Can Stabilization and Inhibition of Aquaporins Contribute to Future Development of Biomimetic Membranes?

Science.gov (United States)

To, Janet; Torres, Jaume

2015-08-10

In recent years, the use of biomimetic membranes that incorporate membrane proteins, i.e., biomimetic-hybrid membranes, has increased almost exponentially. Key membrane proteins in these systems have been aquaporins, which selectively permeabilize cellular membranes to water. Aquaporins may be incorporated into synthetic lipid bilayers or to more stable structures made of block copolymers or solid-state nanopores. However, translocation of aquaporins to these alien environments has adverse consequences in terms of performance and stability. Aquaporins incorporated in biomimetic membranes for use in water purification and desalination should also withstand the harsh environment that may prevail in these conditions, such as high pressure, and presence of salt or other chemicals. In this respect, modified aquaporins that can be adapted to these new environments should be developed. Another challenge is that biomimetic membranes that incorporate high densities of aquaporin should be defect-free, and this can only be efficiently ascertained with the availability of completely inactive mutants that behave otherwise like the wild type aquaporin, or with effective non-toxic water channel inhibitors that are so far inexistent. In this review, we describe approaches that can potentially be used to overcome these challenges.

Can Stabilization and Inhibition of Aquaporins Contribute to Future Development of Biomimetic Membranes?

Directory of Open Access Journals (Sweden)

Janet To

2015-08-01

Full Text Available In recent years, the use of biomimetic membranes that incorporate membrane proteins, i.e., biomimetic-hybrid membranes, has increased almost exponentially. Key membrane proteins in these systems have been aquaporins, which selectively permeabilize cellular membranes to water. Aquaporins may be incorporated into synthetic lipid bilayers or to more stable structures made of block copolymers or solid-state nanopores. However, translocation of aquaporins to these alien environments has adverse consequences in terms of performance and stability. Aquaporins incorporated in biomimetic membranes for use in water purification and desalination should also withstand the harsh environment that may prevail in these conditions, such as high pressure, and presence of salt or other chemicals. In this respect, modified aquaporins that can be adapted to these new environments should be developed. Another challenge is that biomimetic membranes that incorporate high densities of aquaporin should be defect-free, and this can only be efficiently ascertained with the availability of completely inactive mutants that behave otherwise like the wild type aquaporin, or with effective non-toxic water channel inhibitors that are so far inexistent. In this review, we describe approaches that can potentially be used to overcome these challenges.

Forward osmosis biomimetic membranes in industrial and environmental applications

DEFF Research Database (Denmark)

Bajraktari, Niada; Madsen, Henrik Tækker; Nielsen, K. H.

consumption and lead to much more stable operations, but is currently limited by the availability of suitable membranes. However, by introducing aquaporin protein channels into a polymeric membrane to make a biomimetic membrane, the vision of both high flux and separation efficiency may be achieved......) a single use filtration module containing a sample reservoir and a biomimetic aquaporin based forward osmosis membrane. 2) a multi-use desktop forward osmosis system containing draw solution mixing, and monitoring devices. The sample is placed in the single use module and the module is then mounted...... a simple unit operation based on osmotic extraction of water from dilute peptide samples with no – or very little loss of sample material. A big challenge in modern water treatment is the handling of micropollutants. One example of these is the pollution of ground-/drinking water with pesticides, which...

Biomimetic membranes for sensor and separation applications

DEFF Research Database (Denmark)

Helix Nielsen, Claus

2009-01-01

preventing the passage of others, a property critical for the overall conservation of the cells internal pH and salt concentration. Both ion and water channels are highly efficient membrane pore proteins capable of transporting solutes at very high rates, up to 109 molecules per second. Carrier proteins...... and biomimetic support matrix. Also the stability of the incorporated protein must be addressed and the protein-biomimetic matrix must be encapsulated in order to protect it and make it sufficiently stable in a final application. Here I will review and discuss these challenges and how they are met in some...

Surface Modifications of Support Partitions for Stabilizing Biomimetic Membrane Arrays

DEFF Research Database (Denmark)

Perry, Mark; Hansen, Jesper Schmidt; Jensen, Karin Bagger Stibius

2011-01-01

with a high signal-to-noise (s/n) ratio. We demonstratesd this by reconstituting gA and α-hemolysin (α-HL) into BLM arrays. The improvement in membrane array lifetime and s/n ratio demonstrates that surface plasma polymerization of the supporting partition can be used to increase the stability of biomimetic......Black lipid membrane (BLM) formation across apertures in an ethylene tetra-fluoroethylene (ETFE) partition separating two aqueous compartments is an established technique for the creation of biomimetic membranes. Recently multi-aperture BLM arrays have attracted interest and in order to increase...... BLM array stability we studied the effect of covalently modifying the partition substrate using surface plasma polymerization with hydrophobic n-hexene, 1-decene and hexamethyldisiloxane (HMDSO) as modification groups. Average lifetimes across singlesided HMDSO modified partitions or using 1-decene...

Aquaporin based biomimetic membrane in forward osmosis: Chemical cleaning resistance and practical operation

KAUST Repository

Li, Zhenyu

2017-07-27

Aquaporin plays a promising role in fabricating high performance biomimetic forward osmosis (FO) membranes. However, aquaporin as a protein also has a risk of denaturation caused by various chemicals, resulting in a possible decay of membrane performance. The present study tested a novel aquaporin based biomimetic membrane in simulated membrane cleaning processes. The effects of cleaning agents on water flux and salt rejection were evaluated. The membrane showed a good resistance to the chemical agents. The water flux after chemical cleaning showed significant increases, particularly after cleaning with NaOCl and Alconox. Changes in the membrane structure and increased hydrophilicity in the surrounding areas of the aquaporin may be accountable for the increase in water permeability. The membrane shows stable salt rejection up to 99% after all cleaning agents were tested. A 15-day experiment with secondary wastewater effluent as the feed solution and seawater as the draw solution showed a stable flux and high salt rejection. The average rejection of the dissolved organic carbon from wastewater after the 15-day test was 90%. The results demonstrated that the aquaporin based biomimetic FO membrane exhibits chemical resistance for most agents used in membrane cleaning procedures, maintaining a stable flux and high salt rejection.

Aquaporin based biomimetic membrane in forward osmosis: Chemical cleaning resistance and practical operation

KAUST Repository

Li, Zhenyu; Valladares Linares, Rodrigo; Bucs, Szilard; Fortunato, Luca; Hé lix-Nielsen, Claus; Vrouwenvelder, Johannes S.; Ghaffour, NorEddine; Leiknes, TorOve; Amy, Gary

2017-01-01

Aquaporin plays a promising role in fabricating high performance biomimetic forward osmosis (FO) membranes. However, aquaporin as a protein also has a risk of denaturation caused by various chemicals, resulting in a possible decay of membrane performance. The present study tested a novel aquaporin based biomimetic membrane in simulated membrane cleaning processes. The effects of cleaning agents on water flux and salt rejection were evaluated. The membrane showed a good resistance to the chemical agents. The water flux after chemical cleaning showed significant increases, particularly after cleaning with NaOCl and Alconox. Changes in the membrane structure and increased hydrophilicity in the surrounding areas of the aquaporin may be accountable for the increase in water permeability. The membrane shows stable salt rejection up to 99% after all cleaning agents were tested. A 15-day experiment with secondary wastewater effluent as the feed solution and seawater as the draw solution showed a stable flux and high salt rejection. The average rejection of the dissolved organic carbon from wastewater after the 15-day test was 90%. The results demonstrated that the aquaporin based biomimetic FO membrane exhibits chemical resistance for most agents used in membrane cleaning procedures, maintaining a stable flux and high salt rejection.

Biomimetic Membrane Arrays on Cast Hydrogel Supports

DEFF Research Database (Denmark)

Roerdink-Lander, Monique; Ibragimova, Sania; Rein Hansen, Christian

2011-01-01

, provides mechanical support but at the cost of small molecule transport through the membrane−support sandwich. To stabilize biomimetic membranes while allowing transport through a membrane−support sandwich, we have investigated the feasibility of using an ethylene tetrafluoroethylene (ETFE......)/hydrogel sandwich as the support. The sandwich is realized as a perforated surface-treated ETFE film onto which a hydrogel composite support structure is cast. We report a simple method to prepare arrays of lipid bilayer membranes with low intrinsic electrical conductance on the highly permeable, self......-supporting ETFE/hydrogel sandwiches. We demonstrate how the ETFE/hydrogel sandwich support promotes rapid self-thinning of lipid bilayers suitable for hosting membrane-spanning proteins....

Biomimetic polymeric membranes for water treatment

DEFF Research Database (Denmark)

Habel, Joachim Erich Otto

This project is about the interplay of the three major components of aquaporin based biomimetic polymeric membranes (ABPMs): Aquaporins (AQPs), amphiphilic block copolymers, serving as a vesicular matrix for the hydrophobic AQP exterior (proteopolymersomes) and a polymeric membrane as embedment....... The interplay of proteopolymersomes and polymeric mesh support (in this case polyethersulfone, PES) was examined via integration of proteopolymersomes in an active layer (AL) formed by interfacial polymerisation between a linker molecule in aqueous phase and another in organic phase on top of the PES....... The resulting thin-film composite (TFC) membrane was analyzed via cross-flow forward osmosis (FO), scanning electron microscopy (SEM), fourier-transformed infrared spectroscopy (FTIR), as well as in the non-supported form over FTIR and a specialized microfluidic visualization approach. Where no clear dierences...

Challenges in commercializing biomimetic membranes

DEFF Research Database (Denmark)

Perry, Mark; Madsen, Steen Ulrik; Jørgensen, Tine Elkjær

2015-01-01

category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market—in particular if both...... the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some...... of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments...

Transport of Carbon Dioxide through a Biomimetic Membrane

Directory of Open Access Journals (Sweden)

Efstathios Matsaridis

2011-01-01

Full Text Available Biomimetic membranes (BMM based on polymer filters impregnated with lipids or their analogues are widely applied in numerous areas of physics, biology, and medicine. In this paper we report the design and testing of an electrochemical system, which allows the investigation of CO2 transport through natural membranes such as alveoli barrier membrane system and also can be applied for solid-state measurements. The experimental setup comprises a specially designed two-compartment cell with BMM connected with an electrochemical workstation placed in a Faraday cage, two PH meters, and a nondispersive infrared gas analyzer. We prove, experimentally, that the CO2 transport through the natural membranes under different conditions depends on pH and displays a similar behavior as natural membranes. The influence of different drugs on the CO2 transport process through such membranes is discussed.

Synthesis of robust and high-performance aquaporin-based biomimetic membranes by interfacial polymerization-membrane preparation and RO performance characterization

DEFF Research Database (Denmark)

Zhao, Yang; Qiu, Changquan; Li, Xuesong

2012-01-01

-free ABMs that can be easily scaled up. In the current study, a thin film composite (TFC) ABM was prepared by the interfacial polymerization method, where AquaporinZ-containing proteoliposomes were added to the m-phenylene-diamine aqueous solution. Control membranes, either without aquaporins......Aquaporins are water channel proteins with excellent water permeability and solute rejection, which makes them promising for preparing high-performance biomimetic membranes. Despite the growing interest in aquaporin-based biomimetic membranes (ABMs), it is challenging to produce robust and defect...... or with inactive (mutant) aquaporins, were also similarly prepared. The separation performance of these membranes was evaluated by cross-flow reverse osmosis (RO) tests. Compared to the controls, the active ABM achieved significantly higher water permeability (∼4L/m2hbar) with comparable NaCl rejection (∼97...

Development of supported biomimetic membranes for insertion of aquaporin protein water channels for novel water filtration applications

DEFF Research Database (Denmark)

Hansen, Jesper Søndergaard

). This constitutes a new methodology to correctly and functionally reconstitute membrane proteins in controllable amounts into giant vesicles. The method for formation of giant protein vesicles subsequently led to the first functional prototype of an aquaporin-membrane water filtration device.......Aquaporins represent a class of membrane protein channels found in all living organisms that selectively transport water molecules across biological membranes. The work presented in this thesis was motivated by the conceptual idea of incorporating aquaporin water channels into biomimetic membranes...... to develop novel water separation technologies. To accomplish this, it is necessary to construct an efficient platform to handle biomimetic membranes. Moreover, general methods are required to reliable and controllable reconstitute membrane proteins into artificially made model membranes...

Aquaporin based biomimetic membrane in forward osmosis: Chemical cleaning resistance and practical operation

DEFF Research Database (Denmark)

Li, Zhenyu; Linares, Rodrigo Valladares; Bucs, Szilard

2017-01-01

Aquaporin plays a promising role in fabricating high performance biomimetic forward osmosis (FO) membranes. However, aquaporin as a protein also has a risk of denaturation caused, by various chemicals, resulting in a possible decay of membrane performance. The present study tested a novel aquaporin...

Aquaporin based biomimetic membrane in forward osmosis: Chemical cleaning resistance and practical operation

DEFF Research Database (Denmark)

Li, Zhenyu; Linares, Rodrigo Valladares; Bucs, Szilard

2017-01-01

Aquaporin plays a promising role in fabricating high performance biomimetic forward osmosis (FO) membranes. However, aquaporin as a protein also has a risk of denaturation caused, by various chemicals, resulting in a possible decay of membrane performance. The present study tested a novel aquapor...

Automated sampling and data processing derived from biomimetic membranes

DEFF Research Database (Denmark)

Perry, Mark; Vissing, Thomas; Boesen, P.

2009-01-01

data processing software to analyze and organize the large amounts of data generated. In this work, we developed an automated instrumental voltage clamp solution based on a custom-designed software controller application (the WaveManager), which enables automated on-line voltage clamp data acquisition...... applicable to long-time series experiments. We designed another software program for off-line data processing. The automation of the on-line voltage clamp data acquisition and off-line processing was furthermore integrated with a searchable database (DiscoverySheet (TM)) for efficient data management......Recent advances in biomimetic membrane systems have resulted in an increase in membrane lifetimes from hours to days and months. Long-lived membrane systems demand the development of both new automated monitoring equipment capable of measuring electrophysiological membrane characteristics and new...

Use of biomimetic forward osmosis membrane for trace organics removal

DEFF Research Database (Denmark)

Madsen, Henrik T.; Bajraktari, Niada; Helix Nielsen, Claus

2015-01-01

The use of forward osmosis for the removal of trace organics from water has recently attracted considerable attention as an alternative to traditional pressure driven membrane filtration. However, the existing forward osmosis membranes have been found to be ineffective at rejecting small neutral...... organic pollutants, which limits the applicability of the forward osmosis process. In this study a newly developed biomimetic membrane was tested for the removal of three selected trace organics that can be considered as a bench marking test for a membrane[U+05F3]s ability to reject small neutral organic....... This difference is caused by differences in the transport mechanisms. For the cellulose acetate membrane rejection is controlled by steric hindrance, which results in a size dependent rejection of the trace organics, whereas rejection by the aquaporin membrane is controlled by diffusion of the trace organics...

Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges

Science.gov (United States)

Habel, Joachim; Hansen, Michael; Kynde, Søren; Larsen, Nanna; Midtgaard, Søren Roi; Jensen, Grethe Vestergaard; Bomholt, Julie; Ogbonna, Anayo; Almdal, Kristoffer; Schulz, Alexander; Hélix-Nielsen, Claus

2015-01-01

In recent years, aquaporin biomimetic membranes (ABMs) for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs: aquaporin proteins (AQPs), block copolymers for AQP reconstitution, and polymer-based supporting structures. First, we briefly cover challenges and review recent developments in understanding the interplay between AQP and block copolymers. Second, we review some experimental characterization methods for investigating AQP incorporation including freeze-fracture transmission electron microscopy, fluorescence correlation spectroscopy, stopped-flow light scattering, and small-angle X-ray scattering. Third, we focus on recent efforts in embedding reconstituted AQPs in membrane designs that are based on conventional thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes. PMID:26264033

Automated sampling and data processing derived from biomimetic membranes

International Nuclear Information System (INIS)

Perry, M; Vissing, T; Hansen, J S; Nielsen, C H; Boesen, T P; Emneus, J

2009-01-01

Recent advances in biomimetic membrane systems have resulted in an increase in membrane lifetimes from hours to days and months. Long-lived membrane systems demand the development of both new automated monitoring equipment capable of measuring electrophysiological membrane characteristics and new data processing software to analyze and organize the large amounts of data generated. In this work, we developed an automated instrumental voltage clamp solution based on a custom-designed software controller application (the WaveManager), which enables automated on-line voltage clamp data acquisition applicable to long-time series experiments. We designed another software program for off-line data processing. The automation of the on-line voltage clamp data acquisition and off-line processing was furthermore integrated with a searchable database (DiscoverySheet(TM)) for efficient data management. The combined solution provides a cost efficient and fast way to acquire, process and administrate large amounts of voltage clamp data that may be too laborious and time consuming to handle manually. (communication)

Automated sampling and data processing derived from biomimetic membranes

Energy Technology Data Exchange (ETDEWEB)

Perry, M; Vissing, T; Hansen, J S; Nielsen, C H [Aquaporin A/S, Diplomvej 377, DK-2800 Kgs. Lyngby (Denmark); Boesen, T P [Xefion ApS, Kildegaardsvej 8C, DK-2900 Hellerup (Denmark); Emneus, J, E-mail: Claus.Nielsen@fysik.dtu.d [DTU Nanotech, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

2009-12-15

Recent advances in biomimetic membrane systems have resulted in an increase in membrane lifetimes from hours to days and months. Long-lived membrane systems demand the development of both new automated monitoring equipment capable of measuring electrophysiological membrane characteristics and new data processing software to analyze and organize the large amounts of data generated. In this work, we developed an automated instrumental voltage clamp solution based on a custom-designed software controller application (the WaveManager), which enables automated on-line voltage clamp data acquisition applicable to long-time series experiments. We designed another software program for off-line data processing. The automation of the on-line voltage clamp data acquisition and off-line processing was furthermore integrated with a searchable database (DiscoverySheet(TM)) for efficient data management. The combined solution provides a cost efficient and fast way to acquire, process and administrate large amounts of voltage clamp data that may be too laborious and time consuming to handle manually. (communication)

Research on Biomimetic Models and Nanomechanical Behaviour of Membranous Wings of Chinese Bee Apis cerana cerana Fabricius

Directory of Open Access Journals (Sweden)

Yanru Zhao

2018-01-01

Full Text Available The structures combining the veins and membranes of membranous wings of the Chinese bee Apis cerana cerana Fabricius into a whole have excellent load-resisting capacity. The membranous wings of Chinese bees were taken as research objects and the mechanical properties of a biomimetic model of membranous wings as targets. In order to understand and learn from the biosystem and then make technical innovation, the membranous wings of Chinese bees were simulated and analysed with reverse engineering and finite element method. The deformations and stress states of the finite element model of membranous wings were researched under the concentrated force, uniform load, and torque. It was found that the whole model deforms evenly and there are no unusual deformations arising. The displacements and deformations are small and transform uniformly. It was indicated that the veins and membranes combine well into a whole to transmit loads effectively, which illustrates the membranous wings of Chinese bees having excellent integral mechanical behaviour and structure stiffness. The realization of structure models of the membranous wings of Chinese bees and analysis of the relativity of structures and performances or functions will provide an inspiration for designing biomimetic thin-film materials with superior load-bearing capacity.

Patterns of Growth—Biomimetics and Architectural Design

OpenAIRE

Petra Gruber; Barbara Imhof

2017-01-01

This paper discusses the approach of biomimetic design in architecture applied to the theme of growth in biology by taking two exemplary research projects at the intersection of arts and sciences. The first project, ‘Biornametics’, dealt with patterns from nature; the second project ‘Growing as Building (GrAB)’ took on biological growth as a specific theme for the transfer to architecture and the arts. Within a timeframe of five years (2011–2015), the research was conducted under the Program ...

Fouling Characterization of Forward Osmosis Biomimetic Aquaporin Membranes Used for Water Recovery from Municipal Wastewater

DEFF Research Database (Denmark)

Zarebska, Agata; Petrinic, Irena; Hey, Tobias

, organic, and biological fouling, membrane characterization is not a trivial task. The aim of this work is to characterize fouling of FO biomimetic aquaporin membranes during water recovery from municipal wastewater. Membrane fouling was characterized using Scanning Electron Microscopy, X-ray Dispersive......Generally more than 99.93% of municipal wastewater is composed of water, therefore water recovery can alleviate global water stress which currently exists. Traditional ways to extract water from wastewater by the use of membrane bioreactors combined with reverse osmosis (RO), or micro...... compared to other pressure driven membrane processes, some fouling can occur. This entails that by reducing fouling, increased FO membrane performance can be expected, thus increasing the economic viability of FO processes. Since various types of fouling might occur in membrane systems such as inorganic...

Cell membrane-based nanoparticles: a new biomimetic platform for tumor diagnosis and treatment

Directory of Open Access Journals (Sweden)

Ruixiang Li

2018-01-01

Full Text Available Taking inspiration from nature, the biomimetic concept has been integrated into drug delivery systems in cancer therapy. Disguised with cell membranes, the nanoparticles can acquire various functions of natural cells. The cell membrane-coating technology has pushed the limits of common nano-systems (fast elimination in circulation to more effectively navigate within the body. Moreover, because of the various functional molecules on the surface, cell membrane-based nanoparticles (CMBNPs are capable of interacting with the complex biological microenvironment of the tumor. Various sources of cell membranes have been explored to camouflage CMBNPs and different tumor-targeting strategies have been developed to enhance the anti-tumor drug delivery therapy. In this review article we highlight the most recent advances in CMBNP-based cancer targeting systems and address the challenges and opportunities in this field.

Synthetic nanoparticles camouflaged with biomimetic erythrocyte membranes for reduced reticuloendothelial system uptake

International Nuclear Information System (INIS)

Rao, Lang; Xu, Jun-Hua; Cai, Bo; Liu, Huiqin; Li, Ming; Jia, Yan; Xiao, Liang; Guo, Shi-Shang; Liu, Wei; Zhao, Xing-Zhong

2016-01-01

Suppression of the reticuloendothelial system (RES) uptake is one of the most challenging tasks in nanomedicine. Coating stratagems using polymers, such as poly(ethylene glycol) (PEG), have led to great success in this respect. Nevertheless, recent observations of immunological response toward these synthetic polymers have triggered a search for better alternatives. In this work, natural red blood cell (RBC) membranes are camouflaged on the surface of Fe 3 O 4 nanoparticles for reducing the RES uptake. In vitro macrophage uptake, in vivo biodistribution and pharmacokinetic studies demonstrate that the RBC membrane is a superior alternative to the current gold standard PEG for nanoparticle ‘stealth’. Furthermore, we systematically investigate the in vivo potential toxicity of RBC membrane-coated nanoparticles by blood biochemistry, whole blood panel examination and histology analysis based on animal models. The combination of synthetic nanoparticles and natural cell membranes embodies a novel and biomimetic nanomaterial design strategy and presents a compelling property of functional materials for a broad range of biomedical applications. (paper)

Biomimetic and Bioinspired Synthesis of Nanomaterials/Nanostructures.

Science.gov (United States)

Zan, Guangtao; Wu, Qingsheng

2016-03-16

In recent years, due to its unparalleled advantages, the biomimetic and bioinspired synthesis of nanomaterials/nanostructures has drawn increasing interest and attention. Generally, biomimetic synthesis can be conducted either by mimicking the functions of natural materials/structures or by mimicking the biological processes that organisms employ to produce substances or materials. Biomimetic synthesis is therefore divided here into "functional biomimetic synthesis" and "process biomimetic synthesis". Process biomimetic synthesis is the focus of this review. First, the above two terms are defined and their relationship is discussed. Next different levels of biological processes that can be used for process biomimetic synthesis are compiled. Then the current progress of process biomimetic synthesis is systematically summarized and reviewed from the following five perspectives: i) elementary biomimetic system via biomass templates, ii) high-level biomimetic system via soft/hard-combined films, iii) intelligent biomimetic systems via liquid membranes, iv) living-organism biomimetic systems, and v) macromolecular bioinspired systems. Moreover, for these five biomimetic systems, the synthesis procedures, basic principles, and relationships are discussed, and the challenges that are encountered and directions for further development are considered. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiscale fabrication of biomimetic scaffolds for tympanic membrane tissue engineering

International Nuclear Information System (INIS)

Mota, Carlos; Danti, Serena; D’Alessandro, Delfo; Trombi, Luisa; Ricci, Claudio; Berrettini, Stefano; Puppi, Dario; Dinucci, Dinuccio; Chiellini, Federica; Milazzo, Mario; Stefanini, Cesare; Moroni, Lorenzo

2015-01-01

The tympanic membrane (TM) is a thin tissue able to efficiently collect and transmit sound vibrations across the middle ear thanks to the particular orientation of its collagen fibers, radiate on one side and circular on the opposite side. Through the combination of advanced scaffolds and autologous cells, tissue engineering (TE) could offer valuable alternatives to autografting in major TM lesions. In this study, a multiscale approach based on electrospinning (ES) and additive manufacturing (AM) was investigated to fabricate scaffolds, based on FDA approved copolymers, resembling the anatomic features and collagen fiber arrangement of the human TM. A single scale TM scaffold was manufactured using a custom-made collector designed to confer a radial macro-arrangement to poly(lactic-co-glycolic acid) electrospun fibers during their deposition. Dual and triple scale scaffolds were fabricated combining conventional ES with AM to produce poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer scaffolds with anatomic-like architecture. The processing parameters were optimized for each manufacturing method and copolymer. TM scaffolds were cultured in vitro with human mesenchymal stromal cells, which were viable, metabolically active and organized following the anisotropic character of the scaffolds. The highest viability, cell density and protein content were detected in dual and triple scale scaffolds. Our findings showed that these biomimetic micro-patterned substrates enabled cell disposal along architectural directions, thus appearing as promising substrates for developing functional TM replacements via TE. (paper)

Probing Induced Structural Changes in Biomimetic Bacterial Cell Membrane Interactions with Divalent Cations

Energy Technology Data Exchange (ETDEWEB)

Holt, Allison M [ORNL; Standaert, Robert F [ORNL; Jubb, Aaron M [ORNL; Katsaras, John [ORNL; Johs, Alexander [ORNL

2017-01-01

Biological membranes, formed primarily by the self-assembly of complex mixtures of phospholipids, provide a structured scaffold for compartmentalization and structural processes in living cells. The specific physical properties of phospholipid species present in a given membrane play a key role in mediating these processes. Phosphatidylethanolamine (PE), a zwitterionic lipid present in bacterial, yeast, and mammalian cell membranes, is exceptional. In addition to undergoing the standard lipid polymorphic transition between the gel and liquid-crystalline phase, it can also assume an unusual polymorphic state, the inverse hexagonal phase (HII). Divalent cations are among the factors that drive the formation of the HII phase, wherein the lipid molecules form stacked tubular structures by burying the hydrophilic head groups and exposing the hydrophobic tails to the bulk solvent. Most biological membranes contain a lipid species capable of forming the HII state suggesting that such lipid polymorphic structural states play an important role in structural biological processes such as membrane fusion. In this study, the interactions between Mg2+ and biomimetic bacterial cell membranes composed of PE and phosphatidylglycerol (PG) were probed using differential scanning calorimetry (DSC), small-angle x-ray scattering (SAXS), and fluorescence spectroscopy. The lipid phase transitions were examined at varying ratios of PE to PG and upon exposure to physiologically relevant concentrations of Mg2+. An understanding of these basic interactions enhances our understanding of membrane dynamics and how membrane-mediated structural changes may occur in vivo.

