Use Of Biomimetic Approaches Research Articles

The Fractal Approach in the Biomimetic Urban Design: Le Corbusier and Patrick Schumacher

Biomimetic design process approaches have been emphasized systematically as a result of works among disciplines of current technology and biological science. In order to find solutions for a decrease in biodiversity, pollution, and issues of the ecosystem, the nature experience shows itself in areas of biomimetic products, architecture, and urban designs in which nature-focused invasions are basically being imitated. Nature-focused designs have set their own framework by examining forms of different nature dynamics (scale, function, formation process) by presenting a sustainable environment. It can be seen that designs are made real by adhering to the resolution of forms, understanding, and interpretation of nature and by embracing fractal designs with the effort of creating a sustainable environment. In this study, emphasis was placed on revealed nature-based design approaches. The article addresses biomimetic design processes, reveals the role of fractal parameters in the design process, and examines the use of biomimetic approaches. By drawing attention to the importance of studying and understanding these internal dynamics, the contribution of natural inspiration and fractal concepts to the design process is examined. We examine research related to the concept of biomimetics, creation/development of conceptual proposals, and analysis of the established theoretical proposal through selected urban design examples in order to determine the respective overlaps between these areas. Our study takes the form of an analysis of the formal organization of living things together with a formal analysis focusing on the design principles. We try to analyze the design principles and the changes in the principles, and discuss the resulting data within the framework of these concepts. The urban designs of Le Corbusier and Patrick Schumacher, who are important names of the 20th century, were examined in line with the findings obtained in terms of biomimesis levels, namely, the organism level, behavior level, ecosystem level, and functional level. Comparisons of urban design approaches are made using the meta-analysis method with respect to findings obtained as a result of an examination of the golden ratio, modular system, fractal, and parameter concepts of urban design. For this reason, when the fractal concept, which is one of the dynamics of biomimetic-oriented nature, is handled with biomimetic levels and its contribution to the design processes is investigated, we are able to determine that it has important parameters in terms of sustainability. This study aims to contribute to the field of industrial products and urban design disciplines in architectural design.

Production of high molecular-ordered stilbene oligomers for the study of their biological activity: total synthesis, bio-catalyzed synthesis and production by plant systems.

Though the iconic stilbene resveratrol and its related dimers constitute a top storyline in the field of natural product research, resveratrol oligomers (condensation >2) have been left aside despite their higher biological activity compared to that of the monomers. This situation largely results from the difficulty of getting them in sufficient quantities to enable evaluation of their biological properties in vivo. We present here a synthetic and critical analysis of the methods used for the production of high molecular-ordered stilbene oligomers of potential biomedical interest, gathering the most salient data regarding the approaches employed to prepare them by total synthesis, use of biomimetic approaches or through plant systems.

BIOMIMETIC APPROACHES TO STUDY OF PROPERTIES OF MEDICINAL SUBSTANCES

The review is devoted to an assessment of the current level of use of biomimetic approaches to the study of the properties of known drugs and the development of new drugs. In this review, we consider the main biological functions of superoxide dismutase, namely the catalytic decomposition of toxic superoxide anion of oxygen to the molecular form of oxygen and protection against induced apoptosis. The biomimetic enzymes-Mn- and TEMPO-containing equivalents of superoxide dismutase SOD with antitumor and antioxidant activity were discussed more detail. The relationship between the properties and activity of SOD mimetics with their structure among them the nature of the anion and ligands, the coordination number, the geometry of the presence of conjugated bonds, and other parameters of the molecules. The study of the properties of Mn-SOD mimetics makes it possible to develop a new class of drugs successfully tested by in vivo and in vitro experiments and which are at the stages of clinical trials. Stable TEMPO radicals containing compounds are able to perform SOD functions, exhibiting antioxidant activity in relation not only to superoxide-anion, but also to peroxynitrile, and moreover to act as a spin label. The biomimetic membrane systems (monolayers, planar lipid bilayers, liposomes and other nano-sized objects) are discussed too for studying properties in in vitro experiments and for delivering potent and medicinal substances. The biomimetic approach combination allows to create the new promising drugs, including those based on SOD mimetics, and to develop the synthetic analogues of biologically active substances and methods of their delivery. The advantages of such dosage forms are lower toxicity of the preparations, lack of immunogenicity and a decrease in the dose of potent drugs.

Supramolecular Self-Assembly in a Sub-micrometer Electrodic Cavity: Fabrication of Heat-Reversible π-Gel Memristor.

The use of biomimetic approaches toward the production of nonsolid yet functional architectures holds potential for the emergence of novel device concepts. Gels, in particular those obtained via self-assembly of π-conjugated molecules, are dynamic materials possessing unique (opto)electronic properties. Their adaptive nature imparts unprecedented responsivity to various stimuli. Hitherto, a viable device platform to electrically probe in situ a sol-gel transition is still lacking. Here we describe the fabrication of a sub-micrometer electrodic cavity, which enables low-voltage electrical operation of π-gels. Thanks to the in situ supramolecular self-assembly of the π-gelator occurring within the cavity, we conceived a novel gel-based memristor whose sol-gel transition is reversible and can be controlled via heating and dc bias. This work opens perspectives toward the fabrication of a novel generation of nonsolid multiresponsive devices.

Silica morphogenesis by lysine-leucine peptides with hydrophobic periodicity.

