Preparation of oleylethylene glycol-sreptavidin surfaces for SPR v2

Surface plasmon resonance uses gold surfaces for sensing. Manufacturers provide a range of pre-functionalised surfaces, but these are often prone to non-specific binding problems. In other surface science sensing techniques a range of surface functionalisation approaches have been described. Here, the preparation of a self-assembled monolayer (SAM) of a thiolated oleyl ethylene glycol, incorporating a defined mole % of biotinylated ligands , on a gold surface is described. This allows the formation of a streptavidin layer on the SAM with control over the average surface coverage of streptavidin. Biotinylated ligands can then be immobilised on the streptavidin. Such surfaces have proved to be very resistant to non-specific binding and they are easily implemented on the sensor surfaces of commercial (surface plasmon resonance) SPR instruments. This is adapted from a published method: Migliorini, E. et al. Well-defined biomimetic surfaces to characterize glycosaminoglycan-mediated interactions on the molecular, supramolecular and cellular levels. Biomaterials (2014) doi:10.1016/j.biomaterials.2014.07.017.

Closure to Discussion -Fabrication and Testing of Bioinspired Surface Designs for Friction Reduction at the Piston Ring and Liner Interface- [DOI: 10.1115/1.4050795] (2021, ASME J. Tribol., 143(5): 051109)

We thank the discussant for their interest in our manuscript and their very helpful remarks. Existing tribological studies of biomimetic surfaces were mostly focused on dry friction and biological surfaces are highly deformable. Therefore, the learnings on the effects of textures may not be directly translate to fully lubricated interfaces. Nonetheless, we agree that we can still learn much from these studies. Investigating additional orientations of the elongated hexagon could possibly improve the frictional response of the lubricated surfaces. Given that existing literature indicates that orienting the hexagons with two edges perpendicular to the sliding direction yields lower friction than in the case of edges parallel to the sliding direction [1], the experimental conditions in the manuscript could be the worst-case scenario and thus a lower bound for frictional improvement. Additionally, the hexagon was designed based not only on the design of the frog toe (and other natural hexagonal surfaces such as snakes) but also on existing industrial piston cylinder liner designs, where the crossing grooves are oriented nearly perpendicular to the sliding direction [2, 3]. Hence, our tested design is an extension of that existing technology with learning from nature. However, the suggestions to expand the experiment with additional hexagonal orientations is well received and will be considered for future work.

Celebrating the centenary in polymer science: drawing inspiration from nature to develop anti-fouling coatings. The development of biomimetic polymer surfaces and their effect on bacterial fouling

The development of self-cleaning biomimetic surfaces has the potential to be of great benefit to human health, in addition to reducing the economic burden on industries worldwide. Consequently, this study developed a biomimetic wax surface using a moulding technique which emulated the topography of the self-cleaning Gladiolus hybridus (Gladioli) leaf. A comparison of topographies was performed for unmodified wax surfaces (control), biomimetic wax surfaces, and Gladioli leaves using optical profilometry and scanning electron microscopy. The results demonstrated that the biomimetic wax surface and Gladioli leaf had extremely similar surface roughness parameters, but the water contact angle of the Gladioli leaf was significantly higher than the replicated biomimetic surface. The self-cleaning properties of the biomimetic and control surfaces were compared by measuring their propensity to repel Escherichia coli and Listeria monocytogenes attachment, adhesion, and retention in mono- and co-culture conditions. When the bacterial assays were carried out in monoculture, the biomimetic surfaces retained fewer bacteria than the control surfaces. However, when using co-cultures of the bacterial species, only following the retention assays were the bacterial numbers reduced on the biomimetic surfaces. The results demonstrate that such surfaces may be effective in reducing biofouling if used in the appropriate medical, marine, and industrial scenarios. This study provides valuable insight into the antifouling physical and chemical control mechanisms found in plants, which are particularly appealing for engineering purposes.

Mineralization of Titanium Surfaces: Biomimetic Implants

The surface modification by the formation of apatitic compounds, such as hydroxyapatite, improves biological fixation implants at an early stage after implantation. The structure, which is identical to mineral content of human bone, has the potential to be osteoinductive and/or osteoconductive materials. These calcium phosphates provoke the action of the cell signals that interact with the surface after implantation in order to quickly regenerate bone in contact with dental implants with mineral coating. A new generation of calcium phosphate coatings applied on the titanium surfaces of dental implants using laser, plasma-sprayed, laser-ablation, or electrochemical deposition processes produces that response. However, these modifications produce failures and bad responses in long-term behavior. Calcium phosphates films result in heterogeneous degradation due to the lack of crystallinity of the phosphates with a fast dissolution; conversely, the film presents cracks, which produce fractures in the coating. New thermochemical treatments have been developed to obtain biomimetic surfaces with calcium phosphate compounds that overcome the aforementioned problems. Among them, the chemical modification using biomineralization treatments has been extended to other materials, including composites, bioceramics, biopolymers, peptides, organic molecules, and other metallic materials, showing the potential for growing a calcium phosphate layer under biomimetic conditions.

Gaseous Plastron on Natural and Biomimetic Surfaces for Resisting Marine Biofouling

In recent years, various biomimetic materials capable of forming gaseous plastron on their surfaces have been fabricated and widely used in various disciplines and fields. In particular, on submerged surfaces, gaseous plastron has been widely studied for antifouling applications due to its ecological and economic advantages. Gaseous plastron can be formed on the surfaces of various natural living things, including plants, insects, and animals. Gaseous plastron has shown inherent anti-biofouling properties, which has inspired the development of novel theories and strategies toward resisting biofouling formation on different surfaces. In this review, we focused on the research progress of gaseous plastron and its antifouling applications.

Recent Advances in Biomimetic Surfaces Inspired by Creatures for Fog Harvesting

The shortage of water resource is more serious and attract widespread attention all over the world. After years of evolution and natural selection, through interacting with natural environment, creatures have...