Biomimetic Multilayer Nanofibrous Membranes with Elaborated Superwettability for Effective Purification of Emulsified Oily Wastewater.

Science.gov (United States)

Ge, Jianlong; Jin, Qing; Zong, Dingding; Yu, Jianyong; Ding, Bin

2018-05-09

Creating a porous membrane to effectively separate the emulsified oil-in-water emulsions with energy-saving property is highly desired but remains a challenge. Herein, a multilayer nanofibrous membrane was developed with the inspiration of the natural architectures of earth for gravity-driven water purification. As a result, the obtained biomimetic multilayer nanofibrous membranes exhibited three individual layers with designed functions; they were the inorganic nanofibrous layer to block the serious intrusion of oil to prevent the destructive fouling of the polymeric matrix; the submicron porous layer with designed honeycomb-like cavities to catch the smaller oil droplets and ensures a satisfactory water permeability; and the high porous fibrous substrate with larger pore size provided a template support and allows water to pass through quickly. Consequently, with the cooperation of these three functional layers, the resultant composite membrane possessed superior anti-oil-fouling property and robust oil-in-water emulsion separation performance with good separation efficiency and competitive permeation flux solely under the drive of gravity. The permeation flux of the membrane for the emulsion was up to 5163 L m -2 h -1 with a separation efficiency of 99.5%. We anticipate that our strategy could provide a facile route for developing a new generation of specific membranes for oily wastewater remediation.

Biomimetic design method for innovation and sustainability

CERN Document Server

Helfman Cohen, Yael

2017-01-01

Presenting a novel biomimetic design method for transferring design solutions from nature to technology, this book focuses on structure-function patterns in nature and advanced modeling tools derived from TRIZ, the theory of inventive problem-solving. The book includes an extensive literature review on biomimicry as an engine of both innovation and sustainability, and discusses in detail the biomimetic design process, current biomimetic design methods and tools. The structural biomimetic design method for innovation and sustainability put forward in this text encompasses (1) the research method and rationale used to develop and validate this new design method; (2) the suggested design algorithm and tools including the Findstructure database, structure-function patterns and ideality patterns; and (3) analyses of four case studies describing how to use the proposed method. This book offers an essential resource for designers who wish to use nature as a source of inspiration and knowledge, innovators and sustain...

Characterization of a Biomimetic Mesophase Composed of Nonionic Surfactants and an Aqueous Solvent.

Science.gov (United States)

Adrien, V; Rayan, G; Reffay, M; Porcar, L; Maldonado, A; Ducruix, A; Urbach, W; Taulier, N

2016-10-11

We have investigated the physical and biomimetic properties of a sponge (L 3 ) phase composed of pentaethylene glycol monododecyl ether (C 12 E 5 ), a nonionic surfactant, an aqueous solvent, and a cosurfactant. The following cosurfactants, commonly used for solubilizing membrane proteins, were incorporated: n-octyl-β-d-glucopyranoside (β-OG), n-dodecyl-β-d-maltopyranoside (DDM), 4-cyclohexyl-1-butyl-β-d-maltoside (CYMAL-4), and 5-cyclohexyl-1-pentyl-β-d-maltoside (CYMAL-5). Partial phase diagrams of these systems were created. The L 3 phase was characterized using crossed polarizers, diffusion of a fluorescent probe by fluorescence recovery after pattern photobleaching (FRAPP), and freeze fracture electron microscopy (FFEM). By varying the hydration of the phase, we were able to tune the distance between adjacent bilayers. The characteristic distance (d b ) of the phase was obtained from small angle scattering (SAXS/SANS) as well as from FFEM, which yielded complementary d b values. These d b values were neither affected by the nature of the cosurfactant nor by the addition of membrane proteins. These findings illustrate that a biomimetic surfactant sponge phase can be created in the presence of several common membrane protein-solubilizing detergents, thus making it a versatile medium for membrane protein studies.

BIOMIMETIC STRATEGIES IN ORGANIC SYNTHESIS. TERPENES

Directory of Open Access Journals (Sweden)

V. Kulcitki

2012-12-01

Full Text Available The current paper represents an outline of the selected contributions to the biomimetic procedures and approaches for the synthesis of terpenes with complex structure and diverse functionalisation pattern. These include homologation strategies, cyclisations, rearrangements, as well as biomimetic remote functionalisations.

Iron porphyrin-modified PVDF membrane as a biomimetic material and its effectiveness on nitric oxide binding

Science.gov (United States)

Can, Faruk; Demirci, Osman Cahit; Dumoulin, Fabienne; Erhan, Elif; Arslan, Leyla Colakerol; Ergenekon, Pınar

2017-10-01

Nitric oxide (NO) is a reactive gas well-known as an air pollutant causing severe environmental problems. NO is also an important signaling molecule having a strong affinity towards heme proteins in the body. Taking this specialty as a model, a biomimetic membrane was developed by modification of the membrane surface with iron-porphyrin which depicts very similar structure to heme proteins. In this study, PVDF membrane was coated with synthesized (4-carboxyphenyl)-10,15,20-triphenyl-porphyrin iron(III) chloride (FeCTPP) to promote NO fixation on the surface. The coated membrane was characterized in terms of ATR-IR spectra, contact angle measurement, chemical composition, and morphological structure. Contact angle of original PVDF first decreased sharply after plasma treatment and surface polymerization steps but after incorporation of FeCTPP, the surface acquired its hydrophobicity again. NO binding capability of modified membrane surface was evaluated on the basis of X-ray Photoelectron. Upon exposure to NO gas, a chemical shift of Fe+3 and appearance of new N peak was observed due to the electron transfer from NO ligand to Fe ion with the attachment of nitrosyl group to FeCTPP. This modification brings the functionality to the membrane for being used in biological systems such as membrane bioreactor material in biological NO removal technology.

Heparan Sulfate: A Potential Candidate for the Development of Biomimetic Immunomodulatory Membranes

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Bruna Corradetti

2017-09-01

Full Text Available Clinical trials have demonstrated that heparan sulfate (HS could be used as a therapeutic agent for the treatment of inflammatory diseases. Its anti-inflammatory effect makes it suitable for the development of biomimetic innovative strategies aiming at modulating stem cells behavior toward a pro-regenerative phenotype in case of injury or inflammation. Here, we propose collagen type I meshes fabricated by solvent casting and further crosslinked with HS (HS-Col to create a biomimetic environment resembling the extracellular matrix of soft tissue. HS-Col meshes were tested for their capability to provide physical support to stem cells’ growth, maintain their phenotypes and immunosuppressive potential following inflammation. HS-Col effect on stem cells was investigated in standard conditions as well as in an inflammatory environment recapitulated in vitro through a mix of pro-inflammatory cytokines (tumor necrosis factor-α and interferon-gamma; 20 ng/ml. A significant increase in the production of molecules associated with immunosuppression was demonstrated in response to the material and when cells were grown in presence of pro-inflammatory stimuli, compared to bare collagen membranes (Col, leading to a greater inhibitory potential when mesenchymal stem cells were exposed to stimulated peripheral blood mononuclear cells. Our data suggest that the presence of HS is able to activate the molecular machinery responsible for the release of anti-inflammatory cytokines, potentially leading to a faster resolution of inflammation.

Biomimetics materials, structures and processes : examples, ideas and case studies

CERN Document Server

Bruckner, Dietmar; Hellmich, Christian; Schmiedmayer, Heinz-Bodo; Stachelberger, Herbert; Gebeshuber, Ille

2011-01-01

The book presents an outline of current activities in the field of biomimetics and integrates a variety of applications comprising biophysics, surface sciences, architecture and medicine. Biomimetics as innovation method is characterised by interdisciplinary information transfer from the life sciences to technical application fields aiming at increased performance, functionality and energy efficiency. The contributions of the book relate to the research areas: - Materials and structures in nanotechnology and biomaterials - Biomimetic approaches to develop new forms, construction principles and design methods in architecture - Information and dynamics in automation, neuroinformatics and biomechanics Readers will be informed about the latest research approaches and results in biomimetics with examples ranging from bionic nano-membranes to function-targeted design of tribological surfaces and the translation of natural auditory coding strategies.

Highly penetrative liposome nanomedicine generated by a biomimetic strategy for enhanced cancer chemotherapy.

Science.gov (United States)

Jia, Yali; Sheng, Zonghai; Hu, Dehong; Yan, Fei; Zhu, Mingting; Gao, Guanhui; Wang, Pan; Liu, Xin; Wang, Xiaobing; Zheng, Hairong

2018-04-25

Liposome nanomedicine has been successfully applied for cancer chemotherapy in patients. However, in general, the therapeutic efficacy is confined by its limited accumulation and penetration in solid tumors. Here, we established a biomimetic strategy for the preparation of highly penetrative liposome nanomedicine for enhanced chemotherapeutic efficacy. By applying this unique type of nanomedicine, membrane proteins on the cancer cells are used as highly penetrative targeting ligands. Biomimetic liposomes are highly stable, exhibiting a superior in vitro homologous targeting ability, and a 2.25-fold deeper penetration in 3D tumor spheroids when compared to conventional liposome nanomedicine. The fluorescence/photoacoustic dual-modal imaging approach demonstrated enhanced tumor accumulation and improved tumor penetration of the biomimetic liposome in C6 glioma tumor-bearing nude mice. Following the intravenous administration of biomimetic liposome nanomedicine, the tumor inhibition rate reached up to 93.3%, which was significantly higher when compared to that of conventional liposome nanomedicine (69.3%). Moreover, histopathological analyses demonstrated that biomimetic liposome nanomedicine has limited side effects. Therefore, these results suggested that a cancer cell membrane-based biomimetic strategy may provide a breakthrough approach for enhancing drug penetration and improving treatment efficacy, holding a great promise for further clinical studies.

Small Molecule and Polymer Effects on Bio-mimetic Sensors

OpenAIRE

Garcia, Ignacio J.; Branan, Nicole; Wells, Todd A.

2005-01-01

Formation of biomimetic membranes for the purpose of producing a protein based infrared biosensor has proven to be a difficult obstacle. Several methods have been employed and reproducibility is becoming more frequent. The use of polystyrene as an adhesion layer between the biomimetic and diamond surfaces is the most reliable form of reproducibility yet encountered. Unique properties of acetylcholine esterase based biosensors include infrared absorption bands that are not present in either th...

Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

International Nuclear Information System (INIS)

Sameoto, D; Menon, C

2010-01-01

We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

Differential Interaction of Synthetic Glycolipids with Biomimetic Plasma Membrane Lipids Correlates with the Plant Biological Response.

Science.gov (United States)

Nasir, Mehmet Nail; Lins, Laurence; Crowet, Jean-Marc; Ongena, Marc; Dorey, Stephan; Dhondt-Cordelier, Sandrine; Clément, Christophe; Bouquillon, Sandrine; Haudrechy, Arnaud; Sarazin, Catherine; Fauconnier, Marie-Laure; Nott, Katherine; Deleu, Magali

2017-09-26

Natural and synthetic amphiphilic molecules including lipopeptides, lipopolysaccharides, and glycolipids are able to induce defense mechanisms in plants. In the present work, the perception of two synthetic C14 rhamnolipids, namely, Alk-RL and Ac-RL, differing only at the level of the lipid tail terminal group have been investigated using biological and biophysical approaches. We showed that Alk-RL induces a stronger early signaling response in tobacco cell suspensions than does Ac-RL. The interactions of both synthetic RLs with simplified biomimetic membranes were further analyzed using experimental and in silico approaches. Our results indicate that the interactions of Alk-RL and Ac-RL with lipids were different in terms of insertion and molecular responses and were dependent on the lipid composition of model membranes. A more favorable insertion of Alk-RL than Ac-RL into lipid membranes is observed. Alk-RL forms more stable molecular assemblies than Ac-RL with phospholipids and sterols. At the molecular level, the presence of sterols tends to increase the RLs' interaction with lipid bilayers, with a fluidizing effect on the alkyl chains. Taken together, our findings suggest that the perception of these synthetic RLs at the membrane level could be related to a lipid-driven process depending on the organization of the membrane and the orientation of the RLs within the membrane and is correlated with the induction of early signaling responses in tobacco cells.

Micro-and/or nano-scale patterned porous membranes, methods of making membranes, and methods of using membranes

KAUST Repository

Wang, Xianbin; Chen, Wei; Wang, Zhihong; Zhang, Xixiang; Yue, Weisheng; Lai, Zhiping

2015-01-01

Embodiments of the present disclosure provide for materials that include a pre-designed patterned, porous membrane (e.g., micro- and/or nano-scale patterned), structures or devices that include a pre-designed patterned, porous membrane, methods of making pre-designed patterned, porous membranes, methods of separation, and the like.

Micro-and/or nano-scale patterned porous membranes, methods of making membranes, and methods of using membranes

KAUST Repository

Wang, Xianbin

2015-01-22

Embodiments of the present disclosure provide for materials that include a pre-designed patterned, porous membrane (e.g., micro- and/or nano-scale patterned), structures or devices that include a pre-designed patterned, porous membrane, methods of making pre-designed patterned, porous membranes, methods of separation, and the like.

Ultrathin Ceramic Membranes as Scaffolds for Functional Cell Coculture Models on a Biomimetic Scale

Science.gov (United States)

Jud, Corinne; Ahmed, Sher; Müller, Loretta; Kinnear, Calum; Vanhecke, Dimitri; Umehara, Yuki; Frey, Sabine; Liley, Martha; Angeloni, Silvia; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2015-01-01

Abstract Epithelial tissue serves as an interface between biological compartments. Many in vitro epithelial cell models have been developed as an alternative to animal experiments to answer a range of research questions. These in vitro models are grown on permeable two-chamber systems; however, commercially available, polymer-based cell culture inserts are around 10 μm thick. Since the basement membrane found in biological systems is usually less than 1 μm thick, the 10-fold thickness of cell culture inserts is a major limitation in the establishment of realistic models. In this work, an alternative insert, accommodating an ultrathin ceramic membrane with a thickness of only 500 nm (i.e., the Silicon nitride Microporous Permeable Insert [SIMPLI]-well), was produced and used to refine an established human alveolar barrier coculture model by both replacing the conventional inserts with the SIMPLI-well and completing it with endothelial cells. The structural–functional relationship of the model was evaluated, including the translocation of gold nanoparticles across the barrier, revealing a higher translocation if compared to corresponding polyethylene terephthalate (PET) membranes. This study demonstrates the power of the SIMPLI-well system as a scaffold for epithelial tissue cell models on a truly biomimetic scale, allowing construction of more functionally accurate models of human biological barriers. PMID:26713225

The preosteoblast response of electrospinning PLGA/PCL nanofibers: effects of biomimetic architecture and collagen I

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Qian YZ

2016-08-01

Full Text Available Yunzhu Qian,1,2 Hanbang Chen,1 Yang Xu,1 Jianxin Yang,2 Xuefeng Zhou,3 Feimin Zhang,1 Ning Gu3 1Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 2Center of Stomatology, The Second Affiliated Hospital of Soochow University, Suzhou, 3School of Biological Science and Medical Engineering, Southeast University, Nanjing, People’s Republic of China Abstract: Constructing biomimetic structure and incorporating bioactive molecules is an effective strategy to achieve a more favorable cell response. To explore the effect of electrospinning (ES nanofibrous architecture and collagen I (COL I-incorporated modification on tuning osteoblast response, a resorbable membrane composed of poly(lactic-co-glycolic acid/poly(caprolactone (PLGA/PCL; 7:3 w/w was developed via ES. COL I was blended into PLGA/PCL solution to prepare composite ES membrane. Notably, relatively better cell response was delivered by the bioactive ES-based membrane which was fabricated by modification of 3,4-dihydroxyphenylalanine and COL I. After investigation by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurement, and mechanical test, polyporous three-dimensional nanofibrous structure with low tensile force and the successful integration of COL I was obtained by the ES method. Compared with traditional PLGA/PCL membrane, the surface hydrophilicity of collagen-incorporated membranes was largely enhanced. The behavior of mouse preosteoblast MC3T3-E1 cell infiltration and proliferation on membranes was studied at 24 and 48 hours. The negative control was fabricated by solvent casting. Evaluation of cell adhesion and morphology demonstrated that all the ES membranes were more favorable for promoting the cell adhesion and spreading than the casting membrane. Cell Counting Kit-8 assays revealed that biomimetic architecture, surface topography, and bioactive properties of membranes were favorable for cell

Image Classification Using Biomimetic Pattern Recognition with Convolutional Neural Networks Features

Science.gov (United States)

Huo, Guanying

2017-01-01

As a typical deep-learning model, Convolutional Neural Networks (CNNs) can be exploited to automatically extract features from images using the hierarchical structure inspired by mammalian visual system. For image classification tasks, traditional CNN models employ the softmax function for classification. However, owing to the limited capacity of the softmax function, there are some shortcomings of traditional CNN models in image classification. To deal with this problem, a new method combining Biomimetic Pattern Recognition (BPR) with CNNs is proposed for image classification. BPR performs class recognition by a union of geometrical cover sets in a high-dimensional feature space and therefore can overcome some disadvantages of traditional pattern recognition. The proposed method is evaluated on three famous image classification benchmarks, that is, MNIST, AR, and CIFAR-10. The classification accuracies of the proposed method for the three datasets are 99.01%, 98.40%, and 87.11%, respectively, which are much higher in comparison with the other four methods in most cases. PMID:28316614

Pore-Confined Carriers and Biomolecules in Mesoporous Silica for Biomimetic Separation and Targeting

Science.gov (United States)

Zhou, Shanshan

Selectively permeable biological membranes composed of lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. This work imparts selective permeability to lipid-filled pores of silica thin film composite membranes using carrier molecules that reside in the lipophilic self-assemblies. The lipids confined inside the pores of silica are proven to be a more effective barrier than bilayers formed on the porous surface through vesicle fusion, which is critical for quantifying the function of an immobilized carrier. The ability of a lipophilic carrier embedded in the lipid bilayer to reversibly bind the target solute and transport it through the membrane is demonstrated. Through the functionalization of the silica surface with enzymes, enzymatic catalysis and biomimetic separations can be combined on this nanostructured composite platform. The successful development of biomimetic nanocomposite membrane can provide for efficient dilute aqueous solute upgrading or separations using engineered carrier/catalyst/support systems. While the carrier-mediated biomimetic membranes hold great potential, fully understanding of the transport processes in composite synthetic membranes is essential for improve the membrane performance. Electrochemical impedance spectroscopy (EIS) technique is demonstrated to be a useful tool for characterizing the thin film pore accessibility. Furthermore, the effect of lipid bilayer preparation methods on the silica thin film (in the form of pore enveloping, pore filling) on ion transport is explored, as a lipid bilayer with high electrically insulation is essential for detecting activity of proteins or biomimetic carriers in the bilayer. This study provides insights for making better barriers on mesoporous support for carrier-mediated membrane separation process. Porous silica nanoparticles (pSNPs) with pore sizes appropriate for biomolecule loading are potential for encapsulating dsRNA within the

Impact of monoolein on aquaporin1-based supported lipid bilayer membranes

International Nuclear Information System (INIS)

Wang, Zhining; Wang, Xida; Ding, Wande; Wang, Miaoqi; Gao, Congjie; Qi, Xin

2015-01-01

Aquaporin (AQP) based biomimetic membranes have attracted considerable attention for their potential water purification applications. In this paper, AQP1 incorporated biomimetic membranes were prepared and characterized. The morphology and structure of the biomimetic membranes were characterized by in situ atomic force microscopy (AFM), infrared absorption spectroscopy, fluorescence microscopy, and contact angle measurements. The nanofiltration performance of the AQP1 incorporated membranes was investigated at 4 bar by using 2 g l −1 NaCl as feed solution. Lipid mobility plays an important role in the performance of the AQP1 incorporated supported lipid bilayer (SLB) membranes. We demonstrated that the lipid mobility is successfully tuned by the addition of monoolein (MO). Through in situ AFM and fluorescence recovery after photo-bleaching (FRAP) measurements, the membrane morphology and the molecular mobility were studied. The lipid mobility increased in the sequence DPPC < DPPC/MO (R MO = 5/5) < DOPC/MO (R MO = 5/5) < DOPC, which is consistent with the flux increment and salt rejection. This study may provide some useful insights for improving the water purification performance of biomimetic membranes. (paper)

Online Monitoring of Electrochemical Degradation of Paracetamol through a Biomimetic Sensor

OpenAIRE

Mariana Calora Quintino de Oliveira; Marcos Roberto de Vasconcelos Lanza; José Luis Paz Jara; Maria Del Pilar Taboada Sotomayor

2011-01-01

This paper reports, for the first time, the online monitoring to the electrochemical degradation of the paracetamol using a biomimetic sensor coupled to a Flow Injection Analysis (FIA) system. The electrochemical degradation of the drug was carried out in aqueous medium using a flow-by reactor with a DSA anode. The process efficiency was monitored at real time by the biomimetic sensor constructed by modifying a glassy carbon electrode with a Nafion membrane doped with iron tetrapyridinoporphy...

Catalytic molecularly imprinted polymer membranes: development of the biomimetic sensor for phenols detection.

Science.gov (United States)

Sergeyeva, T A; Slinchenko, O A; Gorbach, L A; Matyushov, V F; Brovko, O O; Piletsky, S A; Sergeeva, L M; Elska, G V

2010-02-05

Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)-catechol-urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes' structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers-biomimics with the optimized composition comprised 0.063 mM, while the linear range of the sensor comprised 0.063-1 mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols

Patterns of Growth—Biomimetics and Architectural Design

Directory of Open Access Journals (Sweden)

Petra Gruber

2017-04-01

Full Text Available This paper discusses the approach of biomimetic design in architecture applied to the theme of growth in biology by taking two exemplary research projects at the intersection of arts and sciences. The first project, ‘Biornametics’, dealt with patterns from nature; the second project ‘Growing as Building (GrAB’ took on biological growth as a specific theme for the transfer to architecture and the arts. Within a timeframe of five years (2011–2015, the research was conducted under the Program for Arts-based Research PEEK (Programm zur Entwicklung und Erschliessung der Künste of the Austrian Science Fund FWF (Fonds zur Förderung der wissenschaftlichen Forschung. The underlying hypothesis was that growth processes in nature have not been studied for transfer into technology and architecture yet and that, with advanced software tools, promising applications could be found. To ensure a high degree of innovation, this research was done with an interdisciplinary team of architects, engineers, and scientists (mainly biologists to lay the groundwork for future product-oriented technological solutions. Growth, as one of the important characteristics of living organisms, is used as a frame for research into systems and principles that shall deliver innovative and sustainable solutions in architecture and the arts. Biomimetics as a methodology was used to create and guide information transfer from the life sciences to innovative proto-architectural solutions. The research aimed at transferring qualities present in biological growth; for example, adaptiveness, exploration, or local resource harvesting into technical design and production processes. In contrast to our current building construction, implementing principles of growth could potentially transform building towards a more integrated and sustainable setting, a new living architecture. Tools and methods, especially Quality Function Deployment (QFD for matching biological role models with

Growth of aragonite calcium carbonate nanorods in the biomimetic anodic aluminum oxide template

Science.gov (United States)

Lee, Inho; Han, Haksoo; Lee, Sang-Yup

2010-04-01

In this study, a biomimetic template was prepared and applied for growing calcium carbonate (CaCO 3) nanorods whose shape and polymorphism were controlled. A biomimetic template was prepared by adsorbing catalytic dipeptides into the pores of an anodic aluminum oxide (AAO) membrane. Using this peptide-adsorbed template, mineralization and aggregation of CaCO 3 was carried out to form large nanorods in the pores. The nanorods were aragonite and had a structure similar to nanoneedle assembly. This aragonite nanorod formation was driven by both the AAO template and catalytic function of dipeptides. The AAO membrane pores promoted generation of aragonite polymorph and guided nanorod formation by guiding the nanorod growth. The catalytic dipeptides promoted the aggregation and further dehydration of calcium species to form large nanorods. Functions of the AAO template and catalytic dipeptides were verified through several control experiments. This biomimetic approach makes possible the production of functional inorganic materials with controlled shapes and crystalline structures.

