The kinetics and mechanism of bone morphogenetic protein 2 release from calcium phosphate-based implant-coatings

The objective of the present study was to incorporate strontium into calcium phosphate cement combined with a lower single-dose local administration of bone morphogenetic protein-2 to enhance its in vivo biodegradation and bone tissue growth. After the creation of a rodent critical-sized femoral metaphyseal bone defect, strontium-modified calcium phosphate cement was prepared by mixing sieved granules of calcium phosphate cement and 5% SrCO3 for medical use, and then strontium-modified calcium phosphate cement with dripped bone morphogenetic protein-2 solution (5 µg) was implanted into the defect of OVX rats until death at eight weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, and biomechanics. The results of our study show that a lower single-dose local administration of bone morphogenetic protein-2 combined local usage of strontium-modified calcium phosphate cement can increase the healing of defects in OVX rats. Furthermore, treatments with single-dose local administration of bone morphogenetic protein-2 and strontium-modified calcium phosphate cement showed a stronger effect on accelerating the local bone formation than calcium phosphate cement and strontium-modified calcium phosphate cement used alone. The results from our study demonstrate that combination of a lower single-dose local administration of bone morphogenetic protein-2 and strontium-modified calcium phosphate cement had an additive effect on local bone formation in osteoporosis rats.

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Premixed calcium phosphate cement as a carrier for bone morphogenetic protein 2

Bone Abstracts ◽

10.1530/boneabs.1.pp87 ◽

2013 ◽

Author(s):

Nick Walters ◽

Gry Hulsart-Billstrom ◽

Hakan Engqvist ◽

Sune Larsson

Keyword(s):

Calcium Phosphate ◽

Bone Morphogenetic Protein ◽

Calcium Phosphate Cement ◽

Bone Morphogenetic Protein 2 ◽

Morphogenetic Protein

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Delivery Mode and Efficacy of BMP-2 in Association with Implants

Journal of Dental Research ◽

10.1177/154405910708600114 ◽

2007 ◽

Vol 86 (1) ◽

pp. 84-89 ◽

Cited By ~ 100

Author(s):

Y. Liu ◽

R.O. Huse ◽

K. de Groot ◽

D. Buser ◽

E.B. Hunziker

Keyword(s):

Calcium Phosphate ◽

Bone Matrix ◽

Bone Morphogenetic Protein 2 ◽

Calcium Phosphate Coating ◽

Delivery Mode ◽

Implant Surface ◽

Morphogenetic Protein ◽

Mode Of Application ◽

Mineralized Bone Matrix ◽

Implant Coatings

Bone healing may be improved in implant patients by the administration of osteogenic agents, such as bone morphogenetic protein 2 (BMP-2). But the efficacy of BMP-2 depends upon its mode of application. We hypothesized that BMP-2 is capable of a higher osteogenic efficacy when delivered physiologically, viz., when incorporated into a calcium-phosphate carrier that mimics mineralized bone matrix, than when administered via simple pharmacological modes, such as by adsorption onto a carrier surface. Using an ectopic rat model, we compared the osteoinductive efficacies of calcium-phosphate implant-coatings bearing either incorporated, adsorbed, or incorporated and adsorbed BMP-2. When adsorbed directly onto the naked implant surface, BMP-2 was not osteogenic. When adsorbed onto a calcium-phosphate coating, it was osteoinductive, but not highly efficacious. When BMP-2 was incorporated into calcium-phosphate coatings, it was a potent bone-inducer, whose efficacy was compromised, not potentiated, by the additional deposition of an adsorbed pool.

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Potential of bone scaffolds containing vancomycin and bone morphogenetic protein-2 in a rat model of osteomyelitis

Asian Biomedicine ◽

10.5372/1905-7415.0805.340 ◽

2014 ◽

Vol 8 (5) ◽

pp. 651-658 ◽

Cited By ~ 3

Author(s):

Suphannee Thanyaphoo ◽

Jasadee Kaewsrichan

Keyword(s):

Calcium Phosphate ◽

Bone Graft ◽

Bone Morphogenetic Protein ◽

Rat Model ◽

Drug Carrier ◽

Bone Diseases ◽

Bone Morphogenetic Protein 2 ◽

Bone Scaffolds ◽

Morphogenetic Protein ◽

Antibiotic Drug

Abstract Background: Infected bone is often intractable. An ideal approach is to simultaneously eradicate infection and repair the bone defect. The development of osteoinductive bone graft composites to control antibiotic drug release would be useful for the treatment of intractable bone infections. Objectives: To develop a rat model of osteomyelitis for assessing osteoinductive bone graft scaffolds containing antibiotics and a bone morphogenetic protein. Methods: Si-imprinted calcium phosphate is a new hydroxyapatite derivative used in fabricating bone scaffolds. Vancomycin and bone morphogenetic protein-2 (BMP-2) were loaded onto scaffolds of Si-imprinted calcium phosphate using an established method. The efficiency of the scaffold as a drug carrier system was assessed in vivo. Osteomyelitis was induced in rats by infection of the tibial epiphysis with Staphylococcus aureus (BAA 1680). The success of inducing disease was checked after 4 weeks using bacterial culture and radiography. A 10 mm metaphysis bone was surgically removed and replaced with a drug-loaded scaffold. Histology and X-ray imaging were used to evaluate the implants at 8 weeks post implantation. Results: We successfully established a rat model of osteomyelitis. The causative bacteria were effectively eradicated by vancomycin released from the implants. Enhanced bone formation was observed for the implant samples containing vancomycin and BMP-2 compared with those containing either vancomycin or BMP2 alone. Conclusions: The newly developed bone scaffold has potential as a vehicle for therapeutic agents to treat bone diseases.

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