Adhesion Mechanisms Research Articles

The preparation and construction of biomimetic mineralization compatible interface of wood fiber/foamed magnesium oxychloride lightweight composites

The purpose of this study is to improve the application performance of foamed magnesium oxychloride cement (FMOC) and solve the problem of poor interfacial compatibility between the organic-inorganic interface of traditional inorganic composite materials. Inspired by the adhesion mechanism of barnacles to inorganic substrates through amyloid nanofibers and phosphoprotein, a simple green method was proposed to improve the strength and water resistance of the system. The FMOC composites (30×30×30 mm) were prepared by adding wood flour (WF) and phytic acid (PA) to the mixture of magnesium oxide and magnesium chloride. The influences of WF and PA on the compressive strength, composition, microstructure, pore structure, water resistance and flame retardant properties of FMOC were investigated. WF was used as a skeleton structure to induce cement particle aggregation, the PA molecule was used as a connecting bridge to activate the fiber skeleton to increase the active sites, and promote crystal nucleation and aggregation through hydrogen and ionic bond interactions to construct the biomimetic mineralized structure. The results show that the introduction of PA improves the compressive strength and water resistance of the FMOC/WF/PA composite system. When the PA addition amount is 0.8 %, the compressive strength of FMOC/WF/PA-0.8 % composites reached 6.64 MPa, which was 3 times compared to the FMOC composites. The softening coefficient and water absorption of the obtained FMOC/WF/PA-0.8 % composites were 0.81 and 13.84 %, respectively, which were superior to FMOC composites and presented better behavior in water resistance. Meanwhile, the modified composites have more stable pore structure and flame retardant properties, thus these green FMOC/WF/PA composites displayed potential application value in building energy conservation, aerospace and other fields.

Zinc and copper effect mechanical cell adhesion properties of the amyloid precursor protein.

The amyloid precursor protein (APP) can be modulated by the binding of copper and zinc ions. Both ions bind with low nanomolar affinities to both subdomains (E1and E2) in the extracellular domain of APP. However, the impact of ion binding on structural and mechanical trans-dimerization properties is yet unclear. Using a bead aggregation assay (BAA), we found that zinc ions increase the dimerization of both subdomains, while copper promotes only dimerization of the E1 domain. In line with this, scanning force spectroscopy (SFS) analysis revealed an increase in APP adhesion force up to three-fold for copper and zinc. Interestingly, however, copper did not alter the separation length of APP dimers, whereas high zinc concentrations caused alterations in the structural features and a decrease of separation length. Together, our data provide clear differences in copper and zinc mediated APP trans-dimerization and indicate that zinc binding might favor a less flexible APP structure. This fact is of significant interest since changes in zinc and copper ion homeostasis are observed in Alzheimer's disease (AD) and were reported to affect synaptic plasticity. Thus, modulation of APP trans-dimerization by copper and zinc could contribute to early synaptic instability in AD.

Mussel-inspired biomimetic modification to enhance adhesion properties between granite and asphalt: Multi-scales characterizations and molecular mechanisms

Mussel-inspired biomimetic modifiers and amine surface modifiers were used to biomimetic modify granite surface to improve adhesion properties of granite with asphalt. Adhesion properties of granite were characterized at multi-scales, where the fire-scouring effect during hot mixing on adhesion properties of surface modified granite was considered. Meanwhile, adhesion mechanism between surface modified granite and asphalt was explored based on molecular simulation. The results of study were as follows: (1) Mussel-inspired biomimetic surface modification of granite could significantly enhance adhesion properties of granite with asphalt, as demonstrated by 115.59 % increase in tensile fracture strength, 81.18 % increase in surface energy, and 82.77 % increase in adhesion force. (2) Mussel-inspired surface biomimetic modification of granite had better resistance fire-scorching effect. Adhesion properties of surface modification by SCA after fire-scorching decreased by 18.51 %, 34.14 %, and 20.07 % at multi-scales, while adhesion properties of mussel-inspired biomimetic modification after fire-scouring decreased by 14.29 %, 9.14 %, and 12.27 % at multi-scales. (3) Molecular simulations showed that surface modified granite could enhance adhesion properties not only by increasing electrostatic interactions, but also by improving granite-asphalt interaction and attracting heavy components of asphalt to rearrangement. Among them, polarity adhesion induced by mussel-inspired biomimetic modification plays dominant role in enhancing adhesion properties.