Impedance and dielectric characterizations of ionic partitioning in interfaces that membranous, biomimetic and gold surfaces form with electrolytes

International Nuclear Information System (INIS)

Chilcott, Terry C.; Guo, Chuan

2013-01-01

Silicon dioxide, organic monolayers covalently attached to silicon and gold are used as biosensor substrates and anchoring platforms for hybrid, tethered and supported lipid membranes used in membrane-protein studies. Electrical impedance spectroscopy (EIS) studies of gold in contact with potassium chloride electrolytes of concentrations ranging from 1 mM to 300 mM, characterized the gold–electrolyte interface as principally a Stern layer 20–30 Å thick and conductivity many orders of magnitude less than that of the bulk electrolyte. EIS studies of SiO 2 –electrolyte system that were similar to studies of a tetradecane–electrolyte system are presented herein that reveal an interface comprised of at least two interfacial layers and extending some 10 5 Å into the electrolyte. The average conductivity and thickness values for the layer in contact with the SiO 2 surface (∼10 −6 S m −1 and ∼28 Å, respectively) were of the order of magnitude expected for the Gouy–Chapman layer but the dependency of the thickness on concentration did not reflect the expected dependency of the Debye length over the full range of concentrations. The average values for the next layer (∼10 −3 S m −1 and ∼10 5 Å) exhibited a dependency on concentration similar to that expected for the bulk electrolyte. The theoretical derivations of ionic partitioning arising from the Born (dielectric) energy distributions in both the SiO 2 and gold interfaces were generally consistent with the respective EIS studies and revealed that partitioning in the SiO 2 interface mimicked that in bio-membranous interfaces. The dielectric characterizations suggest that; ionic partitioning in biomimetic interfaces play a role in long-ranging sequestration of organic molecules, the extensiveness of these interfaces contributes to differences in the lipid densities of bilayers formed on biomimetic substrates, and chloride ions have a greater affinity than the smaller potassium ions for gold

Modulation and interactions of charged biomimetic membranes with bivalent ions

Science.gov (United States)

Kazadi Badiambile, Adolphe

biomolecules in a dynamic environment and the lack of appropriate physical and biochemical tools. In contrast, biomimetic membrane models that rely on the amphiphilic properties of phospholipids are powerful tools that enable the study of these molecules in vitro. By having control over the different experimental parameters such as temperature and pH, reliable and repeatable experimental conditions can be created. One of the key questions I investigated in this thesis is related to the clustering mechanism of PtdIns(4, 5)P2 into pools or aggregates that enable independent cellular control of this species by geometric separation. The lateral aggregation of PtdIns(4, 5)P2 and its underlying physical causes is still a matter of debate. In the first part of this thesis I introduce the general information on lipid membranes with a special focus on the PtdIns family and their associated signaling events. In addition, I explain the Langmuir-Blodgett film balance (LB) system as tool to study lipid membranes and lipid interactions. In the second chapter, I describe my work on the lateral compressibility of PtdIns(4, 5)P2, PtdIns and DOPG monolayers and its modulation by bivalent ions using Langmuir monolayers. In addition, a theoretical framework of compressibility that depends on a surface potential induced by a planar layer of charged molecules and ions in the bulk was provided. In the third part, I present my work on the excess Gibbs free energy of the lipid systems PtdIns(4, 5)P2 --POPC, PtdIns(4, 5)P2, and POPC as they are modulated by bivalent ions. In the fourth part, I report on my foray in engineering a light-based system that relies on different dye properties to simulate calcium induced calcium release (CICR) that occurs in many cell types. In the final chapter, I provide a general conclusion and present directions for future research that would build on my findings.

Printing-assisted surface modifications of patterned ultrafiltration membranes

International Nuclear Information System (INIS)

Wardrip, Nathaniel C.; Dsouza, Melissa; Urgun-Demirtas, Meltem; Snyder, Seth W.

2016-01-01

Understanding and restricting microbial surface attachment will enhance wastewater treatment with membranes. We report a maskless lithographic patterning technique for the generation of patterned polymer coatings on ultrafiltration membranes. Polyethylene glycol, zwitterionic, or negatively charged hydrophilic polymer compositions in parallel- or perpendicular-striped patterns with respect to feed flow were evaluated using wastewater. Membrane fouling was dependent on the orientation and chemical composition of the coatings. Modifications reduced alpha diversity in the attached microbial community (Shannon indices decreased from 2.63 to 1.89) which nevertheless increased with filtration time. Sphingomonas species, which condition membrane surfaces and facilitate cellular adhesion, were depleted in all modified membranes. Microbial community structure was significantly different between control, different patterns, and different chemistries. Lastly, this study broadens the tools for surface modification of membranes with polymer coatings and for understanding and optimization of antifouling surfaces.

Enhanced Neural Cell Adhesion and Neurite Outgrowth on Graphene-Based Biomimetic Substrates

Directory of Open Access Journals (Sweden)

Suck Won Hong

2014-01-01

Full Text Available Neural cell adhesion and neurite outgrowth were examined on graphene-based biomimetic substrates. The biocompatibility of carbon nanomaterials such as graphene and carbon nanotubes (CNTs, that is, single-walled and multiwalled CNTs, against pheochromocytoma-derived PC-12 neural cells was also evaluated by quantifying metabolic activity (with WST-8 assay, intracellular oxidative stress (with ROS assay, and membrane integrity (with LDH assay. Graphene films were grown by using chemical vapor deposition and were then coated onto glass coverslips by using the scooping method. Graphene sheets were patterned on SiO2/Si substrates by using photolithography and were then covered with serum for a neural cell culture. Both types of CNTs induced significant dose-dependent decreases in the viability of PC-12 cells, whereas graphene exerted adverse effects on the neural cells just at over 62.5 ppm. This result implies that graphene and CNTs, even though they were the same carbon-based nanomaterials, show differential influences on neural cells. Furthermore, graphene-coated or graphene-patterned substrates were shown to substantially enhance the adhesion and neurite outgrowth of PC-12 cells. These results suggest that graphene-based substrates as biomimetic cues have good biocompatibility as well as a unique surface property that can enhance the neural cells, which would open up enormous opportunities in neural regeneration and nanomedicine.

Biomimetic shark skin: design, fabrication and hydrodynamic function.

Science.gov (United States)

Wen, Li; Weaver, James C; Lauder, George V

2014-05-15

Although the functional properties of shark skin have been of considerable interest to both biologists and engineers because of the complex hydrodynamic effects of surface roughness, no study to date has successfully fabricated a flexible biomimetic shark skin that allows detailed study of hydrodynamic function. We present the first study of the design, fabrication and hydrodynamic testing of a synthetic, flexible, shark skin membrane. A three-dimensional (3D) model of shark skin denticles was constructed using micro-CT imaging of the skin of the shortfin mako (Isurus oxyrinchus). Using 3D printing, thousands of rigid synthetic shark denticles were placed on flexible membranes in a controlled, linear-arrayed pattern. This flexible 3D printed shark skin model was then tested in water using a robotic flapping device that allowed us to either hold the models in a stationary position or move them dynamically at their self-propelled swimming speed. Compared with a smooth control model without denticles, the 3D printed shark skin showed increased swimming speed with reduced energy consumption under certain motion programs. For example, at a heave frequency of 1.5 Hz and an amplitude of ± 1 cm, swimming speed increased by 6.6% and the energy cost-of-transport was reduced by 5.9%. In addition, a leading-edge vortex with greater vorticity than the smooth control was generated by the 3D printed shark skin, which may explain the increased swimming speeds. The ability to fabricate synthetic biomimetic shark skin opens up a wide array of possible manipulations of surface roughness parameters, and the ability to examine the hydrodynamic consequences of diverse skin denticle shapes present in different shark species. © 2014. Published by The Company of Biologists Ltd.

Biomimetic Hybridization of Kevlar into Silk Fibroin: Nanofibrous Strategy for Improved Mechanic Properties of Flexible Composites and Filtration Membranes.

Science.gov (United States)

Lv, Lili; Han, Xiangsheng; Zong, Lu; Li, Mingjie; You, Jun; Wu, Xiaochen; Li, Chaoxu

2017-08-22

Silk, one of the strongest natural biopolymers, was hybridized with Kevlar, one of the strongest synthetic polymers, through a biomimetic nanofibrous strategy. Regenerated silk materials have outstanding properties in transparency, biocompatibility, biodegradability and sustainability, and promising applications as diverse as in pharmaceutics, electronics, photonic devices and membranes. To compete with super mechanic properties of their natural counterpart, regenerated silk materials have been hybridized with inorganic fillers such as graphene and carbon nanotubes, but frequently lose essential mechanic flexibility. Inspired by the nanofibrous strategy of natural biomaterials (e.g., silk fibers, hemp and byssal threads of mussels) for fantastic mechanic properties, Kevlar was integrated in regenerated silk materials by combining nanometric fibrillation with proper hydrothermal treatments. The resultant hybrid films showed an ultimate stress and Young's modulus two times as high as those of pure regenerated SF films. This is not only because of the reinforcing effect of Kevlar nanofibrils, but also because of the increasing content of silk β-sheets. When introducing Kevlar nanofibrils into the membranes of silk nanofibrils assembled by regenerated silk fibroin, the improved mechanic properties further enabled potential applications as pressure-driven nanofiltration membranes and flexible substrates of electronic devices.

Cupula-Inspired Hyaluronic Acid-Based Hydrogel Encapsulation to Form Biomimetic MEMS Flow Sensors.

Science.gov (United States)

Kottapalli, Ajay Giri Prakash; Bora, Meghali; Kanhere, Elgar; Asadnia, Mohsen; Miao, Jianmin; Triantafyllou, Michael S

2017-07-28

Blind cavefishes are known to detect objects through hydrodynamic vision enabled by arrays of biological flow sensors called neuromasts. This work demonstrates the development of a MEMS artificial neuromast sensor that features a 3D polymer hair cell that extends into the ambient flow. The hair cell is monolithically fabricated at the center of a 2 μm thick silicon membrane that is photo-patterned with a full-bridge bias circuit. Ambient flow variations exert a drag force on the hair cell, which causes a displacement of the sensing membrane. This in turn leads to the resistance imbalance in the bridge circuit generating a voltage output. Inspired by the biological neuromast, a biomimetic synthetic hydrogel cupula is incorporated on the hair cell. The morphology, swelling behavior, porosity and mechanical properties of the hyaluronic acid hydrogel are characterized through rheology and nanoindentation techniques. The sensitivity enhancement in the sensor output due to the material and mechanical contributions of the micro-porous hydrogel cupula is investigated through experiments.

Phospholipid-sepiolite biomimetic interfaces for the immobilization of enzymes.

Science.gov (United States)

Wicklein, Bernd; Darder, Margarita; Aranda, Pilar; Ruiz-Hitzky, Eduardo

2011-11-01

Biomimetic interfaces based on phosphatidylcholine (PC) assembled to the natural silicate sepiolite were prepared for the stable immobilization of the urease and cholesterol oxidase enzymes. This is an important issue in practical advanced applications such as biocatalysis or biosensing. The supported lipid bilayer (BL-PC), prepared from PC adsorption, was used for immobilization of enzymes and the resulting biomimetic systems were compared to several other supported layers including a lipid monolayer (ML-PC), a mixed phosphatidylcholine/octyl-galactoside layer (PC-OGal), a cetyltrimethylammonium monolayer (CTA), and also to the bare sepiolite surface. Interfacial characteristics of these layers were investigated with a focus on layer packing density, hydrophilicity/hydrophobicity, and surface charge, which are being considered as key points for enzyme immobilization and stabilization of their biological activity. Cytoplasmic urease and membrane-bound cholesterol oxidase, which served as model enzymes, were immobilized on the different PC-based hybrid materials to probe their biomimetic character. Enzymatic activity was assessed by cyclic voltammetry and UV-vis spectrophotometry. The resulting enzyme/bio-organoclay hybrids were applied as active phase of a voltammetric urea biosensor and cholesterol bioreactor, respectively. Urease supported on sepiolite/BL-PC proved to maintain its enzymatic activity over several months while immobilized cholesterol oxidase demonstrated high reusability as biocatalyst. The results emphasize the good preservation of bioactivity due to the accommodation of the enzymatic system within the biomimetic lipid interface on sepiolite.

Biomimetic aquaporin membranes coming of age

DEFF Research Database (Denmark)

Tang, Chuyang; Wang, Zhining; Petrinić, Irena

2015-01-01

Membrane processes have been widely used for water purification because of their high stability, efficiency, low energy requirement and ease of operation. Traditional desalting membranes are mostly dense polymeric films with a "trade off" effect between permeability and selectivity. Biological...

Assessing the efficacy of vesicle fusion with planar membrane arrays using a mitochondrial porin as reporter

International Nuclear Information System (INIS)

Pszon-Bartosz, Kamila; Hansen, Jesper S.; Stibius, Karin B.; Groth, Jesper S.; Emneus, Jenny; Geschke, Oliver; Helix-Nielsen, Claus

2011-01-01

Research highlights: → We have established a vesicle fusion efficacy assay based on the major non-specific porin of Fusobacterium nucleatum (FomA). → Maximal fusion obtained was almost 150,000 porin insertions during 20 min. → Incorporation can be either first order or exponential kinetics which has implications for establishing protein delivery to biomimetic membranes. -- Abstract: Reconstitution of functionally active membrane protein into artificially made lipid bilayers is a challenge that must be overcome to create a membrane-based biomimetic sensor and separation device. In this study we address the efficacy of proteoliposome fusion with planar membrane arrays. We establish a protein incorporation efficacy assay using the major non-specific porin of Fusobacterium nucleatum (FomA) as reporter. We use electrical conductance measurements and fluorescence microscopy to characterize proteoliposome fusion with an array of planar membranes. We show that protein reconstitution in biomimetic membrane arrays may be quantified using the developed FomA assay. Specifically, we show that FomA vesicles are inherently fusigenic. Optimal FomA incorporation is obtained with a proteoliposome lipid-to-protein molar ratio (LPR) = 50 more than 10 5 FomA proteins could be incorporated in a bilayer array with a total membrane area of 2 mm 2 within 20 min. This novel assay for quantifying protein delivery into lipid bilayers may be a useful tool in developing biomimetic membrane applications.

Biomimetic self-assembly of a functional asymmetrical electronic device.

Science.gov (United States)

Boncheva, Mila; Gracias, David H; Jacobs, Heiko O; Whitesides, George M

2002-04-16

This paper introduces a biomimetic strategy for the fabrication of asymmetrical, three-dimensional electronic devices modeled on the folding of a chain of polypeptide structural motifs into a globular protein. Millimeter-size polyhedra-patterned with logic devices, wires, and solder dots-were connected in a linear string by using flexible wire. On self-assembly, the string folded spontaneously into two domains: one functioned as a ring oscillator, and the other one as a shift register. This example demonstrates that biomimetic principles of design and self-organization can be applied to generate multifunctional electronic systems of complex, three-dimensional architecture.

Deterministically patterned biomimetic human iPSC-derived hepatic model via rapid 3D bioprinting.

Science.gov (United States)

Ma, Xuanyi; Qu, Xin; Zhu, Wei; Li, Yi-Shuan; Yuan, Suli; Zhang, Hong; Liu, Justin; Wang, Pengrui; Lai, Cheuk Sun Edwin; Zanella, Fabian; Feng, Gen-Sheng; Sheikh, Farah; Chien, Shu; Chen, Shaochen

2016-02-23

The functional maturation and preservation of hepatic cells derived from human induced pluripotent stem cells (hiPSCs) are essential to personalized in vitro drug screening and disease study. Major liver functions are tightly linked to the 3D assembly of hepatocytes, with the supporting cell types from both endodermal and mesodermal origins in a hexagonal lobule unit. Although there are many reports on functional 2D cell differentiation, few studies have demonstrated the in vitro maturation of hiPSC-derived hepatic progenitor cells (hiPSC-HPCs) in a 3D environment that depicts the physiologically relevant cell combination and microarchitecture. The application of rapid, digital 3D bioprinting to tissue engineering has allowed 3D patterning of multiple cell types in a predefined biomimetic manner. Here we present a 3D hydrogel-based triculture model that embeds hiPSC-HPCs with human umbilical vein endothelial cells and adipose-derived stem cells in a microscale hexagonal architecture. In comparison with 2D monolayer culture and a 3D HPC-only model, our 3D triculture model shows both phenotypic and functional enhancements in the hiPSC-HPCs over weeks of in vitro culture. Specifically, we find improved morphological organization, higher liver-specific gene expression levels, increased metabolic product secretion, and enhanced cytochrome P450 induction. The application of bioprinting technology in tissue engineering enables the development of a 3D biomimetic liver model that recapitulates the native liver module architecture and could be used for various applications such as early drug screening and disease modeling.

Online Monitoring of Electrochemical Degradation of Paracetamol through a Biomimetic Sensor

Directory of Open Access Journals (Sweden)

Mariana Calora Quintino de Oliveira

2011-01-01

Full Text Available This paper reports, for the first time, the online monitoring to the electrochemical degradation of the paracetamol using a biomimetic sensor coupled to a Flow Injection Analysis (FIA system. The electrochemical degradation of the drug was carried out in aqueous medium using a flow-by reactor with a DSA anode. The process efficiency was monitored at real time by the biomimetic sensor constructed by modifying a glassy carbon electrode with a Nafion membrane doped with iron tetrapyridinoporphyrazine (FeTPyPz. Simultaneously, we carried out off-line analysis by liquid chromatography (HPLC during the experiments in order to validate the proposed system. In addition, to investigate the degradation products of the paracetamol electrolysis, we used the techniques of UPLC/MS and GC/MS.

Patterned ion exchange membranes for improved power production in microbial reverse-electrodialysis cells

KAUST Repository

Liu, Jia

2014-12-01

Power production in microbial reverse-electrodialysis cells (MRCs) can be limited by the internal resistance of the reverse electrodialysis stack. Typical MRC stacks use non-conductive spacers that block ion transport by the so-called spacer shadow effect. These spacers can be relatively thick compared to the membrane, and thus they increase internal stack resistance due to high solution (ohmic) resistance associated with a thick spacer. New types of patterned anion and cation exchange membranes were developed by casting membranes to create hemispherical protrusions on the membranes, enabling fluid flow between the membranes without the need for a non-conductive spacer. The use of the patterned membrane decreased the MRC stack resistance by ∼22 Ω, resulting in a 38% increase in power density from 2.50 ± 0.04 W m-2 (non-patterned membrane with a non-conductive spacer) to 3.44 ± 0.02 W m-2 (patterned membrane). The COD removal rate, coulombic efficiency, and energy efficiency of the MRC also increased using the patterned membranes compared to the non-patterned membranes. These results demonstrate that these patterned ion exchange membranes can be used to improve performance of an MRC. © 2014 Elsevier B.V. All rights reserved.

Macrophage membrane-coated iron oxide nanoparticles for enhanced photothermal tumor therapy

Science.gov (United States)

Meng, Qian-Fang; Rao, Lang; Zan, Minghui; Chen, Ming; Yu, Guang-Tao; Wei, Xiaoyun; Wu, Zhuhao; Sun, Yue; Guo, Shi-Shang; Zhao, Xing-Zhong; Wang, Fu-Bing; Liu, Wei

2018-04-01

Nanotechnology possesses the potential to revolutionize the diagnosis and treatment of tumors. The ideal nanoparticles used for in vivo cancer therapy should have long blood circulation times and active cancer targeting. Additionally, they should be harmless and invisible to the immune system. Here, we developed a biomimetic nanoplatform with the above properties for cancer therapy. Macrophage membranes were reconstructed into vesicles and then coated onto magnetic iron oxide nanoparticles (Fe3O4 NPs). Inherited from the Fe3O4 core and the macrophage membrane shell, the resulting Fe3O4@MM NPs exhibited good biocompatibility, immune evasion, cancer targeting and light-to-heat conversion capabilities. Due to the favorable in vitro and in vivo properties, biomimetic Fe3O4@MM NPs were further used for highly effective photothermal therapy of breast cancer in nude mice. Surface modification of synthetic nanomaterials with biomimetic cell membranes exemplifies a novel strategy for designing an ideal nanoplatform for translational medicine.

A single molecule approach for measuring the transport properties and energetics of membrane proteins in heterogeneous planar bio-mimetic assemblies

Science.gov (United States)

Poudel, Kumud Raj

The significance of transmembrane protein research is well documented. Numerous studies have clearly established the biological, biophysical and pharmaceutical importance that these membrane components serve. Communications through receptors regulate countless body functions and they also provide structural support to the cell. However, a lack of high-resolution structure data has limited our understanding of these proteins that make it necessary to study them in in-vitro platforms or 'bio-mimetic' assemblies. Albeit that an assortment of platforms have been suggested for in-vitro studies, the issues, however, remain the same. The lack of mobility of the proteins in artificial environments, the question of functionality that arises with mobility and the search in general for the best assembly, is still a work in progress. In this work, we have taken some of the most accepted platforms in the field and characterized them through the lens of single molecule spectroscopy. We have addressed the question of mobility by reducing it down to a single molecule and comparing it with the bulk. By utilizing the Serotonin Receptor 5HT3A we have shown that techniques such as passivation of the substrates in the assemblies by Bovine Serum Albumin has a significant effect at the molecular level. The larger size of the intracellular domain for the 5HT3A served as a great probe to understand and evaluate the interaction of a surface passivator with the integrated membrane protein. We have also taken this a step further by developing a novel, single cushion 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) assembly and added another degree of complexity- through a phase transition. We have utilized phase transition to get an insight into the local protein environment, activation energies, heterogeneity and diffusion characteristics by using Annexin V as our probe. The work presented here studies two completely different biological platforms using two entirely different transmembrane

Surface patterning of polymeric separation membranes and its influence on the filtration performance

Science.gov (United States)

Maruf, Sajjad

Polymeric membrane based separation technologies are crucial for addressing the global issues such as water purification. However, continuous operations of these processes are often hindered by fouling which increases mass transport resistance of the membrane to permeation and thus the energy cost, and eventually replacement of the membrane in the system. In comparison to other anti-fouling strategies, the use of controlled surface topography to mitigate fouling has not been realized mainly due to the lack of methods to create targeted topography on the porous membrane surface. This thesis aims to develop a new methodology to create surface-patterned polymeric separation membrane to improve their anti-fouling characteristics during filtration. First, successful fabrication of sub-micron surface patterns directly on a commercial ultrafiltration (UF) membrane surface using nanoimprint lithographic (NIL) technique was demonstrated. Comprehensive filtration studies revealed that the presence of these sub-micron surface patterns mitigates not only the onset of colloidal particle deposition, but also lowers the rate of growth of cake layer after initial deposition, in comparison with un-patterned membranes. The anti-fouling effects were also observed for model protein solutions. Staged filtration experiments, with backwash cleaning, revealed that the permeate flux of the patterned membrane after protein fouling was considerably higher than that of the pristine or un-patterned membrane. In addition to the surface-patterning of UF membranes, successful fabrication of a surface-patterned thin film composite (TFC) membrane was shown for the first time. A two-step fabrication process was carried out by (1) nanoimprinting a polyethersulfone (PES) support using NIL, and (2) forming a thin dense film atop the PES support via interfacial polymerization (IP). Fouling experiments suggest that the surface patterns alter the hydrodynamics at the membrane-feed interface, which is

Electrochemical characterization of hydrogels for biomimetic applications

DEFF Research Database (Denmark)

Peláez, L.; Romero, V.; Escalera, S.

2011-01-01

) or a photoinitiator (P) to encapsulate and stabilize biomimetic membranes for novel separation technologies or biosensor applications. In this paper, we have investigated the electrochemical properties of the hydrogels used for membrane encapsulation. Specifically, we studied the crosslinked hydrogels by using...... electrochemical impedance spectroscopy (EIS), and we demonstrated that chemically crosslinked hydrogels had lower values for the effective electrical resistance and higher values for the electrical capacitance compared with hydrogels with photoinitiated crosslinking. Transport numbers were obtained using......〉 and 〈Pw〉 values than PEG‐1000‐DMA‐P and PEG‐400‐DA‐P hydrogels. In conclusion, our results show that hydrogel electrochemical properties can be controlled by the choice of polymer and type of crosslinking used and that their water and salt permeability properties are congruent with the use of hydrogels...

Biomimetic Flow Sensors

NARCIS (Netherlands)

Casas, J.; Liu, Chang; Krijnen, Gijsbertus J.M.

2012-01-01

Biomimetic flow sensors are biologically inspired devices that measure the speed and direction of fluids. This survey starts by describing the role and functioning of airflow-sensing hairs in arthropods and in fishes, carries on with the biomimetic MEMS implementations, both for air and water flow

Towards supported bolaamphiphile membranes for water filtration: Roles of lipid and substrate

NARCIS (Netherlands)

Kaufman, Y.; Grinberg, S.; Linder, C..; Heldman, E.; Gilron, J.; Shen, Yue-xiao; Kumar, M.; Lammertink, Rob G.H.; Freger, V.

2014-01-01

Supported biomimetic membranes hold potential for applications such as biosensors and water purification by filtration. The current paper reports on the preparation of a supported bolaamphiphile membrane on two polymeric nanofiltration membranes: NF-270 made of polyamide with carboxylic surface

Biomimetics in drug delivery systems: A critical review.

Science.gov (United States)

Sheikhpour, Mojgan; Barani, Leila; Kasaeian, Alibakhsh

2017-05-10

Today, the advanced drug delivery systems have been focused on targeted drug delivery fields. The novel drug delivery is involved with the improvement of the capacity of drug loading in drug carriers, cellular uptake of drug carriers, and the sustained release of drugs within target cells. In this review, six groups of therapeutic drug carriers including biomimetic hydrogels, biomimetic micelles, biomimetic liposomes, biomimetic dendrimers, biomimetic polymeric carriers and biomimetic nanostructures, are studied. The subject takes advantage of the biomimetic methods of productions or the biomimetic techniques for the surface modifications, similar to what accrues in natural cells. Moreover, the effects of these biomimetic approaches for promoting the drug efficiency in targeted drug delivery are visible. The study demonstrates that the fabrication of biomimetic nanocomposite drug carriers could noticeably promote the efficiency of drugs in targeted drug delivery systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Micro-patterned Nafion membranes for direct methanol fuel cell applications

NARCIS (Netherlands)

Yildirim, M.H.; te Braake, J.; Aran, H.C.; Stamatialis, Dimitrios; Wessling, Matthias

2010-01-01

In this work, we report the direct methanol fuel cell (DMFC) performance of micro-patterned (μp) Nafion® 117 (N117) membranes prepared by hot embossing and compare them with that of normal N117 and heat and pressure treated (hp) N117 non-patterned (smooth) membranes. Our results suggest that the

Biomimetic architectures by plasma processing fabrication and applications

CERN Document Server

Chattopadhyay, Surojit

2014-01-01

Photonic structures in the animal kingdom: valuable inspirations for bio-mimetic applications. Moth eye-type anti-reflecting nanostructures by an electron cyclotron resonance plasma. Plasma-processed biomimetic nano/microstructures. Wetting properties of natural and plasma processed biomimetic surfaces. Biomimetic superhydrophobic surface by plasma processing. Biomimetic interfaces of plasma modified titanium alloy.

