Deposition Of Calcium Phosphate Coatings Research Articles

Bioactive calcium phosphate coatings applied to flexible poly(carbonate urethane) foils

Long-term fixation of orthopaedic implants can be enhanced by tissue ingrowth techniques. As such, the deposition of a bioactive bone-like coating could be considered a promising method to facilitate the integration of implants onto bone tissue. In this study, we identified the optimized osteo-conductive Calcium Phosphate (CaP) coating parameters for deposition on PolyCarbonate-Urethane (PCU) foils. The oxygen plasma surface-activated PCU specimens were suspended in simulated body fluid (SBF) and supersaturated SBFs for 4 h, 8 h, 24 h, or 6 days at a temperature of 20 °C, 37 °C, or 50 °C. This resulted in semi-crystalline CaP coatings on a thin flexible foil via a one-step low-temperature aqueous technique. The deposited CaP coatings demonstrated high stability and remained intact upon bending deformation. According to the in vitro cell assessments, the conducted CaP coatings did not influence cell viability nor cell proliferation compared to the bare PCU substrate. In addition, the deposited CaP coatings enhanced the cell-mediated calcium deposition. All in all, this paper demonstrates a promising method to apply stable bioactive coatings to flexible PCU foils, which can be a promising strategy for the enhanced integration of PCU implants onto bone.

Antibacterial and biocompatible Zn and Cu containing CaP magnetron coatings for MgCa alloy functionalization

The application of bioresorbable magnesium-based alloys in medical implants has been limited by their rapid dissolution rate. In order to enhance their suitability for medical use, this study proposes the deposition of calcium phosphate (CaP) onto Mg (0.8) Ca alloy using an RF magnetron sputtering with stoichiometric hydroxyapatite and Zn- or Cu-substituted hydroxyapatites. The comparison study assessed structure, composition, and mechanical properties of Mg (0.8) Ca alloy, Zn, and Cu containing CaP coatings. CaP coatings showed an increased Ca/P ratio due to re-sputtering. Sputtering of Zn- and Cu-substituted hydroxyapatites resulted in CaP dopant concentrations of 0.6 ± 0.2 wt% and 0.4 ± 0.1 wt%, respectively. All deposited coatings were found to be amorphous. Addition of Cu or Zn dopant slightly changed the CaP coatings' scratch resistance, with critical loads of 2.19 ± 0.60 N, 2.55 ± 0.95 N, and 2.76 ± 1.29 N for CaP, Zn–CaP, and Cu–CaP coatings, respectively. CaP coatings reduced corrosion current and increased electrical resistance compared to MgCa samples, but Cu addition accelerated corrosion. Biological tests revealed that the hAMSCs survival was improved and the bacteriostatic effect on the pathogenic SA strain was enhanced for Zn–CaP coatings when compared to CaP and Cu–CaP coatings. These findings suggest that the deposition of CaP coatings onto Mg (0.8) Ca alloy, and particularly the use of Zn-substituted hydroxyapatites, could be a promising approach to enhance the suitability of magnesium-based alloys for medical implant applications.

A comparative study of apatite growth and adhesion on a laser-functionalized titanium surface

The laser processing of titanium has been proven to improve biological responses of the surface. In this paper, the Direct Laser Interference Patterning (DLIP) method has been proposed as a single-step functionalization of pre-modified titanium surfaces for biomedical applications. Immersion in Hank’s solution for the deposition of calcium phosphate coatings was applied to evaluate the biomedical potential of modified Ti substrates. The bioactive effect and adhesion force of the Ca-P coating were investigated by X-ray photoelectron spectroscopy and scratch tests with subsequent scanning electron microscopy observations and energy dispersive spectroscopy measurements. In general, the results confirmed that laser treatment positively influences bone-like apatite formation and has an impact on the surface wear resistance.

