Composite Coatings of Chitosan and Silver Nanoparticles Obtained by Galvanic Deposition for Orthopedic Implants

Abstract

In this work, composite coatings of chitosan and silver nanoparticles were presented as an antibacterial coating for orthopedic implants. Coatings were deposited on AISI 304L using the galvanic deposition method. In galvanic deposition, the difference of the electrochemical redox potential between two metals (the substrate and a sacrificial anode) has the pivotal role in the process. In the coupling of these two metals a spontaneous redox reaction occurs and thus no external power supply is necessary. Using this process, a uniform deposition on the exposed area and a good adherence of the composite coating on the metallic substrate were achieved. Physical-chemical characterizations were carried out to evaluate morphology, chemical composition, and the presence of silver nanoparticles. These characterizations have shown the deposition of coatings with homogenous and porous surface structures with silver nanoparticles incorporated and distributed into the polymeric matrix. Corrosion tests were also carried out in a simulated body fluid at 37 °C in order to simulate the same physiological conditions. Corrosion potential and corrosion current density were obtained from the polarization curves by Tafel extrapolation. The results show an improvement in protection against corrosion phenomena compared to bare AISI 304L. Furthermore, the ability of the coating to release the Ag+ was evaluated in the simulated body fluid at 37 °C and it was found that the release mechanism switches from anomalous to diffusion controlled after 3 h.

Improvement of Osteogenic Differentiation of Mouse Pre-Osteoblastic MC3T3-E1 Cells on Core–Shell Polylactic Acid/Chitosan Electrospun Scaffolds for Bone Defect Repair

“…According to the literature, the ATR-FTIR spectrum of PLA showed various absorption bands usually attributed to this polyester, such as the carbonyl stretch at 1747 cm −1 ; the C–O stretch at 1180 cm −1 , 1129 cm −1 and 1083 cm −1 ; and the OH bend at 1044 cm −1 [ 41 ]. The FTIR-ATR spectrum of neat chitosan powder reveals main absorption bands at 3352 cm (stretching vibration of O–H group) [ 42 ], 3290 cm −1 (stretching vibration of N–H) [ 42 ], 1645 cm −1 (stretching vibration of the carbonyl group (C=O) in amide I) [ 43 , 44 ], and 1039 cm −1 (stretch vibrations of C–O) [ 45 ].…”

Behavior of Calcium Phosphate–Chitosan–Collagen Composite Coating on AISI 304 for Orthopedic Applications

“…Galvanic deposition was carried out in a two-compartment electrochemical cell connected via a saturated potassium chloride salt bridge. A scheme of the apparatus can be found in our previous works [ 67 , 68 , 69 , 71 ]. The electrodes were short-circuited through a copper wire.…”

“…Separately, 11.93 g of HEPES (2-(4-(2-hydroxyethyl)-1-piperazinyl)-ethanesulfonic acid) was added in 100 mL of MilliQ water at 37 °C, which afterward was mixed into the first solution. pH was kept up to 7.40 with 0.8 mL of NaOH 1.0 M. The corrosion test consisted of the monitoring of (OCP), potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS) in a conventional three-electrode cell with a Pt wire as the counter electrode and a 3.0 M Ag/AgCl as the reference electrode [ 65 , 66 , 67 , 68 , 69 ]. Corrosion potential (E corr ) and corrosion current density (i corr ) were calculated by extrapolation of Tafel’s curves.…”

“…This consolidated and very versatile technology is also appropriate for producing numerous materials [ 53 , 54 , 55 ] in the nanostructured form [ 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ]. In our other previous works, CaP-based, CS-based, and composite coatings were obtained through galvanic deposition on stainless steel [ 65 , 66 , 67 , 68 , 69 ]. In these works, we have demonstrated that, among other things, galvanic deposition is also able to produce coatings with good adhesion on the substrates and a lack of cytotoxicity.…”

Cold-Sprayed Composite Metal-Fluoropolymer Coatings for Alloy Protection against Corrosion and Wear

“…However, the most rational, effective, and inexpensive method of protection is the application of coatings [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. It is possible to use a paintwork material [13,19,30] (including those with additives of nanoparticles [25,[31][32][33][34][35][36][37][38] and inhibitors [13,14,20,[39][40][41][42][43][44][45][46][47]) and zinc coating to protect the material against its intensive destruction [48]. There is also a plasma electrolytic oxidation (PEO) method that allows one to create dense heterooxide coatings on valve metals (for example, Al, Mg, Ti, Nb, etc.)…”