Osteoclast Response of Biomimetically Processed Silica and Carbonate Containing Calcium Phosphate Layers on Bioactive Glass S53P4

2005 ◽  
Vol 284-286 ◽  
pp. 549-552 ◽  
Author(s):  
Minna Vaahtio ◽  
Timo Peltola ◽  
Teuvo Hentunen ◽  
Heimo O. Ylänen ◽  
Sami Areva ◽  
...  

Different silica and carbonate containing calcium phosphate (CaP) layers were prepared on bioactive glass S53P4 in conventional C-SBF and revised R-SBF. In R-SBF the CaP layer formed faster compared to C-SBF, and the CaP layer formed in R-SBF was amorphous compared to the poorly crystalline bonelike HCA formed in C-SBF. In addition, the influence of chemical composition, dissolution and structure of biomimetically processed CaP layers on osteoclast and osteoblast activity was studied. In general, biomimetic CaP layers on bioactive glass S53P4 did not affect so much on bone cell activity as it was expected compared to the untreated glass. Additionally, it was observed that the mechanism for good osteoclast activity is multifactorial. The optimal surface for osteoclast adhesion and growth was an amorphous CaP having mesoporous nanotopography and proper dissolution rate of calcium and silica. Also osteoblasts grew well on such surface.

Author(s):  
Vincenzo Bucci-Sabattini ◽  
Clara Cassinelli ◽  
Paulo G. Coelho ◽  
Alberto Minnici ◽  
Alberto Trani ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ukrit Thamma ◽  
Tia J. Kowal ◽  
Matthias M. Falk ◽  
Himanshu Jain

AbstractThe nanostructure of engineered bioscaffolds has a profound impact on cell response, yet its understanding remains incomplete as cells interact with a highly complex interfacial layer rather than the material itself. For bioactive glass scaffolds, this layer comprises of silica gel, hydroxyapatite (HA)/carbonated hydroxyapatite (CHA), and absorbed proteins—all in varying micro/nano structure, composition, and concentration. Here, we examined the response of MC3T3-E1 pre-osteoblast cells to 30 mol% CaO–70 mol% SiO2 porous bioactive glass monoliths that differed only in nanopore size (6–44 nm) yet resulted in the formation of HA/CHA layers with significantly different microstructures. We report that cell response, as quantified by cell attachment and morphology, does not correlate with nanopore size, nor HA/CHO layer micro/nano morphology, or absorbed protein amount (bovine serum albumin, BSA), but with BSA’s secondary conformation as indicated by its β-sheet/α-helix ratio. Our results suggest that the β-sheet structure in BSA interacts electrostatically with the HA/CHA interfacial layer and activates the RGD sequence of absorbed adhesion proteins, such as fibronectin and vitronectin, thus significantly enhancing the attachment of cells. These findings provide new insight into the interaction of cells with the scaffolds’ interfacial layer, which is vital for the continued development of engineered tissue scaffolds.


2021 ◽  
Vol 22 (15) ◽  
pp. 8182
Author(s):  
Yongguang Gao ◽  
Suryaji Patil ◽  
Jingxian Jia

Osteoporosis is one of the major bone disorders that affects both women and men, and causes bone deterioration and bone strength. Bone remodeling maintains bone mass and mineral homeostasis through the balanced action of osteoblasts and osteoclasts, which are responsible for bone formation and bone resorption, respectively. The imbalance in bone remodeling is known to be the main cause of osteoporosis. The imbalance can be the result of the action of various molecules produced by one bone cell that acts on other bone cells and influence cell activity. The understanding of the effect of these molecules on bone can help identify new targets and therapeutics to prevent and treat bone disorders. In this article, we have focused on molecules that are produced by osteoblasts, osteocytes, and osteoclasts and their mechanism of action on these cells. We have also summarized the different pharmacological osteoporosis treatments that target different molecular aspects of these bone cells to minimize osteoporosis.


