SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Bionics

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Hydrogel microfish featuring biomimetic structures, locomotive capabilities, and functionalized nanoparticles are engineered using a rapid 3D printing platform: microscale continuous -optical printing (μCOP). The 3D-printed -microfish exhibit chemically powered and magnetically guided propulsion, as well as highly efficient detoxification capabilities that highlight the technical versatility of this platform for engineering advanced functional microswimmers for diverse biomedical applications.

Concepts: Inkjet printer, Mathematics, Rail transport, Application software, Physics, Biomedical engineering, Bionics, Engineering

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Bioinspiration, biomorphy, biomimicry, biomimetics, bionics, and biotemplating are terms used to describe the fabrication of materials or, more generally, systems to solve technological problems by abstracting, emulating, using, or transferring structures from biological paradigms. Herein, a brief overview of how the different terminologies are being typically applied is provided. It is proposed that there is a rich field of research that can be expanded by utilizing various novel approaches for the guidance of living organisms for “bio-mediated” material structuring purposes. As examples of contact-based or contact-free guidance, such as substrate patterning, the application of light, magnetic fields, or chemical gradients, potentially interesting methods of creating hierarchically structured monolithic engineering materials, using live patterned biomass, biofilms, or extracellular substances as scaffolds, are presented. The potential advantages of such materials are discussed, and examples of live self-patterning of materials are given.

Concepts: Chemical substance, Problem solving, Biology, Biomimicry, Structure, Materials science, Bionics, Engineering

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Epicolactone is a recently isolated fungal metabolite that is highly complex for its size, and yet racemic. With its array of quaternary stereocentres, high degree of functionalization and intricate polycyclic structure, it poses a considerable challenge to synthesis, a challenge that can be met by understanding its biosynthetic origin. If drawn in a certain way, epicolactone reveals a pattern that resembles purpurogallin, the archetype of ubiquitous natural colourants formed via oxidative dimerization. Based on this insight, we designed a biomimetic synthesis of epicolactone that proceeds in only eight steps from vanillyl alcohol. We have isolated a key intermediate that supports our biosynthetic hypothesis and anticipate that an isomer of epicolactone stemming from our synthetic efforts could also be found as a natural product.

Concepts: Bionics, Metabolism, Cell cycle, Engineering, Enzyme

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One of the major challenges in orthopedics is to develop implants that overcome current postoperative problems such as osteointegration, proper load bearing, and stress shielding. Current implant techniques such as allografts or endoprostheses never reach full bone integration, and the risk of fracture due to stress shielding is a major concern. To overcome this, a novel technique of reverse engineering to create artificial scaffolds was designed and tested. The purpose of the study is to create a new generation of implants that are both biocompatible and biomimetic.

Concepts: Bionics, Major, Design, Reverse engineering, Implants, Dental implant, Orthopedic surgery, Engineering

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Three-dimensional (3D) cell-printing has been emerging as a promising technology with which to build up human skin models by enabling rapid and versatile design. Despite the technological advances, challenges remain in the development of fully functional models that recapitulate complexities in the native tissue. Moreover, although several approaches have been explored for the development of biomimetic human skin models, the present skin models based on multistep fabrication methods using polydimethylsiloxane chips and commercial transwell inserts could be tackled by leveraging 3D cell-printing technology. In this paper, we present a new 3D cell-printing strategy for engineering a 3D human skin model with a functional transwell system in a single-step process. A hybrid 3D cell-printing system was developed, allowing for the use of extrusion and inkjet modules at the same time. We began by revealing the significance of each module in engineering human skin models; by using the extrusion-dispensing module, we engineered a collagen-based construct with polycaprolactone (PCL) mesh that prevented the contraction of collagen during tissue maturation; the inkjet-based dispensing module was used to uniformly distribute keratinocytes. Taking these features together, we engineered a human skin model with a functional transwell system; the transwell system and fibroblast-populated dermis were consecutively fabricated by using the extrusion modules. Following this process, keratinocytes were uniformly distributed onto the engineered dermis by the inkjet module. Our transwell system indicates a supportive 3D construct composed of PCL, enabling the maturation of a skin model without the aid of commercial transwell inserts. This skin model revealed favorable biological characteristics that included a stabilized fibroblast-stretched dermis and stratified epidermis layers after 14 days. It was also observed that a 50 times reduction in cost was achieved and 10 times less medium was used than in a conventional culture. Collectively, because this single-step process opens up chances for versatile designs, we envision that our cell-printing strategy could provide an attractive platform in engineering various human skin models.

Concepts: Dermis, Physics, Bionics, Time, Engineering, Technology, Epidermis, Skin

1

We introduce our active experts' communications and reviews (Part II) of 2015 Korea-China Joint Symposium on Biomimetic Medical Materials in Republic of Korea, which reflect their perspectives on current research trends of biomimetic medical materials for tissue regeneration in both Korea and China. The communications covered three topics of biomimetics, i.e., 1) hydrogel for therapeutics and extracellular matrix environments, 2) design of electrical polymers for communications between electrical sources and biological systems and 3) design of biomaterials for nerve tissue engineering. The reviews in the Part II will cover biomimetics of 3D bioprinting materials, surface modifications, nano/micro-technology as well as clinical aspects of biomaterials for cartilage.

