Biomimetics, Volume 3, Issue 2 (June 2018) – 9 articles

Targeted delivery of chemotherapeutics in order to overcome side effects and enhance chemosensitivity remains a major issue in cancer research. In this context, biocompatible oil-in-water (O/W) microemulsions were developed as matrices for the encapsulation of DPS-2 a benzothiophene analogue, exhibiting high cytotoxicity in various cancer cell lines, among them the MW 164 skin melanoma and Caco-2 human epithelial colorectal adenocarcinoma cell lines. The microemulsion delivery system was structurally characterized by dynamic light scattering (DLS) and electron paramagnetic resonance (EPR) spectroscopy. The effective release of a lipophilic encapsulated compound was evaluated via confocal microscopy. The cytotoxic effect, in the presence and absence of DPS-2, was examined through the thiazolyl blue tetrazolium bromide (MTT) cell proliferation assay. When encapsulated, DPS-2 was as cytotoxic as when dissolved in dimethyl sulfoxide (DMSO). Hence, the oil cores of O/W microemulsions were proven effective biocompatible carriers of lipophilic bioactive molecules in biological assessment experiments. Further investigation through fluorescence-activated cell sorting (FACS) analysis, comet assay, and Western blotting, revealed that DPS-2, although non-genotoxic, induced S phase delay accompanied by cdc25A degradation and a nonapoptotic cell death in both cell lines, which implies that this benzothiophene analogue is a deoxyribonucleic acid (DNA) replication inhibitor. Full article

Locomotion of walking insects is exceptionally efficient. The function of their leg joints in different movement scenarios depends on their kinematics and contacting conditions between moving parts. The kinematics was previously studied in some insects, but contact mechanics within the joints remains largely unknown. In order to understand the complex topology of the contacting surfaces of the leg joints in the Congo rose beetle Pachnoda marginata peregrina (Scarabaeidae, Cetoniinae), we have investigated the shape, the waviness, and the roughness of the joint base and its counter body by applying confocal laser scanning microscopy and white light interferometry. Additionally, we performed nanoindentation tests on the contacting joint surfaces, in order to analyze material properties (elasticity modulus and hardness) of the joint cuticle. We found two topological design principles of the contact surfaces that might be considered as adaptations for reducing frictional drag during leg movements. First, the contact pairs of all leg joints studied consist of convex and concave counterparts. Second, there is a smooth and a rough surface in contact in which microprotuberances are present on the rough surface. These principles might be potentially interesting for technical implications, to design bioinspired joints with both reduced friction and wear rate. Full article

Living Light is a biennial conference focused on all aspects of light–matter interaction in biological organisms with a broad, interdisciplinary outlook. The 2018 edition was held at the Møller Centre in Cambridge, UK, from April 11th to April 14th, 2018. Living Light’s main goal is to bring together researchers from different backgrounds (e.g., biologists, physicists and engineers) in order to discuss the current state of the field and sparkle new collaborations and new interdisciplinary projects. With over 90 national and international attendees, the 2018 edition of the conference was strongly multidisciplinary: oral and poster presentations encompassed a wide range of topics ranging from the evolution and development of structural colors in living organisms and their genetic manipulation to the study of fossil photonic structures. Full article

Next Generation is a series of interviews with the awardees of the Biomimetics Travel Awards aimed at supporting early-career researchers and helping them promote their work. Sébastien R. Mouchet is a postdoctoral fellow in the Natural Photonics group led by Prof. Pete Vukusic at the University of Exeter, UK, working in collaboration with his former Ph.D. supervisor, Prof. Olivier Deparis, at the University of Namur, Belgium. His research focuses on fluorescence emission and coloration changes in photonic structures of insects induced by contact with fluids aiming to develop bioinspired technological solutions for chemical sensing and biosensing. Full article