Polymerization-Induced Self-Assembly Providing PEG-Gels with Dynamic Micelle-Crosslinked Hierarchical Structures and Overall Improvement of Their Comprehensive Performances.

Polymer gels are fascinating soft materials and have become excellent candidates for wearable electronics, biomedicine, sensors, etc. Synthetic gels usually suffer from poor mechanical properties, and integrating good mechanical properties, adhesiveness, stability, and self-healing performances in one gel is more difficult. Herein, polymerization-induced self-assembly (PISA) providing PEG-gels with an overall improvement in their comprehensive performances is reported. PISA synthesis is carried out in PEG (solvent) to efficiently produce various nanoparticles, which are used as the nanofillers in the subsequent synthesis of PEG-gels with dynamic micelle-crosslinked hierarchical structures. Compared to hydrogels, PEG-gels show excellent long-term stability due to the nonvolatile feature of PEG solvent. The hierarchical PEG-gels (with nanofillers) exhibit better mechanical and adhesive properties than the homogeneous-gels (without nanofillers). The energy dissipation mechanism of the PEG-gels is analyzed via stress relaxation and cyclic mechanical tests. High-density hydrogen bonds between the micelles and PAA matrix can be broken and reformed, endowing better self-healing properties of the dynamic micelle-crosslinked PEG gels. This work provides a simple strategy for producing hierarchical structural gels with enhanced properties, which offers fundamentals and inspirations for the designing of various advanced functional materials.

Antifreezing/Antiswelling Hydrogels: Synthesis Strategies and Applications as Flexible Motion Sensors.

Hydrogels are excellent materials for fabricating flexible electronic devices, such as flexible sensors. However, obtaining hydrogels with superior swelling capacity and good hydrophilicity suitable for use under extreme environments, such as cold and underwater conditions, is still challenging due to the occurrence of freezing and excessive swelling. Alternatively, hydrogels with antifreezing and antiswelling capacities exhibit minimal changes in their physical and chemical properties under extreme conditions with retained original performance, such as mechanical properties, conductivity, and adhesiveness, making them suitable for various applications. Accordingly, various multifunctional antifreezing/antiswelling hydrogels meeting practical application requirements have been developed thanks to the advancement of hydrogel technology. Examples include flexible sensors for monitoring various motion signals, such as changes during sports events. However, comprehensive reviews describing these hydrogels in terms of synthesis and application in sensors are still lacking. Herein, the design and synthetic strategies of antifreezing/antiswelling hydrogels reported in recent years are comprehensively analyzed along with their mechanisms and applications in flexible motion sensors. This review aims to provide a comprehensive understanding of the research of antifreezing/antiswelling hydrogels and offer valuable insights for researchers engaged in the development of advanced materials suitable for practical applications.

Physical-Vapor-Deposition-Coated Natural Rocks as Sustainable Cutting Material: First Insights into the Effect of Substrate Integrity on Properties of TiN Thin Film

The most important cutting materials for machining are carbides. Their production requires both tungsten and cobalt; however, these materials are becoming increasingly difficult to obtain and are sometimes mined under ethically questionable conditions. As a result, increasing efforts are being made to expand the range of cutting materials. The basic suitability of natural rocks for cutting tools in less demanding processes has already been demonstrated. PVD coating of the natural rocks could improve their performance. The adhesion mechanisms in TiN-coated natural rock samples are discussed below. The TiN thin film is characterized in depth.

