Bone-like growth of hydroxyapatite in the biomimetic coating of Ti-6Al-4V alloy pretreated with protein at 25 °C

Abstract

Commercial-grade dense Ti-6Al-4V alloy substrate was mechanically roughened, cleaned, and treated with a globular protein [bovine serum albumin (BSA)] for 4 h. Biomimetic calcium phosphate (Ca-P) coating was applied onto the above-treated substrate by immersion into simulated body fluid (SBF) at 25 °C for a period of 4 days, with periodic replacement by freshly prepared SBF at 48-h intervals. After 4 days, branched micron-sized fibers of hydroxyapatite (HAp), resembling the structure of bone, were obtained, connecting the clusters of HAp crystal plates in the coating (thickness ∼200 μm) on the substrate surface. Structural and compositional characterization of the coating was carried out using field emission scanning electron microscopy (FE-SEM) with energy-dispersive x-ray analysis unit (EDX) facility, x-ray diffraction (XRD), and Fourier transform infrared (FTIR) data. In vitro cytotoxicity (ISO 10993-5, 1999), cell adhesion assays, and phase contrast microscopy were performed using NIH 3T3 fibroblast cell lines to ascertain the bioactivity of the coated substrates, with and without protein treatment. Based on our study, we propose a correlation between a specific physical structure of the HAp coating and its biological properties.

Effects of titania nanotubes with or without bovine serum albumin loaded on human gingival fibroblasts

“…28,29 Furthermore, serum protein may promote mineral deposition because they contain structures, such as -OH, -NH, and -SH, with strong affinities for inorganic cations and anions, causing them to become commonly used in simulated biomineralization experiments. 30 Therefore, a Ti surface modified with bovine serum albumin (BSA)-loaded TNTs may also be conducive for preserving the crestal bone, while the effects of these materials on soft tissue remains to be studied in detail.…”

Bioinspired and Biomimetic Functional Hybrids as Tools for Regeneration of Orthopedic Interfaces

“…In our method, the metal /ceramic substrates were incubated in simulated body fluid (SBF) at 25°C for different time points with prior treatment with globular protein BSA (bovine serum albumin) [Chakraborty et al, 2009;Kapoor et al, 2010]. This process leads to the formation of HAp coating exhibiting bone like apatite growth on the surface.…”

“…The surface treatment by globular protein i.e., BSA might provide a functionalized template comprising of charged amino-acids which resulted in more nucleation sites [Chakraborty et al, 2009] hence led to the even coverage of HAp (about 280-300µm) by immersion of the materials in SBF at desired temperature of 25°C between the pH range of 5-7, which resulted in the formation 30-40 nm albumin globules, under specified conditions, on both ceramic and Ti-6Al-4V alloy substrates. In comparison with the untreated substrates the coverage of HAp was very much poor(less than 200µm), hence BSA treatment has led to the development of nano-sized globules after HAp coating which have led to the better cellular-activity in-vitro which is due to "cooperativity" reaction [Chakraborty et al, 2009] between protein molecules and the charged surface of HAp, depending on the concentration of the protein molecules in the coating [SBF] solutions. We have done a comparative study of biological properties of the unique coating of HAp developed on both metal and non-metal which is less reported.…”

“…Mg-Zn-Zr, HA-PEEK poly (aryl-etherether-ketone), Polyphospha zenes, BG-COL-HYA-PS (glass-collagen hyaluronic acid-phosphatidylserine) Yeung et al,2007;Aksakal et al, 2008;Seligson et al,1997;Marti 2000Aksakal et al, 2008Chakraborty et al, 2009;Yeung et al,2007;Banerjee et al, 2004;Banerjee et al, 2006;Niinomi 2003;Ning et al, 2010;Seligson et al,1997Kapoor et al, 2010Christel et al, 1988;Gorustovich et al, 2010;Yuan et al, 2001Andersson et al, 2004Reis et al, 2010;Oral et al, 2007;Butler et al, 2001;Athanasiou et al, 1998;Smith et al,2007;Geary et al, 2008;Shalumon et al, 2009;Jayabalan et al, 2001Ye et al,2010Kurtz et al, 2007;Sethuraman et al, 2010;Xu et al, 2010 Since there is no material available that can per se become a bone substitute, several modifications on the original material are required to make it biocompatible. The aim to do these modifications is that the new material should be nontoxic and biologically inert but yet it should show orthopedic bioactivity and its production should be cost effective.…”

“…The design and manufacturing of orthopedic bimimetic implants is meant to replace parts of the hard and weight-bearing bones [Rigo et al, 2004;Chakraborty et al, 2009;Kapoor et al, 2010;Nair et al, 2009;Geary et al, 2008] and replacing soft orthopedic tissue [Balasundaram & Webster, 2007]. Further improvements in the implant's properties, which could include the incorporation of bioactive molecules such as long chain proteins or short peptide sequences [Chakraborty et al, 2009;Kapoor et al, 2010;Balasundaram & Webster, 2007;Keselowsky et al, 2005;Le et al, 2006;Stevens et al, 2008;Sato &Webster, 2004], are necessary to make them more acceptable by the cells at the site and thus ensure their long term success. This is an ongoing process and several new developments have taken in this field in recent years.…”