The effect of surface treatments on the adhesion of electrochemically deposited hydroxyapatite coating to titanium and on its interaction with cells and bacteria

Abstract

The effect of different mechanical and chemical pre-treatments on the adhesion strength of hydroxyapatite (HAp) coating on a commercially pure titanium (CP-Ti) substrate was studied by means of a standard tensile test followed by microscopic and chemical analysis to determine the locus of fracture. In addition, the effects of either these pre-treatments or post-treatment by low-energy electron irradiation, which allowed tuning the wettability of the surface, on both osteoblast progenitor attachment and S. aureus bacteria attachment were investigated. A dedicated program was developed for unambiguous identification and count of stained cells. A single-phase HAp coating was formed by electrodeposition. A series of surface pre-treatments consisted of grinding down to P1000, etching in HNO₃/HF solution, grit blast, soaking in NaOH and subsequent heat treatment provided the highest adhesion strength to the HAp coating. Osteoblast progenitors derived from rats may be attached preferentially to a hydrophilic surface (post-treatment to θ = 30°), while the bacteria seemed to be less attached to hydrophobic surfaces (post-treatment to θ = 105°). However, the results were not statistically different. The bacteria seemed to be less attached to the smoother, uncoated surfaces.

Calcium orthophosphate deposits: Preparation, properties and biomedical applications

“…Furthermore, the nature, structure and chemical composition of the substrate surface also play an important role [36]. Besides, the adhesion strength of plasma-spayed deposits was found to decrease when either the plate power was reduced (from 28 to 22 kW) or the working distance was increased (from 90 to 130 mm) [186].…”

“…Positive effects were discovered for both the glow-discharge [69,70] and ultraviolet [47,70,71] pre-treatments of the same polymers. Other types of pre-treatments of various surfaces were found to influence as well [36].…”

“…The interactions of CaPO 4 deposits with either cells in vitro or surrounding tissues in vivo have been studied a lot [36,120,130,236,244,269,314,316,317,391,478,559,566,574,[824][825][826][827][828][829][830][831][832][833][834][835][836][837][838][839][840][841][842]. Similar to the aforementioned, until the CaPO 4 deposits become so thin that cells and tissues will get the direct access to the surface of the substrates, their interactions with cells appear to be similar to that of CaPO 4 bulk bioceramics having the same structure, composition and properties.…”

Electrochemical Deposition of Hydroxyapatite Coatings on CoCrMo Alloy

“…Samples labeled as B and M and were held by conductive carbon glue to a thin copper strip. The surface of the samples were cut before deposition of hydroxyapatite by sandpaper Hermes grit abrasives 1000 because it was shown at cpTi Gr.2 that the different surface treatment (grinding, etching, immersion, blasting or heat treatment) increases the adhesion of the electrochemically deposited coatings (44). Deposition of the coating parameters are listed in Table II.…”

An in vivo comparison study in goats for a novel motion-preserving cervical joint system

“…Various biocoatings have been proposed as effective methods for improving the bone-implant interface stability. In recent decades, hydroxyapatite ((Ca 10 (PO 4 ) 6 (OH) 2 ; HA) has been reported to have a high biocompatibility, a low degradation rate, and the ability to increase the efficiency of bone-implant integration in order to improve osteointegration of implants because of its similar composition to bone tissue and its ability tocreate chemical bonding withbones[9]. Xie and Luan[10] reported that the precoated HA could further improve the stability of the Ti6Al4V alloy with a composite layer of TiO 2 and HA.…”