ADAM10 modulates the efficacy of T-cell-mediated therapy in solid tumors.

T-cell-mediated therapeutic strategies are the most potent effectors of cancer immunotherapy. However, an essential barrier to this therapy in solid tumors is disrupting the anti-cancer immune response, cancer-immunity cycle, T-cell priming, trafficking and T-cell cytotoxic capacity. Thus, reinforcingtheanti-cancer immune response is needed to improve the effectiveness of T-cell-mediated therapy. Tumor-associated protease ADAM10, endothelial cells (ECs) and cytotoxic CD8+ Tcells engage in complex communication via adhesion, transmigration and chemotactic mechanisms to facilitate an anti-cancer immune response. The precise impact of ADAM10 on the intricate mechanisms underlying these interactions remains unclear. This paper broadly explores how ADAM10, through different routes, influences the efficacy of T-cell-mediated therapy. ADAM10 cleaves CD8+ T-cell-targeting genes and impacts their expression and specificity. In addition, ADAM10 mediates the interactions of adhesion molecules with Tcells and influences CD8+ T-cell activity and trafficking. Thus, understanding the role of ADAM10 in these events may lead to innovative strategies for advancing T-cell-mediated therapies.

Effect of thermal shocks on the interfacial bond strength of sandwich composites built with rigid and soft materials produced through extrusion process

The mechanical behavior and adhesion strength of the sandwich composite, which consists of a flexible and a rigid material, were examined using extruded polylactic acid (PLA) and thermoplastic polyurethane (TPU). Three types of binders were combined with the appropriate hardeners to bond the extruded materials. The fabricated specimens are subjected to a different number of thermal shock cycles, with a maximum and minimum temperature of 80 °C and −18 °C, respectively. The sandwich composite's mechanical properties, including tensile, flexural, and impact strength, were assessed after 20, 40, and 80 cycles of thermal shock. The results indicated that the ductility of PLA material was significantly impacted by the thermal shock cycles. After completing the maximal thermal shock cycles, the composites joined with polyester resin exhibited a lower strength reduction in the impact specimens. Maximum tensile strength of 22.3 MPa, flexural strength of 31.6 MPa, and impact strength of 8.3 J were recorded prior to the application of thermal shocks to the specimens. The specimens that were bonded with epoxy resin recorded the maximal tensile, flexural, and impact strength. Following the thermal shock cycles, the composites bonded with epoxy resin exhibited a lesser reduction in tensile and flexural strength, while the composites bonded with polyester resin showed a lower strength reduction for impact specimens. The tensile and flexural specimens encountered a 7.54 % and 20.24 % reduction in strength, respectively, after undergoing 80 cycles of thermal shocks. The impact specimens experienced an 8.62 % reduction in strength.

Density Functional Theory Study of Adhesion Mechanism between Epoxy Resins Cured with 4,4'-Diaminodiphenyl Sulfone and 4,4'-Diaminodiphenylmethane and Carboxyl Functionalized Carbon Fiber.

