scholarly journals Development of Phosphatized Calcium Carbonate Biominerals as Bioactive Bone Graft Substitute Materials, Part I: Incorporation of Magnesium and Strontium Ions

2018 ◽  
Vol 9 (4) ◽  
pp. 69 ◽  
Author(s):  
Ingo Sethmann ◽  
Cornelia Luft ◽  
Hans-Joachim Kleebe

Synthetic materials based on calcium phosphate (CaP) are frequently used as bone graft substitutes when natural bone grafts are not available or not suitable. Chemical similarity to bone guarantees the biocompatibility of synthetic CaP materials, whereas macroporosity enables their integration into the natural bone tissue. To restore optimum mechanical performance after the grafting procedure, gradual resorption of CaP implants and simultaneous replacement by natural bone is desirable. Mg and Sr ions released from implants support osteointegration by stimulating bone formation. Furthermore, Sr ions counteract osteoporotic bone loss and reduce the probability of related fractures. The present study aimed at developing porous Ca carbonate biominerals into novel CaP-based, bioactive bone implant materials. Macroporous Ca carbonate biominerals, specifically skeletons of corals (aragonite) and sea urchins (Mg-substituted calcite), were hydrothermally converted into pseudomorphic CaP materials with their natural porosity preserved. Sr ions were introduced to the mineral replacement reactions by temporarily stabilizing them in the hydrothermal phosphate solutions as Sr-EDTA complexes. In this reaction system, Na, Mg, and Sr ions favored the formation of correspondingly substituted β-tricalcium phosphate over hydroxyapatite. Upon dissolution, the incorporated functional ions became released, endowing these CaP materials with bioactive and potentially osteoporotic properties.

1969 ◽  
Vol 13 (2) ◽  
Author(s):  
Simon Cartmell

ApaTech is an excellent example of how innovative technology from a British university can be developed and commercialised on a global scale. Its leading product, Actifuse, competes in the crowded bone graft substitute market. Its competitors include autograft, allograft, recombinant proteins and other synthetic materials based on similar calcium phosphate technology. Discoveries regarding the role of ionic species within normal bone lead to the development of greater insights into the subtle interactions of graft structure, graft chemistry and the biology of bone formation. Financing from 3i and MTI allied to the intellectual property residing in the IRC in Biomedical Materials, Queen Mary University London plus strong commercially oriented management has resulted in ApaTech establishing itself as a major force in the bone graft substitute market. ApaTech has successfully differentiated its products and technology from that of established major orthopaedic company offerings and is capturing significant market share, particularly in the UK and USA where ApaTech has established a direct presence.


2018 ◽  
Vol 9 (4) ◽  
pp. 67 ◽  
Author(s):  
Ingo Sethmann ◽  
Sabrina Völkel ◽  
Felicitas Pfeifer ◽  
Hans-Joachim Kleebe

Porous calcium phosphate (CaP) materials as bone graft substitutes can be prepared from Ca carbonate biomineral structures by hydrothermal conversion into pseudomorphic CaP scaffolds. The present study aims at furnishing such phosphatized Ca carbonate biomineral (PCCB) materials with antibacterial Ag ions in order to avoid perisurgical wound infections. Prior to this study, PCCB materials with Mg and/or Sr ions incorporated for stimulating bone formation were prepared from coral skeletons and sea urchin spines as starting materials. The porous PCCB materials were treated with aqueous solutions of Ag nitrate with concentrations of 10 or 100 mmol/L, resulting in the formation of Ag phosphate nanoparticles on the sample surfaces through a replacement reaction. The materials were characterized using scanning electron microscopy (SEM) energy-dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). In contact with Ringer`s solution, the Ag phosphate nanoparticles dissolved and released Ag ions with concentrations up to 0.51 mg/L, as shown by atomic absorption spectroscopy (AAS) analyses. In tests against Pseudomonas aeruginosa and Staphylococcus aureus on agar plates, antibacterial properties were similar for both types of Ag-modified PCCB materials. Concerning the antibacterial performance, the treatment with AgNO3 solutions with 10 mmol/L was almost as effective as with 100 mmol/L.


