Biomimetic collagen/apatite coating formation on Ti6Al4V substrates

Abstract

Hydroxyapatite and type I collagen are two major components of natural bone. They have been used extensively to engineer biomaterial surfaces for enhanced implant-bone integrations. In this study, a collagen/apatite composite coating was successfully deposited on treated Ti6Al4V surfaces by coprecipitation of type I collagen and apatite in a collagen-containing modified simulated body fluid (m-SBF). X-ray diffraction and Fourier-transform infrared spectroscopy results indicated that the coating achieved was a composite of bone-like carbonated apatite and collagen type I, which is similar to the composition of natural bone. The coating composition and morphology could be tailored by carefully adjusting the collagen concentration in the m-SBF. In addition, both the coating thickness and bonding strength were down regulated by the collagen concentration in the m-SBF. Collagen inhibited the apatite nucleation on the metallic substrate, and thereby reduced the bonding strength of the composite coating. In addition, an in vitro cell culture study was conducted on both the apatite and the collagen-apatite coating surfaces. Addition of collagen promoted osteoblast activities, which may lead to early bone formation.

Evaluation of PLAGA/n-HA Composite Scaffold Bioactivity in vitro

“…The accelerated mineral deposition observed on PLAGA/n-HA scaffolds implied that incorporation of hydroxyapatite into the microsphere sintered scaffolds could improve their bioactivity in term of mineral deposition. The newly formed apatite layer showed characteristic morphology of tightly packed aggregation of nano particles, which has been observed by other researchers [24][25][26]. This unique morphology combined with Alizarin red staining confirmed that the observed mineral layer was formed during SBF incubation instead of the n-HA incorporated during scaffold fabrication.…”

Calcium orthophosphates (CaPO 4 ): Occurrence and properties

“…A step further would be to perform the precipitation from the simulating solutions on templates of biomineralization proteins for the control of crystal organization and properties. For example, there are successful attempts to crystallize CaPO 4 on collagen to obtain bone-like composites (Nassif et al 2010;Li et al 2011;Xia et al 2012Xia et al , 2013Xia et al , 2014Antebi et al 2013). Such collagen/CaPO 4 biocomposites are currently under investigation for clinical use.…”

Cell-material interaction

“…Matrix proteins can be adsorbed to nearly all biomaterial surfaces, including metals, ceramics, and organic polymers. For bone implants, titanium was coated with collagen or collagen in combination with apatite, which promoted osteoblast activities [71,72]. However, the use of full-length matrix proteins to coat material surfaces revealed several limitations.…”