The molecular mechanism of adhesion of two epoxy resins based on diglycidylether of bisphenol A (DGEBA) cured with 4,4'-diaminodiphenyl sulfone (DDS) and 4,4'-diaminodiphenylmethane (DDM) to the carbon fiber (CF) surface is investigated by employing density functional theory (DFT) calculations. The CF surface was modeled by the armchair-edge structure of graphite functionalized with carboxyl (COOH) groups. Two adhesion interfaces were constructed using the CF surface: one with the DGEBA-DDS molecule (CF/DGEBA-DDS interface) and the other with the DGEBA-DDM molecule (CF/DGEBA-DDM interface). The interfacial properties were analyzed by calculating the maximum adhesion stress (Smax) at the interface. The adhesion stress-displacement curve revealed that Smax is 1160.37 MPa, higher for the CF/DGEBA-DDS interface compared to the CF/DGEBA-DDM interface, which is 1060.48 MPa. The energy decomposition analysis showed a similar DFT contribution to adhesion stress for both interfaces, but the dispersion contribution is more significant at the CF/DGEBA-DDS interface. The crystal orbital Hamilton population (COHP) analysis revealed distinct interfacial interactions despite similar DFT contributions. Hydrogen bonding (H-bonding) between the functional groups at both interfaces including feeble OH-π interactions between the benzene rings of epoxy resins and COOH groups on the CF surface were observed. The orbital interaction energies calculated from integrated COHP, i.e., IpCOHP, revealed that the CF/DGEBA-DDS interface has six H-bonding interactions with large absolute IpCOHP values (>1 eV), whereas the CF/DGEBA-DDM interface has five. The interaction between the amine group of the DGEBA-DDM molecule and the CF surface has a large IpCOHP value among all interactions. The sulfone group being at the center of the DDS molecule and its strong surface interaction positioned the DGEBA-DDS molecule closer to the CF surface than the DGEBA-DDM molecule, enhancing dispersion interaction at the CF/DGEBA-DDS interface. Hence, the CF surface exhibits a stronger affinity toward the DGEBA-DDS molecule than the DGEBA-DDM molecule through dispersion interaction.

Role of Tail Dynamics on the Climbing Performance of Gecko-Inspired Robots: A Simulation and Experimental Study.

Geckos are renowned for their exceptional climbing abilities, enabled by their specialized feet with hairy toes that attach to surfaces using van der Waals forces. Inspired by these capabilities, various gecko-like robots have been developed for high-risk applications, such as search and rescue. While most research has focused on adhesion mechanisms, the gecko's tail also plays a critical role in maintaining balance and stability. In this study, we systematically explore the impact of tail dynamics on the climbing performance of gecko-inspired robots through both simulation and experimental analysis. We developed a dynamic climbing simulation system that models the robot's specialized attachment devices and predicts contact failures. Additionally, an adjustable-angle force measurement platform was constructed to validate the simulation results. Our findings reveal the significant influence of the tail on the robot's balance, stability, and maneuverability, providing insights for further optimizing climbing robot performance.

Evaluation of Fracture Durability and Wear Resistance Properties for Orthopaedic Implant Application

Hydroxyapatite (HA) coated metallic substrates are commonly used for load-bearing orthopedic implants. In the present work Titanium grade 2 and Titanium grade 5 substrates were coated with hydroxyapatite and hydroxyapatite reinforced with 5% (by wt.) multiwalled carbon nanotubes (MCNT) separately using plasma spray coating. The wear behavior of these coated substrates was studied with the simulated body fluid (SBF) having a pH between 7.20 to 7.40. Fracture toughness and wear resistance of HA reinforced with 5 % (by wt.) MCNT composite coating was found to be higher as compared to pure HA coating. This improvement is by virtue of inherent mechanical properties and the crack bridging effect offered by MCNT. The addition of MCNT also helped in restricting crack propagation in the coatings. As evident from SEM images, abrasive and adhesive wear mechanism were observed which reduces greatly with reinforcement of MCNT.

Quercetin-enriched animal-free scaffolds for promoted cell proliferation and differentiation in cultured meat production

To solve the challenges posed by increasing meat consumption, it is imperative to develop polysaccharide composite edible scaffolds for cell-cultured meat production using novel food production technologies. This study developed some non-animal-origin polysaccharide composite scaffolds for cell-cultured meat production, based on chitin‑sodium alginate and crosslinked with quercetin. The results indicated that the chitin‑sodium alginate-quercetin (CH-SA-QR) scaffolds exhibited a porous and loose structure, and excellent mechanical support capability and cell adhesion sites. Meanwhile, QR1 and QR1.5 scaffolds were screened by immunofluorescence staining, RT-qPCR, and SEM imaging results to facilitate the proliferation and differentiation of cells and enhance the generation of myotube fusion and extracellular matrix protein. Importantly, the texture of the fried cultured meat was similar to traditional beef or even more tender, while the color appearance of the cultured meat was different from beef, but more similar to fried meat cutlets. These results suggest that cultured meat produced based on CH-SA-QR scaffolds could provide consumers with more choices.

