In Vitro Osteogenesis Stimulation via Nano-Hydroxyapatite/Carbon Nanotube Thin Films on Biomedical Stainless Steel.

Natalia M Martinelli,Fernanda Roberta Marciano,Anderson Oliveira Lobo,Maria Julia G Ribeiro,Miller A Marques,Ritchelli Ricci

doi:10.3390/ma11091555

Natalia M Martinelli, Fernanda Roberta Marciano + Show 4 more

Open Access

https://doi.org/10.3390/ma11091555

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Journal: Materials	Publication Date: Aug 29, 2018
Citations: 16	License type: CC BY 4.0

Affiliation: Universidade Brasil, Universidade do Vale do Paraíba

Abstract

We evaluated the electrophoretic deposition of nanohydroxyapatite/superhydrop hilic multiwalled carbon nanotube composites (nHAp/MWCNT) onto stainless steel biomedical alloys for applications in bone tissue engineering. First, nHAp/MWCNT composites were dispersed into 0.042 mol·L−1 of Ca(NO3)2·4H2O + 0.025 mol·L−1 NH4H2PO4 electrolytes (pH = 4.8) at two different concentrations. Next, a voltage of −2 V was applied using 316L stainless steel as a working electrode (0.27 cm2), a high-purity platinum coil wire was used as the auxiliary electrode, and an Ag/AgCl (3 M) electrode was used as the reference electrode. The nHAp/MWCNT composites were characterized by transmission electron microscopy. The deposited nHAp and nHAp/MWCNT films were characterized by profilometry, scanning electron microscopy, X-ray diffractometry and Raman spectroscopy. Human osteoblast cells were cultivated with the different materials and in vitro cytotoxicity was evaluated using lactate dehydrogenase (LDH) assay. The osteogenesis process was evaluated by mRNA levels of the three genes that are directly related to bone repair: Alkaline Phosphatase, Osteopontin and Osteocalcin. We showed that rough, crystalline apatite thin films containing phases of nHAp were successfully deposited onto 316L stainless steel alloys. Also, we noticed that nHAp/MWCNT thin films deposited onto 316L stainless steel alloys upregulated the expression of important genes related to bone mineralization and maturation. Our results strongly support the possibility of this new alternative to modify the surface of metallic biomedical alloys to promote bone tissue regeneration.

Highlights

Metallic alloys are the most common metal used to fabricate protheses that promote bone tissue regeneration during the last few decades
We showed that nHAp/multiwalled carbon nanotube (MWCNT) nanocomposites were bioactive and suitable for biomedical applications, with a demonstrated bactericidal effect against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), with no osteoblast cytotoxicity
The electrophoretic process was carried out using a classical electrophoretic apparatus (Autolab, PGSTAT 128N, Netherland). 316L stainless steel alloys were used as working electrodes (0.27 cm2), a high-purity platinum coil wire used as the auxiliary electrode, and an Ag/AgCl (3 M) electrode used as the reference electrode

Summary

Introduction

Metallic alloys are the most common metal used to fabricate protheses that promote bone tissue regeneration during the last few decades. 316L stainless steel [1], Ti6Al4V [2], cobalt alloy [3], titanium, Niquel-Titanium, among others [4] These have many advantages, including high corrosion resistance, desirable mechanical properties, and partial biocompatibility. Nanofeature structures are promising because they are similar to the natural components of the extracellular matrix, making them extremely important in the field of bioengineering. Their configurations and physicochemical properties influence the cellular interactions, leading to tissue regeneration, and have incredible potential for the development of improved implantable surfaces [8]

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