APATITIC NANOPOWDERS AND COATINGS: A COMPREHENSIVE REVIEW

The use of artificial biomaterials has been acclaiming potential therapeutic scope in diverse clinical applications. This review started with the description of the basics of biomaterials, and desirable properties, which are the prerequisites to understand biomaterials. The orthopedic biomaterials, their classification and the importance of calcium phosphate (CaP) materials for hard-tissue applications were utterly discussed. Furthermore, among the various CaP biominerals, the importance of hydroxyapatite (HAP) and its synthesis techniques was comprehensively reviewed. The sol–gel route for the synthesis of HAP nanoparticles and deposition of coatings were systematically studied. Among the metallic substrates, Ti6Al4V alloy remained the focus of this study. Moreover, several film pre-preparation methods were also given due importance. The importance of other surface modification techniques, especially in the context of Ti6Al4V substrates, was also discussed. Among several coating techniques to deposit CaP coatings, special attention was paid to the spin and dip coating techniques. In addition to monolithic HAP coatings, reinforced and antimicrobial HAP coatings were also reviewed from broad perspectives. Therefore, this review provides an in-depth insight into the preparation and properties of apatitic nanoparticles and their coatings for orthopedic and dental applications.

Improving the in vitro Degradation, Mechanical and Biological Properties of AZ91-3Ca Mg Alloy via Hydrothermal Calcium Phosphate Coatings

For many years, calcium phosphate coatings to tailor the degradation behavior of magnesium and magnesium-based alloys for orthopaedic applications have received lots of research attention. However, prolong degradation behavior, its effect on biological and mechanical properties as well as osteoblastic response to single-step hydrothermally deposited calcium phosphate coatings remain poorly documented. In this study, Alamar blue assay, cell attachment, live/dead assay, and qRT-PCR were done to study the biological response of the coatings. Furthermore, immersion testing in SBF for 28 days and compression testing of the degraded samples were carried out to examine the degradation behavior and its effect on mechanical properties. The results indicated that coatings have a significant influence on both the substrate performance and structural integrity of coated AZ91-3Ca alloy. Immersion test revealed that coating deposited at pH 7, 100°C (CP7100) improves the hydrogen evolution rate by 65% and the degradation rate by 60%. As the degradation performance of coated samples improves so does the mechanical strength. CP7100 samples successfully retained 90% of their compressive strength after 14 days of immersion while bare AZ91-3Ca alloy lost its mechanical integrity. Furthermore, biological studies show that cells are happily proliferating, differentiating, and adhering to the coating surfaces, which indicates, improved osteointegration and osteogenesis with no sign of alkaline poisoning. qRT-PCR results showed that calcium phosphate coatings enhanced the mRNA levels for RUNX2, Col1A, and ALP that may exhibit a speedy bone recovery. Thus, calcium phosphate coatings produced via a single-step hydrothermal method improve the degradation behavior, mechanical integrity and stimulate the differentiation of osteoblast lining. This leads toward faster bone regeneration, which shows a great potential of these coatings to be used on degradable implants as a bioactive protective layer.

Effects of strontium-substitution in sputter deposited calcium phosphate coatings on the rate of corrosion of magnesium alloys

Magnesium (Mg) alloys have significant potential for use as bioresorbable orthopaedic implant devices due to their controllable mechanical properties and an ability to promote new bone growth. However, difficulty lies with controlling the rate of corrosion in physiological conditions to ensure the load-bearing capability of the device is maintained for the required period of time, specifically until an adequate quantity of new bone tissue is formed. In this work, RF magnetron sputtering has been used to create calcium phosphate (CaP) and strontium-substituted calcium phosphate (SrCaP) thin film coatings on two Mg alloy systems (denoted WJK and ZEWX) that have been formulated for the fabrication of orthopaedic fracture fixation devices. A 14-day static-dynamic immersion study in simulated body fluid (SBF), shows that uncoated WJK substrates had a corrosion rate of 4.04 ± 0.15 millimetres per year (mmpy), which was reduced to 3.22 ± 0.17 mmpy with the application of a CaP coating, and to 2.92 ± 0.05 mmpy with a SrCaP coating. Uncoated ZEWX substrates had a corrosion rate of 3.36 ± 0.05 mmpy which was reduced to 2.98 ± 0.19 mmpy and 2.79 ± 0.03 mmpy, for CaP and SrCaP coatings, respectively. Whereas the sputter-deposited CaP and SrCaP coatings completely dissolve in SBF over the period of immersion, their presence at the outset significantly decreases the corrosion rate of both Mg alloys, as compared to the values for the uncoated substrates. Successful incorporation of Sr within the coating offers the potential for improved bioactivity with respect to directing the bone cell response to create new tissue.