Separation of Peptides with Forward Osmosis Biomimetic Membranes

DEFF Research Database (Denmark)

Bajraktari, Niada; Madsen, Henrik T; Gruber, Mathias Felix

2016-01-01

Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions...

Separation of Peptides with Forward Osmosis Biomimetic Membranes

OpenAIRE

Bajraktari, Niada; Madsen, Henrik T.; Gruber, Mathias F.; Truelsen, Sigurd; Jensen, Elzbieta L.; Jensen, Henrik; H?lix-Nielsen, Claus

2016-01-01

Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of...

Separation of Peptides with Forward Osmosis Biomimetic Membranes

Science.gov (United States)

Bajraktari, Niada; Madsen, Henrik T.; Gruber, Mathias F.; Truelsen, Sigurd; Jensen, Elzbieta L.; Jensen, Henrik; Hélix-Nielsen, Claus

2016-01-01

Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of larger biomolecules with often flexible conformations. In this study, transport of two chemically similar peptides with molecular weight (Mw) of 375 and 692 Da across a thin film composite Aquaporin Inside™ Membrane (AIM) FO membrane was investigated. Despite the relative large size, both peptides were able to permeate the dense active layer of the AIM membrane and the transport mechanism was determined to be diffusion-based. Interestingly, the membrane permeability increased 3.65 times for the 692 Da peptide (1.39 × 10−12 m2·s−1) compared to the 375 Da peptide (0.38 × 10−12 m2·s−1). This increase thus occurs for an 85% increase in Mw but only for a 34% increase in peptide radius of gyration (Rg) as determined from molecular dynamics (MD) simulations. This suggests that Rg is a strong influencing factor for membrane permeability. Thus, an increased Rg reflects the larger peptide chains ability to sample a larger conformational space when interacting with the nanostructured active layer increasing the likelihood for permeation. PMID:27854275

Biomimetic electroactive polyimide with rose petal-like surface structure for anticorrosive coating application

Directory of Open Access Journals (Sweden)

W. F. Ji

2017-08-01

Full Text Available In this work, an electroactive polyimide (EPI coating with biomimetic surface structure of rose petal used in anticorrosion application was first presented. First of all, amino-capped aniline trimer (ACAT was synthesized by oxidative coupling reaction, followed by characterized through Fourier transform infrared spectroscooy (FTIR, liquid chromatography – mass spcerometry (LC-MS and proton nuclear magnetic resonance (1H-NMR spectroscopy. Subsequently, as-prepared ACAT was reacted with isopropylidenediphenoxy-bis(phthalic anhydride (BPADA to give electroactive poly(amic acid (EPAA. Moreover, poly(dimethylsiloxane (PDMS was used to be the soft negative template for pattern transfer from the surface of rose petal to the surface of polymer coating. The EPI coating with biomimetic structure was obtained by programmed heating the EPAA slurry casting onto the negative PDMS template. The anticorrosive performance of as-prepared biomimetic EPI coating was demonstrated by performing a series of electrochemical measurements (Tafel, Nyquist, and Bode plots upon cold-rolled steel (CRS electrode in a NaCl aqueous solution. It should be noted that the biomimetic EPI coating with rose petal-like structure was found to exhibit better anticorrosion than that of EPI without biomimetic structure. Moreover, the surface contact angle of water droplets for biomimetic EPI coating was found to be ~150°, which is significantly higher than that of EPI coating with smooth structure (~87°, indicating that the EPI coating with biomimetic structure reveals better hydrophobicity. The apparent mechanism for improved anticorrosive properties is twofold: (1 the biomimetic structure of EPI coating can repel water droplets. (2 electroactivity of EPI coating promotes the formation of densely passive layer of metal oxide on metallic surface.

Zwitterionic materials for antifouling membrane surface construction.

Science.gov (United States)

He, Mingrui; Gao, Kang; Zhou, Linjie; Jiao, Zhiwei; Wu, Mengyuan; Cao, Jialin; You, Xinda; Cai, Ziyi; Su, Yanlei; Jiang, Zhongyi

2016-08-01

Membrane separation processes are often perplexed by severe and ubiquitous membrane fouling. Zwitterionic materials, keeping electric neutrality with equivalent positive and negative charged groups, are well known for their superior antifouling properties and have been broadly utilized to construct antifouling surfaces for medical devices, biosensors and marine coatings applications. In recent years, zwitterionic materials have been more and more frequently utilized for constructing antifouling membrane surfaces. In this review, the antifouling mechanisms of zwitterionic materials as well as their biomimetic prototypes in cell membranes will be discussed, followed by the survey of common approaches to incorporate zwitterionic materials onto membrane surfaces including surface grafting, surface segregation, biomimetic adhesion, surface coating and so on. The potential applications of these antifouling membranes are also embedded. Finally, we will present a brief perspective on the future development of zwitterionic materials modified antifouling membranes. Membrane fouling is a severe problem hampering the application of membrane separation technology. The properties of membrane surfaces play a critical role in membrane fouling and antifouling behavior/performance. Antifouling membrane surface construction has evolved as a hot research issue for the development of membrane processes. Zwitterionic modification of membrane surfaces has been recognized as an effective strategy to resist membrane fouling. This review summarizes the antifouling mechanisms of zwitterionic materials inspired by cell membranes as well as the popular approaches to incorporate them onto membrane surfaces. It can help form a comprehensive knowledge about the principles and methods of modifying membrane surfaces with zwitterionic materials. Finally, we propose the possible future research directions of zwitterionic materials modified antifouling membranes. Copyright © 2016 Acta Materialia Inc

Gambogic acid-loaded biomimetic nanoparticles in colorectal cancer treatment

Directory of Open Access Journals (Sweden)

Zhang Z

2017-02-01

Full Text Available Zhen Zhang,1 Hanqing Qian,2 Mi Yang,2 Rutian Li,2 Jing Hu,1 Li Li,1 Lixia Yu,2 Baorui Liu,1,2 Xiaoping Qian1,2 1Comprehensive Cancer Center, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, 2Comprehensive Cancer Center, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute, Nanjing University, Nanjing, China Abstract: Gambogic acid (GA is expected to be a potential new antitumor drug, but its poor aqueous solubility and inevitable side effects limit its clinical application. Despite these inhe­rent defects, various nanocarriers can be used to promote the solubility and tumor targeting of GA, improving antitumor efficiency. In addition, a cell membrane-coated nanoparticle platform that was reported recently, unites the customizability and flexibility of a synthetic copolymer, as well as the functionality and complexity of natural membrane, and is a new synthetic biomimetic nanocarrier with improved stability and biocompatibility. Here, we combined poly(lactic-co-glycolic acid (PLGA with red blood-cell membrane (RBCm, and evaluated whether GA-loaded RBCm nanoparticles can retain and improve the antitumor efficacy of GA with relatively lower toxicity in colorectal cancer treatment compared with free GA. We also confirmed the stability, biocompatibility, passive targeting, and few side effects of RBCm-GA/PLGA nanoparticles. We expect to provide a new drug carrier in the treatment of colorectal cancer, which has strong clinical application prospects. In addition, the potential antitumor drug GA and other similar drugs could achieve broader clinical applications via this biomimetic nanocarrier. Keywords: gambogic acid, nanocarriers, RBCm-GA/PLGA nanoparticles, colorectal cancer

Biomimetic thin film synthesis

Energy Technology Data Exchange (ETDEWEB)

Graff, G.L.; Campbell, A.A.; Gordon, N.R.

1995-05-01

The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

Modal radiation patterns of baffled circular plates and membranes.

Science.gov (United States)

Christiansen, Thomas Lehrmann; Hansen, Ole; Thomsen, Erik Vilain; Jensen, Jørgen Arendt

2014-05-01

The far field velocity potential and radiation pattern of baffled circular plates and membranes are found analytically using the full set of modal velocity profiles derived from the corresponding equation of motion. The derivation is valid for a plate or membrane subjected to an external excitation force, which is used as a sound receiver in any medium or as a sound transmitter in a gaseous medium. A general, concise expression is given for the radiation pattern of any mode of the membrane and the plate with arbitrary boundary conditions. Specific solutions are given for the four special cases of a plate with clamped, simply supported, and free edge boundary conditions as well as for the membrane. For all non-axisymmetric modes, the velocity potential along the axis of the radiator is found to be strictly zero. In the long wavelength limit, the radiation pattern of all axisymmetric modes approaches that of a monopole, while the non-axisymmetric modes exhibit multipole behavior. Numerical results are also given, demonstrating the implications of having non-axisymmetric excitation using both a point excitation with varying eccentricity and a homogeneous excitation acting on half of the circular radiator.

Early Forming a Hummingbird-like Hovering Neural Network Circuitry Pattern with Reentrant Spatiotemporal Energy-Sensory Orientation Privileged to Avoid “Epilepsy” Based on a Biomimetic Acetylcholinesterase Memcapacitor Prosthesis

Directory of Open Access Journals (Sweden)

Ellen T. Chen

2015-08-01

Full Text Available The hummingbird’s significant asymmetry hovering flight with energy conservation pattern is remarkable among all vertebrates. However, little is known to human’s neuronal network circuitry current flow pattern for whether or not has this privilege during slow wave sleeping (SWS. What is the advantage in order to avoid diseases if we have this network pattern ? A memory device was developed with nanostructured biomimetic acetylcholinesterase (ACHE gorge membrane on gold chips as memcapacitor 1, served as a normal brain network prosthesis, compared with a mutated ACHE prosthesis as device 2, for evaluation of neuronal network circuitry integrity in the presence of Amyloid- beta (Ab under the conditions of free from tracers and antibodies in spiked NIST SRM 965A human serum. Three categories of Reentrant Energy-Sensory images are presented based on infused brain pulse energies in a matrix of “Sensory Biomarkers” having frequencies over 0.25-333 Hz at free and fixed Ab levels, respectively. Early non-symptomatic epilepsy was indentified and predicted by device 2 due to Pathological High Frequency Oscillation (pHFO and large areas of 38 µM Ab re-depositions. Device 1 sensitively “feels” Ab damage because of its Frequency Oscillation (HFO enhanced the hummingbird- like hovering pattern with higher reentrant energy sensitivity of 0.12 pj/bit/s/µm3 without Ab compared with Ab, 13 aj/bit/s/µm3/nM over 3.8-471 nM range over 0.003-4s. Device 1 reliably detected early CR dysfunction privileged to avoid epilepsy.

A biomimetic membrane device that modulates the excessive inflammatory response to sepsis.

Directory of Open Access Journals (Sweden)

Feng Ding

Full Text Available OBJECTIVE: Septic shock has a clinical mortality rate approaching fifty percent. The major clinical manifestations of sepsis are due to the dysregulation of the host's response to infection rather than the direct consequences of the invading pathogen. Central to this initial immunologic response is the activation of leukocytes and microvascular endothelium resulting in cardiovascular instability, lung injury and renal dysfunction. Due to the primary role of leukocyte activation in the sepsis syndrome, a synthetic biomimetic membrane, called a selective cytopheretic device (SCD, was developed to bind activated leukocytes. The incorporation of the SCD along an extracorporeal blood circuit coupled with regional anticoagulation with citrate to lower blood ionized calcium was devised to modulate leukocyte activation in sepsis. DESIGN: Laboratory investigation. SETTING: University of Michigan Medical School. SUBJECTS: Pigs weighing 30-35 kg. INTERVENTIONS: To assess the effect of the SCD in septic shock, pigs were administered 30×10(10 bacteria/kg body weight of Escherichia coli into the peritoneal cavity and within 1 hr were immediately placed in an extracorporeal circuit containing SCD. MEASUREMENTS AND MAIN RESULTS: In this animal model, the SCD with citrate compared to control groups without the SCD or with heparin anticoagulation ameliorated the cardiovascular instability and lung sequestration of activated leukocytes, reduced renal dysfunction and improved survival time compared to various control groups. This effect was associated with minimal elevations of systemic circulating neutrophil activation. CONCLUSIONS: These preclinical studies along with two favorable exploratory clinical trials form the basis of an FDA-approved investigational device exemption for a pivotal multicenter, randomized control trial currently underway.

COST Action CM1201 "Biomimetic Radical Chemistry": free radical chemistry successfully meets many disciplines

Czech Academy of Sciences Publication Activity Database

Ferreri, C.; Golding, B. T.; Jahn, Ullrich; Ravanat, J. L.

2016-01-01

Roč. 50, Suppl 1 (2016), S112-S128 ISSN 1071-5762 Institutional support: RVO:61388963 Keywords : radical enzyme * membrane stress * phospholipid remodeling * DNA damage and repair * biomimetic models * bio-inspired synthetic methodologies Subject RIV: CC - Organic Chemistry Impact factor: 3.188, year: 2016 http://www.tandfonline.com/doi/full/10.1080/10715762.2016.1248961

Multifunctional surfaces with biomimetic nanofibres and drug-eluting micro-patterns for infection control and bone tissue formation

Directory of Open Access Journals (Sweden)

XN Chen

2012-09-01

Full Text Available For long-term orthopaedic implants, the creation of a surface that is repulsive to bacteria while adhesive to tissue cells represents a promising strategy to control infection. To obtain such multifunctional surfaces, two possible approaches were explored to incorporate a model antibiotic, rifampicin (Rf, into the osteogenic polycaprolactone (PCL/chitosan (CHS biomimetic nanofibre meshes by (1 blending Rf into the electrospinning solutions and then electrospinning into nanofibres (i.e., Rf-incorporating fibres, or (2 depositing Rf-containing poly(D,L-lactic-co-glycolic acid (PLGA micro-patterns onto the PCL/chitosan nanofibre meshes via ink-jet printing (i.e., Rf-eluting micro-pattern/fibre. Rapid release of Rf from both meshes was measured even though a relatively slower release rate was obtained from the Rf-eluting micro-pattern ones. Antibacterial assay with Staphylococcus epidermidis showed that both mesh surfaces could effectively kill bacteria and prevent biofilm formation. However, only Rf-eluting micro-pattern meshes favoured the attachment, spreading and metabolic activity of preosteoblasts in the cell culture study. Furthermore, the Rf-eluting micro-pattern meshes could better support the osteogenic differentiation of preosteoblasts by up-regulating the gene expression of bone markers (type I collagen and alkaline phosphatase. Clearly, compared to Rf-incorporating nanofibre meshes, Rf-eluting micro-patterns could effectively prevent biofilm formation without sacrificing the osteogenic properties of PCL/chitosan nanofibre surfaces. This finding provides an innovative avenue to design multifunctional surfaces for enhancing bone tissue formation while controlling infection.

Biomimetic engineering: towards a self-assembled nanotechnology

International Nuclear Information System (INIS)

Braach-Maksvytis, V.

2002-01-01

Full text: The Nanoscience and Systems program was set up within CSIRO Telecommunications and Industrial Physics three years ago with an emphasis on biomimetic engineering, with the aim of developing new cross-disciplinary research in traditional physics areas. By combining expertise in experimental and theoretical physics with biology and chemistry, new approaches towards understanding and using nanoscale systems and devices are being explored. Research in the program ranges from using self-assembled lipid membranes for surface passivation of GaAs transistors to the electrical properties of nanoparticle films and devices. An overview of the research will be given, highlighting the diversity of nanotechnology applications

Biomimetics

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

Biomimetics is the field of scientific endeavour, which attempts to design systems and syn- thesise materials through ... natural systems with a view to achieve analogous synthetic design and manufacture. On the ..... Industrial production.

Synthesis of Nanogels via Cell Membrane-Templated Polymerization.

Science.gov (United States)

Zhang, Jianhua; Gao, Weiwei; Fang, Ronnie H; Dong, Anjie; Zhang, Liangfang

2015-09-09

The synthesis of biomimetic hydrogel nanoparticles coated with a natural cell membrane is described. Compared to the existing strategy of wrapping cell membranes onto pre-formed nanoparticle substrates, this new approach forms the cell membrane-derived vesicles first, followed by growing nanoparticle cores in situ. It adds significant controllability over the nanoparticle properties and opens unique opportunities for a broad range of biomedical applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and characterization of tethered lipid assemblies for membrane protein reconstitution (Review).

Science.gov (United States)

Veneziano, Rémi; Rossi, Claire; Chenal, Alexandre; Brenner, Catherine; Ladant, Daniel; Chopineau, Joël

2017-09-28

Biological membranes and their related molecular mechanisms are essential for all living organisms. Membranes host numerous proteins and are responsible for the exchange of molecules and ions, cell signaling, and cell compartmentation. Indeed, the plasma membrane delimits the intracellular compartment from the extracellular environment and intracellular membranes. Biological membranes also play a major role in metabolism regulation and cellular physiology (e.g., mitochondrial membranes). The elaboration of membrane based biomimetic systems allows us to reconstitute and investigate, in controlled conditions, biological events occurring at the membrane interface. A whole variety of model membrane systems have been developed in the last few decades. Among these models, supported membranes were developed on various hydrophilic supports. The use of solid supports enables the direct use of surface sensitive techniques (e.g., surface plasmon resonance, quartz crystal microbalance, and atomic force microscopy) to monitor and quantify events occurring at the membrane surface. Tethered bilayer membranes (tBLMs) could be considered as an achievement of the first solid supported membranes described by the McConnell group. Tethered bilayers on solid supports were designed to delimit an inside compartment from an outside one. They were used for measuring interactions with ligands or incorporating large membrane proteins or complexes without interference with the support. In this context, the authors developed an easy concept of versatile tBLMs assembled on amino coated substrates that are formed upon the vesicle fusion rupture process applicable to protein-free vesicles as well as proteoliposomes. The phospholipid bilayer (natural or synthetic lipids) incorporated 5% of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly ethylene glycol-N-hydroxy succinimide to ensure the anchorage of the bilayer to the amino coated surface. The conditions for the formation of tBLMs on amino

Assessing the efficacy of vesicle fusion with planar membrane arrays using a mitochondrial porin as reporter

DEFF Research Database (Denmark)

Pszon-Bartosz, Kamila Justyna; Hansen, Jesper S.; Stibius, Karin B.

2011-01-01

Reconstitution of functionally active membrane protein into artificially made lipid bilayers is a challenge that must be overcome to create a membrane-based biomimetic sensor and separation device. In this study we address the efficacy of proteoliposome fusion with planar membrane arrays. We...... establish a protein incorporation efficacy assay using the major non-specific porin of Fusobacterium nucleatum (FomA) as reporter. We use electrical conductance measurements and fluorescence microscopy to characterize proteoliposome fusion with an array of planar membranes. We show that protein...... reconstitution in biomimetic membrane arrays may be quantified using the developed FomA assay. Specifically, we show that FomA vesicles are inherently fusigenic. Optimal FomA incorporation is obtained with a proteoliposome lipid-to-protein molar ratio (LPR)=50 more than 105 FomA proteins could be incorporated...

Biomimetic nanoparticles for inflammation targeting

Directory of Open Access Journals (Sweden)

Kai Jin

2018-01-01

Full Text Available There have been many recent exciting developments in biomimetic nanoparticles for biomedical applications. Inflammation, a protective response involving immune cells, blood vessels, and molecular mediators directed against harmful stimuli, is closely associated with many human diseases. As a result, biomimetic nanoparticles mimicking immune cells can help achieve molecular imaging and precise drug delivery to these inflammatory sites. This review is focused on inflammation-targeting biomimetic nanoparticles and will provide an in-depth look at the design of these nanoparticles to maximize their benefits for disease diagnosis and treatment.

Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

International Nuclear Information System (INIS)

Wang Zhenlong; Hang Guanrong; Wang Yangwei; Li Jian; Du Wei

2008-01-01

An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s −1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s −1 and 22° s −1 , respectively

Biomimetics: determining engineering opportunities from nature

Science.gov (United States)

Fish, Frank E.

2009-08-01

The biomimetic approach seeks to incorporate designs based on biological organisms into engineered technologies. Biomimetics can be used to engineer machines that emulate the performance of organisms, particularly in instances where the organism's performance exceeds current mechanical technology or provides new directions to solve existing problems. For biologists, an adaptationist program has allowed for the identification of novel features of organisms based on engineering principles; whereas for engineers, identification of such novel features is necessary to exploit them for biomimetic development. Adaptations (leading edge tubercles to passively modify flow and high efficiency oscillatory propulsive systems) from marine animals demonstrate potential utility in the development of biomimetic products. Nature retains a store of untouched knowledge, which would be beneficial in advancing technology.

Sensing in nature: using biomimetics for design of sensors

DEFF Research Database (Denmark)

Lenau, Torben Anker; Cheong, Hyunmin; Shu, Li

2010-01-01

The paper illustrates how biomimetics can be applied in sensor design. Biomimetics is an engineering discipline that uses nature as an inspiration source for generating ideas for how to solve engineering problems. Using biomimetics involves a search for relevant cases, a proper analysis...... of biomimetic studies of sense organs in animals....

Biomimetic electrochemistry from conducting polymers. A review

International Nuclear Information System (INIS)

Otero, T.F.; Martinez, J.G.; Arias-Pardilla, J.

2012-01-01

Highlights: ► Composition and properties of conducting polymers change during reactions. ► These properties are being exploited to develop biomimetic reactive and soft devices. ► The state of the art for artificial muscles sensing working conditions was reviewed. ► Smart membranes, drug delivery devices and nervous interfaces were also reviewed. - Abstract: Films of conducting polymers in the presence of electrolytes can be oxidized or reduced by the flow of anodic or cathodic currents. Ions and solvent are exchanged during a reaction for charge and osmotic pressure balance. A reactive conducting polymer contains ions and solvent. Such variation of composition during a reaction is reminiscent of the biological processes in cells. Along changes to the composition of the material during a reaction, there are also changes to other properties, including: volume (electrochemomechanical), colour (electrochromic), stored charge (electrical storage), porosity or permselectivity (electroporosity), stored chemicals, wettability and so on. Most of those properties mimic similar property changes in organs during their functioning. These properties are being exploited to develop biomimetic reactive and soft devices: artificial muscles and polymeric actuators; supercapacitors and all organic batteries; smart membranes; electron-ion transducers; nervous interfaces and artificial synapses, or drug delivery devices. In this review we focus on the state of the art for artificial muscles, smart membranes and electron-ion transducers. The reactive nature of those devices provide them with a unique advantage related to the present days technologies: any changes in the surrounding physical or chemical variable acting on the electrochemical reaction rate will be sensed by the device while working. Working under constant current (driving signal), the evolution of the device potential or the evolution of the consumed electrical energy (sensing signals) senses and quantifies the

Bio-mimetic Flow Control

Science.gov (United States)

Choi, Haecheon

2009-11-01

Bio-mimetic engineering or bio-mimetics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology (from Wikipedia). The concept itself is old, but successful developments have been made recently, especially in the research field of flow control. The objective of flow control based on the bio-mimetic approach is to develop novel concepts for reducing drag, increasing lift and enhancing aerodynamic performance. For skin friction reduction, a few ideas have been suggested such as the riblet from shark, compliant surface from dolphin, microbubble injection and multiple front-body curvature from penguin, and V-shaped protrusion from sailfish. For form drag reduction, several new attempts have been also made recently. Examples include the V-shaped spanwise grooves from saguaro cactus, overall shape of box fish, longitudinal grooves on scallop shell, bill of swordfish, hooked comb on owl wing, trailing-edge protrusion on dragonfly wing, and fillet. For the enhancement of aerodynamic performance, focuses have been made on the birds, fish and insects: e.g., double layered feather of landing bird, leading-edge serration of humpback-whale flipper, pectoral fin of flying fish, long tail on swallowtail-butterfly wing, wing flapping motion of dragonfly, and alula in birds. Living animals adapt their bodies to better performance in multi purposes, but engineering requires single purpose in most cases. Therefore, bio-mimetic approaches often produce excellent results more than expected. However, they are sometimes based on people's wrong understanding of nature and produce unwanted results. Successes and failures from bio-mimetic approaches in flow control will be discussed in the presentation.

Polymeric membrane materials for artificial organs.

Science.gov (United States)

Kawakami, Hiroyoshi

2008-01-01

Many polymeric materials have already been used in the field of artificial organs. However, the materials used in artificial organs are not necessarily created with the best material selectivity and materials design; therefore, the development of synthesized polymeric membrane materials for artificial organs based on well-defined designs is required. The approaches to the development of biocompatible polymeric materials fall into three categories: (1) control of physicochemical characteristics on material surfaces, (2) modification of material surfaces using biomolecules, and (3) construction of biomimetic membrane surfaces. This review will describe current issues regarding polymeric membrane materials for use in artificial organs.

Axial ion channeling patterns from ultra-thin silicon membranes

International Nuclear Information System (INIS)

Motapothula, M.; Dang, Z.Y.; Venkatesan, T.; Breese, M.B.H.; Rana, M.A.; Osman, A.

2012-01-01

We present channeling patterns produced by MeV protons transmitted through 55 nm thick [0 0 1] silicon membranes showing the early evolution of the axially channeled beam angular distribution for small tilts away from the [0 0 1], [0 1 1] and [1 1 1] axes. Instead of a ring-like “doughnut” distribution previously observed at small tilts to major axes in thicker membranes, geometric shapes such as squares and hexagons are observed along different axes in ultra-thin membranes. The different shapes arise because of the highly non-equilibrium transverse momentum distribution of the channeled beam during its initial propagation in the crystal and the reduced multiple scattering which allows the fine angular structure to be resolved. We describe a simple geometric construction of the intersecting planar channels at an axis to gain insight into the origin of the geometric shapes observed in such patterns and how they evolve into the ‘doughnut’ distributions in thicker crystals.

Vibrations and spatial patterns in biomimetic surfaces: using the shark-skin effect to control blood clotting.

