Osteoblast response to phospholipid modified titanium surface
Introduction
Titanium (Ti) is the implant material of choice for use in dental and orthopedic applications. The stable oxide that formed readily on Ti surfaces was reported to attribute to its excellent biocompatibility [1]. However, it was also reported that bone response to implant surfaces was dependent on the chemical and physical properties of Ti surfaces, thereby affecting implant success [2]. As such, attention has been focused on the surface preparation of the Ti implant.
Several techniques such as plasma spraying, laser deposition, ion beam dynamic mixing, ion beam deposition, magnetic sputtering, hot isostatic pressing, electrophoretic deposition, sol–gel, ion implantation, NaOH treatment, and electrochemical methods have been employed to deposit hydroxyapatite (HA) or calcium phosphate coatings on Ti surfaces [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18]. Among the different processes described, plasma spraying of HA and Ti has been the most common method for modifying implant surfaces. However, numerous problems with the plasma-sprayed coatings have also been cited, including variation in bond strength between the coatings and the metallic substrates, non-uniformity in coating density as a result of the process, poor adhesion between the coatings and metallic substrates, and microcracks on the coating surface [19], [20], [21], [22]. However, these problems do not reflect shortcomings inherent in the rationale for HA coating, but rather in the plasma spray and other technologies currently used to apply the coatings.
Recently, an alternative implant surface modification using phospholipids coatings have been suggested. It has been reported that various kind of calcium deposition processes involve the use of phospholipids [23], [24], [25], [26], [27]. It has also been reported that a complex between calcium-inorganic phosphate and the phospholipid was essential for inducing the deposition of calcium phosphate [28]. Despite numerous chemical and structural characterizations, cellular responses to these phospholipids-coated implants anodized surfaces have yet to be evaluated. As such, the effect of different phospholipid coatings on in vitro osteoblast responses was evaluated in this study.
Section snippets
Materials
Phospholipids [phosphatidylcholine (PC), phosphatidylserine (PS, and phosphatidylinositol (PI); Fig. 1] were purchased from Sigma Chemical Company, St. Louis, MO. Commercial pure titanium (Ti) grade 2 disks were obtained from Metal Samples, Munford, AL. Plastic cell culture 24 and 96 well cluster plates were obtained from Costar, Corning, New York. Human Embryonic Palatal Mesenchyme cell suspension (HEPM; the osteoblast precursor cell line; Catalog ♯CRL-1486) was purchased from American type
Results and discussion
Matrix proteins in bone have been shown to play a crucial role in the calcification and architectural construction of these hard tissues [29]. As evident from Fig. 2, only phosphatidylserine was able to enhance total protein production on coated surface on day 7 and day 14.
The alkaline phosphatase specific activity is widely recognized as a biochemical marker for the osteoblast phenotype, and may be considered an important factor in bone mineralization. As shown in Fig. 3, the alkaline
Conclusion
The purpose of this research was to investigate if Ti surfaces modified with the calcium phosphate complex of different natural phospholipids induce a substantial enhancement in osteoblast differentiation and growth from their progenitor cells in culture, as compared to non-coated surface. Based on the data and results obtained in this study, it can be concluded that the variation in polar head group of the phospholipid part of Ca–PL–PO4, imparts a pronounced effect on osteoblast
Acknowledgements
The authors are very thankful to National Institutes of Health, National Institute for Dental and Cranofacial Research for financial supported to carry out this research (NIH/NIDCR grant♯ 1 R43 DE13996-01A1).
References (30)
- et al.
Structural analysis of hydroxyapatite coating on titanium
Biomaterials
(1986) - et al.
Excimer laser deposition of hydroxyapatite thin films
Biomaterials
(1994) - et al.
Formation of hydroxyapatite coating on pure titanium substrates by ion beam dynamic mixing
Surface Coat Technol
(1994) - et al.
Structure, solubility and bond strength of thin calcium phosphate coatings produced by ion beam sputter deposition
Biomaterials
(1992) - et al.
Modification of titanium by ion implantation of calcium and or phosphorus
Surf Coating Technol
(1999) - et al.
Calcium phosphate coatings for orthopaedic prosthesis
Surf Coat Technol
(1991) - et al.
Some characteristics of hydroxylapatite powders after plasma spraying
Biomaterials
(1998) - et al.
Crystallographic changes in calcium phosphates during plasma-spraying
Biomaterials
(1992) - et al.
Effect of protein on the dissolution of HA coatings
Biomaterials
(2000) Hydroxyapatite coating
Ann NY Acad Sci
(1988)
Biocamics
J Am Ceram Soc
Plasma sprayed coating of hydroxyaptite
J Biomed Mater Res
Pulsed laser deposition of hydroxyapatite thin films on Ti-6A1-4V
J Appl Biomater
Study of the surface characteristics of magnetron-sputter calcium phosphate coatings
J Biomed Mater Res
Hydroxyapatite coatings on Ti produced by hot isostatic pressing
J Biomed Mater Res
Cited by (33)
Multilayered coating on titanium for controlled release of antimicrobial peptides for the prevention of implant-associated infections
2013, BiomaterialsCitation Excerpt :To create a coating that had dual beneficial effects, i.e. antimicrobial and osteoconductive, thin layers of titania NT and CaP coatings were impregnated with AMPs. These films were topped with a thin phospholipid (POPC, palmitoyl-oleoyl phosphatidyl-choline) film to control the release of AMP based on a bio-inspired cell membrane [21,22]. POPC is found naturally in eukaryotic cell membranes and offers the least support for bacteria growth (81% reduction), and the most suitable platform for bone cell attachment [23].
Phosphatidylserine enhances osteogenic differentiation in human mesenchymal stem cells via ERK signal pathways
2013, Materials Science and Engineering CCitation Excerpt :The above results indicate that PS had positive effects on the expression of different genes associated with early and late stages of osteogenesis in hMSCs. Satsangi et al. evaluated the effect of PS-coated Ti surfaces on osteoblast responses in vitro and demonstrated that these coated surfaces exhibited enhanced protein synthesis and alkaline phosphatase activity compared to uncoated surfaces [20]. To explore the molecular mechanism of PS-promoted hMSC osteogenic differentiation, we examined the role of the ERK signaling pathway.
Biocompatibility and osteogenesis of biomimetic Bioglass-Collagen-Phosphatidylserine composite scaffolds for bone tissue engineering
2011, BiomaterialsCitation Excerpt :Differentiation of MSCs is one of the key processes for bone regeneration. Satsangi et al., evaluated the effect of PS-coated Ti surfaces on osteoblast responses in vitro and have demonstrated that Ti surfaces coated with PS exhibited enhanced protein synthesis and alkaline phosphatase activity compared to uncoated surfaces [28]. M. Bosetti et al., further confirmed that phosphatidylserine improves the nucleation process for bone formation by promoting the formation of bone-like tissue [29].
Improved bone-forming functionality on diameter-controlled TiO<inf>2</inf> nanotube surface
2009, Acta BiomaterialiaSurface modification of titanium by etching in concentrated sulfuric acid
2006, Dental Materials