Mechanism of calcium phosphate deposition in a hydrothermal coating process

Asl, Sara Kaabi Falahieh; Németh, Sándor; Tan, Ming Jen

doi:10.1016/j.surfcoat.2015.03.003

Cited by 25 publications

(12 citation statements)

References 47 publications

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“…However, to minimize product cost and environmental load, a single-step hydrothermal method seems a preferable option. The calcium phosphate coatings using this method has been investigated and reported by many authors utilizing different deposition parameters (Hiromoto and Yamamoto, 2009;Hiromoto and Tomozawa, 2010;Asl et al, 2014;Asl et al, 2015a;Asl et al, 2015b;Ali et al, 2019). In addition, investigation on the effect of process parameters of single-step hydrothermal CaP coating performance such as biological response, prolonged degradation behavior, and its effect on the mechanical strength of magnesium alloy is rarely found in the literature.…”

Section: Introductionmentioning

confidence: 99%

Improving the in vitro Degradation, Mechanical and Biological Properties of AZ91-3Ca Mg Alloy via Hydrothermal Calcium Phosphate Coatings

et al. 2021

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For many years, calcium phosphate coatings to tailor the degradation behavior of magnesium and magnesium-based alloys for orthopaedic applications have received lots of research attention. However, prolong degradation behavior, its effect on biological and mechanical properties as well as osteoblastic response to single-step hydrothermally deposited calcium phosphate coatings remain poorly documented. In this study, Alamar blue assay, cell attachment, live/dead assay, and qRT-PCR were done to study the biological response of the coatings. Furthermore, immersion testing in SBF for 28 days and compression testing of the degraded samples were carried out to examine the degradation behavior and its effect on mechanical properties. The results indicated that coatings have a significant influence on both the substrate performance and structural integrity of coated AZ91-3Ca alloy. Immersion test revealed that coating deposited at pH 7, 100°C (CP7100) improves the hydrogen evolution rate by 65% and the degradation rate by 60%. As the degradation performance of coated samples improves so does the mechanical strength. CP7100 samples successfully retained 90% of their compressive strength after 14 days of immersion while bare AZ91-3Ca alloy lost its mechanical integrity. Furthermore, biological studies show that cells are happily proliferating, differentiating, and adhering to the coating surfaces, which indicates, improved osteointegration and osteogenesis with no sign of alkaline poisoning. qRT-PCR results showed that calcium phosphate coatings enhanced the mRNA levels for RUNX2, Col1A, and ALP that may exhibit a speedy bone recovery. Thus, calcium phosphate coatings produced via a single-step hydrothermal method improve the degradation behavior, mechanical integrity and stimulate the differentiation of osteoblast lining. This leads toward faster bone regeneration, which shows a great potential of these coatings to be used on degradable implants as a bioactive protective layer.

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Section: Introductionmentioning

confidence: 99%

Improving the in vitro Degradation, Mechanical and Biological Properties of AZ91-3Ca Mg Alloy via Hydrothermal Calcium Phosphate Coatings

et al. 2021

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“…Deposition Mechanism of Coatings 110 phosphate in this case most probably followed the pH induce deposition mechanism [190]. As it reported earlier Mg is actively corroded at low pH, as a result of Mg corrosion, hydrogen gas releases and consequently, the pH close to the substrate surface increases and should reach the pH stability range of tricalcium phosphate which results in the solution's super saturation, and promotes the deposition of tricalcium phosphate as a first deposited layer [190].…”

Section: Chaptersupporting

confidence: 65%

“…Interestingly results showed in the case of HEPAA composite coating, in the beginning of the deposition process a layer of polymer (PAA) was adsorbed on the AZ31 surface as shown in Fig.5-15, it means that we have a COOfunctionalized surface which has a strong negative charge. This adsorbed polymer layer protected the AZ31 substrate from further corrosion as well, which means that the deposition process cannot be affected by corrosion of the AZ31 substrate and local pH increase and deposition following a different route [190].…”

Section: Deposition Mechanism Of Composite Coatingsmentioning

confidence: 99%

“…Until now, Ca-P inorganic and Ca-P/Polymer composite coatings were successfully deposited on the AZ31 substrate by means of hydrothermal method, which offered good corrosion performance, mechanical properties, degradation behavior as well as cell attachments [174,190,216,217]. Apart from that, inhibiting bacterial adhesion is essential to prevent implant-associated infection, because biofilms are extremely resistant to both the immune system and antibiotics.…”