Electrochemically Deposited Calcium Phosphate Coatings Using a Potentiostat of In-house Design and Implementation

Abstract The effect of growth conditions and post treatments on the properties of calcium phosphate films electrodeposited by a potentiostat of the authors’ design and construction is presented. The electrolyte used was formed with 0.025 M (NH4)H2PO4 and 0.042 M Ca(NO3)2.4H2O, and its pH was kept at 5. A voltametric analysis was performed to determine the necessary potential values to obtain the films. Additionally, the temperature of the electrolyte was varied to determine its influence on the properties of the deposited films. The films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The films deposited at -1.4 V and -1.7 V present the brushite phase. The thermal post-treatment favored the formation of octagonal calcium phosphate in amorphous phase, while the basic treatment provided the OH- groups necessary for the formation of hydroxyapatite. The low cost potentiostat implemented presents excellent characteristics for obtaining films with similar characteristics to those obtained with a conventional potentiostat.

Effect of Bioactivity of Surface Topography and Coating Forming by Infrared Light-Induced on Titanium for Bone Repair

Calcium ions and phosphate ions are usually present in biological organisms and human bodies. Different ratios of calcium to phosphorus result in different types of calcium-to-phosphorus crystals. Hydroxyapatite (HA) is the main component of human hard bony tissues. It has good biocompatibility and is often used in bone repair. With the addition of cobalt ions, it can act as a hypoxia-inducing factor to accelerate the regeneration of hard bony tissues. At present, the laser-assisted biomimetic (LAB) method can very quickly deposit calcium phosphate coatings, which can be used on polymer and titanium surfaces. In this study, we first used anodization treatment (with TiO2 nanotubes (TNTs)), alkali treatment (with NaOH), and acid treatment (with HCl) to form nanopore structures on titanium surfaces in the laboratory. Subsequently, LAB treatment was used to deposit calcium phosphate and cobalt-substituted hydroxyapatite onto titanium pieces with different surface treatments. The results showed that smaller holes resulted in better deposition (TNTs), and controlling the pH value in the solution changed the crystal morphology. LAB treatment imbued the titanium surface with super-hydrophilic properties and improved biocompatibility. A human osteoblast cell line (MG-63) used for the cell viability test showed that LAB treatment can improve cell growth. In particular, TNT-CoHA (cobalt-substituted hydroxyapatite) cells grew the best. Immersion in simulated bodily fluid confirmed that LAB treatment with a CoHA solution improved the hydrophilicity, biocompatibility, and bioactivity of titanium surfaces. It is hoped that this study provides useful information for surface coating of biomedical materials in the future.

Morphological, Chemical, and Biological Investigation of Ionic Substituted, Pulse Current Deposited Calcium Phosphate Coatings.

Ionic substituted calcium phosphate coatings (iCP) have been prepared by the electrochemical pulse current deposition technique with an alternate pulse on and off time of 5 ms onto a titanium alloy substrate. The elemental distribution and morphology of the deposited layers have been extensively studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM). The crystallinity and phase structure of iCPs have been investigated by X-ray diffraction (XRD). The corrosion characteristics and biodegradability of coatings have been determined by electrochemical measurements, recording potentiodynamic curves in a physiological solution over a long-term immersion period. The cell viability tests confirmed that the iCP coating was biocompatible, while the corrosion tests proved its biodegradable characteristic. In our paper, we compare the morphological, chemical, and biological characteristics of silver and zinc substituted calcium phosphate layers deposited by the electrochemical method.

Glancing Angle Deposition of Zn-Doped Calcium Phosphate Coatings by RF Magnetron Sputtering

Zn-substituted hydroxyapatite with antibacterial effect was used in radiofrequency (RF) magnetron deposition of calcium phosphate coating onto Ti- and Si-inclined substrates. The development of surface nanopatterns for direct bacteria killing is a growing area of research. Here, we combined two approaches for possible synergetic antibacterial effect by manufacturing a patterned surface of Zn-doped calcium phosphate using glancing angle deposition (GLAD) technique. A significant change in the coating morphology was revealed with a substrate tilt angle of 80°. It was shown that an increase in the coating crystallinity for samples deposited at a tilt angle of 80° corresponds to the formation of crystallites in the bulk structure of the thin film. The variation in the coating thickness, uniformity, and influence of sputtered species energy on Si substrates was analyzed. Coatings deposited on tilted samples exhibit higher scratch resistance. The coating micro- and nano-roughness and overall morphology depended on the tilt angle and differently affected the rough Ti and smooth Si surfaces. GLAD of complex calcium phosphate material can lead to the growth of thin films with significantly changed morphological features and can be utilized to create self-organized nanostructures on various types of surfaces.