Science.gov (United States)

Ramachandran, Rahul; Maani, Nazanin; Rayz, Vitaliy L; Nosonovsky, Michael

2016-08-06

We study the effect of small-amplitude fast vibrations and small-amplitude spatial patterns on various systems involving wetting and liquid flow, such as superhydrophobic surfaces, membranes and flow pipes. First, we introduce a mathematical method of averaging the effect of small spatial and temporal patterns and substituting them with an effective force. Such an effective force can change the equilibrium state of a system as well as a phase state, leading to surface texture-induced and vibration-induced phase control. Vibration and patterns can effectively jam holes in vessels with liquid, separate multi-phase flow, change membrane properties, result in propulsion and locomotion and lead to many other multi-scale, nonlinear effects including the shark-skin effect. We discuss the application of such effects to blood flow for novel biomedical 'haemophobic' applications which can prevent blood clotting and thrombosis by controlling the surface pattern at a wall of a vessel (e.g. a catheter or stent).This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

An anti-bacterial approach to nanoscale roughening of biomimetic rice-like pattern PP by thermal annealing

Science.gov (United States)

Jafari Nodoushan, Emad; Ebrahimi, Nadereh Golshan; Ayazi, Masoumeh

2017-11-01

In this paper, we introduced thermal annealing treatment as an effective way of increasing the nanoscale roughness of a semi-crystalline polymer surface. Annealing treatment applied to a biomimetic microscale pattern of rice leaf to achieve a superhydrophobic surface with a hierarchical roughness. Resulted surfaces was characterized by XRD, AFM and FE-SEM instruments and showed an increase of roughness and cristallinity within both time and temperature of treatment. These two parameters also impact on measured static contact angle up to 158°. Bacterial attachment potency has an inverse relationship with the similarity of surface pattern dimensions and bacterial size and due to that, thermal annealing could be an effective way to create anti-bacterial surface beyond its effect on water repellency. Point in case, the anti-bacterial properties of produced water-repellence surfaces of PP were measured and counted colonies of both gram-negative (E. coli) and gram-positive (S. aureus) bacteria reduced with the nature of PP and hierarchical pattern on that. Anti-bacterial characterization of the resulted surface reveals a stunning reduction in adhesion of gram-positive bacteria to the surface. S. aureus reduction rates equaled to 95% and 66% when compared to control blank plate and smooth surface of PP. Moreover, it also could affect the other type of bacteria, gram-negative (E. coli). In the latter case, adhesion reduction rates calculated 66% and 53% when against to the same controls, respectively.

Biomimetics

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

Abstract. The well-organised multifunctional structures, systems and biogenic materials found in nature have attracted the interest of scientists working in many disciplines. The efforts have resulted in the development of a new and rapidly growing field of scientific effort called biomimetics. In this article we present a.

Biomimetic micromechanical adaptive flow-sensor arrays

Science.gov (United States)

Krijnen, Gijs; Floris, Arjan; Dijkstra, Marcel; Lammerink, Theo; Wiegerink, Remco

2007-05-01

We report current developments in biomimetic flow-sensors based on flow sensitive mechano-sensors of crickets. Crickets have one form of acoustic sensing evolved in the form of mechanoreceptive sensory hairs. These filiform hairs are highly perceptive to low-frequency sound with energy sensitivities close to thermal threshold. In this work we describe hair-sensors fabricated by a combination of sacrificial poly-silicon technology, to form silicon-nitride suspended membranes, and SU8 polymer processing for fabrication of hairs with diameters of about 50 μm and up to 1 mm length. The membranes have thin chromium electrodes on top forming variable capacitors with the substrate that allow for capacitive read-out. Previously these sensors have been shown to exhibit acoustic sensitivity. Like for the crickets, the MEMS hair-sensors are positioned on elongated structures, resembling the cercus of crickets. In this work we present optical measurements on acoustically and electrostatically excited hair-sensors. We present adaptive control of flow-sensitivity and resonance frequency by electrostatic spring stiffness softening. Experimental data and simple analytical models derived from transduction theory are shown to exhibit good correspondence, both confirming theory and the applicability of the presented approach towards adaptation.

Evolving application of biomimetic nanostructured hydroxyapatite

Directory of Open Access Journals (Sweden)

Norberto Roveri

2010-11-01

Full Text Available Norberto Roveri, Michele IafiscoLaboratory of Environmental and Biological Structural Chemistry (LEBSC, Dipartimento di Chimica ‘G. Ciamician’, Alma Mater Studiorum, Università di Bologna, Bologna, ItalyAbstract: By mimicking Nature, we can design and synthesize inorganic smart materials that are reactive to biological tissues. These smart materials can be utilized to design innovative third-generation biomaterials, which are able to not only optimize their interaction with biological tissues and environment, but also mimic biogenic materials in their functionalities. The biomedical applications involve increasing the biomimetic levels from chemical composition, structural organization, morphology, mechanical behavior, nanostructure, and bulk and surface chemical–physical properties until the surface becomes bioreactive and stimulates cellular materials. The chemical–physical characteristics of biogenic hydroxyapatites from bone and tooth have been described, in order to point out the elective sides, which are important to reproduce the design of a new biomimetic synthetic hydroxyapatite. This review outlines the evolving applications of biomimetic synthetic calcium phosphates, details the main characteristics of bone and tooth, where the calcium phosphates are present, and discusses the chemical–physical characteristics of biomimetic calcium phosphates, methods of synthesizing them, and some of their biomedical applications.Keywords: hydroxyapatite, nanocrystals, biomimetism, biomaterials, drug delivery, remineralization

Probing the interactions of mitoxantrone with biomimetic membranes with electrochemical and spectroscopic techniques

International Nuclear Information System (INIS)

Nieciecka, Dorota; Królikowska, Agata; Krysinski, Paweł

2015-01-01

Graphical abstract: Display Omitted - Abstract: Mitoxantrone – an anticancer drug – was used to probe the interactions of this class of cytostatic molecules with biomimetic monolayers. The drug effect was monitored with electrochemical (cyclic voltammetry and electrochemical impedance spectroscopy), as well as spectroscopic techniques (surface enhanced Raman scattering), during its passive partitioning/penetration through the mixed Langmuir and Langmuir–Blodgett monolayers after their transfer on gold electrodes. This approach allowed us to discriminate between the drug interactions with hydrophilic head-group region and hydrophobic alkyl chains moiety of such monolayers

Biomimetic vibrissal sensing for robots.

Science.gov (United States)

Pearson, Martin J; Mitchinson, Ben; Sullivan, J Charles; Pipe, Anthony G; Prescott, Tony J

2011-11-12

Active vibrissal touch can be used to replace or to supplement sensory systems such as computer vision and, therefore, improve the sensory capacity of mobile robots. This paper describes how arrays of whisker-like touch sensors have been incorporated onto mobile robot platforms taking inspiration from biology for their morphology and control. There were two motivations for this work: first, to build a physical platform on which to model, and therefore test, recent neuroethological hypotheses about vibrissal touch; second, to exploit the control strategies and morphology observed in the biological analogue to maximize the quality and quantity of tactile sensory information derived from the artificial whisker array. We describe the design of a new whiskered robot, Shrewbot, endowed with a biomimetic array of individually controlled whiskers and a neuroethologically inspired whisking pattern generation mechanism. We then present results showing how the morphology of the whisker array shapes the sensory surface surrounding the robot's head, and demonstrate the impact of active touch control on the sensory information that can be acquired by the robot. We show that adopting bio-inspired, low latency motor control of the rhythmic motion of the whiskers in response to contact-induced stimuli usefully constrains the sensory range, while also maximizing the number of whisker contacts. The robot experiments also demonstrate that the sensory consequences of active touch control can be usefully investigated in biomimetic robots.

Biomimetic chromatographic analysis of selenium species: Application for the estimation of their pharmacokinetic properties

Energy Technology Data Exchange (ETDEWEB)

Tsopelas, Fotios [National Technical University of Athens, Laboratory of Inorganic and Analytical Chemistry, School of Chemical Engineering, Athens (Greece); University of Athens, Laboratory of Pharmaceutical Chemistry, School of Pharmacy, Athens (Greece); Tsantili-Kakoulidou, Anna [University of Athens, Laboratory of Pharmaceutical Chemistry, School of Pharmacy, Athens (Greece); Ochsenkuehn-Petropoulou, Maria [National Technical University of Athens, Laboratory of Inorganic and Analytical Chemistry, School of Chemical Engineering, Athens (Greece)

2010-07-15

The retention behavior of selenites, selenates, seleno-dl-methionine, selenocystine, selenocystamine, selenourea, dimethyl selenide, and dimethyl diselenide was investigated by means of biomimetic liquid chromatography. For this purpose, two immobilized artificial membrane (IAM) columns, namely, IAM.PC.DD2 and IAM.PC.MG, and two immobilized plasma protein columns, human serum albumin (HSA) and {alpha}{sub 1}-acid glycoprotein (AGP) columns, were employed using different mobile phase conditions in respect to pH and buffer composition. In general, satisfactory interrelations between retention factors obtained with the two IAM stationary phases and HSA/AGP columns were obtained. Large differences were observed between biomimetic retention factors and octanol-water logD values, since the latter fail to describe electrostatic interactions. In contrast, despite the column diversity, the net retention outcome on all four biomimetic columns was quite similar, especially in the presence of phosphate-buffered saline, which by its effective shielding alleviates the differences between the stationary phases. Of the two IAM columns, IAM.PC.DD2 showed better performance when compared with HSA and AGP columns as well as to octanol-water partitioning. Biomimetic chromatographic indices were further used to estimate the percentage of human oral absorption and plasma protein binding of the eight selenium species investigated, according to equations previously reported in the literature. The estimated values of human oral absorption imply moderate absorption only for dimethyl diselenide, which also may exhibit considerable plasma protein binding. Moderate affinity for plasma proteins should also be expected for dimethyl selenide and selenocystamine. (orig.)

Biomimetic Membranes for Water Purification and Wastewater Treatment

DEFF Research Database (Denmark)

Tang, Chuyang Y.; Wang, Zhining; Hélix-Nielsen, Claus

2016-01-01

Reverse osmosis (RO)-based desalination and wastewater reclamation are gaining increasing popularity driven by water shortages and population growth. Advances in membrane technology in the past few decades have resulted in great savings in energy consumption of RO processes. Further reduction...... in energy consumption calls for novel membranes with significantly enhanced water permeability compared to the current state of the art thin-film composite polyamides. An attractive option is to learn from nature's high efficiently water filtration systems that involve a group of specialised water transport...

Lateral Membrane Waves Constitute a Universal Dynamic Pattern of Motile Cells

Science.gov (United States)

Döbereiner, Hans-Günther; Dubin-Thaler, Benjamin J.; Hofman, Jake M.; Xenias, Harry S.; Sims, Tasha N.; Giannone, Grégory; Dustin, Michael L.; Wiggins, Chris H.; Sheetz, Michael P.

2006-07-01

We have monitored active movements of the cell circumference on specifically coated substrates for a variety of cells including mouse embryonic fibroblasts and T cells, as well as wing disk cells from fruit flies. Despite having different functions and being from multiple phyla, these cell types share a common spatiotemporal pattern in their normal membrane velocity; we show that protrusion and retraction events are organized in lateral waves along the cell membrane. These wave patterns indicate both spatial and temporal long-range periodic correlations of the actomyosin gel.

Biomimetic approaches for green tribology: from the lotus effect to blood flow control

International Nuclear Information System (INIS)

Maani, Nazanin; Rayz, Vitaliy S; Nosonovsky, Michael

2015-01-01

The research in Green tribology combines several areas including biomimetic tribomaterials and surfaces for controlled adhesion. Biomimetic surfaces mimic living nature and thus they are eco-friendly. The most famous biomimetic surface effect is the Lotus effect (reduction of water adhesion to a solid surface due to micro/nanostructuring of the solid surface). Several extensions of the Lotus effect have been discussed in the literature including the oleophobicity (repelling organic liquids such as oils), underwater oleophobicity to reduce fouling, and the shark skin effect (flow drag reduction due to specially oriented micro-riblets). Here we suggest a potentially important application of micro/nanostructured surfaces in the biomedical area: the micro/nanostructure controlled adhesion in blood flow. Blood is a suspension, and its adhesion properties are different from those of water and oil. For many cardiovascular applications, it is desirable to reduce stagnation and clotting of blood. Therefore, both the underwater oleophobicuity and shark-skin effect can be used. We discuss how computational fluid dynamics models can be used to investigate the structure–property relationships of surface pattern-controlled blood flow adhesion. (paper)

Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

Energy Technology Data Exchange (ETDEWEB)

Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing, E-mail: shisq@nwu.edu.cn; Gong, Yongkuan

2016-11-15

Highlights: • Biomimetic surface modification of PP was successfully conducted by integrating mussel-inspired technology, thiol chemistry and cell outer membranes-like structures. • The resultant biomimetic surface exhibits good interface and surface stability. • The obvious suppression of protein adsorption and platelet adhesion is also achieved. • The residue thoil groups on the surface could be further functionalized. - Abstract: Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH{sub 2}) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such

Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

International Nuclear Information System (INIS)

Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing; Gong, Yongkuan

2016-01-01

Highlights: • Biomimetic surface modification of PP was successfully conducted by integrating mussel-inspired technology, thiol chemistry and cell outer membranes-like structures. • The resultant biomimetic surface exhibits good interface and surface stability. • The obvious suppression of protein adsorption and platelet adhesion is also achieved. • The residue thoil groups on the surface could be further functionalized. - Abstract: Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH 2 ) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such

Biomimetics: forecasting the future of science, engineering, and medicine.

Science.gov (United States)

Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

2015-01-01

Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark's skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations.

Biomimetics: forecasting the future of science, engineering, and medicine

Science.gov (United States)

Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

2015-01-01

Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark’s skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations. PMID:26388692

Biomimetic magnetic nanocomposite for smart skins

KAUST Repository

Alfadhel, Ahmed; Kosel, Jü rgen

2015-01-01

We report a biomimetic tactile sensor consisting of magnetic nanocomposite artificial cilia and magnetic sensors. The nanocomposite is fashioned from polydimethylsiloxane and iron nanowires and exhibits a permanent magnetic behavior. This enables remote operation without an additional magnetic field to magnetize the nanowires, which simplifies device integration. Moreover, the highly elastic and easy patternable nanocomposite is corrosion resistant and thermally stable. The highly sensitive and power efficient tactile sensors can detect vertical and shear forces from interactions with objects. The sensors can operate in dry and wet environment with the ability to measure different properties such as the texture and the movement or stability of objects, with easily adjustable performance.

Biomimetic magnetic nanocomposite for smart skins

KAUST Repository

Alfadhel, Ahmed

2015-11-01

We report a biomimetic tactile sensor consisting of magnetic nanocomposite artificial cilia and magnetic sensors. The nanocomposite is fashioned from polydimethylsiloxane and iron nanowires and exhibits a permanent magnetic behavior. This enables remote operation without an additional magnetic field to magnetize the nanowires, which simplifies device integration. Moreover, the highly elastic and easy patternable nanocomposite is corrosion resistant and thermally stable. The highly sensitive and power efficient tactile sensors can detect vertical and shear forces from interactions with objects. The sensors can operate in dry and wet environment with the ability to measure different properties such as the texture and the movement or stability of objects, with easily adjustable performance.

Hydroxyapatite-doped polycaprolactone nanofiber membrane improves tendon-bone interface healing for anterior cruciate ligament reconstruction.

Science.gov (United States)

Han, Fei; Zhang, Peng; Sun, Yaying; Lin, Chao; Zhao, Peng; Chen, Jiwu

2015-01-01

Hamstring tendon autograft is a routine graft for anterior cruciate ligament (ACL) reconstruction. However, ways of improving the healing between the tendon and bone is often overlooked in clinical practice. This issue can be addressed by using a biomimetic scaffold. Herein, a biomimetic nanofiber membrane of polycaprolactone/nanohydroxyapatite/collagen (PCL/nHAp/Col) is fabricated that mimics the composition of native bone tissue for promoting tendon-bone healing. This membrane has good cytocompatibility, allowing for osteoblast cell adhesion and growth and bone formation. As a result, MC3T3 cells reveal a higher mineralization level in PCL/nHAp/Col membrane compared with PCL membrane alone. Further in vivo studies in ACL reconstruction in a rabbit model shows that PCL/nHAp/Col-wrapped tendon may afford superior tissue integration to nonwrapped tendon in the interface between the tendon and host bone as well as improved mechanical strength. This study shows that PCL/nHAp/Col nanofiber membrane wrapping of autologous tendon is effective for improving tendon healing with host bone in ACL reconstruction.

Biomimetics applied to centering in micro-assembly

DEFF Research Database (Denmark)

Shu, L.H.; Lenau, Torben Anker; Hansen, Hans Nørgaard

2003-01-01

This paper describes the application of a biomimetic search method to develop ideas for centering objects in micro-assembly. Biomimetics involves the imitation of biological phenomena to solve problems. An obstacle to the use of biomimetics in engineering is knowledge of biological phenomena...... that is relevant to the problem at hand. The method described here starts with an engineering problem, and then systematically searches for analogous biological phenomena using functional keywords. This method is illustrated by finding and using analogies for the problem of positioning and centering objects during...

The dynamic interplay of plasma membrane domains and cortical microtubules in secondary cell wall patterning

Directory of Open Access Journals (Sweden)

Yoshihisa eOda

2013-12-01

Full Text Available Patterning of the cellulosic cell wall underlies the shape and function of plant cells. The cortical microtubule array plays a central role in the regulation of cell wall patterns. However, the regulatory mechanisms by which secondary cell wall patterns are established through cortical microtubules remain to be fully determined. Our recent study in xylem vessel cells revealed that a mutual inhibitory interaction between cortical microtubules and distinct plasma membrane domains leads to distinctive patterning in secondary cell walls. Our research revealed that the recycling of active and inactive ROP proteins by a specific GAP and GEF pair establishes distinct de novo plasma membrane domains. Active ROP recruits a plant-specific microtubule-associated protein, MIDD1, which mediates the mutual interaction between cortical microtubules and plasma membrane domains. In this mini review, we summarize recent research regarding secondary wall patterning, with a focus on the emerging interplay between plasma membrane domains and cortical microtubules through MIDD1 and ROP.

Jacobsen Catalyst as a Cytochrome P450 Biomimetic Model for the Metabolism of Monensin A

Directory of Open Access Journals (Sweden)

Bruno Alves Rocha

2014-01-01

Full Text Available Monensin A is a commercially important natural product isolated from Streptomyces cinnamonensins that is primarily employed to treat coccidiosis. Monensin A selectively complexes and transports sodium cations across lipid membranes and displays a variety of biological properties. In this study, we evaluated the Jacobsen catalyst as a cytochrome P450 biomimetic model to investigate the oxidation of monensin A. Mass spectrometry analysis of the products from these model systems revealed the formation of two products: 3-O-demethyl monensin A and 12-hydroxy monensin A, which are the same ones found in in vivo models. Monensin A and products obtained in biomimetic model were tested in a mitochondrial toxicity model assessment and an antimicrobial bioassay against Staphylococcus aureus, S. aureus methicillin-resistant, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. Our results demonstrated the toxicological effects of monensin A in isolated rat liver mitochondria but not its products, showing that the metabolism of monensin A is a detoxification metabolism. In addition, the antimicrobial bioassay showed that monensin A and its products possessed activity against Gram-positive microorganisms but not for Gram-negative microorganisms. The results revealed the potential of application of this biomimetic chemical model in the synthesis of drug metabolites, providing metabolites for biological tests and other purposes.

Interaction of multiple biomimetic antimicrobial polymers with model bacterial membranes

Energy Technology Data Exchange (ETDEWEB)

Baul, Upayan, E-mail: upayanb@imsc.res.in; Vemparala, Satyavani, E-mail: vani@imsc.res.in [The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113 (India); Kuroda, Kenichi, E-mail: kkuroda@umich.edu [Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48109 (United States)

2014-08-28

Using atomistic molecular dynamics simulations, interaction of multiple synthetic random copolymers based on methacrylates on prototypical bacterial membranes is investigated. The simulations show that the cationic polymers form a micellar aggregate in water phase and the aggregate, when interacting with the bacterial membrane, induces clustering of oppositely charged anionic lipid molecules to form clusters and enhances ordering of lipid chains. The model bacterial membrane, consequently, develops lateral inhomogeneity in membrane thickness profile compared to polymer-free system. The individual polymers in the aggregate are released into the bacterial membrane in a phased manner and the simulations suggest that the most probable location of the partitioned polymers is near the 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) clusters. The partitioned polymers preferentially adopt facially amphiphilic conformations at lipid-water interface, despite lacking intrinsic secondary structures such as α-helix or β-sheet found in naturally occurring antimicrobial peptides.

Membrane engineering in biotechnology: quo vamus?

Science.gov (United States)

Rios, Gilbert M; Belleville, Marie-Pierre; Paolucci-Jeanjean, Delphine

2007-06-01

Membranes are essential to a range of applications, including the production of potable water, energy generation, tissue repair, pharmaceutical production, food packaging, and the separations needed for the manufacture of chemicals, electronics and a range of other products. Therefore, they are considered to be "dominant technologies" by governments and industry in several prominent countries--for example, USA, Japan and China. When combined with catalysts, membranes are at the basis of life, and membrane-based biomimetism is a key tool to obtain better quality products and environmentally friendly developments for our societies. Biology has a main part in this global landscape because it simultaneously provides the "model" (with natural biological membranes) and represents a considerable field of applications for new artificial membranes (biotreatments, bioconversions and artificial organs). In this article, our objective is to open up this enthralling area and to give our views about the future of membranes in biotechnology.

Biomimetic propulsion under random heaving conditions, using active pitch control

Science.gov (United States)

Politis, Gerasimos; Politis, Konstantinos

2014-05-01

Marine mammals travel long distances by utilizing and transforming wave energy to thrust through proper control of their caudal fin. On the other hand, manmade ships traveling in a wavy sea store large amounts of wave energy in the form of kinetic energy for heaving, pitching, rolling and other ship motions. A natural way to extract this energy and transform it to useful propulsive thrust is by using a biomimetic wing. The aim of this paper is to show how an actively pitched biomimetic wing could achieve this goal when it performs a random heaving motion. More specifically, we consider a biomimetic wing traveling with a given translational velocity in an infinitely extended fluid and performing a random heaving motion with a given energy spectrum which corresponds to a given sea state. A formula is invented by which the instantaneous pitch angle of the wing is determined using the heaving data of the current and past time steps. Simulations are then performed for a biomimetic wing at different heave energy spectra, using an indirect Source-Doublet 3-D-BEM, together with a time stepping algorithm capable to track the random motion of the wing. A nonlinear pressure type Kutta condition is applied at the trailing edge of the wing. With a mollifier-based filtering technique, the 3-D unsteady rollup pattern created by the random motion of the wing is calculated without any simplifying assumptions regarding its geometry. Calculated unsteady forces, moments and useful power, show that the proposed active pitch control always results in thrust producing motions, with significant propulsive power production and considerable beneficial stabilizing action to ship motions. Calculation of the power required to set the pitch angle prove it to be a very small percentage of the useful power and thus making the practical application of the device very tractable.

Biomimetic Materials and Fabrication Approaches for Bone Tissue Engineering.

Science.gov (United States)

Kim, Hwan D; Amirthalingam, Sivashanmugam; Kim, Seunghyun L; Lee, Seunghun S; Rangasamy, Jayakumar; Hwang, Nathaniel S

2017-12-01

Various strategies have been explored to overcome critically sized bone defects via bone tissue engineering approaches that incorporate biomimetic scaffolds. Biomimetic scaffolds may provide a novel platform for phenotypically stable tissue formation and stem cell differentiation. In recent years, osteoinductive and inorganic biomimetic scaffold materials have been optimized to offer an osteo-friendly microenvironment for the osteogenic commitment of stem cells. Furthermore, scaffold structures with a microarchitecture design similar to native bone tissue are necessary for successful bone tissue regeneration. For this reason, various methods for fabricating 3D porous structures have been developed. Innovative techniques, such as 3D printing methods, are currently being utilized for optimal host stem cell infiltration, vascularization, nutrient transfer, and stem cell differentiation. In this progress report, biomimetic materials and fabrication approaches that are currently being utilized for biomimetic scaffold design are reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic High-Density Lipoproteins from a Gold Nanoparticle Template

Science.gov (United States)

Luthi, Andrea Jane

For hundreds of years the field of chemistry has looked to nature for inspiration and insight to develop novel solutions for the treatment of human diseases. The ability of chemists to identify, mimic, and modifiy small molecules found in nature has led to the discovery and development of many important therapeutics. Chemistry on the nanoscale has made it possible to mimic natural, macromolecular structures that may also be useful for understanding and treating diseases. One example of such a structure is high-density lipoprotein (HDL). The goal of this work is to use a gold nanoparticle (Au NP) as a template to synthesize functional mimics of HDL and characterize their structure and function. Chapter 1 details the structure and function of natural HDL and how chemistry on the nanoscale provides new strategies for mimicking HDL. This Chapter also describes the first examples of using nanoparticles to mimic HDL. Chapter 2 reports the synthesis and characterization of biomimetic HDL using different sizes of Au NPs and different surface chemistries and how these variables can be used to tailor the properties of biomimetic HDL. From these studies the optimal strategy for synthesizing biomimetic HDL was determined. In Chapter 3, the optimization of the synthesis of biomimetic HDL is discussed as well as a full characterization of its structure. In addition, the work in this chapter shows that biomimetic HDL can be synthesized on a large scale without alterations to its structure or function. Chapter 4 focuses on understanding the pathways by which biomimetic HDL accepts cholesterol from macrophage cells. The results of these studies demonstrate that biomimetic HDL is able to accept cholesterol by both active and passive pathways of cholesterol efflux. In Chapter 5 the preliminary results of in vivo studies to characterize the pharmacokinetics and pharmacodynamics of biomimetic HDL are presented. These studies suggest that biomimetic HDL traffics through tissues prone to

Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

Energy Technology Data Exchange (ETDEWEB)

Harel, Elad [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

2012-05-07

Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

International Nuclear Information System (INIS)

Harel, Elad

2012-01-01

Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

Reverse Engineering Nature to Design Biomimetic Total Knee Implants.

