Fluid Environment Research Articles

A reduced graphene oxide-coated conductive surgical silk suture targeting microresistance sensing changes for wound healing

AbstractConventional sutures used in surgical procedures often lack the capability to effectively monitor physical and chemical activities or the microbial environment of surgical wounds due to their inadequate mechanical properties, insufficient electrical accuracy and unstability. Here, we present a straightforward layer-by-layer coating technique that utilizes 3-glycidoxypropyltrimethoxysilane (CA), graphene oxide (GO), and ascorbic acid (AA) to develop conductive silk-based surgical sutures (CA-rGSFS). The CA-rGSFS feature a continuous reduced graphene oxide (rGO) film on their surface, forming robust hydrogen bonds with silk fibroin. The reduction process of rGO is confirmed through Raman analysis, demonstrating an enhanced D peak to G peak ratio. Notably, the CA-rGSFS exhibit exceptional mechanical properties and efficient electron transmission, with a knot-pull tensile strength of 2089.72 ± 1.20 cN and an electrical conductivity of 130.30 ± 11.34 S/m, respectively, meeting the requirements specified by the United States Pharmacopeia (USP) for 2-0 sutures. These novel CA-rGSFS demonstrate the ability to accurately track resistance changes in various fluid environments with rapid response, including saline, intestinal, and gastric fluids. The suture also retains remarkable stretchablility and stability even after enduring 3000 tensile cycles, highlighting their potential for precise surgical site monitoring during the wound healing process.

An exploration of the wake of an in-stream water wheel

Research on low-impact, low capital-cost hydropower is increasing as efforts to decarbonise energy systems accelerate. The in-stream water wheel can potentially aid in this decarbonisation effort, but there is little research into the fluid environment around these turbines. This is despite the potential impact that the fluid environment can have on turbine power characteristics and hydrography of the local stream. This paper provides a qualitative analysis of the wake of an in-stream water wheel using dye injection and analysis, supported by quantitative analysis of the near-wake using particle image velocimetry. The results demonstrate that the wake of an in-stream water wheel is primarily characterised by large periodic vortices generated by the shedding of the leading edge vortex as the blade rotates through the fluid, with smaller counter-rotating vortices shed as the local flow angle reverses near the blade entry and exit. The wake maintains a coherent structure three diameters downstream of the turbine, which could potentially impact the power generation of downstream turbines. This wake coherence is largely consistent across different numbers of turbine blades and blade depth ratios.

The SCC behavior of MAO/EPD biocomposite coatings on Ti-6Al-4V alloy

Aseptic loosening and inadequate osseointegration are significant issues associated with titanium alloy implants in complex body fluid environments. Surface coatings techniques are often employed to enhance the bioactivity and osseointegration capabilities. In this research, biocomposite coatings were fabricated on Ti-6Al-4V alloy employing micro-arc oxidation (MAO) and the integration of micro-arc oxidation/electrophoretic deposition (MAO/EPD) technology. Microstructure, bioactivity, and corrosion resistance of the coatings were studied. To investigate the effect of the coatings on the stress corrosion cracking (SCC) behavior of Ti-6Al-4V alloy, slow strain rate tension (SSRT) tests were conducted in simulated body fluid (SBF). Results show that the adhesive strength of the MAO/EPD composite coatings is around 28.41N, with an average contact angle of 19.05 °, indicating excellent wettability and biocompatibility. The corrosion rate of biocomposite coatings is 3.43 μm·a−1 and the biocomposite coatings exhibit excellent SCC resistance, with a SCC sensitivity of 9.21%, which is significantly lower than the 18.39% of Ti-6Al-4V alloy. This can be attributed to the lower porosity of the coatings, which can provide excellent protection for the alloy.

An investigation on tribological behavior of TC bearing materials: Effect of nano-SiO2 concentrations under different loads in the drilling fluid environment

Both Nano-SiO2 (Silicon dioxide nanoparticles) additive concentration and axial load have profound effects on the friction and wear of Tungsten Carbide bearings in the drilling fluid environment. However, the coordinated role of them remains unknown. In this work, the effects of Nano-SiO2 concentrations and axial loads on the tribological behavior of bearing materials were investigated simultaneously. Results show that the water-based drilling fluid containing Nano-SiO2 exhibits more excellent lubrication properties under 200 N as compared with 70 N, and the optimal concentration of Nano-SiO2 additive is 1.0 wt% under all loads. High axial loads are conducive to improve the lubrication performance, and the lubrication mechanisms of Nano-SiO2 under different loads in water-based drilling fluid are the multitudinousness of synergistic effects, including rolling bearing, polishing, shielding, and self-healing effect, which all manifested there is an remarkable load dependence of Nano-SiO2 particles.