Deposition of calcium phosphate coatings using radio frequency magnetron sputtering of substituted β-tricalcium phosphate targets

The influence of magnesium and/or strontium substitutions on the deposition rate of P-TCP was investigated. Pure β-TCP, Mg-β-TCP, Sr-β-TCP and Mg/Sr-β-TCP targets were used for the coating formation. It was shown that strontium substitutions in the structure of β-TCP target increase the deposition rate of coatings. Magnesium substitutions, on the contrary, decrease this parameter. It makes it possible to increase the deposition rate of coatings formed by radio frequency magnetron sputtering without any negative effect on coatings properties. It was demonstrated that all coatings formed by radio frequency magnetron sputtering of β-TCP targets were calcium-rich. The methods of AFM and SEM revealed that coatings under study were characterized by various morphologies. Magnesium-containing coatings (Mg-β-TCP and Mg/Sr-β-TCP) had the lower value of nanohardness than other ones. All coatings were characterized by the higher value of surface free energy than titanium substrate. The coatings formed by sputtering of β-TCP, Mg-β-TCP, Sr-β-TCP had approximately the same value of this parameter.

Antibacterial and bioactive coatings on titanium implant surfaces.

Various surface modifications have been tried for enhancing osseointegration of the dental implants like mechanical and/or chemical treatments and deposition of calcium phosphate coatings. The objective of this research was to develop calcium-phosphate based thin coatings with antibacterial and bioactive properties for potential application in dental implants. Titanium (Ti) discs were immersed in different calcifying solutions: CaP (positive control), F-CaP, Zn-CaP, and FZn-CaP and incubated for 24 h. Negative control was uncoated Ti discs. Coated surfaces were characterized using X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Antibacterial properties were tested using Porphyromonas gingivalis because of its strong association with periodontal and peri-implant infections. Bacterial adhesion and colonization were studied at different timepoints. The coated surfaces had compositional characteristics similar to that of bone mineral and they inhibited the growth, colonization and adherence of P. gingivalis, resulted in reduced thickness of biofilms and bacterial inhibition in the culture medium as compared to the positive and negative controls (p < 0.05). There was no significant difference between the experimental groups (p > 0.05). It has been previously demonstrated that these coatings have excellent in vitro bioactivity (formed carbonate hydroxyapatite when immersed in a simulated body fluid). Such coatings can enhance osseointegration and prevent infection in implants, thereby improving the success rates of implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2218-2227, 2017.

Incorporation of silver and strontium in hydroxyapatite coating on titanium surface for enhanced antibacterial and biological properties

Implant-related infection in primary total joint prostheses has attracted considerable research attention. As a measure to improve the antimicrobial properties of implant materials, silver (Ag) was incorporated into calcium phosphate (CaP) coatings on Titanium (Ti) via a hydrothermal method. Further, strontium (Sr) was added as a binary dopant to reduce the cytotoxicity of Ag in the coatings. Results showed that the CaP coatings were uniformly deposited on Ti with enhanced hydrophilicity and nanoscale surface roughness. Moreover, cell adhesion, proliferation, and differentiation were improved after the CaP coating deposition. The antibacterial properties of the coatings were distinctly improved by the incorporation of Ag, but the cell proliferation and differentiation were significantly decreased. Owing to the incorporation of Sr, the Ag-CaP coatings were able to effectively counteract the negative effects of Ag while maintaining good antibacterial properties. In summary, hydrothermally deposited CaP coatings doped with Ag and Sr exhibit excellent biocompatibility and antimicrobial activity. Thus, such co-doped CaP coatings have considerable potential for orthopaedic implant modification.

