Electrodeposition of Hydroxyapatite on a Metallic 3D-Woven Bioscaffold

Abstract

In this study, we demonstrate that a uniform coating of hydroxyapatite (HAp, Ca10(PO4)6(OH)2) can be electrochemically deposited onto metallic 3D-woven bone scaffolds to enhance their bioactivity. The HAp coatings were deposited onto metallic scaffolds using an electrolyte containing Ca(NO3)2·4H2O, NH4H2PO4, and NaNO3. The deposition potential was varied to maximize the uniformity and adhesion of the coating. Using X-ray diffraction (XRD), Raman spectroscopy, and energy-dispersive spectroscopy (EDS), we found crystallized HAp on the 3D-woven lattice under all deposition potentials, while the −1.5 V mercury sulfate reference electrode potential provided the best local uniformity with a satisfactory deposition rate. The coatings generated under this optimized condition were approximately 5 µm thick and uniform throughout the internal and external sections of the woven lattice. We seeded and cultured both coated and uncoated scaffolds with human adipose-derived stromal/stem cells (ASCs) for 12 h and 4 days. We observed that the HAp coating increased the initial cell seeding efficiency by approximately 20%. Furthermore, after 4 days of culture, ASCs cultured on HAp-coated stainless-steel scaffolds increased by 32% compared to only 17% on the uncoated scaffold. Together, these results suggest that the HAp coating improves cellular adhesion.

Influence of Thermal Processing on Resoloy Wire Microstructure and Properties

“…They can also be knitted or woven to fabricate cardiovascular stents and bone scaffolds. [1][2][3] Conventionally, such devices are made by metals such as stainless steel (SS), titanium (Ti) alloys, and cobalt-chromium (CoCr) alloys because of their excellent corrosion resistance and superior mechanical properties compared to local biological tissues. [4] However, the nondegradability of these alloys can require a secondary surgery, and their high stiffness may enable stress shielding.…”

Hydroxyapatite coatings: a critical review on electrodeposition parametric variations influencing crystal facet orientation towards enhanced electrochemical sensing

“…Furthermore, the crystal orientation of ultrasonically grown HAp may result in formation of either plate or needle-like microstructure depending on applied current density 240 . The effects of electrolytic additives like KOH and NaOH augments the formation of HAp while addition of NaNO 3 witnesses an enhancement in ionic conductivity of the electrolyte 241 . The presence of chelating agents such as EDTA results in crystal orientation along a,b-axes via the control of supersaturation of Ca-EDTA chelate complex.…”

“…The rate of growth and adhesion to substrate increases when TiO 2 NTs are employed 248 . The ease of electrochemically coating HAp over complex substrates such as TiO 2 nanofibers 249 , carbon fiber cloth 240 , transparent MEA chip 250 , foam 162 , mesh 241,251 and Nafion substrates 163 is highlighted. Employing cation exchange membrane-assisted electrodeposition technique significantly alters the HAp formation as hollow tubular microstructures 163,164,196 and in the phase evolution of the coating 252 .…”

“…240 The effects of electrolytic additives like KOH and NaOH augment the formation of HAp while addition of NaNO 3 witnesses an enhancement in the ionic conductivity of the electrolyte. 241 The presence of chelating agents such as EDTA results in crystal orientation along the a , b -axes via the control of supersaturation of the Ca-EDTA chelate complex. The addition of H 2 O 2 to the electrolytic system witnesses an increase in cathodic pH resulting in increased PO 4 3− formation.…”

Nanohydroxyapatite Electrodeposition onto Electrospun Nanofibers: Technique Overview and Tissue Engineering Applications

“…HAp coatings can be electrodeposited using different forms of current, including continuous direct current, pulsed current, or pulsed reverse current, with significant morphological and mechanical differences in the material formed [ 51 ]. Regarding the composition of the electrolyte, in addition to the wide variety of precursors of phosphate (NH 4 H 2 PO 4 [ 56 ], (NH 4 ) 2 HPO 4 [ 57 ], and KH 2 PO 4 [ 58 ]) and calcium (CaCl 2 [ 58 ], Ca(NO 3 ) 2 [ 59 ], and Ca(NO 4 ) 2 [ 60 ]) in their different concentrations, some additives are commonly incorporated into the electrolyte during the electrodeposition of HAp, each with a specific purpose—for example, the addition of NaCl to increase electrolytic conductivity [ 61 ], the incorporation of NaNO 3 to improve ionic strength [ 62 ], and the inclusion of H 2 O 2 that contributes to the formation of hydroxyl ions favoring the formation of HAp [ 58 ]. A detailed discussion of the influence of each of these variables on the electrodeposition process of HAp can be found in a recently published review about this topic [ 49 ].…”