Section: Anti-infective Coatings With Local Drug Delivery Abilitymentioning

confidence: 99%

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Surface modification and corrosion properties of Mg based alloys for bio-implant application

Asl¹

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The use of implants for bone repair has a considerable and successful history. Traditionally, metallic implants have been used in such a way that the implant would be surgically removed after sufficient bone healing has been achieved. During the last decade, interest in biodegradable magnesium (Mg) implants has increased dramatically. The use of Mg is based on the fact that Mg is one of the essential elements for human metabolism, and the density and elastic modulus of Mg are close to the human bone, thus, avoiding stress shielding effect. However, Mg alloys corrodes too rapidly, resulting in hydrogen evolution and consequently, local alkalization close to the surgery region as well as premature degradation in the implant's mechanical integrity before bone healing occurred. All these factors impede the practical applications of Mg implants. In this study, a hydrothermal coating process was used to provide, uniform and biodegradable inorganic calcium-phosphate (Ca-P) and calcium-phosphate/polymer (Ca-P/Polymer) composite coatings on AZ31 magnesium substrate that slow the corrosion of Mg and to meet different requirements for implant application. In the current study two different types of novel Ca-P/Polymer composites coatings were successfully deposited for the first time on AZ31 magnesium alloy to reduce CaP material brittleness by using polyacrylic acid and carboxymethyl cellulose polymers. The results showed, crystal phase and coating's morphology could be successfully controlled by the type and concentration of polymer used which could affect the coating's degradation rate as well. Incorporation of polymer in the CaP coatings reduced the coating elastic modulus bringing it close to that of Mg and that of human bone. Apart from mechanical properties, cell proliferation studies indicated that composite coatings induced better cell attachment compared to the purely inorganic CaP coating.

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“…This adsorbed polymer layer can protect the Mg substrate from rapid corrosion as well; therefore, the subsequent deposition process is less affected by corrosion of Mg substrate and local pH increase unlike in a purely inorganic Ca-P coating. 46 In the case of composite coating with PAA, the negatively charged surface attracts Ca 21 ions easily from solution resulting in high local concentration of Ca 21 . The high calcium concentration, presence of solid surface, and polymer promotes nucleation.…”

Section: Structure and Chemical Composition Of Coatingsmentioning

confidence: 99%

Novel biodegradable calcium phosphate/polymer composite coating with adjustable mechanical properties formed by hydrothermal process for corrosion protection of magnesium substrate

2015

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Ceramic type coatings on metallic implants, such as calcium phosphate (Ca-P), are generally stiff and brittle, potentially leading to the early failure of the bone-implant interface. To reduce material brittleness, polyacrylic acid and carboxymethyl cellulose were used in this study to deposit two types of novel Ca-P/polymer composite coatings on AZ31 magnesium alloy using a one-step hydrothermal process. X-ray diffraction and scanning electron microscopy showed that the deposited Ca-P crystal phase and morphology could be controlled by the type and concentration of polymer used. Incorporation of polymer in the Ca-P coatings reduced the coating elastic modulus bringing it close to that of magnesium and that of human bone. Nanoindentation test results revealed significantly decreased cracking tendency with the incorporation of polymer in the Ca-P coating. Apart from mechanical improvements, the protective composite layers had also enhanced the corrosion resistance of the substrate by a factor of 1000 which is sufficient for implant application. Cell proliferation studies indicated that the composite coatings induced better cell attachment compared with the purely inorganic Ca-P coating, confirming that the obtained composite materials could be promising candidates for surface protection of magnesium for implant application with the multiple functions of corrosion protection, interfacial stress reduction, and cell attachment/cell growth promotion. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1643-1657, 2016.

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Mechanism of calcium phosphate deposition in a hydrothermal coating process

Cited by 25 publications

References 47 publications

Improving the in vitro Degradation, Mechanical and Biological Properties of AZ91-3Ca Mg Alloy via Hydrothermal Calcium Phosphate Coatings

Improving the in vitro Degradation, Mechanical and Biological Properties of AZ91-3Ca Mg Alloy via Hydrothermal Calcium Phosphate Coatings

Surface modification and corrosion properties of Mg based alloys for bio-implant application

Novel biodegradable calcium phosphate/polymer composite coating with adjustable mechanical properties formed by hydrothermal process for corrosion protection of magnesium substrate

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