Superhydrophobicity induced antibacterial adhesion and durability of laser bidirectionally-textured zirconia surfaces with different inclination angles

Femtosecond laser bidirectional texturing with different laser energy densities and inclination angles was performed on zirconia (ZrO2) surfaces. The laser bidirectional texturing models under different inclination angles were constructed to predict the water contact angles (WCAs), and the superhydrophobicity induced antibacterial adhesion mechanism was analyzed. The results revealed that under the combined effect of the optimal laser energy density (7.0 J/cm2) and inclination angle (90°), the laser-textured ZrO2 surface could obtain a micro-nano dual-scale structure composed of periodic regular micro-cones and nanoparticles. This structure not only promoted the adsorption of carbon-containing hydrophobic groups from the stearic acid and the air to form a superhydrophobic surface with excellent chemical/mechanical durability and anti-fouling/self-cleaning abilities, but also minimized the contact area with the bacterial suspension (solid/liquid contact area ratio of 6 %) to enhance antibacterial ability. The optimal stearic acid-modified laser-textured ZrO2 surface exhibited an extremely low adhesive force (Fadhesive=6.69 μN) to the bacterial suspension, and thus achieved the highest antibacterial ratio of 85.3 %. This study is expected to enrich the application of ZrO2 ceramics in the medical field.

Repair overlays of modified polymer mortar containing glass powder and composite fibers-reinforced slag: mechanical properties, energy absorption, and adhesion to substrate concrete

This article aims to investigate the mechanical properties and substrate adhesion of the pull-off method in polymer mortars modified with styrene-butadiene resin polymer (SBR) containing glass powder and composite fiber-reinforced slag. Different mix designs were investigated with and without SBR, taking into account different amounts of glass powder and slag separately and in combination, along with the effect of glass, polypropylene, and steel fibers alone and in combination. The flexural performance and energy absorption of beams retrieved with these layers were also assessed. The results revealed significant differences and increases in the substrate adhesion of the restored modified polymer layers containing SBR compared to the polymer-free repair overlays. Furthermore, an improvement was observed in the adhesion performance of the repair overlay using a combination of slag and glass powder and the glass and polypropylene fiber composite. The highest adhesion was related to the modified polymer mortar design containing composite fibers of glass, polypropylene, and steel with 25% replacement of SBR polymer for 10% glass powder, 10% slag, and 5% slag with 5% glass powder. The adhesion was increased by about 3.74, 3.72, and 3.78 times compared to the repair overlay of the control design. Modified polymer mortars had a higher T150D toughness. Moreover, the energy absorption was significantly improved by the presence of SBR polymer. The highest toughness values were found in the beams restored with modified polymer mortars containing polypropylene, glass, and steel composite fibers with an increase of 48.51%–66.42% compared to the samples without polymer as a result of the pozzolans used in this mix.

A novel efficient flame-retardant curing agent for epoxy resin based on P-N synergistic effect: Bio-based benzoxazine phosphate ester