Improving the Bioactivity and Antibiofilm Properties of Metallic Implant Materials via Controlled Surface Microdeformation.

Although metallic implants provide most of the required properties for bone-related applications, especially orthopedic implants, insufficient osseointegration, which may lead to loosening of the implant or prolonged healing time, is still an issue to be resolved. Osseointegration can be improved via application of various surface treatments on the metal surface. The current study focuses on a novel surface microdeformation method, which enables the formation of controlled surface patterns of various parameters. With this purpose, a surface microdeformation procedure was applied on 316L stainless steel surfaces, forming four different patterns which affected various surface parameters such as roughness, surface energy, dislocation activities close to the surface, and wettability. Static immersion tests in a simulated body fluid (SBF) environment showed that modifying the surface parameters via controlled surface patterning promoted the formation of a stable oxide layer and calcium-phosphate (CaP) deposition on the metal surfaces, improving bioactivity. Moreover, the higher amount of CaP deposition and oxide layer formation on the modified surfaces led to reduced ion release, which contributed to improved corrosion resistance. Finally, the effect of the formed surface patterns on antibiofilm formation was investigated via incubation with C. albicans for 24 h, which exhibited that microdeformation patterns remarkably inhibited the biofilm formation. Throughout the experiments, certain patterns yielded outstanding results among the four patterns formed. Overall, it was concluded that forming controlled patterns on stainless steel surfaces via surface microdeformation significantly contributed to the metal's biocompatibility via improving bioactivity, corrosion resistance, and antibiofilm formation properties. Especially, the specific surface properties such as increased surface energy, high surface roughness, and dislocation density close to the metal surface as well as increased hydrophilicity obtained via forming the pattern with relatively deeper and narrowly spaced indents yielded the most promising outcomes. These methodologies constitute novel approaches to be used while designing new methodologies for the surface modification of metallic implant materials for improved osseointegration.

Octopus-Inspired Adhesives with Switchable Attachment to Challenging Underwater Surfaces.

Adhesives that excel in wet or underwater environments are critical for applications ranging from healthcare and underwater robotics to infrastructure repair. However, achieving strong attachment and controlled release on difficult substrates, such as those that are curved, rough, or located in diverse fluid environments, remains a major challenge. Here, an octopus-inspired adhesive with strong attachment and rapid release in challenging underwater environments is presented. Inspired by the octopus's infundibulum structure, a compliant, curved stalk, and an active deformable membrane for multi-surface adhesion are utilized. The stalk's curved shape enhances conformal contact on large-scale curvatures and increases contact stress for adaptability to small-scale roughness. These synergistic mechanisms improve contact across multiple length scales, resulting in switching ratios of over 1000 within ≈30 ms with consistent attachment strength of over 60 kPa on diverse surfaces and conditions. These adhesives are demonstrated through the robust attachment and precise manipulation of rough underwater objects.

The role of selected cytokines from the interleukin-1 family in the peritoneal fluid of women with endometriosis.

Endometriosis is a complex, chronic inflammatory disease in which immune system disorders play an important role. Soluble mediators of the immune and inflammatory response, including cytokines, are involved in these processes. Therefore, the aim of the conducted research was to understand the role of selected cytokines belonging to the Interleukin-1(IL-1) family, including IL-36α, IL-36β, IL-36γ, IL-36R, IL-37 and IL-38, in the onset and development of endometriosis by analysing the concentration of the tested molecules and to determine whether their concentration depends on the stage of the disease. The study group included 60 women who had pelvic endometriosis diagnosed during laparoscopy and subsequently confirmed by histopathology. The reference group consisted of 20 women who had no endometriosis or other pelvic lesions during laparoscopy. Immunoenzymatic assays were used to determine the concentration of the cytokines studied. In the peritoneal fluid of women with endometriosis, a statistically significant increase in the concentrations of all parameters tested was observed: IL-36α, IL-36β, IL-36γ, IL-36R, IL-37 and IL-38. The concentration of these cytokines depended on the severity of the disease. Disturbances of the immune system involving the network of cytokines belonging to the IL-1 family occurring in the peritoneal fluid environment testify to the involvement of these molecules in the development of the disease and are one of many factors involved in the pathogenesis of endometriosis. The use of some of them in the treatment of endometriosis may be a hope for effective causal treatment of this disease, but this requires further, more advanced research.