Ille C. Gebeshuber is Professor of Physics at the Institute of Applied Physics at the Vienna University of Technology, Austria, where she graduated and completed her Ph.D. on technical biophysics of the inner ear in 1998. In 1999, she undertook postdoctoral training in scanning probe microscopy and biomimetics at the University of California, Santa Barbara, CA, USA, and soon after she returned to Austria to her home university to work on ion surface interactions, tribology and (bio-)nanotechnology. From 2009 to 2015, she joined the Institute of Microengineering and Nanoelectronics at the National University of Malaysia. During her expeditions, together with her students from cultural diverse backgrounds and expertise, she learned from the rainforest how nature develops well-adapted structures and materials, inspiring her to apply these principles to solve technological problems for humans to face global challenges in a safe and sustainable way. Her research focuses on nanotechnology and biomimetics, and takes a multidisciplinary approach, from biology and engineering to the fine arts and the social sciences. In 2017, she was elected Austrian of the Year in the “Research” category. We asked Ille about her career, her thoughts about the potential of biomimetic nanotechnology, and her experience during her editorship with Biomimetics. Full article

Several flora and fauna species found in arid areas have adapted themselves to collect water by developing unique structures and to intake the collected moisture. Apart from the capture of the moisture and fog on the surface, water transport and collection both play an important part in fog-harvesting systems as it prevents the loss of captured water through evaporation and makes the surface available for the capture of water again. Here, we report the remarkable fog collection and water-channeling properties of Dryopteris marginata. The surface of D. marginata has developed an integrated system of multiscale channels so that the water spreads quickly and is transported via these channels very efficiently. These integrated multiscale channels have also been replicated using a facile soft lithography technique to prepare biomimetic surfaces and it has been proved that it is the surface architecture that plays a role in the water transport rather than the material’s properties (waxes present on the surface of the leaves). Based on our studies, we infer that the microlevel hierarchy of the structures make the surface hydrophilic and the multiscale channels allow the efficient passage and transport of water. The understanding of the efficient and well-directed water transport and collection in D. marginata is expected to provide valuable insights to design efficient surfaces for fog-harvesting applications. Full article

Among the different species of flower beetles, there is one of particular notoriety: the Goliath beetle. This large insect can grow up to 11 cm long and is well-known for its distinctive black and white shield. In this paper, we focus on a particular Goliathus species: G. orientalis (Moser, 1909). We investigated the variations in properties of both the black and white parts of the upper face of G. orientalis; more precisely, the variation in surface properties with respect to the wettability of these two parts. This work reveals that the white parts of the shield have a higher hydrophobic character when compared to the black regions. While the black parts are slightly hydrophobic (θ = 91 ± 5°) and relatively smooth, the white parts are highly hydrophobic (θ = 130 ± 3°) with strong water adhesion (parahydrophobic); similar to the behavior observed for rose petals. Roughness and morphology analyses revealed significant differences between the two parts, and, hence, may explain the change in wettability. The white surfaces are covered with horizontally aligned nanohairs. Interestingly, vertically aligned microhairs are also present on the white surface. Furthermore, the surfaces of the microhairs are not smooth, they contain nanogrooves that are qualitatively similar to those observed in cactus spines. The nanogrooves may have an extremely important function regarding water harvesting, as they preferentially direct the migration of water droplets; this process could be mimicked in the future to capture and guide a large volume of water. Full article

The aquatic unicellular organism Paramecium caudatum uses cilia to swim around its environment and to graze on food particles and bacteria. Paramecia use waves of ciliary beating for locomotion, intake of food particles and sensing. There is some evidence that Paramecia pre-sort food particles by discarding larger particles, but intake the particles matching their mouth cavity. Most prior attempts to mimic cilia-based manipulation merely mimicked the overall action rather than the beating of cilia. The majority of massive-parallel actuators are controlled by a central computer; however, a distributed control would be far more true-to-life. We propose and test a distributed parallel cilia platform where each actuating unit is autonomous, yet exchanging information with its closest neighboring units. The units are arranged in a hexagonal array. Each unit is a tileable circuit board, with a microprocessor, color-based object sensor and servo-actuated biomimetic cilia actuator. Localized synchronous communication between cilia allowed for the emergence of coordinated action, moving different colored objects together. The coordinated beating action was capable of moving objects up to 4 cm/s at its highest beating frequency; however, objects were moved at a speed proportional to the beat frequency. Using the local communication, we were able to detect the shape of objects and rotating an object using edge detection was performed; however, lateral manipulation using shape information was unsuccessful. Full article