Biosurface and Biotribology最新文献

Hydrogels, characterised as highly hydrophilic three-dimensional polymer networks, have gained increasing attention due to their unique physicochemical properties, finding applications in various fields. Natural polymer hydrogels exhibit higher biocompatibility and biodegradability compared to traditional synthetic polymer hydrogels. Proteins, being the principal materials of natural polymer hydrogels, bear numerous modifiable functional groups. The resultant hydrogel possesses responsiveness, adjustable degradability, and underway as an excellent biomaterial. Seven common raw materials used to construct protein hydrogels are introduced. In terms of comparing natural polymer hydrogels with traditional synthetic polymer hydrogels, the authors conduct a detailed analysis and comparison, highlighting the advantages of natural polymer hydrogels in terms of biocompatibility and biodegradability, and summarising their characteristics. The authors also address the limitations of various protein hydrogels and list existing strengthening cross-linking strategies, proposing new insights to overcome the application limits of protein hydrogels. Additionally, the applications of protein hydrogels in drug delivery, biosensing, bio-inks and tissue engineering are discussed. The authors conclude by summarising the current challenges faced by protein hydrogels and prospecting its future development.

Improving energy efficiency and cost reduction is a perennial challenge in engineering. Natural biological systems have evolved unique functional surfaces or special physiological functions over centuries to adapt to their complex environments. Among these biological wonders, fish, one of the oldest vertebrate groups, has garnered significant attention due to its exceptional fluid dynamics capabilities. Researchers are actively exploring the potential of fish skin's distinctive structural and material characteristics in reducing resistance. In this study, models of biomimetic imbricated fish scale are established, and the evolution characteristics of the flow field and drag reduction performance on these bionic surfaces are investigated. The results showed a close relationship between the high–low velocity stripes generated and the fluid motion by the imbricated fish scale surface. The stripes' prominence increases with the spacing of the adjacent scales and tilt angle of the fish scale, and the velocity amplitude of the stripes decreases as the exposed length of the imbricated fish scale surface increases. Moreover, the biomimetic imbricated fish scale surface can decrease the velocity gradient and thereby reduce the wall shear stress. The insights gained from the fish skin-inspired imbricated fish surface provide valuable perspectives for an in-depth analysis of fish hydrodynamics and offer fresh inspiration for drag reduction and antifouling strategies in engineering applications.

Bionic lubricant materials are a class of materials inspired by natural organisms and offer excellent lubrication properties and biocompatibility. In the field of sports medicine, their application opens up new possibilities for the prevention and treatment of sports-related diseases. The authors will introduce the existing theoretical models of friction in the locomotor system, the characteristics and advantages of biomimetic lubrication materials and discuss in depth their applications in the field of sports medicine. The development of bionic lubrication materials opens up unprecedented opportunities for sports medicine to provide more effective and long-lasting treatment options for patients.

Due to trauma and disease, bone defects endanger the healthy life of human beings. At present, the gold standard for bone defect repair is still autologous bone transplantation and allogeneic bone transplantation. However, its insufficient source, potential disease transmission and immune rejection limit its clinical application. Therefore, the development of bone repair materials plays an important role in promoting bone repair. As the interface between material and tissue, the surface of the material plays an important role in the reaction after implantation, which determines the effectiveness of defect repair treatment. With the development of surface engineering and technology, bone repair materials have developed from biological inertia to biological activity by endowing various biological functions by controlling the composition, topological morphology and structure of the material surface etc. The inspired biofunctionalisation of material surface includes the capacities of inducing osteogenesis, promoting angiogenesis, antibacterial, immune regulation etc., as well as integration of postoperative repair and treatment. The authors review the biofunctionalisation of biomaterial surface and the inspired biological effects for bone repair, mainly including physical and chemical properties of material surface to regulate osteogenesis, and functional strategy of bone repair material surface.

Biomaterials with exceptional performance are crucial for addressing the challenges of complex bone regeneration. Compared with traditional three-dimensional scaffolds, injectable microspheres enable new strategies for the treatment of irregular bone defects. Biodegradable poly (lactic-co-glycolic acid) has found widespread applications as microcarriers of drugs, proteins, and other active macromolecules. Applied to the surface of poly (lactic-co-glycolic acid) cage-like structures (PLGA-CAS), hydroxyapatite (HA) effectively reduces inflammation while enhancing biological effects. In this study, we loaded the surface of PLGA-CAS with micro- and nano-hydroxyapatite particles, referred to as μHA/PLGA-CAS and nHA/PLGA-CAS, respectively. Subsequently, their material characteristics and biological effects were assessed. The incorporation of hydroxyapatite onto PLGA-CAS resulted in enhanced surface roughness and hydrophilicity, coupled with improved thermal stability and delayed degradation. Furthermore, μHA/PLGA-CAS induced osteogenic differentiation of osteoblast precursor cells, while nHA/PLGA-CAS improved endothelial cell adhesion and stimulated angiogenic differentiation in vitro. Collectively, these findings suggest that μHA/PLGA-CAS and nHA/PLGA-CAS, each with distinct characteristics, hold significant potential for application as microcarriers in various biomedical contexts.