Construction of Lactobacillus casei-loaded Water-in-oil High Internal Phase Emulsion and its Study on Anti-breast Cancer Properties

Objective: To prepare an oil-in-water high internal phase emulsion containing Lactobacillus casei, and to optimize and characterize the preparation process. To explore the therapeutic effect of the probiotic-carrying emulsion on in situ breast cancer in mice. Methods: Using corn oil, sodium alginate, polyglycerin ricinoleate and L. casei as raw materials, the high internal phase emulsion containing probiotic oil-in-water was prepared by high-speed homogenization method. The optimal preparation process was obtained through single factor investigation, microstructure characterization, stability investigation and in vitro simulation digestion experiment. Ten female BALB/c mice (SPF grade, 18–20 g) were selected. After the in situ breast cancer model was successfully established, the mice were randomly divided into experimental group and control group, with 5 mice in each group. The mice were administrated with probiotic-loaded emulsion and normal saline respectively, and were administrated with the stomach every other day for 10 days. The change of tumor volume during treatment and tumor mass at the end of treatment were recorded. Results: The optimum process of emulsion was: With the concentration of 5% Polyglycerin ricinolate, 75% aqueous volume, 3000r/min homogenizing speed, 30 s homogenizing time and 2% aqueous sodium alginate concentration, a high internal phase emulsion with a particle size of 9.33 ± 1.74 μm and an appearance of milky paste was prepared. The inclusion rate of probiotics reached 90.97 ± 27.09%. Breast cancer anti-tumor experiment showed that the tumor inhibition rate of the experimental group reached 33.78% compared with the control group. Conclusion: Water-in-oil high internal phase emulsion can effectively protect L. casei and reduce the loss of live probiotic when probiotics pass through the digestive fluid environment. Oral intragastric high internal phase emulsion containing L. casei oil-in-water has a certain therapeutic effect on breast cancer.

A novel highly sensitive test reaction for micromixing: Acid‐base neutralization and alkaline hydrolysis of ethyl oxalate

AbstractMicromixing in chemical reactors can be characterized through test reactions that are sensitive to mixing. A new pair of parallel competitive reactions, including acid–base neutralization and diethyl oxalate hydrolysis, is proposed in this work. It has clear principles and high sensitivity to micromixing with quantitative accuracy and operational simplicity. The measurement results obtained from stopped‐flow spectra show that the alkaline hydrolysis of diethyl oxalate follows second‐order kinetics, and the rate constant conforms to the Arrhenius equation k2 = 2.331 × 108 exp(−26.92 × 103/RT) (L/mol/s). The estimated half‐life of hydrolysis is approximately 3 × 10−4 s under the selected concentration combinations, which provides significant advantages for the micromixing assessment in the strong turbulent fluid environment. In the same stirred tank, the critical feed time of new test reaction is shorter than that of the Villermaux–Dushman reaction. Overall, this work provides practical ideas for screening other desired esters for fast hydrolysis to construct more test reactions for micromixing.

Microstructure, Mechanical Properties and Corrosion Performance of Laser-Welded NiTi Shape Memory Alloy in Simulated Body Fluid.

Laser-welding is a promising technique for welding NiTi shape memory alloys with acceptable tensile strength and comparable corrosion performance for biomedical applications. The microstructural characteristics and localized corrosion behavior of NiTi alloys in a simulated body fluid (SBF) environment are evaluated. A microstructural examination indicated the presence of fine and equiaxed grains with a B2 austenite phase in the base metal (BM), while the weld metal (WM) had a coarse dendritic microstructure with intermetallic precipitates including Ti2Ni and Ni4Ti3. The hardness decreased from the BM to the WM, and the average hardness for the BM was 352 ± 5 HV, while it ranged between 275 and 307 HV and 265 and 287 HV for the HAZ and WM, respectively. Uni-axial tensile tests revealed a substantial decrease in the tensile strength of NiTi WM (481 ± 19 MPa), with a reduced joint efficiency of 34%. The localized corrosion performance of NiTi BM was superior to the WM, with electrochemical test responses indicating a pitting potential and low corrosion rate in SBF environments. The corrosion rate of the NiTi BM and WM was 0.048 ± 0.0018 mils per year (mpy) and 0.41 ± 0.019 mpy, respectively. During welding, NiTi's strength and biocompatibility properties changed due to the alteration in microstructure and formation of intermetallic phases as a result of Ti enrichment. The performance and safety of welded medical devices may be impacted during welding, and it is essential to preserve the biocompatibility of NiTi components for biomedical applications.

