-7. Other dosage or release modes were found to be significantly less effective. BMP-7 was highly efficacious in promoting and accelerating bone formation in the peri-implant space in a hostile osteopenic environment if released by a slow-mode mechanism over time at near physiological activities. Therefore, biological functionalisation of dental implants by a high-power osteogenic factor may improve their healing success in hostile bony environments (osteopenia, osteoporosis, bone atrophy etc.).

P0869EXOGENOUS OSTEOGENIC FACTOR 1 ADMINISTRATION ATTENUATED VASCULAR CALCIFICATION AND IMPROVED BONE DISORDERS IN CHRONIC UREMIC RATS

Background and Aims Hyperphosphatemia and secondary hyperparathyroidism are frequent complications in chronic kidney disease (CKD) which both contribute to increased morbidity and mortality in CKD. Osteogenic factor-1 (OP-1) is an important member of BMPs subfamily and its effects on CKD-associated mineral and bone disorders (MBD) is controversial. The study examined whether exogenous OP-1 administration can modulate disturbed CKD-MBD in adenine-induced chronic uremic rats Method Chronic renal failure was induced in adult male SD rats by feeding adenine-containing diet. After adenine diet feeding 3 weeks, animals were injected with OP-1 (5μg/kg/day) intraperitoneally for 2 weeks. The serum and urine phosphorus levels and associated mineral parameters, including fibroblast growth factor 23(FGF-23), DKK-1 and sclerostin were measured. Vascular calcification was assessed by immunohistochemistry staining on aortic tissue. Bony structure was evaluated by microCT (Bruker-microCT, Kontich, Belgium). Results A significant decrease of body weight and deteriorated renal function was observed in adenine and OP-1 treatment groups during study period and serum creatinine levels were similar (5.23 ±1.1 mg/dL vs. 5.4 ±1.2 mg/dL, p>0.05). Animals in OP-1 group had lower serum phosphorous (18.7±5.1 vs. 29.0±9.6 mg/dL, p<0.05) and intact parathyroid hormone levels (2906.1±1206.9 vs. 4669.7±2505.9 pg/dL, p<0.05) compared to adenine group. Decreased urine phosphorous excretion was noted in both groups without significant difference. Levels of serum FGF-23, sclerostin and DKK-1 were significantly lower in OP-1 treatment group (all p< 0.05). OP-1 administration diminished the staining of RUNX2 (59.1±3% of adenine-treated group), alkaline-phosphatase (49.4±5.7%), β-caterin (39.3±1.8%), BMP2 (43.2%±6.7%), and BMP7 (51.9±10%, all p <0.05). MicroCT revealed that bone mineral density was increased by OP-1 treatment (0.46±0.1 vs.0.39±0.06 g/cm3). Total volume was increased but bone volume was not changed. OP-1 administration did not affect trabecular thickness and trabecular number. Conclusion Our data indicated administration of exogenous OP-1 improved hyperparathyroidism and attenuated vascular calcification. OP-1 treatment was also associated with beneficial effects on bony structure in animals with renal failure.

Biomimetic cues from poly(lactic-co-glycolic acid)/hydroxyapatite nano-fibrous scaffolds drive osteogenic commitment in human mesenchymal stem cells in the absence of osteogenic factor supplements

Culturing of hBMSCs on aligned electrospun nanocomposite fibers, composed of PLGA modified with rod-shape n-HA.

Dual release of a hydrophilic and a hydrophobic osteogenic factor from a single liposome

Dual release of growth/differentiation factors from liposomes induced osteogenic differentiation of mesenchymal stem cells.