Author(s):  
Niketa Chauhan ◽  
Nilay Lakhkar ◽  
Amol Chaudhari

AbstractThe process of bone regeneration in bone grafting procedures is greatly influenced by the physicochemical properties of the bone graft substitute. In this study, porous phosphate glass (PPG) morsels were developed and their physicochemical properties such as degradation, crystallinity, organic content, surface topography, particle size and porosity were evaluated using various analytical methods. The in vitro cytotoxicity of the PPG morsels was assessed and the interaction of the PPG morsels with Dental Pulp Stem Cells (DPSCs) was studied by measuring cell proliferation and cell penetration depth. The cell-material interactions between PPG morsels and a commercially available xenograft (XG) were compared. The PPG morsels were observed to be amorphous, biocompatible and highly porous (porosity = 58.45%). From in vitro experiments, PPG morsels were observed to be non-cytotoxic and showed better cell proliferation. The internal surface of PPG was easily accessible to the cells compared to XG.


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
A Aljawadi ◽  
I Madhi ◽  
T Naylor ◽  
M Elmajee ◽  
A Islam ◽  
...  

Abstract Background Management of traumatic bone void associated with Gustilo IIIB open fractures is challenging. Gentamicin eluting synthetic bone graft substitute (Cerament-G) had been recently utilised for the management of patients with these injuries. This study aims to assess radiological signs of Cerament-G remodelling. Method Retrospective data analysis of all patients admitted to our unit with IIIB open fractures who had Cerament-G applied as avoid filler. Postoperative radiographic images of the fracture site at 6-weeks, 3-months, 6-months and at the last follow-up were reviewed. The radiological signs of Cerament-G integration, percent of void healing, and bone cortical thickness at the final follow-up were assessed. Results 34 patients met our inclusion criteria, mean age: 42 years. Mean follow-up time was 20 months. 59% of patients had excellent (>90%) void filling, 26.4% of patients had 50-90% void filling, and 14.6% had < 50% void filling. Normal bone cortical thickness was restored on AP and Lateral views in 55.8% of patients. No residual Cerement-G was seen on X-rays at the final follow-up in any of the patients. Conclusions Our results showed successful integration of Cerament-G with excellent void filling and normal cortical thickness achieved in more than half of the patients.


2021 ◽  
Vol 11 (4) ◽  
pp. 1906
Author(s):  
Marwa Y. Shaheen ◽  
Amani M. Basudan ◽  
Abdurahman A. Niazy ◽  
Jeroen J. J. P. van den Beucken ◽  
John A. Jansen ◽  
...  

The aim of this study was to evaluate the regeneration of bone defects created in the femoral condyle of osteoporotic rats, following intravenous (IV) zoledronate (ZA) treatment in three settings: pre-bone grafting (ZA-Pre), post-bone grafting (ZA-Post), and pre- plus post-bone grafting (ZA-Pre+Post). Twenty-four female Wistar rats were ovariectomized (OVX). After 12 weeks, bone defects were created in the left femoral condyle. All defects were grafted with a particulate inorganic cancellous bovine bone substitute. ZA (0.04 mg/kg, weekly) was administered to six rats 4 weeks pre-bone graft placement. To another six rats, ZA was given post-bone graft placement creation and continued for 6 weeks. Additional six rats received ZA treatment pre- and post-bone graft placement. Control animals received weekly saline intravenous injections. At 6 weeks post-bone graft placement, samples were retrieved for histological evaluation of the bone area percentage (BA%) and remaining bone graft percentage (RBG%). BA% for ZA-Pre (50.1 ± 3.5%) and ZA-Post (49.2 ± 8.2%) rats was significantly increased compared to that of the controls (35.4 ± 5.4%, p-value 0.031 and 0.043, respectively). In contrast, ZA-Pre+Post rats (40.7 ± 16.0%) showed similar BA% compared to saline controls (p = 0.663). For RBG%, all experimental groups showed similar results ranging from 36.3 to 47.1%. Our data indicate that pre- or post-surgical systemic IV administration of ZA improves the regeneration of bone defects grafted with inorganic cancellous bovine-bone particles in osteoporotic bone conditions. However, no favorable effect on bone repair was seen for continued pre- plus post-surgical ZA treatment.


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