1992 ◽  
Vol 73 (2) ◽  
pp. S10-S13 ◽  
Author(s):  
S. B. Doty ◽  
E. R. Morey-Holton ◽  
G. N. Durnova ◽  
A. S. Kaplansky

The Soviet biosatellite COSMOS 2044 carried adult rats on a spaceflight that lasted 13.8 days and was intended to repeat animal studies carried out on COSMOS 1887. Skeletal tissue and tendon from animals flown on COSMOS 2044 were studied by light and electron microscopy, histochemistry, and morphometric techniques. Studies were confined to the bone cells and vasculature from the weight-bearing tibias. Results indicated that vascular changes at the periosteal and subperiosteal region of the tibia were not apparent by light microscopy or histochemistry. However, electron microscopy indicated that vascular inclusions were present in bone samples from the flight animals. A unique combination of microscopy and histochemical techniques indicated that the endosteal osteoblasts from this same mid-diaphyseal region demonstrated a slight (but not statistically significant) reduction in bone cell activity. Electron-microscopic studies of the tendons from metatarsal bones showed a collagen fibril disorganization as a result of spaceflight. Thus changes described for COSMOS 1887 were present in COSMOS 2044, but the changes ascribed to spaceflight were not as evident.


1990 ◽  
Vol 5 (4) ◽  
pp. 337-343 ◽  
Author(s):  
Pascale M. Chavassieux ◽  
Chantal Chenu ◽  
Alexandre Valentin-Opran ◽  
Blandine Merle ◽  
Pierre D. Delmas ◽  
...  

2006 ◽  
Vol 309-311 ◽  
pp. 333-336
Author(s):  
Emiko Amaoka ◽  
Erik Vedel ◽  
Satoshi Nakamura ◽  
Yusuke Moriyoshi ◽  
Jukka I. Salonen ◽  
...  

We investigated the electrical polarizability of MgO and B2O3 containing bioactive glass (MBG). The MBG material with good manufacturing properties but low bioactivity was electrically polarized at a high dc field. The electrical polarizability of MBG was evaluated by thermally stimulated depolarization current (TSDC) measurements and immersion in simulated body fluid (SBF). The early precipitation of calcium phosphate on the negatively charged surface of the treated MBG demonstrated the increased bioactivity of the material and confirmed its polarizability. It is suggested that the electrical interactions between the polarized MBG and ions in SBF promoted the formation of the calcium phosphate precipitation. Accordingly, the increased bioactivity of the MBG in SBF is suggested to demonstrate the conversion of MBG into electrovector ceramics by the polarization treatment.


QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ahmed Salah Mahmoud Ahmed Shehata ◽  
Mohamed Rafik El-Halaby ◽  
Ahmed Mohamed Saafan

Abstract Objectives to make a reliable correlation between the chemical composition of the urinary calculi and its Hounsfield unit on CT scan, upon which we can depend on it for prediction of the type of the urinary calculi. The prediction of the chemical structure of the stone would help us to reach a more efficient therapeutic and prophylactic plan. Methods A retrospective study was performed by interpretation of the preoperative CT scans for patients who were presented by urinary stones. Identification of the chemical structure of the calculi was implemented using Fourier Transform Infrared Spectroscopy (FT-IR spectroscopy). The laboratory report revealed multiple types of stones either of pure or mixed composition. Afterwards, a comparison was done between Hounsfield units of the stones and the chemical structure. Results The chemical structure of the urinary stones revealed four pure types of stones (Uric acid, Calcium Oxalate, Struvite and Cystine) and two types of mixed stones (mixed calcium oxalate+ Uric, and mixed calcium oxalate+ calcium phosphate). Uric acid stone had a mean Hounsfield Unit (HU) density of428 ± 81, which was quite less than the other stones, followed by struvite stones with density ranging about 714 ± 38. Mixed calcium oxalate stones could be differentiated from other types of stones like uric acid, pure calcium oxalate and struvite stones by the Hounsfield unit of Computed Tomography (the mean Hounsfield Unit was 886 ± 139 and 1427 ± 152 for mixed calcium oxalate + uric stone and mixed calcium oxalate + calcium phosphate stones respectively). Moreover, pure calcium oxalate stones were easily differentiated from all other stones using the mean Hounsfield density as it was 1158 ± 83. It was challenging only when it was compared to cystine stones, as they were quiet similar to HU value (997 ± 14). The variation of Hounsfield values among the previously mentioned stones, was statistically significant (p < 0.001). Conclusion The study proved that the Hounsfield Unit of CT scanning is a convenient measure to predict the chemical structure of urinary calculi.


2020 ◽  
pp. 177-204
Author(s):  
Bart O. Williams ◽  
Mark L. Johnson

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