Societal Shifts in Central Asia: Figures and Trends

Central Asia has been undergoing considerable transformations by becoming mature independent states in international arena and experiencing socio-demographic shifts. It clearly resembles the dynamics described in Moises Naím’s “The End of power” where he argues that “the more, mobility, and mentality” revolutions challenge political leaders with fluid and unpredictable environment. This article aims to do an empirical analysis of the socio-demographic changes in Central Asia to test the assumption in the regional context.

Physical, chemical, and biological property of silk reinforced polycaprolactone composites for bone tissue engineering

To develop a biodegradable implantable bone material with compatible mechanics with the bone tissue, providing a new biomaterial for clinical bone repair and regeneration. Silk reinforced polycaprolactone composites (SPC) containing 20%, 40%, and 60% silk were prepared by layer-by-layer assembly and hot-pressing technology. Macroscopic morphology was observed and microstructure were observed by scanning electron microscopy, compressive mechanical properties were detected by compression test, surface wettability was detected by surface contact angle test, degradation of materials was observed after soaking in PBS for 180 days, and proliferation of MC3T3-E1 cells was detected by cell counting kit 8 assay. Six Sprague Dawley rats were subcutaneously implanted with polycaprolactone (PCL) and 20%-SPC, respectively. Masson staining was used to analyze the in vivo degradation behavior and vascularization effect within 180 days. The pore defects of the three SPC sections were relatively few. In the range of 20% to 60%, as the silk content increased and the PCL content decreased, the interlayer spacing of silk fabric decreased, and the fibers almost covered the entire cross-section. The compressive modulus and compressive strength of SPC showed an increasing trend, and the compressive modulus of 60%-SPC was slightly lower than that of 40%-SPC. There were significant differences in compressive modulus and compressive strength between the materials ( P<0.05). In vitro simulated fluid degradation experiments showed that the mass loss of the three types of SPC after 180 days of degradation was within 5%, with the highest mass loss observed in 60%-SPC. The differences in mass loss between the materials were significant ( P<0.05). As the silk content increased, the static water contact angle of each material gradually decreased, and all could promote the proliferation of MC3T3-E1 cells. The subcutaneous degradation experiment in rats showed that 20%-SPC began to degrade at 30 days after implantation, and material degradation and vascularization were significant at 180 days, which was in sharp contrast to PCL. SPC has the mechanical and hydrophilic properties that are compatible with bone tissue. It maintains its mechanical strength for a long time in a simulated body fluid environment in vitro, and achieves dynamic synchronization of material degradation, tissue regeneration, and vascularization through the body's immune regulation mechanism in vivo. It is expected to provide a new type of implant material for clinical bone repair.

Multicellularity and increasing Reynolds number impact on the evolutionary shift in flash-induced ciliary response in Volvocales

BackgroundVolvocales in green algae have evolved by multicellularity of Chlamydomonas-like unicellular ancestor. Those with various cell numbers exist, such as unicellular Chlamydomonas, four-celled Tetrabaena, and Volvox species with different cell numbers (~1,000, ~5,000, and ~10,000). Each cell of these organisms shares two cilia and an eyespot, which are used for swimming and photosensing. They are all freshwater microalgae but inhabit different fluid environments: unicellular species live in low Reynolds-number (Re) environments where viscous forces dominate, whereas multicellular species live in relatively higher Re where inertial forces become non-negligible. Despite significant changes in the physical environment, during the evolution of multicellularity, they maintained photobehaviors (i.e., photoshock and phototactic responses), which allows them to survive under changing light conditions.ResultsIn this study, we utilized high-speed imaging to observe flash-induced changes in the ciliary beating manner of 27 Volvocales strains. We classified flash-induced ciliary responses in Volvocales into four patterns: “1: temporal waveform conversion”, “2: no obvious response”, “3: pause in ciliary beating”, and “4: temporal changes in ciliary beating directions”. We found that which species exhibit which pattern depends on Re, which is associated with the individual size of each species rather than phylogenetic relationships.ConclusionsThese results suggest that only organisms that acquired different patterns of ciliary responses survived the evolutionary transition to multicellularity with a greater number of cells while maintaining photobehaviors. This study highlights the significance of the Re as a selection pressure in evolution and offers insights for designing propulsion systems in biomimetic micromachines.

