Improved antibacterial properties of an Mg‐Zn‐Ca alloy coated with chitosan nanofibers incorporating silver sulfadiazine multiwall carbon nanotubes for bone implants

Abstract

Bacteria‐caused infection remains an issue in the treatment of bone defects by means of Mg‐Zn‐Ca alloy implants. This study aimed to improve the antibacterial properties of an Mg‐Zn‐Ca alloy by coating with chitosan‐based nanofibers with incorporated silver sulfadiazine (AgSD) and multiwall carbon nanotubes (MWCNTs). AgSD and MWCNTs were prepared at a weight ratio of 1:1 and then added to chitosan at varying concentrations (ie, 0, 0.25, 0.5, and 1.5 wt.%) to form composites. The obtained composites were ejected in nanofiber form using an electrospinning technique and coated on the surface of an Mg‐Zn‐Ca alloy to improve its antibacterial properties. A microstructural examination by scanning electron microscopy (SEM) revealed the diameter of chitosan nanofiber ejected increased with the concentration of AgSD‐MWCNTs. The incorporation of AgSD‐MWCNTs into the chitosan nanofibers was confirmed by Fourier transform infrared spectroscopy (FTIR). Examination of the antibacterial activity shows that chitosan nanofibers with AgSD‐MWCNTs can significantly inhibit the growth and infiltration of Escherichia coli and Staphylococcus aureus. Biocompatibility assay and cell morphology observations demonstrate that AgSD‐MWCNTs incorporated into nanofibers are cytocompatible. Taken together, the results of this study demonstrate the potential application of electrospun chitosan with AgSD‐MWCNTs as an antibacterial coating on Mg‐Zn‐Ca alloy implants for bone treatment.

Recent Progress in Carbon Nanotube Polymer Composites in Tissue Engineering and Regeneration

“…In an in vivo experimental study of chitosan–CNT membranes inserted into rats with cranial defects, this polymer did not cause chronic inflammation over five weeks [ 53 , 54 ]. In another tricomposite scaffold, Ag sulfadiazine (AgSD) MWCNTs were integrated into chitosan (CS)-based nanofibers and used as a coating to enhance the antimicrobial activity of magnesium, zinc, and calcium catecholamine alloy implants for skeletal therapy ( Figure 4 ) [ 55 ].…”

“… ( a ) SEM images of Mg alloys coated with chitosan–Ag sulfadiazine (CS/AgSD)–MWCNT nanofibers; ( b ) TEM images of CS/AgSD–MWCNT nanofibers; ( c ) the antibacterial activity of CS/AgSD–MWCNT nanofiber coatings for Esherichia coli and Staphylococcus aureus bacteria ((A1) is uncoated mg alloy, (A2) is CS, (A3) is CS/0.25AgSD-MWCNTs, (A4) is CS/0.5AgSD-MWCNTs, (A5) is CS/1.5AgSD-MWCNTs, and (control) is doxycycline); ( d ) the antibacterial mechanism of CS/AgSD–MWCNT nanofiber coatings. Reproduced with permission from [ 55 ]. …”

Ni-Cu matrix composite reinforced with CNTs: preparation, characterization, wear and corrosion behavior, inhibitory effects

“…CNT shifts the potential of the specimens to more positive and noble values. This decreases the thermodynamic ten-dency of the specimens to perform corrosion reactions [48]. It is further clear that the anodic and cathodic slopes will undergo drastic changes if reinforcement particles are added.…”

Coatings based on mucin‐tannic acid assembled multilayers. Influence of pH

“…Considering that the first event occurring postimplantation is related to the protein adsorption on the surface of the implanted material, it is only natural to assume that, in addition to topography, mechanical properties, and patient‐related factors, the success of such a procedure is greatly dictated by the implant's surface chemistry. As a result, biocompatible coatings became of great interest for most of the metal or ceramic‐based implants . Not only that the adsorbed proteins improve the biocompatibility of the implanted material, but they also play a pivotal role with regard to the tribological properties and in the biocorrosion process …”

“…As a result, biocompatible coatings became of great interest for most of the metal or ceramic-based implants. [1][2][3] Not only that the adsorbed proteins improve the biocompatibility of the implanted material, but they also play a pivotal role with regard to the tribological properties 4 and in the biocorrosion process. 5,6 Natural biopolymers have been extensively studied for such applications due to their ability to act as a protection barrier against physiological corrosion, their resemblance to the extracellular matrix, and proven improvement of cell attachment and proliferation.…”