Manufacture of nanosized apatite coatings on titanium with different surface treatments using a supersaturated calcification solution

The biomimetic method is used for the deposition of calcium phosphate coatings (Ca - P) on the surface of different biomaterials. However, the application of this method requires long exposure times in order to obtain a suitable layer thickness for its use in medical devices. In this paper, we present a fast approach to obtain apatite coatings on titanium, using a combination of supersaturated calcification solution (SCS) with chemical modification of the titanium surface. Also, it was evaluated the effect of four different surface treatments on the apatite deposition rate. Commercially pure titanium plates were activated by chemical or thermochemical treatments. Then, the activated samples were immersed in a solution with high content of calcium and phosphate ions at 37 oC for 24 h, mimicking the physiological conditions. The coatings were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The use of SCS solutions allowed the formation of crystalline hydroxyapatite coatings within a period of 24 h with a thickness between 1 and 5.3 µm. Besides, precipitates of hydroxyapatite nanoparticles with a globular configuration, forming aggregates with submicrometer size, were found in SCS solutions.

Deposition of calcium phosphate coatings using condensed phosphates (P2O74 − and P3O105 −) as phosphate source through induction heating

In present work condensed phosphates (P2O74− and P3O105−) were used as phosphate source in induction heating to deposit calcium phosphate coatings. The phase, morphology, and composition of different phosphate-related coatings were characterized and compared using XRD, FTIR, and SEM analyses. Results showed that P2O74−formed calcium pyrophosphate hydrate coatings with interconnected cuboid-like particles. The as-deposited calcium tripolyphosphate hydrate coating with P3O105− was mainly composed of flower-like particles assembled by plate-like crystals. The bioactivity and cytocompatibility of the coatings were also studied. Moreover, the feasibility of using hybrid phosphate sources for preparing and depositing coatings onto magnesium alloy was investigated.

On the electrocrystallization of pure hydroxyapatite nanowalls on Nitinol alloy using a bipolar pulsed current

In this study a bipolar pulsed current was used for the electrochemical deposition of calcium phosphate coatings on the Nitinol superelastic alloy. The coatings were characterized using FE-SEM, XRD, FTIR, HRTEM, and gas adsorption techniques. Results show that the electrodeposited coating is a crystalline film which is composed of pure hydroxyapatite (HA) nanowalls. According to the FTIR data, the coating is free from other metastable calcium phosphate phases like octacalcium phosphate. It was shown that both monoclinic and hexagonal phases can be detected in HRTEM images and related SAED patterns. The coating, which is deposited at direct and reverse current densities of −3.0 and 0.1 mA/cm2 respectively, revealed a surface area of 38.5 m2/g and ultra-fine pores were detected in the surface of the coating plates. Study on the effect of the reverse pulse current revealed that the volume of porosity is increased by increasing in the current density of the reverse pulse. Also in this condition the resulted film was composed of nanosized HA crystals. It seems that the reverse current step can influence the porosity and the structure of the coatings by dissolution of the unstable phases which are formed during direct current step of the bipolar pulse deposition.

Improved corrosion protection of magnesium by hydrothermally deposited biodegradable calcium phosphate coating

The corrosion protection of hydrothermally deposited calcium phosphate coatings on AZ31 magnesium alloy were studied for their potential use in biocompatible and bioresorbable temporary implants. The coatings mainly consisted of calcium phosphate phases (monetite and tricalcium phosphate). Potentiodynamic and electrochemical impedance spectroscopy (EIS) confirmed that the coatings provided varying levels of corrosion protection depending on the coating deposition temperature and duration. EIS results showed that the size of capacitance loops and the absolute impedance value (|Z|) increases by increasing the deposition temperature and corresponding growth in coating thickness. In agreement with the electrochemical experiments, immersion tests in simulated body fluid also indicated large improvement in corrosion protection as the mass loss was significantly reduced when coating was applied as compared to the bare metal. Using the thickest coating obtained at 190 °C deposition temperature, the corrosion current density of the coated magnesium was 10,000 fold lower compared to the bare metal. This result confirmed that the new hydrothermal coating is suitable to protect Mg implant against corrosion with further advantage of being bioactive and biodegradable.

