Adsorption on Apatitic Calcium Phosphates: Applications to Drug Delivery

Errassifi, Farid; Menbaoui, Anas; Autefage, Hélène; Benaziz, Lhaj; Ouizat, Saadia; Santran, Véronique; Sarda, Stéphanie; Lebugle, A.; Combes, Christèle; Barroug, Allal; Sfihi, H.; Rey, Christian

doi:10.1002/9780470909898.ch16

Cited by 26 publications

(45 citation statements)

References 38 publications

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“…The structure of the hydrated layer seems very sensitive to its ion content and state of hydration: a loss of the original fine structural details revealed by spectroscopic techniques, in wet state, is observed on drying or when specific ions like magnesium are present, leading to line broadening and amorphization [33,34]. Several rapid and reversible ion exchange reactions have been reported [35][36][37][38] and it has been shown that the adsorption of several ionized organic molecules corresponded to ion exchanges with mineral ions of the hydrated layer [39][40][41]. Consequently, the global chemical formulas of apatites reported in the previous paragraph, which do not take into account the existence of hydrated surface domains, should be re-examined.…”

Section: Non-apatitic Environments and The Hydrated Layermentioning

confidence: 99%

Apatite Biominerals

2016

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Calcium phosphate apatites offer outstanding biological adaptability that can be attributed to their specific physico-chemical and structural properties. The aim of this review is to summarize and discuss the specific characteristics of calcium phosphate apatite biominerals in vertebrate hard tissues (bone, dentine and enamel). Firstly, the structural, elemental and chemical compositions of apatite biominerals will be summarized, followed by the presentation of the actual conception of the fine structure of synthetic and biological apatites, which is essentially based on the existence of a hydrated layer at the surface of the nanocrystals. The conditions of the formation of these biominerals and the hypothesis of the existence of apatite precursors will be discussed. Then, we will examine the evolution of apatite biominerals, especially during bone and enamel aging and also focus on the adaptability of apatite biominerals to the biological function of their related hard tissues. Finally, the diagenetic evolution of apatite fossils will be analyzed.

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Section: Non-apatitic Environments and The Hydrated Layermentioning

confidence: 99%

Apatite Biominerals

2016

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“…Organic molecules (e.g. bioactive ones) often exhibit a high binding affinity for calcium phosphate surfaces, but if adsorption studies of such molecules on well-crystallized HA are well described [226][227][228][229], very few studies have been performed on the adsorption of organic molecules on nanocrystalline apatites despite physico-chemical features much closer to those of bone mineral. As for ion exchanges, the adsorption isotherms are generally well described by the Langmuir model, as it has been published for proteins as bovine serum albumin (BSA) [200,230], or o-phosphoserine [231], although the adsorption on apatitic surface of some aminoacids as serine, or simple molecules weakly interacting with apatite, can be more adequately described by a Freundlich type isotherm [231].…”

Section: Organic Molecules Adsorption On Nanocrystalline Apatitementioning

confidence: 99%

Progress on the preparation of nanocrystalline apatites and surface characterization: Overview of fundamental and applied aspects

Gómez‐Morales¹,

Iafisco

Delgado-López³

et al. 2013

Progress in Crystal Growth and Characterization of Materials

241

268

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International audienceNanocrystalline calcium phosphate apatites constitute the main inorganic part of hard tissues, and a growing focus is devoted to prepare synthetic analogs, so-called "biomimetic", able to precisely mimic the morphological and physico-chemical features of biological apatite compounds. Both from fundamental and applied viewpoints, an accurate characterization of nanocrystalline apatites, including their peculiar surface features, and a deep knowledge of crystallization aspects are prerequisites to attempt understanding mineralization phenomena in vivo as well as for designing innovative bioactive materials that may then find applications in bone tissue engineering, either as self-supported scaffolds and fillers or in the form of coatings, but also in other domains such as drug delivery or else medical imaging. Also,interfacial phenomena are of prime importance for getting a better insight of biomineralization and for following the behavior of biomaterials in or close to their final conditions of use. In this view,both adsorption and ion exchange represent essential processes involving the surface of apatite nanocrystals, possibly doped with foreign elements or functionalized with organic molecules of interest. In this review paper, we will address these various points in details based on a large literature survey. We will also underline the fundamental physico-chemical and behavioral differences that exist between nanocrystalline apatites (whether of biological origin or their synthetic biomimetic analogs) and stoichiometric hydroxyapatite

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“…Adsorption on nanocrystalline apatite of bioactive agents indicates an increase of the affinity constant and a decrease of the amount adsorbed as maturation time increases [125]. The increase of the affinity constant may be correlated with an increase of interfacial energy of nanocrystals during maturation in aqueous media [126]. The hydrated layer probably reduces the surface energy of the nanocrystals in aqueous media.…”

Section: Adsorption and Release Of Drugsmentioning

confidence: 99%