Science.gov (United States)

Varadarajan, Kartik Mangudi; Zumbrunn, Thomas; Rubash, Harry E; Malchau, Henrik; Muratoglu, Orhun K; Li, Guoan

2015-10-01

While contemporary total knee arthroplasty (TKA) provides tremendous clinical benefits, the normal feel and function of the knee is not fully restored. To address this, a novel design process was developed to reverse engineer "biomimetic" articular surfaces that are compatible with normal soft-tissue envelope and kinematics of the knee. The biomimetic articular surface is created by moving the TKA femoral component along in vivo kinematics of normal knees and carving out the tibial articular surface from a rectangular tibial block. Here, we describe the biomimetic design process. In addition, we utilize geometric comparisons and kinematic simulations to show that; (1) tibial articular surfaces of conventional implants are fundamentally incompatible with normal knee motion, and (2) the anatomic geometry of the biomimetic surface contributes directly to restoration of normal knee kinematics. Such biomimetic implants may enable us to achieve the long sought after goal of a "normal" knee post-TKA surgery. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Design of flow-field patterns for proton exchange membrane fuel cell application

International Nuclear Information System (INIS)

Rosli, M.I.; Wan Ramli Wan Daud; Kamaruzzaman Sopian; Jaafar Sahari

2006-01-01

Fuel cells are electrochemical devices that produce electricity at high efficiency without combustion. Fuel cells are emerging as viable candidates as power sources in many applications, including road vehicles, small-scale power stations, and possibly even portable electronics. This paper addresses the design of flow-field patterns for proton exchange membrane fuel cell (PEMFC). The PEMFC is a low-temperature fuel cell, in which a proton conductive polymer membrane is used as the electrolyte. In PEMFC, flow-field pattern is one important thing that effects the performance of PEMFC. This paper present three types of flow-field pattern that will be consider to be testing using CFD analysis and by experimental. The design look detail on to their shape and dimension to get the best pattern in term of more active electrode area compare to electrode area that will be used. Another advantage and disadvantage for these three type of flow-field patterns from literature also compared in this paper

Interactions of sugar-based bolaamphiphiles with biomimetic systems of plasma membranes.

Science.gov (United States)

Nasir, Mehmet Nail; Crowet, Jean-Marc; Lins, Laurence; Obounou Akong, Firmin; Haudrechy, Arnaud; Bouquillon, Sandrine; Deleu, Magali

2016-11-01

Glycolipids constitute a class of molecules with various biological activities. Among them, sugar-based bolaamphiphiles characterized by their biocompatibility, biodegradability and lower toxicity, became interesting for the development of efficient and low cost lipid-based drug delivery systems. Their activity seems to be closely related to their interactions with the lipid components of the plasma membrane of target cells. Despite many works devoted to the chemical synthesis and characterization of sugar-based bolaamphiphiles, their interactions with plasma membrane have not been completely elucidated. In this work, two sugar-based bolaamphiphiles differing only at the level of their sugar residues were chemically synthetized. Their interactions with membranes have been investigated using model membranes containing or not sterol and with in silico approaches. Our findings indicate that the nature of sugar residues has no significant influence for their membrane interacting properties, while the presence of sterol attenuates the interactions of both bolaamphiphiles with the membrane systems. The understanding of this distinct behavior of bolaamphiphiles towards sterol-containing membrane systems could be useful for their applications as drug delivery systems. Copyright © 2016. Published by Elsevier B.V.

Biomimetic mineral coatings in dental and orthopaedic implantology

NARCIS (Netherlands)

Liu, Y.; de Groot, K.; Hunziker, E.B.

2009-01-01

Biomimetic techniques are used to deposit coatings of calcium phosphate upon medical devices. The procedure is conducted under near-physiological, or "biomimetic", conditions of temperature and pH primarily to improve their biocompatibility and biodegradability of the materials. The inorganic layers

Biomimetic superwettable materials with structural colours.

Science.gov (United States)

Wang, Zelinlan; Guo, Zhiguang

2017-12-05

Structural colours and superwettability are of great interest due to their unique characteristics. However, the application of materials with either structural colours or superwettability is limited. Moreover, materials possessing both structural colours and superwettability are crucial for many practical applications. The combination of structural colours and superwettability can result in materials for use various applications, such as in sensors, detectors, bioassays, anti-counterfeiting, and liquid actuators, by controlling surfaces to repel or absorb liquids. Regarding superwettability and structural colours, surface texture and chemical composition are two factors for the construction of materials with superwettable structural colours. This review aims at offering a comprehensive elaboration of the mechanism, recent biomimetic research, and applications of biomimetic superwettable materials with structural colours. Furthermore, this review provides significant insight into the design, fabrication, and application of biomimetic superwettable materials with structural colours.

Challenges in biomimetic design and innovation

DEFF Research Database (Denmark)

Lenau, Torben Anker; Barfoed, Michael; Shu, Li

Biomimetic design copies desired principles found in nature and implement them into artificial applications. Applications could be products we use in our daily life but it can also be used to inspire material innovation. However there are significant challenges in performing biomimetic design. One....... This is a key issue in design and innovation work where problem identification and systematic search for suitable solution principle are major activities. One way to deal with this challenge is to use a biology search method. The use of such a method is illustrated with a case story describing the design...... including the terminology and knowledge organisation. It is often easy to recognise the splendour of a biological solution, but it can be much more difficult to understand the underlying mechanisms. Another challenge in biomimetic design is the search and identification of relevant solutions in nature...

Biomimetic Structural Materials: Inspiration from Design and Assembly.

Science.gov (United States)

Yaraghi, Nicholas A; Kisailus, David

2018-04-20

Nature assembles weak organic and inorganic constituents into sophisticated hierarchical structures, forming structural composites that demonstrate impressive combinations of strength and toughness. Two such composites are the nacre structure forming the inner layer of many mollusk shells, whose brick-and-mortar architecture has been the gold standard for biomimetic composites, and the cuticle forming the arthropod exoskeleton, whose helicoidal fiber-reinforced architecture has only recently attracted interest for structural biomimetics. In this review, we detail recent biomimetic efforts for the fabrication of strong and tough composite materials possessing the brick-and-mortar and helicoidal architectures. Techniques discussed for the fabrication of nacre- and cuticle-mimetic structures include freeze casting, layer-by-layer deposition, spray deposition, magnetically assisted slip casting, fiber-reinforced composite processing, additive manufacturing, and cholesteric self-assembly. Advantages and limitations to these processes are discussed, as well as the future outlook on the biomimetic landscape for structural composite materials.

Biomimetic Structural Materials: Inspiration from Design and Assembly

Science.gov (United States)

Yaraghi, Nicholas A.; Kisailus, David

2018-04-01

Nature assembles weak organic and inorganic constituents into sophisticated hierarchical structures, forming structural composites that demonstrate impressive combinations of strength and toughness. Two such composites are the nacre structure forming the inner layer of many mollusk shells, whose brick-and-mortar architecture has been the gold standard for biomimetic composites, and the cuticle forming the arthropod exoskeleton, whose helicoidal fiber-reinforced architecture has only recently attracted interest for structural biomimetics. In this review, we detail recent biomimetic efforts for the fabrication of strong and tough composite materials possessing the brick-and-mortar and helicoidal architectures. Techniques discussed for the fabrication of nacre- and cuticle-mimetic structures include freeze casting, layer-by-layer deposition, spray deposition, magnetically assisted slip casting, fiber-reinforced composite processing, additive manufacturing, and cholesteric self-assembly. Advantages and limitations to these processes are discussed, as well as the future outlook on the biomimetic landscape for structural composite materials.

Biomimetic dentistry

OpenAIRE

Suchetana Goswami

2018-01-01

“Biomimetics” is the field of science that uses the natural system of synthesizing materials through biomimicry. This method can be widely used in dentistry for regeneration of dental structures and replacement of lost dental tissues. This is a review paper that states its scope, history, different fields of biomimetic dentistry, and its future conditions in India.

Sustainability assessment of a lightweight biomimetic ceiling structure

International Nuclear Information System (INIS)

Antony, Florian; Speck, Thomas; Speck, Olga; Grießhammer, Rainer

2014-01-01

An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions. (paper)

Biomimetic Nanosponges for Treating Antibody-Mediated Autoimmune Diseases.

Science.gov (United States)

Jiang, Yao; Fang, Ronnie H; Zhang, Liangfang

2018-04-18

Autoimmune diseases are characterized by overactive immunity, where the body's defense system launches an attack against itself. If left unchecked, this can result in the destruction of healthy tissue and significantly affect patient well-being. In the case of type II autoimmune hypersensitivities, autoreactive antibodies attack the host's own cells or extracellular matrix. Current clinical treatment modalities for managing this class of disease are generally nonspecific and face considerable limitations. In this Topical Review, we cover emerging therapeutic strategies, with an emphasis on novel nanomedicine platforms. Specifically, the use of biomimetic cell membrane-coated nanosponges that are capable of specifically binding and neutralizing pathological antibodies will be explored. There is significant untapped potential in the application of nanotechnology for the treatment of autoimmune diseases, and continued development along this line may help to eventually change the clinical landscape.

Biomimetic Membranes for Multi-Redox Center Proteins

Directory of Open Access Journals (Sweden)

Renate L. C. Naumann

2016-03-01

Full Text Available His-tag technology was applied for biosensing purposes involving multi-redox center proteins (MRPs. An overview is presented on various surfaces ranging from flat to spherical and modified with linker molecules with nitrile-tri-acetic acid (NTA terminal groups to bind his-tagged proteins in a strict orientation. The bound proteins are submitted to in situ dialysis in the presence of lipid micelles to form a so-called protein-tethered bilayer lipid membrane (ptBLM. MRPs, such as the cytochrome c oxidase (CcO from R. sphaeroides and P. denitrificans, as well as photosynthetic reactions centers (RCs from R. sphaeroides, were thus investigated. Electrochemical and surface-sensitive optical techniques, such as surface plasmon resonance, surface plasmon-enhanced fluorescence, surface-enhanced infrared absorption spectroscopy (SEIRAS and surface-enhanced resonance Raman spectroscopy (SERRS, were employed in the case of the ptBLM structure on flat surfaces. Spherical particles ranging from µm size agarose gel beads to nm size nanoparticles modified in a similar fashion were called proteo-lipobeads (PLBs. The particles were investigated by laser-scanning confocal fluorescence microscopy (LSM and UV/Vis spectroscopy. Electron and proton transfer through the proteins were demonstrated to take place, which was strongly affected by the membrane potential. MRPs can thus be used for biosensing purposes under quasi-physiological conditions.

A review of water treatment membrane nanotechnologies

KAUST Repository

Pendergast, MaryTheresa M.

2011-01-01

Nanotechnology is being used to enhance conventional ceramic and polymeric water treatment membrane materials through various avenues. Among the numerous concepts proposed, the most promising to date include zeolitic and catalytic nanoparticle coated ceramic membranes, hybrid inorganic-organic nanocomposite membranes, and bio-inspired membranes such as hybrid protein-polymer biomimetic membranes, aligned nanotube membranes, and isoporous block copolymer membranes. A semi-quantitative ranking system was proposed considering projected performance enhancement (over state-of-the-art analogs) and state of commercial readiness. Performance enhancement was based on water permeability, solute selectivity, and operational robustness, while commercial readiness was based on known or anticipated material costs, scalability (for large scale water treatment applications), and compatibility with existing manufacturing infrastructure. Overall, bio-inspired membranes are farthest from commercial reality, but offer the most promise for performance enhancements; however, nanocomposite membranes offering significant performance enhancements are already commercially available. Zeolitic and catalytic membranes appear reasonably far from commercial reality and offer small to moderate performance enhancements. The ranking of each membrane nanotechnology is discussed along with the key commercialization hurdles for each membrane nanotechnology. © 2011 The Royal Society of Chemistry.

Biomimetic Sonar for Electrical Activation of the Auditory Pathway

Directory of Open Access Journals (Sweden)

D. Menniti

2017-01-01

Full Text Available Relying on the mechanism of bat’s echolocation system, a bioinspired electronic device has been developed to investigate the cortical activity of mammals in response to auditory sensorial stimuli. By means of implanted electrodes, acoustical information about the external environment generated by a biomimetic system and converted in electrical signals was delivered to anatomically selected structures of the auditory pathway. Electrocorticographic recordings showed that cerebral activity response is highly dependent on the information carried out by ultrasounds and is frequency-locked with the signal repetition rate. Frequency analysis reveals that delta and beta rhythm content increases, suggesting that sensorial information is successfully transferred and integrated. In addition, principal component analysis highlights how all the stimuli generate patterns of neural activity which can be clearly classified. The results show that brain response is modulated by echo signal features suggesting that spatial information sent by biomimetic sonar is efficiently interpreted and encoded by the auditory system. Consequently, these results give new perspective in artificial environmental perception, which could be used for developing new techniques useful in treating pathological conditions or influencing our perception of the surroundings.

Biomimetics: The early years | Michael | Annals of Ibadan ...

African Journals Online (AJOL)

Biomimetics is a relatively new term and an evolving discipline with the potentials for transforming every aspect of medicine. Biomimetics or biomimicry is the imitation of the models, systems, and elements of nature for the purpose of solving complex biological puzzles. Insights into biological processes have already resulted ...

Biomimetics: nature based innovation

National Research Council Canada - National Science Library

Bar-Cohen, Yoseph

2012-01-01

"Based on the concept that nature offers numerous sources of inspiration for inventions related to mechanisms, materials, processes, and algorithms, this book covers the topic of biomimetics and the inspired innovation...

Biomimetic dentistry

Directory of Open Access Journals (Sweden)

Suchetana Goswami

2018-01-01

Full Text Available “Biomimetics” is the field of science that uses the natural system of synthesizing materials through biomimicry. This method can be widely used in dentistry for regeneration of dental structures and replacement of lost dental tissues. This is a review paper that states its scope, history, different fields of biomimetic dentistry, and its future conditions in India.

Exploiting lipopolysaccharide-induced deformation of lipid bilayers to modify membrane composition and generate two-dimensional geometric membrane array patterns

Energy Technology Data Exchange (ETDEWEB)

Adams, Peter G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swingle, Kirstie L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Paxton, Walter F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nogan, John J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stromberg, Loreen R. [Univ. of New Mexico, Albuquerque, NM (United States); Firestone, Millicent A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Harshini [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Consortium, Los Alamos, NM (United States); Montaño, Gabriel A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-05-27

Supported lipid bilayers have proven effective as model membranes for investigating biophysical processes and in development of sensor and array technologies. The ability to modify lipid bilayers after their formation and in situ could greatly advance membrane technologies, but is difficult via current state-of-the-art technologies. Here we demonstrate a novel method that allows the controlled post-formation processing and modification of complex supported lipid bilayer arrangements, under aqueous conditions. We exploit the destabilization effect of lipopolysaccharide, an amphiphilic biomolecule, interacting with lipid bilayers to generate voids that can be backfilled to introduce desired membrane components. We further demonstrate that when used in combination with a single, traditional soft lithography process, it is possible to generate hierarchically-organized membrane domains and microscale 2-D array patterns of domains. Significantly, this technique can be used to repeatedly modify membranes allowing iterative control over membrane composition. This approach expands our toolkit for functional membrane design, with potential applications for enhanced materials templating, biosensing and investigating lipid-membrane processes.

Separation of Peptides with Forward Osmosis Biomimetic Membranes

DEFF Research Database (Denmark)

Bajraktari, Niada; Madsen, Henrik T; Gruber, Mathias Felix

2016-01-01

such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of larger biomolecules with often flexible conformations. In this study, transport of two chemically similar peptides...

Testing of Synthetic Biological Membranes for Forward Osmosis Applications

Science.gov (United States)

Parodi, Jurek; Mangado, Jaione Romero; Stefanson, Ofir; Flynn, Michael; Mancinelli, Rocco; Kawashima, Brian; Trieu, Serena; Brozell, Adrian; Rosenberg, Kevan

2016-01-01

Commercially available forward osmosis membranes have been extensively tested for human space flight wastewater treatment. Despite the improvements achieved in the last decades, there is still a challenge to produce reliable membranes with anti-fouling properties, chemical resistance, and high flux and selectivity. Synthetic biological membranes that mimic the ones present in nature, which underwent millions of years of evolution, represent a potential solution for further development and progress in membrane technology. Biomimetic forward osmosis membranes based on a polymeric support filter and coated with surfactant multilayers have been engineered to investigate how different manufacturing processes impact the performance and structure of the membrane. However, initial results of the first generation prototype membranes tests reveal a high scatter in the data, due to the current testing apparatus set up. The testing apparatus has been upgraded to improve data collection, reduce errors, and to allow higher control of the testing process.

Laser technology in biomimetics basics and applications

CERN Document Server

Belegratis, Maria

2013-01-01

Lasers are progressively more used as versatile tools for fabrication purposes. The wide range of available powers, wavelengths, operation modes, repetition rates etc. facilitate the processing of a large spectrum of materials at exceptional precision and quality. Hence, manifold methods were established in the past and novel methods are continuously under development. Biomimetics, the translation from nature-inspired principles to technical applications, is strongly multidisciplinary. This field offers intrinsically a wide scope of applications for laser based methods regarding structuring and modification of materials. This book is dedicated to laser fabrication methods in biomimetics. It introduces both, a laser technology as well as an application focused approach.  The book covers the most important laser lithographic methods and various biomimetics application scenarios ranging from coatings and biotechnology to construction, medical applications and photonics.

Biomimetics: forecasting the future of science, engineering, and medicine

Directory of Open Access Journals (Sweden)

Hwang J

2015-09-01

Full Text Available Jangsun Hwang,1 Yoon Jeong,1,2 Jeong Min Park,3 Kwan Hong Lee,1,2,4 Jong Wook Hong,1,2 Jonghoon Choi1,2 1Department of Bionano Technology, Graduate School, Hanyang University, Seoul, 2Department of Bionano Engineering, Hanyang University ERICA, Ansan, Korea; 3Department of Biomedical Engineering, Boston University, 4OpenView Venture Partners, Boston, MA, USA Abstract: Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark’s skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations. Keywords: biomimicry, tissue engineering, biomaterials, nature, nanotechnology, nanomedicine

Amelogenin and Enamel Biomimetics

Science.gov (United States)

Ruan, Qichao; Moradian-Oldak, Janet

2015-01-01

Mature tooth enamel is acellular and does not regenerate itself. Developing technologies that rebuild tooth enamel and preserve tooth structure is therefore of great interest. Considering the importance of amelogenin protein in dental enamel formation, its ability to control apatite mineralization in vitro, and its potential to be applied in fabrication of future bio-inspired dental material this review focuses on two major subjects: amelogenin and enamel biomimetics. We review the most recent findings on amelogenin secondary and tertiary structural properties with a focus on its interactions with different targets including other enamel proteins, apatite mineral, and phospholipids. Following a brief overview of enamel hierarchical structure and its mechanical properties we will present the state-of-the-art strategies in the biomimetic reconstruction of human enamel. PMID:26251723

Thermal structural evolutions of DMPC-water biomimetic systems investigated by Raman Spectroscopy.

Science.gov (United States)

Fasanella, A; Cosentino, K; Beneduci, A; Chidichimo, G; Cazzanelli, E; Barberi, R C; Castriota, M

2018-06-01

Many cell membranes of living organisms can be represented as phospholipid bilayers immersed into a water environment. The physical-chemical interactions at the membranes/water interface are responsible for the stabilization of the membranes. In addition, the drug efficiency, the pharmaceutical mechanism and the improvement of the drug design can be addressed to the interactions between the membranes-water interface with the drug and to the membrane-drug interface. In this framework, it is important to find membranes models able to simulate and simultaneously simplify the biological systems to better understand both physical and chemical interactions at the interface level. Dimyristoylphosphatidylcholine (DMPC) is a synthetic phospholipid used in order to make Multilamellar Vesicle (MLV), Large Unilamellar Vesicle (LUV) and Giant Unilamellar Vesicle (GUV). In order to understand the mechanisms of vesicle formation, we have analyzed mixtures of DMPC and water by micro-Raman spectroscopy at different temperatures in the range between 10 and 35 °C. Particularly, we analyzed the temperature dependence of the CN vibrational frequency, which appears well correlated to the order degree of the various phases. These investigations, beyond the determination of phospholipid hydrocarbon chains order, provide information about the conformation of the lipid membranes. We have identified the mixture of DMPC/water that is best suited for Raman studies and can be used as an in-vitro model for biological systems. A peculiar frequency shift across the transition gel-ripple-liquid crystalline phases has been proposed as a useful diagnostic marker to detect the "order degree" and subsequently the phases of biomimetic membranes made by DMPC. Copyright © 2018 Elsevier B.V. All rights reserved.

Gas Transfer in Cellularized Collagen-Membrane Gas Exchange Devices.

Science.gov (United States)

Lo, Justin H; Bassett, Erik K; Penson, Elliot J N; Hoganson, David M; Vacanti, Joseph P

2015-08-01

Chronic lower respiratory disease is highly prevalent in the United States, and there remains a need for alternatives to lung transplant for patients who progress to end-stage lung disease. Portable or implantable gas oxygenators based on microfluidic technologies can address this need, provided they operate both efficiently and biocompatibly. Incorporating biomimetic materials into such devices can help replicate native gas exchange function and additionally support cellular components. In this work, we have developed microfluidic devices that enable blood gas exchange across ultra-thin collagen membranes (as thin as 2 μm). Endothelial, stromal, and parenchymal cells readily adhere to these membranes, and long-term culture with cellular components results in remodeling, reflected by reduced membrane thickness. Functionally, acellular collagen-membrane lung devices can mediate effective gas exchange up to ∼288 mL/min/m(2) of oxygen and ∼685 mL/min/m(2) of carbon dioxide, approaching the gas exchange efficiency noted in the native lung. Testing several configurations of lung devices to explore various physical parameters of the device design, we concluded that thinner membranes and longer gas exchange distances result in improved hemoglobin saturation and increases in pO2. However, in the design space tested, these effects are relatively small compared to the improvement in overall oxygen and carbon dioxide transfer by increasing the blood flow rate. Finally, devices cultured with endothelial and parenchymal cells achieved similar gas exchange rates compared with acellular devices. Biomimetic blood oxygenator design opens the possibility of creating portable or implantable microfluidic devices that achieve efficient gas transfer while also maintaining physiologic conditions.

Hydrogels for in situ encapsulation of biomimetic membrane arrays

DEFF Research Database (Denmark)

Ibragimova, Sania; Jensen, Karin Bagger Stibius; Szewczykowski, Piotr Przemyslaw

2012-01-01

to chemically initiated hydrogels; however, for all hydrogels the permeability was several-fold higher than the water permeability of conventional reverse osmosis (RO) membranes. Lifetimes of freestanding BLM arrays in gel precursor solutions were short compared to arrays formed in buffer. However, polymerizing......Hydrogels are hydrophilic, porous polymer networks that can absorb up to thousands of times their own weight in water. They have many potential applications, one of which is the encapsulation of freestanding black lipid membranes (BLMs) for novel separation technologies or biosensor applications....... We investigated gels for in situ encapsulation of multiple BLMs formed across apertures in a hydrophobic ethylene tetrafluoroethylene (ETFE) support. The encapsulation gels consisted of networks of poly(ethylene glycol)-dimethacrylate or poly(ethylene glycol)-diacrylate polymerized using either...

Biomimetic chemical sensors using bioengineered olfactory and taste cells.

Science.gov (United States)

Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

2014-01-01

Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well.

Biomimetic Materials for Pathogen Neutralization

National Research Council Canada - National Science Library

Ingber, Donald

1997-01-01

...) and polymer chemistry fabrication technologies for the production of synthetic 'biomimetic' materials that exhibit the mechanical responsiveness and biochemical processing capabilities of living cells and tissues...

Biomimetics as a design methodology – possibilities and challenges

DEFF Research Database (Denmark)

Lenau, Torben Anker

2009-01-01

Biomimetics – or bionik as it is called in parts of Europe – offer a number of promising opportunities and challenges for the designer. The paper investigates how biomimetics as a design methodology is used in engineering design by looking at examples of biological searches and highlight...

Biomimetics and the case of the remarkable ragworms

Science.gov (United States)

Hesselberg, Thomas

2007-08-01

Biomimetics is a rapidly growing field both as an academic and as an applied discipline. This paper gives a short introduction to the current status of the discipline before it describes three approaches to biomimetics: the mechanism-driven, which is based on the study of a specific mechanism; the focused organism-driven, which is based on the study of one function in a model organism; and the integrative organism-driven approach, where multiple functions of a model organism provide inspiration. The first two are established approaches and include many modern studies and the famous biomimetic discoveries of Velcro and the Lotus-Effect, whereas the last approach is not yet well recognized. The advantages of the integrative organism-driven approach are discussed using the ragworms as a case study. A morphological and locomotory study of these marine polychaetes reveals their biomimetic potential, which includes using their ability to move in slippery substrates as inspiration for novel endoscopes, using their compound setae as models for passive friction structures and using their three gaits, slow crawling, fast crawling, and swimming as well as their rapid burrowing technique to provide inspiration for the design of displacement pumps and multifunctional robots.

Biomimetic microsensors inspired by marine life

CERN Document Server

Kottapalli, Ajay Giri Prakash; Miao, Jianmin; Triantafyllou, Michael S

2017-01-01

This book narrates the development of various biomimetic microelectromechanical systems (MEMS) sensors, such as pressure, flow, acceleration, chemical, and tactile sensors, that are inspired by sensing phenomenon that exist in marine life. The research described in this book is multi-faceted and combines the expertise and understanding from diverse fields, including biomimetics, microfabrication, sensor engineering, MEMS design, nanotechnology, and material science. A series of chapters examine the design and fabrication of MEMS sensors that function on piezoresistive, piezoelectric, strain gauge, and chemical sensing principles. By translating nature-based engineering solutions to artificial manmade technology, we could find innovative solutions to critical problems.