Investigating resonance frequency in advanced composite structures as the main part of bridge construction: a multi-physics simulation approach

This paper investigates the nonlinear vibration characteristics and resonance frequencies of a graphene oxide powders (GOP) reinforced beam structure, which is in contact with fluid, serving as a crucial component in bridge construction. Utilizing a multi-physics simulation approach, this study integrates both mathematical modeling and COMSOL simulations to analyze the behavior of the GOP-reinforced beam. The fluid in the analysis is modeled as incompressible, non-viscous, and irrotational, contributing to the interaction with the beam structure. The isogeometric approach, coupled with the harmonic balance method and the arc-length technique, is employed to solve the complex nonlinear partial differential equations (PDEs). This coupled method ensures the accurate capture of the nonlinear response and resonance frequencies of the beam, which are critical for the safe design and performance of bridge structures. The findings reveal the significant influence of GOP reinforcement on the vibration and stability characteristics of the beam, highlighting its potential to enhance structural performance under dynamic loading conditions. The study also emphasizes the importance of considering fluid-structure interactions in the design process, as the fluid’s presence substantially affects the vibration behavior. This research contributes to the understanding of the dynamic behavior of advanced composite structures in fluid environments, offering valuable insights for the design and analysis of bridge components. The results demonstrate the efficacy of the proposed simulation approach in addressing the complexities of nonlinear vibrations in fluid-structure interaction systems, paving the way for future developments in civil engineering applications.

3D chitosan scaffolds loaded with ZnO nanoparticles for bone tissue engineering

Bone defect has always been a difficult problem in clinical work. According to the current research results, tissue engineered scaffolds with a single function, structure, and composition are not sufficient to repair complex bone defects. In this work, a three-dimensional (3D) chitosan degradable composite scaffold loaded with zinc oxide (ZnO) was constructed, and the effect of ZnO content on scaffold performance and osteogenesis was explored. The 3D composite scaffold was prepared by freeze-drying technology. The microstructure, porosity, degradation performance, release performance, swelling performance, cytotoxicity, cell adhesion and osteogenic ability of ZnO nanoparticles and chitosan (ZnONPs/CS) composite scaffolds were measured. The results show that an appropriate amount of ZnO may be helpful to regulate the stability and degradation characteristics of the scaffold to a certain extent. Moreover, the composite scaffold could release ZnO into the simulated body fluid environment. The appropriate amount of ZnO helps to promote the proliferation, adhesion, and osteogenic differentiation of MC3T3-E1 cells. At a ZnO content of 3wt%, both in vitro and vivo results showed relatively optimal biocompatibility and bioactivity of the scaffolds. This work could at least provide some positive insights for the selection of ZnO dosage, construction of chitosan-based 3D scaffolds, tissue engineering applications, and clinical treatment.

Optimization of the two-step coating formation process for ZK21 magnesium alloy

Abstract The primary hindrance to the broader utilization of magnesium alloys lies in their insufficient corrosion resistance. This research initiative introduced an advanced two-phase methodology incorporating phosphating and alkali heating to produce a protective Ca-P coating on the surface of magnesium alloys. This innovative approach not only bolsters their corrosion resistance but also facilitates controlled degradation in bodily fluid environments. Following a 60-minute phosphating process in a solution with a pH level of 3, the resultant Ca-P coating achieved full coverage over the magnesium alloy surface, displaying commendable coating density and uniformity. Subsequent treatment with alkali heating for 30 minutes further enhanced the density and smoothness of the coating. Analysis utilizing EDS and XRD revealed that the primary constituents of the phosphate magnesium alloy and the phosphate + alkali heated magnesium alloy coating were DCPD and HA, respectively. Corrosion degradation assessments conducted in SBF solution validated that the two-step coating formation method significantly fortified the corrosion resistance of magnesium alloys.

Temperature- and alkali-resistant induced domestication of Bacillus pasteurii in drilling fluid and its borehole wall enhancement properties