Control the Corrosion of Magnesium for Implant Application By Hydrothermally Deposited Biodegradable Calcium Phosphate Coating

The corrosion protection of hydrothermally deposited calcium phosphate coatings on AZ31 magnesium alloy was studied in simulated body fluid (SBF) solution for their potential use as biodegradable implants. The coating mainly consisted of bioresorbable monetite phases. Potentiodynamic and electrochemical impedance spectroscopy (EIS) confirmed that the coatings provided varying levels of corrosion protection depending on the coating deposition temperature. By increasing the deposition temperature and corresponding growth in coating thickness the corrosion current density of the coated magnesium was 10,000 fold lower compared to the bare metal; indicating significantly enhanced corrosion performance of Mg substrate, reaching the corrosion protection requirement for magnesium implant. The barrier effect of Ca-P layers was further supported by the observed magnitude of anodic and cathodic Tafel slopes. Coated samples displayed much larger slopes than bare Mg substrate. EIS results showed that the size of capacitance loops and the absolute impedance value (|Z|) increases. By increasing the deposition time the corrosion mechanism was changed as a result of partial delamination of top surface of coating. In agreement with the electrochemical experiments, immersion tests in SBF also indicated large improvement in corrosion protection as the mass loss was reduced almost three times when coating was applied as compared to the bare metal. The uncoated Mg substrate undergoes severe and non-uniform corrosion after 28 days immersion in SBF solution; while, the coated samples displayed intact coating and no obvious pits were observed on the coating surface. The described biocompatible and biodegradable coatings significantly improved corrosion resistance of Mg substrate and can be promising candidate for biomedical application. Keywords: Magnesium, Calcium-Phosphate coating, Corrosion resistance, EIS

Control of the Corrosion of Magnesium for Implant Application by Hydrothermally Deposited Biodegradable Calcium Phosphate Coating

The corrosion protection of hydrothermally deposited calcium phosphate coatings on AZ31 magnesium alloy was studied in simulated body fluid (SBF) solution for their potential use as biodegradable implants. The coating mainly consisted of bioresorbable monetite phases. Potentiodynamic and electrochemical impedance spectroscopy (EIS) confirmed that the coatings provided varying levels of corrosion protection depending on the coating deposition temperature. By increasing the deposition temperature and corresponding growth in coating thickness the corrosion current density of the coated magnesium was 10,000 fold lower compared to the bare metal; indicating significantly enhanced corrosion performance of Mg substrate, reaching the corrosion protection requirement for magnesium implant. The barrier effect of Ca-P layers was further supported by the observed magnitude of anodic and cathodic Tafel slopes. Coated samples displayed much larger slopes than bare Mg substrate.EIS results showed that the size of capacitance loops and the absolute impedance value (|Z|) increases. By increasing the deposition time the corrosion mechanism was changed as a result of partial delamination of top surface of coating. In agreement with the electrochemical experiments, immersion tests in SBF also indicated large improvement in corrosion protection as the mass loss was reduced almost three times when coating was applied as compared to the bare metal. The uncoated Mg substrate undergoes severe and non-uniform corrosion after 28 days immersion in SBF solution; while, the coated samples displayed intact coating and no obvious pits were observed on the coating surface.The described biocompatible and biodegradable coatings significantly improved corrosion resistance of Mg substrate and can be promising candidate for biomedical application.

A study of strontium doped calcium phosphate coatings on AZ31

Calcium phosphate (CaP) coatings have been studied to tailor the uncontrolled non-uniform corrosion of Mg based alloys while simultaneously enhancing bioactivity. The use of immersion techniques to deposit CaP coatings is attractive due to the ability of the approach to coat complex structures. In the current study, AZ31 substrates were subjected to various pretreatment conditions prior to depositing Sr2+ doped and undoped CaP coatings. It was hypothesized that the bioactivity and corrosion protection of CaP coatings could be improved by doping with Sr2+. Heat treatment to elevated temperatures resulted in the diffusion of alloying elements, Mg and Zn, into the pretreated layer. Sr2+ doped and undoped CaP coatings formed on the pretreated substrates consisted of biphasic mixtures of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA). Electrochemical corrosion experiments indicated that the extent of Sr2+ doping and pretreatment both influenced the corrosion protection. Cytotoxicity was evaluated with MC3T3-E1 mouse preosteoblasts and human mesenchymal stem cells (hMSCs). For both cell types, proliferation decreased upon increasing the Sr2+ concentration. However, both osteogenic gene and protein expression significantly increased upon increasing Sr2+ concentration. These results suggest that Sr2+ doped coatings are capable of promoting osteogenic differentiation on degradable Mg alloys, while also enhancing corrosion protection, in comparison to undoped CaP coatings.