Most epoxy resins on the market have low thermal stability and flammable defects. As a potential curing agent for epoxy resin, polybenzoxazine (PBz) can effectively improve the thermal properties of the resin due to its low heat release capacity (HRC) and rigid aromatic ring support, and its raw materials can be derived from renewable resources. Here, we have successfully developed a molecular design strategy to obtain a trifunctional benzoxazine monomer with phosphate ester. Firstly, guaiacol-ethanolamine benzoxazine monomer (GE) was synthesized by Mannich condensation using guaiacol and ethanolamine as raw materials. Then trifunctional benzoxazine phosphate ester (TBP) was synthesized by the nucleophilic reaction of GE with phosphorus oxychloride. Finally, the epoxy resin DGEBA was cured by TBP to obtain a PBz modified epoxy resin (EP-TBP polymer) with Tg of 113.7 °C and char yield of 37.4 %. Due to the introduction of TBP rich in phosphorus and nitrogen, it releases phosphorus radicals and nitrogen-containing inert gases during combustion, which leads to quenching effect and dilution effect. In addition, TBP can also promote the dehydration and dehydrogenation of the polymer and accelerate the formation of the aromatic hybrid char layer. Therefore, the THR of TBP modified epoxy resin is 49.3 % lower than that of epoxy resin without TBP, and the char yield is 47 times higher. And when the phosphorus content is 1.76 %, the flame-retardant grade can reach V-0. In addition, the introduction of TBP also enhanced the mechanical properties, adhesion properties and hydrophobicity properties of the polymer. It is worth mentioning that under alkaline conditions, the phosphate ester in the structure of EP-TBP polymer will undergo ammonolysis reaction with ethanolamine, and the resulting oligomers will be dissolved in it, thereby achieving rapid degradation of EP-TBP polymer. This work is to develop a high-performance multifunctional epoxy resin flame retardant curing agent based on renewable raw materials, and provide important insights for the subsequent development of halogen-free bio-based PBz flame retardant materials.

Review of Flexible Robotic Grippers, with a Focus on Grippers Based on Magnetorheological Materials

Flexible grippers are a promising and pivotal technology for robotic grasping and manipulation tasks. Remarkably, magnetorheological (MR) materials, recognized as intelligent materials with exceptional performance, are extensively employed in flexible grippers. This review aims to provide an overview of flexible robotic grippers and highlight the application of MR materials within them, thereby fostering research and development in this field. This work begins by introducing various common types of flexible grippers, including shape memory alloys (SMAs), pneumatic flexible grippers, and dielectric elastomers, illustrating their distinctive characteristics and application domains. Additionally, it explores the development and prospects of magnetorheological materials, recognizing their significant contributions to the field. Subsequently, MR flexible grippers are categorized into three types: those with viscosity/stiffness variation capabilities, magnetic actuation systems, and adhesion mechanisms. Each category is comprehensively analyzed, specifying its unique features, advantages, and current cutting-edge applications. By undertaking an in-depth examination of diverse flexible robotic gripper types and the characteristics and application scenarios of MR materials, this paper offers a valuable reference for fellow researchers. As a result, it facilitates further advancements in this field and contributes to the provision of efficient gripping solutions for industrial automation.

Enhanced adhesion and wear resistance of DLC films on AZ31 alloy achieved with high bias voltage

Diamond-like carbon (DLC) films exhibiting high adhesion and exceptional wear resistance were successfully applied onto the AZ31 surface without a adhesive layer. The structural features of the film were examined utilizing Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Raman spectroscopy. Mechanical properties were evaluated through Nano-indentation testing, while adhesion was evaluated using a scratch tester. Residual stress was determined by Stoney's equation. The results indicate that utilizing a high substrate bias ranging from −500 to −800 V, results in the presence of multiple craters and dislocations, which contribute to the enhancement of high residual compressive stress and hardness in the DLC film. The heightened compressive stress effectively embeds carbon atoms into the surface of the soft AZ31, creating an interfacial layer that significantly improves adhesion and wear resistance of the film. In contrast, at moderate bias levels with a range from −300 to −500 V, an increase in substrate temperature leads to the expansion and discontinuation of adjacent layers that decreases the mechanical properties, adhesion, and wear resistance of the film. When at low bias levels between 0 and -300 V, the hardness, crack resistance, residual stress, and wear resistance all increase with increasing of bias. Additionally, in this work, the mechanisms of adhesion and wear for the biased film are analyzed.

Elevated MMP-9, Survivin, TGB1 and Downregulated Tissue Inhibitor of TIMP-1, Caspase-3 Activities are Independent of the Low Levels miR-183 in Endometriosis.