Evaporation-induced assembly of biomimetic polypeptides

International Nuclear Information System (INIS)

Keyes, Joseph; Junkin, Michael; Cappello, Joseph; Wu Xiaoyi; Wong, Pak Kin

2008-01-01

We report an evaporation assisted plasma lithography (EAPL) process for guided self-assembly of a biomimetic silk-elastinlike protein (SELP). We demonstrate the formation of SELP structures from millimeter to submicrometer range on plasma-treatment surface templates during an evaporation-induced self-assembly process. The self-assembly processes at different humidities and droplet volumes were investigated. The process occurs efficiently in a window of optimized operating conditions found to be at 70% relative humidity and 8 μl volume of SELP solution. The EAPL approach provides a useful technique for the realization of functional devices and systems using these biomimetic materials

Surface charges promote nonspecific nanoparticle adhesion to stiffer membranes

Science.gov (United States)

Sinha, Shayandev; Jing, Haoyuan; Sachar, Harnoor Singh; Das, Siddhartha

2018-04-01

This letter establishes the manner in which the electric double layer induced by the surface charges of the plasma membrane (PM) enhances the nonspecific adhesion (NSA) of a metal nanoparticle (NP) to stiffer PMs (i.e., PMs with larger bending moduli). The NSA is characterized by the physical attachment of the NP to the membrane and occurs when the decrease in the surface energy (or any other mechanism) associated with the attachment process provides the energy for bending the membrane. Such an attachment does not involve receptor-ligand interactions that characterize the specific membrane-NP adhesion. Here, we demonstrate that a significant decrease in the electrostatic energy caused by the NP-attachment-induced destruction of the charged-membrane-electrolyte interface is responsible for providing the additional energy needed for bending the membrane during the NP adhesion to stiffer membranes. A smaller salt concentration and a larger membrane charge density augment this effect, which can help to design drug delivery to cells with stiffer membranes due to pathological conditions, fabricate NPs with biomimetic cholesterol-rich lipid bilayer encapsulation, etc.

Surface Topography and Mechanical Strain Promote Keratocyte Phenotype and Extracellular Matrix Formation in a Biomimetic 3D Corneal Model.

Science.gov (United States)

Zhang, Wei; Chen, Jialin; Backman, Ludvig J; Malm, Adam D; Danielson, Patrik

2017-03-01

The optimal functionality of the native corneal stroma is mainly dependent on the well-ordered arrangement of extracellular matrix (ECM) and the pressurized structure. In order to develop an in vitro corneal model, it is crucial to mimic the in vivo microenvironment of the cornea. In this study, the influence of surface topography and mechanical strain on keratocyte phenotype and ECM formation within a biomimetic 3D corneal model is studied. By modifying the surface topography of materials, it is found that patterned silk fibroin film with 600 grooves mm -1 optimally supports cell alignment and ECM arrangement. Furthermore, treatment with 3% dome-shaped mechanical strain, which resembles the shape and mechanics of native cornea, significantly enhances the expression of keratocyte markers as compared to flat-shaped strain. Accordingly, a biomimetic 3D corneal model, in the form of a collagen-modified, silk fibroin-patterned construct subjected to 3% dome-shaped strain, is created. Compared to traditional 2D cultures, it supports a significantly higher expression of keratocyte and ECM markers, and in conclusion better maintains keratocyte phenotype, alignment, and fusiform cell shape. Therefore, the novel biomimetic 3D corneal model developed in this study serves as a useful in vitro 3D culture model to improve current 2D cultures for corneal studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and mechanical analysis of a 3D-printed biodegradable biomimetic micro air vehicle wing

Science.gov (United States)

Salami, E.; Ganesan, P. B.; Ward, T. A.; Viyapuri, R.; Romli, F. I.

2016-10-01

The biomimetic micro air vehicles (BMAV) are unmanned, micro-scaled aircraft that are bio-inspired from flying organisms to achieve the lift and thrust by flapping their wings. There are still many technological challenges involved with designing the BMAV. One of these is designing the ultra-lightweight materials and structures for the wings that have enough mechanical strength to withstand continuous flapping at high frequencies. Insects achieve this by having chitin-based, wing frame structures that encompass a thin, film membrane. The main objectives of this study are to design a biodegradable BMAV wing (inspired from the dragonfly) and analyze its mechanical properties. The dragonfly-like wing frame structure was bio-mimicked and fabricated using a 3D printer. A chitosan nanocomposite film membrane was applied to the BMAV wing frames through casting method. Its mechanical performance was analyzed using universal testing machine (UTM). This analysis indicates that the tensile strength and Young's modulus of the wing with a membrane is nearly double that of the wing without a membrane, which allow higher wing beat frequencies and deflections that in turn enable a greater lifting performance.

Biomimetic electrospun nanofibers for tissue regeneration

International Nuclear Information System (INIS)

Liao, Susan; Li Bojun; Ma Zuwei; Wei He; Chan Casey; Ramakrishna, Seeram

2006-01-01

Nanofibers exist widely in human tissue with different patterns. Electrospinning nanotechnology has recently gained a new impetus due to the introduction of the concept of biomimetic nanofibers for tissue regeneration. The advanced electrospinning technique is a promising method to fabricate a controllable continuous nanofiber scaffold similar to the natural extracellular matrix. Thus, the biomedical field has become a significant possible application field of electrospun fibers. Although electrospinning has developed rapidly over the past few years, electrospun nanofibers are still at a premature research stage. Further comprehensive and deep studies on electrospun nanofibers are essential for promoting their biomedical applications. Current electrospun fiber materials include natural polymers, synthetic polymers and inorganic substances. This review briefly describes several typically electrospun nanofiber materials or composites that have great potential for tissue regeneration, and describes their fabrication, advantages, drawbacks and future prospects. (topical review)

MAMP (microbe-associated molecular pattern)-induced changes in plasma membrane-associated proteins.

Science.gov (United States)

Uhlíková, Hana; Solanský, Martin; Hrdinová, Vendula; Šedo, Ondrej; Kašparovský, Tomáš; Hejátko, Jan; Lochman, Jan

2017-03-01

Plant plasma membrane associated proteins play significant roles in Microbe-Associated Molecular Pattern (MAMP) mediated defence responses including signal transduction, membrane transport or energetic metabolism. To elucidate the dynamics of proteins associated with plasma membrane in response to cryptogein, a well-known MAMP of defence reaction secreted by the oomycete Phytophthora cryptogea, 2D-Blue Native/SDS gel electrophoresis of plasma membrane fractions was employed. This approach revealed 21 up- or down-regulated protein spots of which 15 were successfully identified as proteins related to transport through plasma membrane, vesicle trafficking, and metabolic enzymes including cytosolic NADP-malic enzyme and glutamine synthetase. Observed changes in proteins were also confirmed on transcriptional level by qRT-PCR analysis. In addition, a significantly decreased accumulation of transcripts observed after employment of a mutant variant of cryptogein Leu41Phe, exhibiting a conspicuous defect in induction of resistance, sustains the contribution of identified proteins in cryptogein-triggered cellular responses. Our data provide further evidence for dynamic MAMP-induced changes in plasma membrane associated proteins. Copyright © 2016 Elsevier GmbH. All rights reserved.

Biomimetic modelling.

OpenAIRE

Vincent, Julian F V

2003-01-01

Biomimetics is seen as a path from biology to engineering. The only path from engineering to biology in current use is the application of engineering concepts and models to biological systems. However, there is another pathway: the verification of biological mechanisms by manufacture, leading to an iterative process between biology and engineering in which the new understanding that the engineering implementation of a biological system can bring is fed back into biology, allowing a more compl...

Myoglobin-biomimetic electroactive materials made by surface molecular imprinting on silica beads and their use as ionophores in polymeric membranes for potentiometric transduction.

Science.gov (United States)

Moreira, Felismina T C; Dutra, Rosa A F; Noronha, Joao P C; Sales, M Goreti F

2011-08-15

Myoglobin (Mb) is among the cardiac biomarkers playing a major role in urgent diagnosis of cardiovascular diseases. Its monitoring in point-of-care is therefore fundamental. Pursuing this goal, a novel biomimetic ionophore for the potentiometric transduction of Mb is presented. It was synthesized by surface molecular imprinting (SMI) with the purpose of developing highly efficient sensor layers for near-stereochemical recognition of Mb. The template (Mb) was imprinted on a silane surface that was covalently attached to silica beads by means of self-assembled monolayers. First the silica was modified with an external layer of aldehyde groups. Then, Mb was attached by reaction with its amine groups (on the external surface) and subsequent formation of imine bonds. The vacant places surrounding Mb were filled by polymerization of the silane monomers 3-aminopropyltrimethoxysilane (APTMS) and propyltrimethoxysilane (PTMS). Finally, the template was removed by imine cleavage after treatment with oxalic acid. The results materials were finely dispersed in plasticized PVC selective membranes and used as ionophores in potentiometric transduction. The best analytical features were found in HEPES buffer of pH 4. Under this condition, the limits of detection were of 1.3 × 10(-6)mol/L for a linear response after 8.0 × 10(-7) mol/L with an anionic slope of -65.9 mV/decade. The imprinting effect was tested by preparing non-imprinted (NI) particles and employing these materials as ionophores. The resulting membranes showed no ability to detect Mb. Good selectivity was observed towards creatinine, sacarose, fructose, galactose, sodium glutamate, and alanine. The analytical application was conducted successfully and showed accurate and precise results. Copyright © 2011 Elsevier B.V. All rights reserved.

Biomimetics in materials science self-healing, self-lubricating, and self-cleaning materials

CERN Document Server

Nosonovsky, Michael

2012-01-01

Biomimetics in Materials Science provides a comprehensive theoretical and practical review of biomimetic materials with self-healing, self-lubricating and self-cleaning properties. These three topics are closely related and constitute rapidly developing areas of study. The field of self-healing materials requires a new conceptual understanding of this biomimetic technology, which is in contrast to traditional  engineering processes such as wear and fatigue.  Biomimetics in Materials Science is the first monograph to be devoted to these materials. A new theoretical framework for these processes is presented based on the concept of multi-scale structure of entropy and non-equilibrium thermodynamics, together with a detailed review of the available technology. The latter includes experimental, modeling, and simulation results obtained on self-healing/lubricating/cleaning materials since their emergence in the past decade. Describes smart, biomimetic materials in the context of nanotechnology, biotechnology, an...

Biomimetic magnetic nanoparticles

OpenAIRE

Klem, Michael T.; Young, Mark; Douglas, Trevor

2005-01-01

Magnetic nanoparticles are of considerable interest because of their potential use in high-density memory devices, spintronics, and applications in diagnostic medicine. The conditions for synthesis of these materials are often complicated by their high reaction temperatures, costly reagents, and post-processing requirements. Practical applications of magnetic nanoparticles will require the development of alternate synthetic strategies that can overcome these impediments. Biomimetic approaches...

Biomimetic conformation-specific assembly of proteins at artificial binding sites nano-patterned on silicon

Science.gov (United States)

de la Rica, Roberto; Matsui, Hiroshi

2009-01-01

Biomolecules such as enzymes and antibodies possess binding sites where the molecular architecture and the physicochemical properties are optimum for their interaction with a particular target, in some cases even differentiating between stereoisomers. Here, we mimic this exquisite specificity via the creation of a suitable chemical environment by fabricating artificial binding sites for the protein calmodulin (CaM). By downscaling well-known surface chemical modification methodologies to the nanometer scale via silicon nanopatterning, the Ca2+-CaM conformer was found to selectively bind the biomimetic binding sites. The methodology could be adapted to mimic other protein-receptor interactions for sensing and catalysis. PMID:19757782

Tissue bionics: examples in biomimetic tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Green, David W [Bone and Joint Research Group, Developmental Origins of Health and Disease, General Hospital, University of Southampton, SO16 6YD (United Kingdom)], E-mail: Hindoostuart@googlemail.com

2008-09-01

Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

Tissue bionics: examples in biomimetic tissue engineering

International Nuclear Information System (INIS)

Green, David W

2008-01-01

Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic

Do Biomimetic Students Think Outside the Box?

DEFF Research Database (Denmark)

Lenau, Torben Anker

2017-01-01

analysed. The empirical material comprises 111 students working on 28 different functional design problems. On average teams identify 9.0 relevant biological phenomena and manage to produce a physical proof-of-principle for the selected biological analogy. 39% of the analogies can be characterised as well...... phenomena? If they concentrate on animals and plants, which they beforehand have knowledge about, it could be expected that solutions will remind of what they would have found without using biomimetics. To investigate this question, the empirical results from a university course in biomimetics have been...

Biomimetics of human movement: functional or aesthetic?

International Nuclear Information System (INIS)

Harris, Christopher M

2009-01-01

How should robotic or prosthetic arms be programmed to move? Copying human smooth movements is popular in synthetic systems, but what does this really achieve? We cannot address these biomimetic issues without a deep understanding of why natural movements are so stereotyped. In this article, we distinguish between 'functional' and 'aesthetic' biomimetics. Functional biomimetics requires insight into the problem that nature has solved and recognition that a similar problem exists in the synthetic system. In aesthetic biomimetics, nature is copied for its own sake and no insight is needed. We examine the popular minimum jerk (MJ) model that has often been used to generate smooth human-like point-to-point movements in synthetic arms. The MJ model was originally justified as maximizing 'smoothness'; however, it is also the limiting optimal trajectory for a wide range of cost functions for brief movements, including the minimum variance (MV) model, where smoothness is a by-product of optimizing the speed-accuracy trade-off imposed by proportional noise (PN: signal-dependent noise with the standard deviation proportional to mean). PN is unlikely to be dominant in synthetic systems, and the control objectives of natural movements (speed and accuracy) would not be optimized in synthetic systems by human-like movements. Thus, employing MJ or MV controllers in robotic arms is just aesthetic biomimetics. For prosthetic arms, the goal is aesthetic by definition, but it is still crucial to recognize that MV trajectories and PN are deeply embedded in the human motor system. Thus, PN arises at the neural level, as a recruitment strategy of motor units and probably optimizes motor neuron noise. Human reaching is under continuous adaptive control. For prosthetic devices that do not have this natural architecture, natural plasticity would drive the system towards unnatural movements. We propose that a truly neuromorphic system with parallel force generators (muscle fibres) and noisy

Biomimetics in Tribology

Science.gov (United States)

Gebeshuber, I. C.; Majlis, B. Y.; Stachelberger, H.

Science currently goes through a major change. Biology is evolving as new Leitwissenschaft, with more and more causation and natural laws being uncovered. The term `technoscience' denotes the field where science and technology are inseparably interconnected, the trend goes from papers to patents, and the scientific `search for truth' is increasingly replaced by search for applications with a potential economic value. Biomimetics, i.e. knowledge transfer from biology to technology, is a field that has the potential to drive major technical advances. The biomimetic approach might change the research landscape and the engineering culture dramatically, by the blending of disciplines. It might substantially support successful mastering of current tribological challenges: friction, adhesion, lubrication and wear in devices and systems from the meter to the nanometer scale. A highly successful method in biomimectics, the biomimicry innovation method, is applied in this chapter to identify nature's best practices regarding two key issues in tribology: maintenance of the physical integrity of a system, and permanent as well as temporary attachment. The best practices identified comprise highly diverse organisms and processes and are presented in a number of tables with detailed references.

Biomimetic synthesis of hierarchical crystalline hydroxyapatite fibers in large-scale

Energy Technology Data Exchange (ETDEWEB)

Xing, Chaogang; Ge, Suxiang; Huang, Baojun; Bo, Yingying [Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, Henan Province 461000 (China); Zhang, Di [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China); Zheng, Zhi, E-mail: zhengzhi9999@yahoo.com.cn [Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, Henan Province 461000 (China)

2012-06-15

Highlights: ► Crystalline hierarchical hydroxyapatite (HAp) fibers are synthesized. ► We employ a biomimetic route by using cotton cloth as a natural bio-template. ► We study the effects of pH, ultrasonic cleaning time, and calcination temperature. ► We obtain an optimized reaction condition. ► This is a low cost method for production of hierarchical HAp fibers. -- Abstract: Crystalline hierarchical hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}, HAp)] fibers were successfully synthesized via a biomimetic route by using cotton cloth as a natural bio-template. The effects of pH value, aging time, ultrasonic cleaning time, and calcination temperature on the purity and morphology of the resulting hydroxyapatite (HAp) were monitored by scanning election microscope (SEM), X-ray diffraction (XRD), and infrared spectrophotometer (IR) to obtain an optimized reaction condition, namely, pH 9, ultrasonic cleaning for 1 min, aging for 24 h, and calcination at 600 °C for 4 h. We found that the natural cellulose could not only control the morphology of HAp but also lower its phase transformation temperature. The impact of this method lies in its low cost and successful production of large-scale patterning of three-dimensional hierarchical HAp fibers.

Biomimetic synthesis of hierarchical crystalline hydroxyapatite fibers in large-scale

International Nuclear Information System (INIS)

Xing, Chaogang; Ge, Suxiang; Huang, Baojun; Bo, Yingying; Zhang, Di; Zheng, Zhi

2012-01-01

Highlights: ► Crystalline hierarchical hydroxyapatite (HAp) fibers are synthesized. ► We employ a biomimetic route by using cotton cloth as a natural bio-template. ► We study the effects of pH, ultrasonic cleaning time, and calcination temperature. ► We obtain an optimized reaction condition. ► This is a low cost method for production of hierarchical HAp fibers. -- Abstract: Crystalline hierarchical hydroxyapatite [Ca 10 (PO 4 ) 6 (OH) 2 , HAp)] fibers were successfully synthesized via a biomimetic route by using cotton cloth as a natural bio-template. The effects of pH value, aging time, ultrasonic cleaning time, and calcination temperature on the purity and morphology of the resulting hydroxyapatite (HAp) were monitored by scanning election microscope (SEM), X-ray diffraction (XRD), and infrared spectrophotometer (IR) to obtain an optimized reaction condition, namely, pH 9, ultrasonic cleaning for 1 min, aging for 24 h, and calcination at 600 °C for 4 h. We found that the natural cellulose could not only control the morphology of HAp but also lower its phase transformation temperature. The impact of this method lies in its low cost and successful production of large-scale patterning of three-dimensional hierarchical HAp fibers.

Understanding carbon nanotube channel formation in the lipid membrane

Science.gov (United States)

Choi, Moon-ki; Kim, Hyunki; Lee, Byung Ho; Kim, Teayeop; Rho, Junsuk; Kim, Moon Ki; Kim, Kyunghoon

2018-03-01

Carbon nanotubes (CNTs) have been considered a prominent nano-channel in cell membranes because of their prominent ion-conductance and ion-selectivity, offering agents for a biomimetic channel platform. Using a coarse-grained molecular dynamics simulation, we clarify a construction mechanism of vertical CNT nano-channels in a lipid membrane for a long period, which has been difficult to observe in previous CNT-lipid interaction simulations. The result shows that both the lipid coating density and length of CNT affect the suitable fabrication condition for a vertical and stable CNT channel. Also, simulation elucidated that a lipid coating on the surface of the CNT prevents the CNT from burrowing into the lipid membrane and the vertical channel is stabilized by the repulsion force between the lipids in the coating and membrane. Our study provides an essential understanding of how CNTs can form stable and vertical channels in the membrane, which is important for designing new types of artificial channels as biosensors for bio-fluidic studies.

New Hybrid Route to Biomimetic Synthesis

National Research Council Canada - National Science Library

Morse, Daniel

2003-01-01

To develop economical low-temperature routes to biomimetic synthesis of high-performance composite materials, with control of composition and structure based on the molecular mechanisms controlling...

A biomimetic jellyfish robot based on ionic polymer metal composite actuators

International Nuclear Information System (INIS)

Yeom, Sung-Weon; Oh, Il-Kwon

2009-01-01

A biomimetic jellyfish robot based on ionic polymer metal composite actuators was fabricated and activated to mimic real locomotive behavior with pulse and recovery processes. To imitate the curved shape of the jellyfish, a thermal treatment was applied to obtain a permanent initial deformation of a hemispherical form. The bio-inspired input signal was generated for mimicking real locomotion of the jellyfish. The vertical floating displacement and the thrust force of the biomimetic jellyfish robot under various input signals were measured and compared. The present results show that the bio-inspired electrical input signal with pulse-recovery process generates much higher floating velocity of the biomimetic jellyfish robot in comparison with pure sinusoidal excitations. The curved shape of the IPMC actuator through thermal treatments can be successfully applied to mimic the real biomimetic robots with smooth curves

Antibacterial Membrane with a Bone-Like Structure for Guided Bone Regeneration

Directory of Open Access Journals (Sweden)

YuYuan Zhang

2015-01-01

Full Text Available An antibacterial membrane with a bone-like structure was developed for guided bone regeneration (GBR by mineralising acellular bovine pericardium (ABP and loading it with the antibiotic minocycline. The bovine pericardium (BP membrane was processed using physical and chemical methods to remove the cellular components and obtain ABP membranes. Then, the ABP membranes were biomimetically mineralised using a calcium phosphate-loaded agarose hydrogel system aided by electrophoresis. Minocycline was adsorbed to the mineralised ABP membrane, and the release profile in vitro was studied. The membranes were characterised through scanning electron microscopy, diffuse reflectance-Fourier transform infrared spectroscopy, and X-ray diffraction. Results showed that the ABP membrane had an asymmetric structure with a layer of densely arranged and irregularly aligned collagen fibrils. Collagen fibrils were calcified with the formation of intrafibrillar and interfibrillar hydroxyapatites similar to the bone structure. Minocycline was incorporated into the mineralised collagen membrane and could be released in vitro. This process endowed the membrane with an antibacterial property. This novel composite membrane offers promising applications in bioactive GBR.

Diffusive Silicon Nanopore Membranes for Hemodialysis Applications.

Directory of Open Access Journals (Sweden)

Steven Kim

Full Text Available Hemodialysis using hollow-fiber membranes provides life-sustaining treatment for nearly 2 million patients worldwide with end stage renal disease (ESRD. However, patients on hemodialysis have worse long-term outcomes compared to kidney transplant or other chronic illnesses. Additionally, the underlying membrane technology of polymer hollow-fiber membranes has not fundamentally changed in over four decades. Therefore, we have proposed a fundamentally different approach using microelectromechanical systems (MEMS fabrication techniques to create thin-flat sheets of silicon-based membranes for implantable or portable hemodialysis applications. The silicon nanopore membranes (SNM have biomimetic slit-pore geometry and uniform pores size distribution that allow for exceptional permeability and selectivity. A quantitative diffusion model identified structural limits to diffusive solute transport and motivated a new microfabrication technique to create SNM with enhanced diffusive transport. We performed in vitro testing and extracorporeal testing in pigs on prototype membranes with an effective surface area of 2.52 cm2 and 2.02 cm2, respectively. The diffusive clearance was a two-fold improvement in with the new microfabrication technique and was consistent with our mathematical model. These results establish the feasibility of using SNM for hemodialysis applications with additional scale-up.

Diffusive Silicon Nanopore Membranes for Hemodialysis Applications

Science.gov (United States)

Kim, Steven; Feinberg, Benjamin; Kant, Rishi; Chui, Benjamin; Goldman, Ken; Park, Jaehyun; Moses, Willieford; Blaha, Charles; Iqbal, Zohora; Chow, Clarence; Wright, Nathan; Fissell, William H.; Zydney, Andrew; Roy, Shuvo

2016-01-01

Hemodialysis using hollow-fiber membranes provides life-sustaining treatment for nearly 2 million patients worldwide with end stage renal disease (ESRD). However, patients on hemodialysis have worse long-term outcomes compared to kidney transplant or other chronic illnesses. Additionally, the underlying membrane technology of polymer hollow-fiber membranes has not fundamentally changed in over four decades. Therefore, we have proposed a fundamentally different approach using microelectromechanical systems (MEMS) fabrication techniques to create thin-flat sheets of silicon-based membranes for implantable or portable hemodialysis applications. The silicon nanopore membranes (SNM) have biomimetic slit-pore geometry and uniform pores size distribution that allow for exceptional permeability and selectivity. A quantitative diffusion model identified structural limits to diffusive solute transport and motivated a new microfabrication technique to create SNM with enhanced diffusive transport. We performed in vitro testing and extracorporeal testing in pigs on prototype membranes with an effective surface area of 2.52 cm2 and 2.02 cm2, respectively. The diffusive clearance was a two-fold improvement in with the new microfabrication technique and was consistent with our mathematical model. These results establish the feasibility of using SNM for hemodialysis applications with additional scale-up. PMID:27438878

Acceleration of biomimetic mineralization to apply in bone regeneration

International Nuclear Information System (INIS)

Jayasuriya, A Champa; Shah, Chiragkumar; Ebraheim, Nabil A; Jayatissa, Ahalapitiya H

2008-01-01

The delivery of growth factors and therapeutic drugs into bone defects is a major clinical challenge. Biomimetically prepared bone-like mineral (BLM) containing a carbonated apatite layer can be used to deliver growth factors and drugs in a controlled manner. In the conventional biomimetic process, BLM can be deposited on the biodegradable polymer surfaces by soaking them in simulated body fluid (SBF) for 16 days or more. The aim of this study was to accelerate the biomimetic process of depositing BML in the polymer surfaces. We accelerated the deposition of mineral on 3D poly(lactic-co-glycolic acid) (PLGA) porous scaffolds to 36-48 h by modifying the biomimetic process parameters and applying surface treatments to PLGA scaffolds. The BLM was coated on scaffolds after surface treatments followed by incubation at 37 0 C in 15 ml of 5x SBF. We characterized the BLM created using the accelerated biomineralization process with wide angle x-ray diffraction (XRD), Fourier transform infrared (FTIR) microscopy, and scanning electron microscopy (SEM). The FTIR and XRD analyses of mineralized scaffolds show similarities between biomimetically prepared BLM, and bone bioapatite and carbonated apatite. We also found that the BLM layer on the surface of scaffolds was stable even after 21 days immersed in Tris buffered saline and cell culture media. This study suggests that BLM was stable for at least 3 weeks in both media, and therefore, BLM has a potential for use as a carrier for biological molecules for localized release applications as well as bone tissue engineering applications

Development of Biomimetic Membranes for Near Zero PC Power Plant Emissions

Energy Technology Data Exchange (ETDEWEB)

Michael Trachtenberg; Robert Cowan; David Smith; Ira Sider

2009-07-31

The first objective of this project was to develop, evaluate and compare two different CO2 separation (capture) systems. The second was to carry the preferred solution to pre-pilot development and testing. To achieve these objectives we undertook several infrastructure enabling elements: (1) development of a preferred catalyst coupled with its immobilization onto a microporous polymer membrane, (2) design and development of a microporous membrane-based, contained liquid membrane permeator and a membrane-based absorber/desorber apparatus, (3) development of a resin-wafer electrodialytic absorber/desorber apparatus, (4) development and demonstration of a pre-treatment process to condition the feed gas stream, (5) and development of computer modeling of the components and of the integrated system. The first technology was an enzyme catalyzed, membrane supported, contained liquid membrane apparatus whose gas capture was pressure/vacuum and temperature driven. A first embodiment was as a permeator, i.e. a combined absorber/desorber in a single housing. The second embodiment was as discrete absorber and desorber units. The second technology was an enzyme catalyzed, ion exchange resin wafer electrodialytically-based separation. For each of these technologies the objective was to design, manufacture, test and demonstrate the apparatus, first in the laboratory and then at pre-pilot scale, and to run it for sufficient time at the pre-pilot scale to demonstrate stability even in the face of upset. Tests would include several ranks of coal, which had been appropriately pre-treated to remove NOx, SOx and particles, to a pre-determined acceptance level, as a basis for demonstrating efficient CO{sub 2} capture. The pre-pilot tests would be run at the Energy and Environmental Research Center (EERC) in North Dakota. A larger scale test (400m{sup 2} test unit) would later be run also at EERC. An economic goal was to compare the cost of CO{sub 2} capture by each of these methods with

Biological and Biomimetic Comb Polyelectrolytes

Directory of Open Access Journals (Sweden)

Aristeidis Papagiannopoulos

2010-05-01

Full Text Available Some new phenomena involved in the physical properties of comb polyelectrolyte solutions are reviewed. Special emphasis is given to synthetic biomimetic materials, and the structures formed by these molecules are compared with those of naturally occurring glycoprotein and proteoglycan solutions. Developments in the determination of the structure and dynamics (viscoelasticity of comb polymers in solution are also covered. Specifically the appearance of multi-globular structures, helical instabilities, liquid crystalline phases, and the self-assembly of the materials to produce hierarchical comb morphologies is examined. Comb polyelectrolytes are surface active and a short review is made of some recent experiments in this area that relate to their morphology when suspended in solution. We hope to emphasize the wide variety of phenomena demonstrated by the vast range of naturally occurring comb polyelectrolytes and the challenges presented to synthetic chemists designing biomimetic materials.

