Key Properties of a Bioactive Ag-SiO2/TiO2 Coating on NiTi Shape Memory Alloy as Necessary at the Development of a New Class of Biomedical Materials

Abstract

Recent years have seen the dynamic development of methods for functionalizing the surface of implants using biomaterials that can mimic the physical and mechanical nature of native tissue, prevent the formation of bacterial biofilm, promote osteoconduction, and have the ability to sustain cell proliferation. One of the concepts for achieving this goal, which is presented in this work, is to functionalize the surface of NiTi shape memory alloy by an atypical glass-like nanocomposite that consists of SiO2-TiO2 with silver nanoparticles. However, determining the potential medical uses of bio(nano)coating prepared in this way requires an analysis of its surface roughness, tribology, or wettability, especially in the context of the commonly used reference coat-forming hydroxyapatite (HAp). According to our results, the surface roughness ranged between (112 ± 3) nm (Ag-SiO2)—(141 ± 5) nm (HAp), the water contact angle was in the range (74.8 ± 1.6)° (Ag-SiO2)—(70.6 ± 1.2)° (HAp), while the surface free energy was in the range of 45.4 mJ/m2 (Ag-SiO2)—46.8 mJ/m2 (HAp). The adhesive force and friction coefficient were determined to be 1.04 (Ag-SiO2)—1.14 (HAp) and 0.247 ± 0.012 (Ag-SiO2) and 0.397 ± 0.034 (HAp), respectively. The chemical data showed that the release of the metal, mainly Ni from the covered NiTi substrate or Ag from Ag-SiO2 coating had a negligible effect. It was revealed that the NiTi alloy that was coated with Ag-SiO2 did not favor the formation of E. coli or S. aureus biofilm compared to the HAp-coated alloy. Moreover, both approaches to surface functionalization indicated good viability of the normal human dermal fibroblast and osteoblast cells and confirmed the high osteoconductive features of the biomaterial. The similarities of both types of coat-forming materials indicate an excellent potential of the silver-silica composite as a new material for the functionalization of the surface of a biomaterial and the development of a new type of functionalized implants.

A Novel Strategy for Creating an Antibacterial Surface Using a Highly Efficient Electrospray-Based Method for Silica Deposition

“…These findings were consistent with the results of a previous study by Pillai et al [ 59 ] who performed the same extraction method and showed that cell viability remained at greater than 80%; thus, these findings suggested that the coating materials did not diffuse out into the growth medium and exhibited excellent biocompatibility without toxicity in HDFs. In addition, our findings were similar to those of Dulski et al who focused on the development of silver-silica coating as a functional biomaterial surface [ 60 ]. Based on their results, the fabricated surface could significantly inhibit E. coli and S. aureus biofilm formation and showed high biocompatibility with HDFs, yielding no dead or deformed cells after 72 h in morphological examinations.…”

Novel Hydrophobic Nanostructured Antibacterial Coatings for Metallic Surface Protection

“…Nowadays, there has been a growing interest in the development of methods for coating the surface of metallic artifacts using materials that can prevent the formation of bacterial biofilm [6] and protect against pollutants corrosion, while maintaining the aesthetic properties of the substrates [7].…”

Determination of the Effect of TiN Coating on Self-Fitting Properties of Dental Implants Made of NiTi Alloy

“…TiN differs from the others in terms of better mechanical properties and biocompatibility; a passive TiO 2 film is formed during its formation. , In a review study, del Castillo et al, investigating TiN coating specific to dental implants, reported that TiN coatings reduce early bacterial colonization and biofilm formation and improve fibroblast cell attachment and adhesion . In addition, Ag–SiO 2 chemically produced by electrophoretic deposition (EPD) method is used in nanocomposite coatings. − Corrosion tests in Ringer’s solution are used to determine the effectiveness of the coatings. , …”