This study aimed to measure the correlation between miR-183 and gene expression that regulates apoptosis and adhesion mechanism that may be linked to the pathogenesis of endometriosis. Forty-four subjects, including 22 control subjects, participated in this study. We collected ectopic endometriosis and endometrial samples. For the control, the sample was taken from endometrial tissue through pipelle biopsy. RNA was extracted from all tissues using RNA mini kit, and the expression was assessed using quantitative-real time PCR. Relative mRNA and miRNA expression were presented using the formula of the Livak method. The data were statistically analyzed using GraphPad Prism 8. The expression of Caspase-3, Survivin, Integrin β1 (ITGB1), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) (adhesion- and apoptosis-related gene) were calculated using the relative expression method. We found significant differences in Caspase-3, Survivin, ITGB1, MMP-9, and TIMP-1 expression between ectopic endometriosis tissues of women with endometriosis compared to healthy endometrium. MMP-9, Survivin, and ITGB1 was significantly increased in the endometriosis group, while Caspase-3, TIMP-1, and miR-183 were significantly reduced in the endometriosis group. No correlation was found between the expression level of miR-183 and Caspase3, Survivin, ITGB1, and Cadherin in both tissue types. Despite the difference in expression levels of miR-183 and associated adhesion- and apoptosis-related genes, there was no significant association between miR-183 with specific adhesion and apoptosis genes in endometriosis tissue.

A coating with hydrogel@nanostructure on Ti surfaces via controllable Nano-mechanical interlocking

The elasticity mismatch between Ti and tissue limits the performance of Ti medical devices. How to create a coating with mimicking natural soft tissue stiffness and possessing strong mechanical bond is a challenge in implant manufacturing. Here, we developed a combined coating, that is, an anodized Ti surface (ATS) with nanostructures coated with a layer of PAAm hydrogel with tunable elasticity. Due to the nano-mechanical interlocking and hydrogen bonding synergy, the PAAm hydrogel layer was tightly anchored in nanostructures on the ATS. By regulating the oxidation voltage, nanostructures including nanopores, nanotubes, and punch-through nanotubes were fabricated on the ATS, and these three kinds of anodized nanostructures increase the porosity of the ATS sequentially. The lap shear test has shown that the shear strength increases linearly with increasing the porosity, and the shear strength of the punch-through nanotube structures with the PAAm hydrogel coating reaches 59.28 kPa. The adhesion mechanism between the anodized Ti nanostructures and the PAAm hydrogel coating is mainly due to the nano-mechanical interlocking and hydrogen bonding synergy, which was proven by morphology analysis, XRD, and ATR-FTIR characterization of the samples subjected to lap shear load. The hydrogel-nanostructures coating has demonstrated the potential to be applied in Ti medical devices.

Rat copper transport protein 2 (CTR2) is involved in fertilization through interaction with IZUMO1 and JUNO

In mammalian reproduction, testis-specific protein IZUMO1 and its receptor JUNO on the oocyte surface are essential for sperm-oocyte recognition, binding, and membrane fusion. However, these factors alone are insufficient to accomplish cytoplasmic membrane fusion. It is believed that other gametic proteins interact with them to facilitate sperm-oocyte interaction on the head and mid-tail of rat spermatozoa as well as on the surface of oocytes. In this study, Copper Transport Protein 2 (CTR2) has been identified on the head and mid-tail of rat spermatozoa as well as on the surface of oocytes. CTR2 directly interacts with both IZUMO1 and JUNO, colocalizing with IZUMO1 on the sperm head and with JUNO on the oocyte membrane. Treatment of the capacitated sperm and zona pellucida-free oocytes with anti-CTR2 antibody resulted in a significant decrease in fertilization rates in IVF experiments. These findings suggest that CTR2 plays an important role in mammalian fertilization by interacting with IZUMO1 and JUNO, providing new insights into the molecular mechanisms of mammalian sperm-oocyte adhesion and fusion.