scholarly journals Urea-functionalized amorphous calcium phosphate nanofertilizers: optimizing the synthetic strategy towards environmental sustainability and manufacturing costs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco J. Carmona ◽  
Gregorio Dal Sasso ◽  
Gloria B. Ramírez-Rodríguez ◽  
Youry Pii ◽  
José Manuel Delgado-López ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Environmental Sustainability ◽  
Amorphous Calcium Phosphate ◽  
Cost Effective ◽  
Shoot Biomass ◽  
One Pot ◽  
Synthetic Strategy ◽  
Urea Release ◽  
Use Efficiency

AbstractNanosized fertilizers are the new frontier of nanotechnology towards a sustainable agriculture. Here, an efficient N-nanofertilizer is obtained by post-synthetic modification (PSM) of nitrate-doped amorphous calcium phosphate (ACP) nanoparticles (NPs) with urea. The unwasteful PSM protocol leads to N-payloads as large as 8.1 w/w%, is well replicated by using inexpensive technical-grade reagents for cost-effective up-scaling and moderately favours urea release slowdown. Using the PSM approach, the N amount is ca. 3 times larger than that obtained in an equivalent one-pot synthesis where urea and nitrate are jointly added during the NPs preparation. In vivo tests on cucumber plants in hydroponic conditions show that N-doped ACP NPs, with half absolute N-content than in conventional urea treatment, promote the formation of an equivalent amount of root and shoot biomass, without nitrogen depletion. The high nitrogen use efficiency (up to 69%) and a cost-effective preparation method support the sustainable real usage of N-doped ACP as a nanofertilizer.

In Vivo Study of Two Carbamide Peroxide Gels with Different Desensitizing Agents

10.2341/07-10 ◽  
2007 ◽  
Vol 32 (6) ◽  
pp. 549-555 ◽  
Author(s):  
B. A. Matis ◽  
M. A. Cochran ◽  
G. J. Eckert ◽  
J. I. Matis
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Clinical Relevance ◽  
Potassium Nitrate ◽  
In Vivo Study ◽  
Carbamide Peroxide ◽  
Desensitizing Agents

Clinical Relevance Under the conditions of this study, 15% carbamide peroxide with potassium nitrate and fluoride exhibited greater bleaching potential but exhibited no difference in sensitivity compared to 16% carbamide peroxide with amorphous calcium phosphate.

scholarly journals Phosphoserine Functionalized Cements Preserve Metastable Phases, and Reprecipitate Octacalcium Phosphate, Hydroxyapatite, Dicalcium Phosphate, and Amorphous Calcium Phosphate, during Degradation, In Vitro

2019 ◽  
Vol 10 (4) ◽  
pp. 54 ◽  
Author(s):  
Joseph Lazraq Bystrom ◽  
Michael Pujari-Palmer
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Octacalcium Phosphate ◽  
Ionic Concentration ◽  
Strong Adhesion ◽  
Acidic Conditions ◽  
Rapid Transformation ◽  
Comparable Mass

Phosphoserine modified cements (PMC) exhibit unique properties, including strong adhesion to tissues and biomaterials. While TTCP-PMCs remodel into bone in vivo, little is known regarding the bioactivity and physiochemical changes that occur during resorption. In the present study, changes in the mechanical strength and composition were evaluated for 28 days, for three formulations of αTCP based PMCs. PMCs were significantly stronger than unmodified cement (38–49 MPa vs. 10 MPa). Inclusion of wollastonite in PMCs appeared to accelerate the conversion to hydroxyapatite, coincident with slight decrease in strength. In non-wollastonite PMCs the initial compressive strength did not change after 28 days in PBS (p > 0.99). Dissolution/degradation of PMC was evaluated in acidic (pH 2.7, pH 4.0), and supersaturated fluids (simulated body fluid (SBF)). PMCs exhibited comparable mass loss (<15%) after 14 days, regardless of pH and ionic concentration. Electron microscopy, infrared spectroscopy, and X-ray analysis revealed that significant amounts of brushite, octacalcium phosphate, and hydroxyapatite reprecipitated, following dissolution in acidic conditions (pH 2.7), while amorphous calcium phosphate formed in SBF. In conclusion, PMC surfaces remodel into metastable precursors to hydroxyapatite, in both acidic and neutral environments. By tuning the composition of PMCs, durable strength in fluids, and rapid transformation can be obtained.

scholarly journals Real Time In Vivo Confocal Microscopic Analysis of the Enamel Remineralization by Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP): A Clinical Proof-of-Concept Study

