Bioactive nanocomposite coatings of collagen/hydroxyapatite on titanium substrates

Abstract

Collagen/hydroxyapatite (HA) nanocomposite thin films containing 10, 20, and 30 wt.% HA were prepared on commercially pure titanium substrates by the spin coating of their homogeneous sols. All of the nanocomposite coatings having a thickness of *7.5 lm exhibited a uniform and dense surface, without any obvious aggregation of the HA particles. A minimum contact angle of 36.5°w as obtained at 20 wt.% HA, suggesting that these coatings would exhibit the best hydrophilicity. The in vitro cellular assays revealed that the coating treatment of the Ti substrates favored the adhesion of osteoblast-like cells and significantly enhanced the cell proliferation rate. The cells on the nanocomposite coatings expressed much higher alkaline phosphatase (ALP) levels than those on the uncoated Ti substrates. Increasing the amount of HA resulted in a gradual improvement in the ALP activity. The nanocomposite coatings on Ti substrates also exhibited much better cell proliferation behaviors and osteogenic potentials than the conventional composite coatings with equivalent compositions, demonstrating the greater potential of the former as implant materials for hard tissue engineering.

Calcium orthophosphate-based biocomposites and hybrid biomaterials

“…Such syntheses were denoted as ''biologically inspired'' which means they reproduce an ordered pattern and an environment very similar to natural ones [594][595][596]. The biologically inspired biocomposites of collagen and calcium orthophosphates (mainly, apatites) for bone substitute have a long history [29,364,499,[597][598][599][600][601][602][603][604][605][606][607][608][609][610][611][612][613][614][615] and started from the pioneering study by Mittelmeier and Nizard [616], who mixed calcium orthophosphate granules with a collagen web. Such combinations were found to be bioactive, osteoconductive, osteoinductive [29,585,[617][618][619] and, in general, artificial grafts manufactured from this type of the biocomposites are likely to behave similarly to bones and be of more use in surgery than those prepared from any other materials.…”

Biocomposites and hybrid biomaterials based on calcium orthophosphates

“…[705][706][707] Such syntheses were denoted as "biologically inspired" which means they reproduce an ordered pattern and an environment very similar to natural ones. [708][709][710] The biologically inspired biocomposites of collagen and calcium orthophosphates (mainly, apatites) for bone substitute have a long history, 33,442,597,[711][712][713][714][715][716][717][718][719][720][721][722][723][724][725][726][727][728][729][730] which began with the pioneering study by Mittelmeier and Nizard, 731 who mixed calcium orthophosphate granules with a collagen web. Such combinations were found to be bioactive, osteoconductive, osteoinductive, 33,699,732-734 and, in general, artificial grafts manufactured from this type of biocomposites are likely to behave similarly to bones and be of more use in surgery than those prepared from any other materials.…”

Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration

“…SEM images of films with different nHA content show that as the nHA content increases the surface of film becomes rougher, which again could provide increased surface area for cell attachment [23].…”