The microbial induced calcium carbonate precipitation (MICP) technology provides a new approach to solve borehole destabilization in broken formations; however, the high-temperature and alkaline environments inhibit the growth of microorganisms, which in turn affects the performance of their wall enhancement performance. In this study, a pH and temperature-coupled induced domestication method was applied to Bacillus pasteurii, and its wall enhancement performance was evaluated. Post domestication, Bacillus pasteurii exhibited high growth activity at pH 10.3 and temperature 45 °C. In a sodium carboxymethyl cellulose (CMC) drilling fluid environment, bacterial concentration reached 1.373 with urease activity at 1.98 after 24 h, and in a xanthan gum (XG) environment, the figures were 0.931 and 1.76, respectively—significantly higher than those before domestication. The Bacillus pasteurii-CMC system exhibited enhanced performance with the unconfined compressive strength of the specimen up to 1.232 MPa, permeability coefficient as low as 0.024, and calcium carbonate production up to 24.685 g. The crushed specimen portions remained lumpy with even calcium carbonate distribution. In contrast, the Bacillus pasteurii-XG system exhibited the highest unconfined compressive strength of 0.561 MPa, lowest permeability coefficient of 0.081, and the greatest calcium carbonate production of 16.03 g, with an externally cemented shell but internally loose structure and uneven calcium carbonate distribution, resulting in weaker mechanical properties. The Bacillus pasteurii induced predominantly vaterite calcium carbonate crystals in the CMC drilling fluid. In the XG drilling fluid, the crystals were mainly calcite. Both types effectively cemented the broken particles, improving formation strength and reducing permeability. However, under the same conditions, the Bacillus pasteurii-CMC system demonstrated a more pronounced enhancement effect.

Maximally efficient exchange in thin flow cells using density gradients

Flow cells are ubiquitous in laboratories and automated instrumentation, and are crucial for ease of sample preparation, analyte addition and buffer exchange. The assumption that the fluids have exchanged completely in a flow cell is often critical to data interpretation. This article describes the buoyancy effects on the exchange of fluids with differing densities or viscosities in thin, circular flow cells. Depending on the flow direction, fluid exchange varies from highly efficient to drastically incomplete, even after a large excess of exchange volume. Numerical solutions to the Navier–Stokes and Cahn–Hilliard equations match well with experimental observations. This leads to quantitative predictions of the conditions where buoyancy forces in thin flow cells are significant. A novel method is introduced for exchanging fluid cells by accounting for and utilizing buoyancy effects that can be essential to obtain accurate results from measurements performed within closed-volume fluid environments.

Preparation and in vitro digestion of algal oil emulsion gel candy with high oxidation stability based on cold‐set gelation method

SummaryAlgal oil emulsion gel candies were prepared by a cold‐set gelation method, and the oxidative stability was analysed. Then, the release of algal oil and the microstructural changes of gel candies were investigated under in vitro simulated digestion conditions. The formula of gel candy was found to be 65% sucrose, 5% algal oil emulsion, 1.8% sodium alginate, 1.2% high methoxy pectin and 2% D‐glucono‐δ‐lactone. Cold‐set gel candies loaded with algal oil emulsion had good oxidative stability. Emulsion gel candies could maintain a relatively intact gel network structure in a gastric fluid environment, in which the DHA release rate was less than 5%, whereas the gel structure was loosened at 30 min of digestion in simulated intestinal fluid and destroyed at 60 min, with a release rate of about 75%. Altogether, these results lay a theoretical foundation for facilitating the development of novel DHA functional foods.

Pulsed laser surface texturing enhancing corrosion resistance of rare-earth WE43 magnesium alloys in simulated body fluid environment

The addition of rare earth (RE) elements in Magnesium (Mg) alloys could optimize alloy microstructures and improve the mechanical property. The corrosion resistance however is a tough issue that limits its application as biomedical materials in human bodies. In this work, a green, fast and economical method of pulsed laser surface texturing (PLST) was employed to modify the RE WE43 Mg alloys and the corresponding corrosion resistance after the PLST treatment in simulated body fluid (SBF) was further examined. The microstructural results show that the surface exhibits petal-like microstructures and an oxide film composed of various oxides with remelting particles are also generated on laser-processed areas after PLST treatment. The electrochemical results reveal that the WE43 sample treated by PLST exhibits a superior corrosion resistance in SBF compared with the as-cast one. As for the PLST treated sample with 24 W, the corrosion potential (Ecorr) positively shifts from −1.788 V to −1.556 V after being immersed in SBF for 7 days, which is also nobler than that of the as-cast one, −1.915 V. While the corrosion current density (icorr) drops to the value of 8.3 μA/cm2, considerably lower than that of the as-cast sample, 1380 μA/cm2. The enhancement of corrosion resistance in the early stage is mainly due to the protective oxide film induced by PLST. Furthermore, long-term immersion in SBF further accelerates the formation of deposited hydroxyapatite (HA) products layer on petal-like microstructures, which would further contribute to its enhancement in corrosion resistance in the long-term service in human bodies.