2020 ◽  
Vol 10 (12) ◽  
pp. 4155
Author(s):  
Maria Contaldo ◽  
Dario Di Stasio ◽  
Fedora della Vella ◽  
Dorina Lauritano ◽  
Rosario Serpico ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Proof Of Concept ◽  
Concept Study ◽  
Casein Phosphopeptide

Enamel defects (EDs) are qualitative and/or quantitative disturbances of the dental surface. To date, the responsiveness to remineralizing treatments has been studied ex vivo, on dental sections from extracted teeth. The present research aims to establish if in vivo reflectance confocal laser scanning microscopy is able to visualize the changes in the enamel architecture on living teeth, before, during and after remineralizing treatments by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). As proof-of-concept study, 17 consecutive children affected by EDs were enrolled and 38 EDs were considered. A CPP-ACP mousse was applied twice a week for 6 weeks and clinical and microscopic images were collected before, during and after the treatment for evaluating the changes occurred. For in vivo microscopic imaging, a reflectance confocal laser scanning microscope (RCM) for in vivo use was adopted. In this study RCM was proven to be able to visualize in vivo and at microscopic resolution the changes occurred during the remineralizing processes without needing for dental extractions and histopathological procedures. This in vivo RCM capability could encourage its clinical application in monitoring responsiveness to enamel therapies.

scholarly journals Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel

2016 ◽  
Vol 2 (9) ◽  
pp. e1601145 ◽  
Author(s):  
Alexandre La Fontaine ◽  
Alexander Zavgorodniy ◽  
Howgwei Liu ◽  
Rongkun Zheng ◽  
Michael Swain ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Dental Enamel ◽  
Atom Probe ◽  
Vital Role ◽  
The Body ◽  
Atomic Scale ◽  
Chemical Attack ◽  
Direct Observations

Human dental enamel, the hardest tissue in the body, plays a vital role in protecting teeth from wear as a result of daily grinding and chewing as well as from chemical attack. It is well established that the mechanical strength and fatigue resistance of dental enamel are derived from its hierarchical structure, which consists of periodically arranged bundles of hydroxyapatite (HAP) nanowires. However, we do not yet have a full understanding of the in vivo HAP crystallization process that leads to this structure. Mg2+ ions, which are present in many biological systems, regulate HAP crystallization by stabilizing its precursor, amorphous calcium phosphate (ACP), but their atomic-scale distribution within HAP is unknown. We use atom probe tomography to provide the first direct observations of an intergranular Mg-rich ACP phase between the HAP nanowires in mature human dental enamel. We also observe Mg-rich elongated precipitates and pockets of organic material among the HAP nanowires. These observations support the postclassical theory of amelogenesis (that is, enamel formation) and suggest that decay occurs via dissolution of the intergranular phase. This information is also useful for the development of more accurate models to describe the mechanical behavior of teeth.

scholarly journals Bone Tissue Regeneration by Collagen Scaffolds with Different Calcium Phosphate Coatings: Amorphous Calcium Phosphate and Low-Crystalline Apatite

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5860
Author(s):  
Syama Santhakumar ◽  
Ayako Oyane ◽  
Maki Nakamura ◽  
Yuto Yoshino ◽  
Mohammed Katib Alruwaili ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Bone Tissue ◽  
Tissue Regeneration ◽  
Amorphous Calcium Phosphate ◽  
Bone Tissue Regeneration ◽  
Apatite Coating ◽  
Low Crystalline ◽  
Mineralized Collagen

Surface-mineralized collagen sponges have attracted much attention as scaffolds for bone tissue engineering. Recently, we developed amorphous calcium phosphate (ACP) and low-crystalline apatite coating processes on collagen sponges. In the present study, we applied these coating processes to granular collagen sponges (referred to as Col) to compare the bone tissue regeneration capabilities of ACP-coated and apatite-coated Col (referred to as Col-ACP and Col-Ap, respectively) using a rat cranial bone defect model. According to micro-CT and histological analyses, Col-Ap enhanced bone tissue regeneration compared to Col, whereas Col-ACP did not. These results not only demonstrated the superior bone tissue regeneration capability of Col-Ap, but also indicated limitations of the in vitro simulated body fluid (SBF) test used in our previous study. Despite the apatite-forming ability of Col-ACP in SBF, it was ineffective in improving bone tissue regeneration in vivo, unlike Col-Ap, most likely due to the quick resorption of the ACP coating in the defect site. The present results clarified the importance of the coating stability in vivo and revealed that the low-crystalline apatite coating was more beneficial than the ACP coating in the fabrication of surface-mineralized collagen sponges for use as bone tissue engineering scaffolds.

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