Characterizing inorganic crystals grown on organic self-assembled bilayers with scanning probe and electron microscopies.
Combined microscopy techniques are used to establish the usability of phosphonic acid layers as promoters of hydroxyapatite (HAp) growth. Using spread coating, octadecylphosphonic acid (OPA) self-assembled bilayers are delivered to the thin natural oxide layer of a titanium film surface with no prior treatment. These bilayers aggregate two major advantages of phosphonic moieties to titanium surfaces: nucleation of hydroxyapatite crystals from ionic solution and affinity for both titanium oxide surface and HAp crystals. The functionalized substrates and bare titanium (control) samples are immersed in an aqueous solution containing calcium and phosphorus ions. Over a 4-week immersion time, OPA-functionalized substrates present numerous large agglomerates of inorganic crystals, in contrast to control samples, with no significant amount of deposits. Initial sample characterization was performed with atomic force microscopy (AFM). Compositional and structural characterization of these agglomerates (using TEM, EDS, and electron diffraction), revealed that they are indeed HAp, the main component of the inorganic bone matrix.
['Prado|Mariana C|MC|', 'Archanjo|Braulio S|BS|', 'Vasconcelos|Thiago L|TL|', 'Ladeira|Luiz O|LO|', 'Neves|Bernardo R A|BR|']
D001857:Bone Matrix D002118:Calcium D020099:Coated Materials, Biocompatible D003460:Crystallization D017886:Durapatite D018625:Microscopy, Atomic Force D046529:Microscopy, Electron, Transmission D020527:Microscopy, Scanning Probe D010757:Phosphorous Acids D010758:Phosphorus D013499:Surface Properties D014025:Titanium
self-assembled bilayers phosphonic acids hydroxyapatite AFM EDS SEM