The use of biomimetic approaches in the production of inorganic nanostructures is of great interest to the scientific and industrial community due to the relatively moderate physical conditions needed. In this vein, taking cues from silaffin proteins used by unicellular diatoms, several studies have identified peptide candidates for the production of silica nanostructures. In the current article, we study intensively one such silica-precipitating peptide, LKα14 (Ac-LKKLLKLLKKLLKL-c), an amphiphilic lysine/leucine repeat peptide that self-organizes into an α-helical secondary structure under appropriate concentration and buffer conditions. The suggested mechanism of precipitation is that the sequestration of hydrophilic lysines on one side of this helix allows interaction with the negatively charged surface of silica nanoparticles, which in turn can aggregate further into larger structures. To investigate the process, we carry out 1D and 2D solid-state NMR (ssNMR) studies on samples with one or two uniformly (13)C- and (15)N-labeled residues to determine the backbone and side-chain chemical shifts. We also further study the dynamics of two leucine residues in the sequence through (13)C spin-lattice relaxation times (T1) to determine the impact of silica coprecipitation on their mobility. Our results confirm the α-helical secondary structure in both the neat and silica-complexed states of the peptide, and the patterns of chemical shift and relaxation time changes between the two states suggest possible mechanisms of self-aggregation and silica precipitation.

Enzyme encapsulation in silica particles prepared using enzyme-assisted sol-gel reactions in ionic liquids

Several studies have demonstrated the use of biomimetic approaches in the synthesis of a variety of inorganic materials. In this study, a low-temperature and natural pH procedure for the synthesis of silica was developed using hydrolytic enzymes. For the preparation of silica particles at room temperature and pH 7, a screening test for enzyme-catalyzing direct hydrolysis and polycondensation of tetraethoxysilane by using 5 types of hydrolases; pepsin, trypsin, esterase, and two lipases were chosen as biocatalysts; moreover, these enzymes can promote the precipitation of silica within 3 days. The 29Si nuclear magnetic resonance (NMR) measurements indicated that the enzyme activity in ionic liquids was higher than that in aqueous buffer solutions, and that the obtained silica particles were highly polycondensed. Under ionic liquid conditions, it was observed that enzymes were effectively encapsulated in the sol–gel silica material. In addition, for siloxane bond formation the catalytic activity of silica–enzyme composites was higher than that of free solution enzymes.

Controlling Cell Behavior Through the Design of Polymer Surfaces

Polymers have gained a remarkable place in the biomedical field as materials for the fabrication of various devices and for tissue engineering applications. The initial acceptance or rejection of an implantable device is dictated by the crosstalk of the material surface with the bioentities present in the physiological environment. Advances in microfabrication and nanotechnology offer new tools to investigate the complex signaling cascade induced by the components of the extracellular matrix and consequently allow cellular responses to be tailored through the mimicking of some elements of the signaling paths. Patterning methods and selective chemical modification schemes at different length scales can provide biocompatible surfaces that control cellular interactions on the micrometer and sub-micrometer scales on which cells are organized. In this review, the potential of chemically and topographically structured micro- and nanopolymer surfaces are discussed in hopes of a better understanding of cell-biomaterial interactions, including the recent use of biomimetic approaches or stimuli-responsive macromolecules. Additionally, the focus will be on how the knowledge obtained using these surfaces can be incorporated to design biocompatible materials for various biomedical applications, such as tissue engineering, implants, cell-based biosensors, diagnostic systems, and basic cell biology. The review focusses on the research carried out during the last decade.

Materials from Renewable Resources

AbstractThe drive for greater use of renewable materials is one that has recently gained momentum due to the need to rely less heavily on petroleum. These renewable materials are defined as such since they are derived from plant-based sources. Some renewable materials also offer properties that conventional materials cannot provide: hierarchical structure, environmental compatibility, low thermal expansion, and the ability to be modified chemically to suit custom-made applications. Nature's materials, particularly from plant- and animal-based polysaccharides and proteins, have hierarchical structures, and these structures can be utilized for conventional applications via biomimetic approaches. This issue begins with an article covering renewable polymers or plastics that can be used to generate block copolymers (where two polymers with specific functions are combined) as an alternative to conventional materials. Applications of renewable polymers, such as cellulose from plants, bacteria, and animal sources, are also covered. Also presented are the use of bacterial cellulose and other plant-based nanofibers for transparent electronic display screens and, in a wider sense, the use of cellulose nanofibers for composite materials, where renewable resources are required to generate larger amounts of material. Finally, this issue shows the use of biomimetic approaches to take the multifunctional properties of renewable materials and use these concepts, or the materials themselves, in conventional materials applications.

Polypeptide-Templated Synthesis of Hexagonal Silica Platelets

Several studies have demonstrated the use of biomimetic approaches in the synthesis of a variety of inorganic materials. Poly-L-lysine (PLL) promotes the precipitation of silica from a silicic acid solution within minutes. The molecular weight of PLL was found to affect the morphology of the resulting silica precipitate. Larger-molecular weight PLL produced hexagonal silica platelets, whereas spherical silica particles were obtained using low-molecular weight PLL. Here we report on the polypeptide secondary-structure transition that occurs during the silicification reaction. The formation of the hexagonal silica platelets is attributed to the PLL helical chains that are formed in the presence of monosilicic acid and phosphate ions. Hexagonal PLL crystals can also serve as templates in directing the growth of the silica in a manner that generates a largely mesoporous silica phase that is oriented with respect to the protein crystal template.