Concepts: Cellular differentiation, Materials science, Bionics, Tissue engineering, Republic of China, Engineering, Medicine, Extracellular matrix

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The tetracyclic carbon skeleton of hainanolidol and harringtonolide was efficiently constructed by an intramolecular oxidopyrylium-based [5 + 2] cycloaddition. An anionic ring-opening strategy was developed for the cleavage of the ether bridge in 8-oxabicyclo[3.2.1]octenes derived from the [5 + 2] cycloaddition. Conversion of cycloheptadiene to tropone was realized by a sequential [4 + 2] cycloaddition, Kornblum-DeLaMare rearrangement, and double elimination. The biomimetic synthesis of harringtonolide from hainanolidol was also confirmed.

Concepts: Bionics, Total synthesis

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Adaptive tendril coiling of climbing plants has long inspired the artificial soft microsystem for actuation and morphing. The current bionic research efforts on tendril coiling focus on either the preparation of materials with the coiling geometry, or the design of self-shaping materials. However, the realization of two key functional features of the tendril, the spring-like buffering connection and the axial contraction, remains elusive. Herein, we devise a conductive tendril by fusing conductive yarns into tendril configuration, bypassing the prevailing conductivity constraints and mechanical limitations. The conductive tendril not only inherits an electrophysiology buffering mechanics with exceptional conductance retention ability against extreme stretching, but also exhibits excellent contractive actuation performance. The integrative design of the ultraelastic conductive tendril shows a combination of compliant mobility, actuation and sensory capabilities. Such smart biomimetic material holds great prospects in the fields of ultrastretchable electronics, artificial muscles, and wearable bioelectronic therapeutics.

Concepts: The Bionic Woman, Bionic, Electricity, Material, Field, Cybernetics, Bionics, Engineering

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Owing to low bearing capacity and efficiency, traditional filters or adsorbents for removal of contaminants like crystal violet (CV) dye required frequent replacement. Besides, the combination of three-dimensional (3D) printing and bionics could break the constraints of traditional configuration. In this study, a novel depth-type hybrid polylactic acid (PLA)@graphene oxide (GO)/chitosan (CS) sponge filter with bionic fish-mouth structure was prepared and fabricated, assisted by 3D printing and double freeze-drying technology, according to the theories of vertical cross-step filtration and swirling flow. And GO/CS sponge and its filtering device were characterized by FITR, SEM, water adsorption and so on. Moreover, it was explained that the impact factors on dye removal mechanism, like GO content (or CS content), contact time, pH, temperature and bionic configuration. As a result, the bionic 3D filtering device demonstrated excellent removal efficiency (97.8±0.5% for CV) and GO/CS sponge exhibited higher strength (74.5±3.5MPa) at the condition of GO content of 9wt%, contact time of 46min, pH of 8 and 35°C, respectively. Therefore, the resulting 3D PLA@GO/CS sponge bionic filter via gravity and vortex driving provided new alternatives for effectively dye-water separation, and it showed great promise for application of biological macromolecules in adsorption.

Concepts: Acid, Bionic, Engineering, Bionics, Polylactic acid, Lactic acid, Filter, Filters

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Biomimetic synthesis of artificial enamel is a promising strategy for the prevention and restoration of defective enamel. We have recently reported that a hydrogel system composed of chitosan-amelogenin (CS-AMEL) and calcium phosphate is effective in forming an enamel-like layer that has a seamless interface with natural tooth surfaces. Here, to improve the mechanical system function and to facilitate the biomimetic enamel regrowth, matrix metalloproteinase-20 (MMP-20) was introduced into the CS-AMEL hydrogel. Inspired by our recent finding that MMP-20 prevents protein occlusion inside enamel crystals, we hypothesized that addition of MMP-20 to CS-AMEL hydrogel could reinforce the newly grown layer. Recombinant human MMP-20 was added to the CS-AMEL hydrogel to cleave full-length amelogenin during the growth of enamel-like crystals on an etched enamel surface. The MMP-20 proteolysis of amelogenin was studied, and the morphology, composition, and mechanical properties of the newly grown layer were characterized. We found that amelogenin was gradually degraded by MMP-20 in the presence of chitosan. The newly grown crystals in the sample treated with MMP-20-CS-AMEL hydrogel showed more uniform orientation and greater crystallinity than the samples treated with CS-AMEL hydrogel without MMP-20. Stepwise processing of amelogenin by MMP-20 in the CS-AMEL hydrogel prevented undesirable protein occlusion within the newly formed crystals. As a result, both the modulus and hardness of the repaired enamel were significantly increased (1.8- and 2.4-fold, respectively) by the MMP-20-CS-AMEL hydrogel. Although future work is needed to further incorporate other enamel matrix proteins into the system, this study brings us one step closer to biomimetic enamel regrowth.

Concepts: Mechanical engineering, Crystal, Protein, Surface, Bionics, Engineering, Teeth, Tooth enamel