Surface Modification of Pure Zinc by Acid Etching: Accelerating the Corrosion Rate and Enhancing Biocompatibility and Antibacterial Characteristics

Abstract

Zinc (Zn) has recently been identified as an auspicious biodegradable metal for medical implants and devices due to its tunable mechanical properties and good biocompatibility. However, the slow corrosion rate of Zn in a physiological environment does not meet the requirements for biodegradable implants, hindering its clinical translation. The present study aimed to accelerate the corrosion rate of pure Zn by utilizing acid etching to roughen the surface and increase the substrate surface area. The effects of acid etching on surface morphology, surface roughness, tensile properties, hardness, electrochemical corrosion and degradation behavior, cytocompatibility, direct cell attachment, and biofilm formation were investigated. Interestingly, acid-treated Zn showed an exceptionally high rate of corrosion (∼226–125 μm/year) compared to untreated Zn (∼62 μm/year), attributed to the increased surface roughness (R a ∼ 1.12 μm) of acid-etched samples. Immersion tests in Hank’s solution revealed that acid etching accelerated the degradation rate of Zn samples. In vitro, MC3T3-E1 cell lines in 50 and 25% conditioned media extracts of treated samples showed good cytocompatibility. Reduced bacterial adhesion, biofilm formation, and dispersion were observed for Staphylococci aureus biofilms cultured on acid-etched pure Zn substrates. These results suggest that the surface modification of biodegradable pure Zn metals by acid etching markedly increases the translation potential of zinc for various biomedical applications.

Anti‐Solvent Synthesis of Three‐Color Indium‐Based Halide Perovskite Microplate/Microcrystal Phosphors for High Color Rendering WLEDs

“…However, the increased amount of HCl (𝜑(HCl) = 24%, 36%, and 48%) leads to the morphology transition from microplates to irregular particles, which is attributed to the strong acid etching effect of Cs 2 InCl 5 (H 2 O):Sb 3+ phosphors at a high concentration of acid. [55][56][57][58][59] 2− octahedron (Figure 3a). [60] Figure S13 octahedrons enable to form the 0D electronic structure.…”

Cytotoxicity of Biodegradable Zinc and Its Alloys: A Systematic Review

“…Jablonska et al confirmed the effect of FBS (fetal bovine serum) in the cell medium on cytotoxicity tests [15,83]. The effect of pretreatments such as pre-cultivation, stabilization treatment [91], sterilization treatment [75], sandblasting [93], and acid etching treatment [102] was also investigated.…”

“…Additionally, some researchers adopted the extraction ratios such as 3 mL/cm 2 , 1.25 mL/cm 2 , and 20 mL/cm 2 without providing any justification [32,52]. Extracts were often filtered via a membrane [19,20,39,49,51,53,60,65,69,72] or centrifuged to withdraw the supernatant fluid in certain studies [18,20,26,40,58,62,80,101,102]. Some studies investigated Zn-based samples precultured in the medium before the cytotoxicity test [25,28,72,74,77,92,102].…”

“…Extracts were often filtered via a membrane [19,20,39,49,51,53,60,65,69,72] or centrifuged to withdraw the supernatant fluid in certain studies [18,20,26,40,58,62,80,101,102]. Some studies investigated Zn-based samples precultured in the medium before the cytotoxicity test [25,28,72,74,77,92,102]. The effect of BSA (bovine serum albumin) on the cytotoxicity in the medium of pre-exposure samples was also examined [72].…”

Surface modifications of biomaterials in different applied fields

“…13 It is common to modify the surface of biomaterials without changing the properties of the substrates on a micro or nano scale. 14,15 Surface modication provides controllable and programmable surface properties for biomaterials at the same time. It provides effective physical or chemical properties to make implanted biomaterials "more compatible" inside the human body.…”