Titanium (Ti) dental scaffolds are widely used in dental prosthetics due to their excellent mechanical properties and biocompatibility. However, conventional Ti scaffolds manufactured through machining often do not fit perfectly with the bone defect site. Laser powder bed fusion (LPBF) technology enables the personalised manufacturing of custom-made Ti scaffolds. A custom-made Ti scaffold was prepared using LPBF and its surface roughness was improved through chemical polishing. To enhance the surface roughness, a nitric acid mixed solution with a specific composition of HF: HNO₃:C₃H₆O₃ = 2:2:3 was used. The polishing mechanism was investigated by adjusting the F/Ti ratio to control the formation and dissolution of the oxide film. As a result, the surface of the Ti scaffold after polishing exhibited a smooth and flat appearance compared to the LPBF part, with a reduced surface roughness (Ra) of 1.23 ± 0.19 μm. The custom-made Ti scaffold also demonstrated favourable mechanical properties, with a bending strength of 335.18 ± 33.62 MPa and stiffness of 2.13 ± 0.21 GPa. Furthermore, in vitro cell tests confirmed the excellent biocompatibility of the custom-made Ti scaffold. The authors present a feasible strategy for the further clinical application of custom-made Ti scaffolds, offering enhanced surface properties and addressing the limitations of conventional machining methods.

It is a developed photosynthetic co-culture system to alleviate the hypoxia and hypoxia/reoxygenation (H/R)-injured human umbilical vein endothelial cells (HUVECs). The algae, Chlorella vulgaris, were encapsulated to slow their growth while not affecting the photosynthetic oxygen-producing capacity by Layer-by-layer (LbL) using gelatin and sodium alginate as the positive and negative charges materials, respectively. Then, the photosynthetic co-culture system of HUVECs and self-oxygenating alginate hydrogel (Algae-gel) was constructed in which the optimal ratios between algae and HUVECs were 5:1 and 20:1 for a 2D or 3D co-cultured manner, respectively. It indicated that the 3D co-cultured manner of HUVECs needed more O₂ by the production of algae than it did in a 2D co-cultured manner. The co-cultured Algae-gel could alleviate hypoxia and the oxidative stress injury of hypoxia and hypoxia/reoxygenation (H/R)-treated HUVECs in the proliferation, intracellular ROS and cellular migratory ability. In addition, the Algae-gel could downregulate the expression of hypoxia-inducible factors 1α (HIF-1α) and vascular endothelial growth factor (VEGF) of hypoxia and H/R-injured HUVECs due to the improvement of hypoxia and H/R injury. This photosynthetic co-culture system could offer a promising approach for repairing hypoxia and H/R-injured cells or tissue by providing safe and stable O₂.

Bone implantation surgery is often accompanied by bacterial infection, resulting in infectious bone non-union, pathological fracture and other serious consequences, which will aggravate the pain of patients. A non-antibiotic coating consisting of sodium dodecyl sulphate (SDS) and levulinic acid (LA) with different concentrations was prepared by the authors on the zinc–aluminium alloy (ZA6-1) using a wet chemistry treatment for orthopaedic application. The influence of SDS/LA concentrations on the surface morphology, composition and performance of the developed coating was investigated. The results showed that as-prepared coating on a zinc alloy surface could improve the substrate's corrosion resistance and increase the degradation rate from 0.82 to 19.70 μm/year upon raising the SDS/LA concentration. Furthermore, higher hydrophilicity (<14°), better cell proliferation (>100%) and morphology, as well as good cell adhesion and differentiation (ALP >95% for 7 days) were observed on coated zinc alloys. The increased SDS/LA concentration slightly weakens the biocompatibility and enhances the antibacterial performance of coated zinc alloys due to the synergistic effect of SDS/LA. Overall, the coating comprising 6 wt.% SDS and 9 wt.% LA showed excellent antibacterial action with a high level of biocompatibility, confirming its potential application for orthopaedic implants.

For high-speed moving objects, drag reduction has been a prolonged major challenge. To address this problem, passive and negative strategies have been proposed in the preceding decades. The integration of creatures and nature has been continuously perfected during biological evolution. Unique structure characteristics, material properties, and special functions of marine organisms can provide inexhaustible inspirations to solve this intractable problem of drag reduction. Therefore, a simple and low-cost laser ablation method was proposed. A multi-scale and multi-level riblet (MSLR) surface inspired by the denticles of the sharkskin was fabricated by controlling the density of the laser path and ablation times. The morphology and topographic features were characterised using an electron microscope and a scanning white-light interfering profilometer. Then, the drag reduction capacity of the bionic riblet surface was measured in a circulating water tunnel. Finally, the mechanism of drag reduction was analysed by the computational fluid dynamics (CFD) method. The results show that the MSLR surface has a stable drag reduction capacity with an increase in Reynold (Re) number which was contributed by high-low velocity stripes formed on the MSLR surface. This study can provide a reference for fabricating spatial riblets with efficient drag reduction at different values of Re and improving marine antifouling.

Harmful components in cigarette smoke, such as nicotine, tar, and organic particulate matter, are the primary culprits behind lung diseases. While conventional filter materials based on cellulose, carbon, and molecular sieves exhibit commendable filtration capabilities, their high cost restricts their widespread applications. Based on this, the authors aim to prepare PET-based filter materials with good adsorption properties through a simple surface functionalisation strategy. The adsorption performance of the PET-based non-woven fabric was enhanced by the introduction of sodium alginate (SA). The gas adsorption experiments results reveal that SA-modified PET (SA-PET) exhibits significantly improved filtration efficiency for nicotine, tar, and total particulate matter—increasing by 27.1%, 26.2%, and 21.3%, respectively. Moreover, SA-PET exhibits more odour control ability than traditional activated carbon-based filter materials. These results prove that surface-functionalised SA-PET has better filtration performance for harmful substances in smoke and provides a new strategy for the design of high-performance filtration materials.