Ultrastructural observation of single-crystal apatite fibres

Aizawa, Mamoru; Porter, Alexandra E.; Best, Serena M.; Bonfield, W.

doi:10.1016/j.biomaterials.2004.09.044

Cited by 135 publications

(119 citation statements)

References 12 publications

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“…Needle-shaped apatite is oriented with the c axis parallel to the long axis of the needles. The observation that needle-shaped apatite is single crystalline is compatible with the recent study of Aiziwa et al 15 on synthetic carbonate-containing apatite fibers. The regions surrounded by needle-shaped apatite exhibit amorphous phases and crystalline grains with the c axis mostly quasi-perpendicular to the long axis of the needleshaped plates (which are parallel to the plane of the substrate).…”

Section: Discussionsupporting

confidence: 91%

“…One consequence of the anisotropic distribution of atoms is the orientation dependence of surface energy, which is dependent on the orientation dependence of the bonding strength of crystalline apatite. The observation 15 that apatite fibers cleave along the long axis (which is parallel to the c axis) when they are fractured suggests that apatite is weak along the planes oriented parallel to the c axis. 15 Because the fracture work of brittle materials is dominated by the surface energy, 37,38 cleavage along the c axis 15 suggests that the surface energy of the planes parallel to the c axis is lower than that of the basal plane of the hexagonal structure of apatite.…”

Section: Discussionmentioning

confidence: 99%

“…3,[10][11][12] The morphology and structure of apatites, in turn, dictate the biomechanical and biochemical properties. 2,3,5,[13][14][15][16] However, few ultrastructurallevel studies (from 0.1 to 100 nm) on apatite films deposited from SBF have been conducted, and most transmission electron microscopy (TEM) studies have been performed on apatite powders or precipitates processed by methods that are subject to limitations. For example, Lu and Leng 13 prepared TEM specimens by extracting the deposited film by an ultrasonic vibration method, and Chou et al 3 prepared specimens by scraping off the deposited film, suspending apatite precipitates in isopropanol, and picking them up on Cu grids.…”

Section: Introductionmentioning

confidence: 99%

“…[10][11][12][13][14][15] Furthermore, recent studies 3,13 on the nanostructure of mineral films deposited from SBF report different crystal structures and morphologies, suggesting a more complicated nature for apatite crystal growth from SBF than synthetic apatite. For example, Lu and Leng 13 reported that they observed ACP and granular OCP, instead of apatite, which is in contrast with the observation of the plate-like and needlelike apatite reported by Chou et al 3 The objective of this study was to analyze the ultra-structure of calcium phosphate films biomimetically deposited onto poly(lactide-co-glycolide) (PLGA) substrates from SBF using high-resolution electron transmission microscopy (HRTEM).…”

Section: Introductionmentioning

confidence: 99%

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Ultrastructural analyses of nanoscale apatite biomimetically grown on organic template

et al. 2008

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The ultrastructure of nanoscale apatite biomimetically formed on an organic template from a supersaturated mineralizing solution was studied to examine the morphological and crystalline arrangement of mineral apatites. Needle-shaped apatite crystal plates with a size distribution of ~100 to ~1000 nm and the long axis parallel to the c axis ([002]) were randomly distributed in the mineral films. Between these randomly distributed needle-shaped apatite crystals, amorphous phases and apatite crystals (~20-40 nm) with the normal of the grains quasi-perpendicular to the c axis were observed. These observations suggest that the apatite film is an interwoven structure of amorphous phases and apatite crystals with various orientations. The mechanisms underlying the shape of the crystalline apatite plate and aggregated apatite nodules are discussed from an energy-barrier point of view. The plate or needle-shaped apatite is favored in single-crystalline form, whereas the granular nodules are favored in the polycrystalline apatite aggregate. The similarity in shape in both singlecrystalline needle-shaped apatite and polycrystalline granular apatite over a wide range of sizes is explained by the principle of similitude, in which the growth and shape are determined by the forces acting upon the surface area and the volume.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Ultrastructural analyses of nanoscale apatite biomimetically grown on organic template

et al. 2008

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“…From the chemical point of view, the developments include synthesis of novel ion-substituted calcium orthophosphates . From the material point of view, the major research topics include nanodimensional and nanocrystalline structures [704][705][706][707][708], organic-inorganic biocomposites and hybrid biomaterials [316], fibers, whiskers and filaments [709][710][711][712][713][714][715][716][717][718][719][720][721][722], micro-and nano-sized spheres and beads [722][723][724][725][726][727][728][729][730][731][732][733][734][735][736][737], micro-and nano-sized tubes [738][739][740], porous 3D scaffolds made of ACP [462,598], TCP [432][433][434][435], HA [176,…”

Section: Bioceramic Scaffolds From Calcium Orthophosphatesmentioning

confidence: 99%

Medical Application of Calcium Orthophosphate Bioceramics

Dorozhkin¹

2011

BIO

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In the late 1960's, a strong interest was raised in biomedical applications of ceramic materials (named bioceramics a little bit later). Bioceramics was initially used as reasonable alternatives to metals in order to increase their biocompatibility. However, within a short period, it has grown into a diverse class of biomaterials, presently including three essential types: relatively bioinert, bioactive (or surface reactive) and bioresorbable bioceramics. This review is limited to bioceramics prepared from calcium orthophosphates only, which belong to the categories of bioactive and bioresorbable compounds. There have been a number of important advances in this field during the past 30 -40 years. The research was shifted from an initial study on the develop-ment of bioinert bioceramics towards bioactive and bioresorbable bioceramics, and these different types of calcium orthophosphate bioceramics can be tuned through the structural and compositional control. At the turn of the millennium, a new concept of calcium orthophosphate bioceramics has been developed to promote a regeneration of bones. Current biomedical applications of calcium orthophosphate bioceramics include artificial replacements for hips, knees, teeth, tendons and ligaments, as well as repair for periodontal disease, maxillofacial reconstruction, augmenttation and stabilization of the jawbone, spinal fusion and bone fillers after tumor surgery. Potential future applications of calcium orthophosphate bioceramics are demonstrated in drug delivery systems, effective carriers of growth factors, bioactive peptides and/or various types of cells for tissue engineering purposes.

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