Influence of Enzymes on the In Vitro Degradation Behavior of Pure Zn in Simulated Gastric and Intestinal Fluids

Abstract

Zinc (Zn) alloys are being developed as the degradable biomaterial. However, the corrosion mechanism of Zn in the gastrointestinal environment is seldom investigated and needs to be addressed. In this study, the impacts of enzymes on the degradation of pure Zn via electrochemical measurements and immersion were investigated. Pepsin and pancreatin affected the degradation of pure Zn. In contrast with the solutions without enzymes, the degradation rates declined with the addition of enzymes in solutions. However, localized corrosion was observed because the adsorption of pepsin was not a perfect barrier to prevent corrosion. The adsorbed pancreatin protected the samples from corrosion mainly at the initial stage of immersion. With immersion in the simulated intestinal fluid, adsorption and desorption of pancreatin occurred simultaneously on the sample surface. These findings allow the development of Zn alloy-implanted devices for the digestive tract as well as the understanding of the Zn corrosion mechanism in the gastrointestinal environment.

A detailed mechanism of degradation behaviour of biodegradable as-ECAPed Zn-0.8Mg-0.2Sr with emphasis on localized corrosion attack

“…It is obvious that the presence of these organic compounds can increase the corrosion rate by binding zinc ions into complexes during the initial stages of exposure (disruption of the system equilibrium). After a certain amount of time, the formed complexes often cover the implant's surface, forming a barrier of corrosion products that protect the surface [ 78 , 79 ]. This process leads to a significant decrease in the corrosion rate.…”

Corrosion Mechanisms of a Biodegradable Zn-0.4Li Alloy in Simulated Gastrointestinal Environment

“…The C-N and C=O-NH bonds that came from the amine or amide groups in enzymes supplied two components at 399.4 and 400.0 eV, respectively, according to the deconvolution of the N 1s spectra (Figure 5(c,c1)) [46,47]. These characteristic bands illustrated the presence of enzymes on the surfaces of the samples after immersion [48]. Additionally, Figure 5(a-c,a1-c1) shows the high-resolution XPS spectra of Zn 2p, C 1s, and N 1s for Zn-0.4 Li alloys following 7 days of immersion in SGF and SIF.…”

“…The C-N and C=O-NH bonds that came from the amine or amide groups in enzymes supplied two components at 399.4 and 400.0 eV, respectively, according to the deconvolution of the N 1s spectra (Figure 5(c,c1)) [46,47]. These characteristic bands illustrated the presence of enzymes on the surfaces of the samples after immersion [48]. XPS is a non-destructive measurement technology that detects material surface information through a photon beam incident onto the sample surface at a depth of 3-10 nm.…”

“…After the first day, the corrosion potentials remained stable with a low fluctuation frequency until 2.5 days. The OCP of SIF changed periodically within a period of about 2.5 days; this may have resulted from the adsorption and subsequent desorption of enzymes or the shedding of corrosion products during immersion [48]. For SGF, OCP shifted cathodically with small fluctuations.…”

Research progress of biodegradable staples in gastrointestinal anastomosis

“…In clinical settings, surgical staples, predominantly crafted from Titanium (Ti) alloy, have revolutionized the healing and reconstruction processes in gastrointestinal anastomosis, spanning the gastrointestinal tract to the small intestine [1][2][3]. Staples offer advantages over traditional suturing by reducing operative durations, minimizing postoperative complications, and alleviating patient discomfort [4].…”