RGD Peptide-Grafted Graphene Oxide as a New Biomimetic Nano interface for Impedance-Monitoring Cell Behaviors

International Nuclear Information System (INIS)

Li, J.; Zheng, L.; Zeng, L.; Zhang, Y.; Jiang, L.; Song, J.; Li, J.; Zheng, L.; Song, J.; Li, J.; Zheng, L.; Song, J.

2016-01-01

A new biomimetic nano interface was constructed by facile grafting the bioactive arginylglycylaspartic acid (RGD) peptide on the graphene oxide (GO) surface through carbodiimide and N-hydroxysuccinimide coupling amidation reaction. The formed RGD-GO nano composites own unique two-dimensional structure and desirable electrochemical performance. The linked RGD peptides could improve GO∼s biocompatibility and support the adhesion and proliferation of human periodontal ligament fibroblasts (HPLFs) on RGD-GO biofilm surface. Furthermore the biologically active RGD-GO nano composites were demonstrated as a potential biomimetic nano interface for monitoring cell bio behaviors by electrochemical impedance spectroscopy (EIS). By analysis of the data obtained from equivalent circuit-fitting impedance spectroscopy, the information related to cell membrane capacitance, cell-cell gap resistance, and cell-electrode interface gap resistance in the process of cell adhesion and proliferation could be obtained. Besides, this proposed impedance-based cell sensor could be used to assess the inhibition effect of the lipopolysaccharide (LPS) on the HPLFs proliferation. Findings from this work suggested that RGD peptide functionalized GO nano materials may be not only applied in dental tissue engineering but also used as a sensor interface for electrochemical detection and analysis of cell behaviors in vitro.

A future of living machines?: International trends and prospects in biomimetic and biohybrid systems

Science.gov (United States)

Prescott, Tony J.; Lepora, Nathan; Vershure, Paul F. M. J.

2014-03-01

Research in the fields of biomimetic and biohybrid systems is developing at an accelerating rate. Biomimetics can be understood as the development of new technologies using principles abstracted from the study of biological systems, however, biomimetics can also be viewed from an alternate perspective as an important methodology for improving our understanding of the world we live in and of ourselves as biological organisms. A biohybrid entity comprises at least one artificial (engineered) component combined with a biological one. With technologies such as microscale mobile computing, prosthetics and implants, humankind is moving towards a more biohybrid future in which biomimetics helps us to engineer biocompatible technologies. This paper reviews recent progress in the development of biomimetic and biohybrid systems focusing particularly on technologies that emulate living organisms—living machines. Based on our recent bibliographic analysis [1] we examine how biomimetics is already creating life-like robots and identify some key unresolved challenges that constitute bottlenecks for the field. Drawing on our recent research in biomimetic mammalian robots, including humanoids, we review the future prospects for such machines and consider some of their likely impacts on society, including the existential risk of creating artifacts with significant autonomy that could come to match or exceed humankind in intelligence. We conclude that living machines are more likely to be a benefit than a threat but that we should also ensure that progress in biomimetics and biohybrid systems is made with broad societal consent.

Novel biomimetic composite material for potentiometric screening of acetylcholine, a neurotransmitter in Alzheimer's disease.

Science.gov (United States)

Sacramento, Ana S; Moreira, Felismina T C; Guerreiro, Joana L; Tavares, Ana P; Sales, M Goreti F

2017-10-01

This work describes a novel approach to produce an antibody-like biomimetic material. It includes preparing composite imprinted material never presented before, with highly conductive support nanostructures and assembling a high conductivity polymeric layer at low temperature. Overall, such highly conductive material may enhance the final features of electrically-based devices. Acetylcholine (ACh) was selected as target analyte, a neurotransmitter of importance in Alzheimer's disease. Potentiometric transduction was preferred, allowing quick responses and future adaptation to point-of-care requirements. The biomimetic material was obtained by bulk polymerization, where ACh was placed in a composite matrix of multiwalled carbon nanotubes (MWCNTs) and aniline (ANI). Subsequent polymerization, initiated by radical species, yielded a polymeric structure of polyaniline (PANI) acting as physical support of the composite. A non-imprinted material (NIM) having only PANI/MWCNT (without ACh) has been prepared for comparison of the biomimetic-imprinted material (BIM). RAMAN and Fourier Transform Infrared spectroscopy (FTIR), Transmission Electron microscopy (TEM), and Scanning Electron microscope (SEM) analysis characterized the structures of the materials. The ability of this biomaterial to rebind ACh was confirmed by including it as electroactive compound in a PVC/plasticizer mixture. The membranes with imprinted material and anionic additive presented the best analytical characteristics, with a sensitivity of 83.86mV decade -1 and limit of detection (LOD) of 3.45×10 -5 mol/L in HEPES buffer pH4.0. Good selectivity was observed against creatinine, creatine, glucose, cysteine and urea. The electrodes were also applied on synthetic serum samples and seemed a reliable tool for screening ACh in synthetic serum samples. The overall performance showed fast response, reusability, simplicity and low price. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors

Science.gov (United States)

Helmuth, Brian; Choi, Francis; Matzelle, Allison; Torossian, Jessica L.; Morello, Scott L.; Mislan, K.A.S.; Yamane, Lauren; Strickland, Denise; Szathmary, P. Lauren; Gilman, Sarah E.; Tockstein, Alyson; Hilbish, Thomas J.; Burrows, Michael T.; Power, Anne Marie; Gosling, Elizabeth; Mieszkowska, Nova; Harley, Christopher D.G.; Nishizaki, Michael; Carrington, Emily; Menge, Bruce; Petes, Laura; Foley, Melissa M.; Johnson, Angela; Poole, Megan; Noble, Mae M.; Richmond, Erin L.; Robart, Matt; Robinson, Jonathan; Sapp, Jerod; Sones, Jackie; Broitman, Bernardo R.; Denny, Mark W.; Mach, Katharine J.; Miller, Luke P.; O’Donnell, Michael; Ross, Philip; Hofmann, Gretchen E.; Zippay, Mackenzie; Blanchette, Carol; Macfarlan, J.A.; Carpizo-Ituarte, Eugenio; Ruttenberg, Benjamin; Peña Mejía, Carlos E.; McQuaid, Christopher D.; Lathlean, Justin; Monaco, Cristián J.; Nicastro, Katy R.; Zardi, Gerardo

2016-01-01

At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10–30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of ~2.0–2.5 °C, during daily fluctuations that often exceeded 15°–20 °C. Geographic patterns in thermal stress based on biomimetic logger measurements were generally far more complex than anticipated based only on ‘habitat-level’ measurements of air or sea surface temperature. This unique data set provides an opportunity to link physiological measurements with spatially- and temporally-explicit field observations of body temperature. PMID:27727238

Flexible bipolar nanofibrous membranes for improving gradient microstructure in tendon-to-bone healing.

Science.gov (United States)

Li, Xiaoxi; Cheng, Ruoyu; Sun, Zhiyong; Su, Wei; Pan, Guoqing; Zhao, Song; Zhao, Jinzhong; Cui, Wenguo

2017-10-01

Enthesis is a specialized tissue interface between the tendon and bone. Enthesis structure is very complex because of gradient changes in its composition and structure. There is currently no strategy to create a suitable environment and to regenerate the gradual-changing enthesis because of the modular complexities between two tissue types. Herein, a dual-layer organic/inorganic flexible bipolar fibrous membrane (BFM) was successfully fabricated by electrospinning to generate biomimetic non-mineralized fibrocartilage and mineralized fibrocartilage in tendon-to-bone integration of enthesis. The growth of the in situ apatite nanoparticle layer was induced on the nano hydroxyapatite-poly-l-lactic acid (nHA-PLLA) fibrous layer in simulated body solution, and the poly-l-lactic acid (PLLA) fibrous layer retained its original properties to induce tendon regeneration. The in vivo results showed that BFM significantly increased the area of glycosaminoglycan staining at the tendon-bone interface and improved collagen organization when compared to the simplex fibrous membrane (SFM) of PLLA. Implanting the bipolar membrane also induced bone formation and fibrillogenesis as assessed by micro-CT and histological analysis. Biomechanical testing showed that the BFM group had a greater ultimate load-to-failure and stiffness than the SFM group at 12weeks after surgery. Therefore, this flexible bipolar nanofibrous membrane improves the healing and regeneration process of the enthesis in rotator cuff repair. In this study, we generated a biomimetic dual-layer organic/inorganic flexible bipolar fibrous membrane by sequential electrospinning and in situ biomineralization, producing integrated bipolar fibrous membranes of PLLA fibrous membrane as the upper layer and nHA-PLLA fibrous membrane as the lower layer to mimic non-mineralized fibrocartilage and mineralized fibrocartilage in tendon-to-bone integration of enthesis. Flexible bipolar nanofibrous membranes could be easily fabricated

Role of plasma membrane surface charges in dictating the feasibility of membrane-nanoparticle interactions

Science.gov (United States)

Sinha, Shayandev; Jing, Haoyuan; Sachar, Harnoor Singh; Das, Siddhartha

2017-12-01

Receptor-ligand (R-L) binding mediated interactions between the plasma membrane (PM) and a nanoparticle (NP) require the ligand-functionalized NPs to come to a distance of separation (DOS) of at least dRL (length of the R-L complex) from the receptor-bearing membranes. In this letter, we establish that the membrane surface charges and the surrounding ionic environment dictate whether or not the attainment of such a critical DOS is possible. The negatively charged membrane invariably induces a negative electrostatic potential at the NP surface, repelling the NP from the membrane. This is countered by the attractive influences of the thermal fluctuations and van der Waals (vdw) interactions that drive the NP close to the membrane. For a NP approaching the membrane from a distance, the ratio of the repulsive (electrostatic) and attractive (thermal and vdW) effects balances at a critical NP-membrane DOS of dg,c. For a given set of parameters, there can be two possible values of dg,c, namely, dg,c,1 and dg,c,2 with dg,c,1 ≫ dg,c,2. We establish that any R-L mediated NP-membrane interaction is possible only if dRL > dg,c,1. Therefore, our study proposes a design criterion for engineering ligands for a NP that will ensure the appropriate length of the R-L complex in order to ensure the successful membrane-NP interaction in the presence of a given electrostatic environment. Finally, we discuss the manner in which our theory can help designing ligand-grafted NPs for targeted drug delivery, design biomimetics NPs, and also explain various experimental results.

Biofouling and Design of a Biomimetic Hull-Grooming Tool

Science.gov (United States)

2007-09-14

have barred the use of organotin compounds such as tributyltin ( TBT ) and copper-based paints, which are currently used by the Navy and have become...copper into the water, killing the fouling organisms. There is new research in biomimetic polymers that deter fouling, but are non- toxic . These polymers...is new research in biomimetic polymers that deter fouling, but are non- toxic . These polymers are rigidly attached to the hull surface extending

Biomimetic hydrogel materials

Science.gov (United States)

Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

2000-01-01

Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

Photoexcited iron porphyrin as biomimetic catalysts

International Nuclear Information System (INIS)

Bartocci, C.; Maldotti, A.; Varani, G.; Consiglio Nazionale delle Ricerche, Ferrara

1996-01-01

Photoexcited iron porphyrins can be of some interest in both fine and industrial chemistry in view of the preparation of new efficient biomimetic catalysts, working with high selectivity under mild temperature and pressure

Interfacing of differential-capacitive biomimetic hair flow-sensors for optimal sensitivity

International Nuclear Information System (INIS)

+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" data-affiliation=" (Transducers Science and Technology Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" >Dagamseh, A M K; + Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" data-affiliation=" (Transducers Science and Technology Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" >Bruinink, C M; + Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" data-affiliation=" (Transducers Science and Technology Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" >Wiegerink, R J; + Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" data-affiliation=" (Transducers Science and Technology Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" >Lammerink, T S J; + Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" data-affiliation=" (Transducers Science and Technology Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" >Droogendijk, H; + Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" data-affiliation=" (Transducers Science and Technology Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands))" >Krijnen, G J M

2013-01-01

Biologically inspired sensor-designs are investigated as a possible path to surpass the performance of more traditionally engineered designs. Inspired by crickets, artificial hair sensors have shown the ability to detect minute flow signals. This paper addresses developments in the design, fabrication, interfacing and characterization of biomimetic hair flow-sensors towards sensitive high-density arrays. Improvement of the electrode design of the hair sensors has resulted in a reduction of the smallest hair movements that can be measured. In comparison to the arrayed hairs-sensor design, the detection-limit was arguably improved at least twelve-fold, down to 1 mm s –1 airflow amplitude at 250 Hz as measured in a bandwidth of 3 kHz. The directivity pattern closely resembles a figure-of-eight. These sensitive hair-sensors open possibilities for high-resolution spatio-temporal flow pattern observations. (paper)

Tubular inverse opal scaffolds for biomimetic vessels

Science.gov (United States)

Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

2016-07-01

There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

Structure, biomimetics, and fluid dynamics of fish skin surfaces*

Science.gov (United States)

Lauder, George V.; Wainwright, Dylan K.; Domel, August G.; Weaver, James C.; Wen, Li; Bertoldi, Katia

2016-10-01

The interface between the fluid environment and the surface of the body in swimming fishes is critical for both physiological and hydrodynamic functions. The skin surface in most species of fishes is covered with bony scales or toothlike denticles (in sharks). Despite the apparent importance of fish surfaces for understanding aquatic locomotion and near-surface boundary layer flows, relatively little attention has been paid to either the nature of surface textures in fishes or possible hydrodynamic effects of variation in roughness around the body surface within an individual and among species. Fish surfaces are remarkably diverse and in many bony fishes scales can have an intricate surface texture with projections, ridges, and comblike extensions. Shark denticles (or scales) are toothlike and project out of the skin to form a complexly textured surface that interacts with free-stream flow. Manufacturing biomimetic foils with fishlike surfaces allows hydrodynamic testing and we emphasize here the importance of dynamic test conditions where the effect of surface textures is assessed under conditions of self-propulsion. We show that simple two-dimensional foils with patterned cuts do not perform as well as a smooth control surface, but that biomimetic shark skin foils can swim at higher self-propelled speeds than smooth controls. When the arrangement of denticles on the foil surface is altered, we find that a staggered-overlapped pattern outperforms other arrangements. Flexible foils made of real shark skin outperform sanded controls when foils are moved with a biologically realistic motion program. We suggest that focus on the mechanisms of drag reduction by fish surfaces has been too limiting and an additional role of fish surface textures may be to alter leading edge vortices and flow patterns on moving surfaces in a way that enhances thrust. Analysis of water flow over an artificial shark skin foil under both static and dynamic conditions shows that a shear layer

Energy-based and biomimetic robotics

NARCIS (Netherlands)

Folkertsma, Gerrit Adriaan

2017-01-01

All physical systems interact by exchanging power, or energy. This energy can be explicitly taken into account when designing robotic systems, in dynamic models of systems and controllers, leading to more insight in energy-related effects. In this thesis, a biomimetic cheetah robot is developed, by

Molecular Transport Studies Through Unsupported Lipid Membranes

Science.gov (United States)

Rock, William; Parekh, Sapun; Bonn, Mischa

2014-03-01

Dendrimers, spherical polymeric nanoparticles made from branched monomers around a central core, show great promise as drug delivery vehicles. Dendrimer size, core contents, and surface functionality can be synthetically tuned, providing unprecedented versatility. Polyamidoamine (PAMAM) dendrimers have been shown to enter cells; however, questions remain about their biophysical interactions with the cell membrane, specifically about the presence and size of transient pores. We monitor dendrimer-lipid bilayer interactions using unsupported black lipid membranes (BLMs) as model cell membranes. Custom bilayer slides contain two vertically stacked aqueous chambers separated by a 25 μm Teflon sheet with a 120 μm aperture where the bilayer is formed. We vary the composition of model membranes (cholesterol content and lipid phase) to create biomimetic systems and study the interaction of PAMAM G6 and G3 dendrimers with these bilayers. Dendrimers, dextran cargo, and bilayers are monitored and quantified using time-lapse fluorescence imaging. Electrical capacitance measurements are simultaneously recorded to determine if the membrane is porous, and the pore size is deduced by monitoring transport of fluorescent dextrans of increasing molecular weight. These experiments shed light on the importance of cholesterol content and lipid phase on the interaction of dendrimer nanoparticles with membranes.

Biomimetic carriers mimicking leukocyte plasma membrane to increase tumor vasculature permeability

Science.gov (United States)

Palomba, R.; Parodi, A.; Evangelopoulos, M.; Acciardo, S.; Corbo, C.; De Rosa, E.; Yazdi, I. K.; Scaria, S.; Molinaro, R.; Furman, N. E. Toledano; You, J.; Ferrari, M.; Salvatore, F.; Tasciotti, E.

2016-10-01

Recent advances in the field of nanomedicine have demonstrated that biomimicry can further improve targeting properties of current nanotechnologies while simultaneously enable carriers with a biological identity to better interact with the biological environment. Immune cells for example employ membrane proteins to target inflamed vasculature, locally increase vascular permeability, and extravasate across inflamed endothelium. Inspired by the physiology of immune cells, we recently developed a procedure to transfer leukocyte membranes onto nanoporous silicon particles (NPS), yielding Leukolike Vectors (LLV). LLV are composed of a surface coating containing multiple receptors that are critical in the cross-talk with the endothelium, mediating cellular accumulation in the tumor microenvironment while decreasing vascular barrier function. We previously demonstrated that lymphocyte function-associated antigen (LFA-1) transferred onto LLV was able to trigger the clustering of intercellular adhesion molecule 1 (ICAM-1) on endothelial cells. Herein, we provide a more comprehensive analysis of the working mechanism of LLV in vitro in activating this pathway and in vivo in enhancing vascular permeability. Our results suggest the biological activity of the leukocyte membrane can be retained upon transplant onto NPS and is critical in providing the particles with complex biological functions towards tumor vasculature.

In-plane mechanics of soft architectured fibre-reinforced silicone rubber membranes.

Science.gov (United States)

Bailly, L; Toungara, M; Orgéas, L; Bertrand, E; Deplano, V; Geindreau, C

2014-12-01

Silicone rubber membranes reinforced with architectured fibre networks were processed with a dedicated apparatus, allowing a control of the fibre content and orientation. The membranes were subjected to tensile loadings combined with continuous and discrete kinematical field measurements (DIC and particle tracking). These tests show that the mechanical behaviour of the membranes is hyperelastic at the first order. They highlight the influence of the fibre content and orientation on both the membrane in-plane deformation and stress levels. They also prove that for the considered fibrous architectures and mechanical loadings, the motion and deformation of fibres is an affine function of the macroscale transformation. These trends are fairly well described by the micromechanical model proposed recently in Bailly et al. (JMBBM, 2012). This result proves that these materials are very good candidates for new biomimetic membranes, e.g. to improve aortic analogues used for in vitro experiments, or existing textiles used for vascular (endo)prostheses. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cosmeceutical product consisting of biomimetic peptides: antiaging effects in vivo and in vitro

Directory of Open Access Journals (Sweden)

Gazitaeva ZI

2017-01-01

Full Text Available Zarema I Gazitaeva,1 Anna O Drobintseva,2 Yongji Chung,3 Victoria O Polyakova,2 Igor M Kvetnoy2 1Institute of Beauty Fijie, Moscow, 2Department of Pathomorphology, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Saint-Petersburg, Russian Federation; 3Caregen Co., Ltd. Research Center, Seoul, South Korea Background: Biomimetic peptides are synthetic compounds that are identical to amino acid sequence synthesized by an organism and can interact with growth factor receptors and provide antiaging clinical effects.Purpose: The purpose of this study was to investigate the effects of biomimetic peptides on the repair processes in the dermis using a model of cell cultures and in vivo.Patients and methods: Five female volunteers were subjected to the injection of biomimetic peptides 1 month prior to the abdominoplasty procedure. Cell culture, immunocytochemistry, and confocal microscopy methods were used in this study.Results: Biomimetic peptides regulate the synthesis of proteins Ki-67, type I procollagen, AP-1, and SIRT6 in cell cultures of human fibroblasts. They contribute to the activation of regeneration processes and initiation of mechanisms that prevent aging. Intradermal administration of complex of biomimetic peptides produces a more dense arrangement of collagen fibers in the dermis and increased size of the fibers after 2 weeks. The complex of biomimetic peptides was effective in the in vivo experiments, where an increase in the proliferative and synthetic activities of fibroblasts was observed.Conclusion: This investigation showed that the studied peptides have biological effects, testifying the stimulation of reparative processes in the skin under their control. Keywords: biomimetic peptides, skin aging, collagen, reparation processes, mesotherapy

A review of underwater bio-mimetic propulsion: cruise and fast-start

Science.gov (United States)

Chao, Li-Ming; Cao, Yong-Hui; Pan, Guang

2017-08-01

This paper reviews recent developments in the understanding of underwater bio-mimetic propulsion. Two impressive models of underwater propulsion are considered: cruise and fast-start. First, we introduce the progression of bio-mimetic propulsion, especially underwater propulsion, where some primary conceptions are touched upon. Second, the understanding of flapping foils, considered as one of the most efficient cruise styles of aquatic animals, is introduced, where the effect of kinematics and the shape and flexibility of foils on generating thrust are elucidated respectively. Fast-start propulsion is always exhibited when predator behaviour occurs, and we provide an explicit introduction of corresponding zoological experiments and numerical simulations. We also provide some predictions about underwater bio-mimetic propulsion.

A review of underwater bio-mimetic propulsion: cruise and fast-start

Energy Technology Data Exchange (ETDEWEB)

Chao, Li-Ming; Cao, Yong-Hui; Pan, Guang, E-mail: PanGuang_010@163.com [School of Marine Science and Technology, Northwestern Polytechnical University, Xian 710072 (China)

2017-08-15

This paper reviews recent developments in the understanding of underwater bio-mimetic propulsion. Two impressive models of underwater propulsion are considered: cruise and fast-start. First, we introduce the progression of bio-mimetic propulsion, especially underwater propulsion, where some primary conceptions are touched upon. Second, the understanding of flapping foils, considered as one of the most efficient cruise styles of aquatic animals, is introduced, where the effect of kinematics and the shape and flexibility of foils on generating thrust are elucidated respectively. Fast-start propulsion is always exhibited when predator behaviour occurs, and we provide an explicit introduction of corresponding zoological experiments and numerical simulations. We also provide some predictions about underwater bio-mimetic propulsion. (review)

Photocatalytic Nanofiltration Membranes with Self-Cleaning Property for Wastewater Treatment

Energy Technology Data Exchange (ETDEWEB)

Lv, Yan [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 China; Zhang, Chao [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 China; He, Ai [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 China; Yang, Shang-Jin [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 China; Wu, Guang-Peng [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 China; Darling, Seth B. [Nanoscience & Technology Division, Argonne National Laboratory, 9700 South Cass Avenue Lemont IL 60439 USA; Institute for Molecular Engineering, University of Chicago, Chicago IL 60637 USA; Xu, Zhi-Kang [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, and Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 China

2017-05-16

Membrane fouling is one of the most severe problems restricting membrane separation technology for wastewater treatment. This work reports a photocatalytic nanofiltration membrane (NFM) with self-cleaning property fabricated using a facile biomimetic mineralization process. In this strategy, a polydopamine (PDA)/polyethyleneimine (PEI) intermediate layer is fabricated on an ultrafiltration membrane via a co-deposition method followed by mineralization of a photocatalytic layer consisting of beta-FeOOH nanorods. The PDA-PEI layer acts both as a nanofiltration selective layer and an intermediate layer for anchoring the beta-FeOOH nanorods via strong coordination complexes between Fe3+ and catechol groups. In visible light, the beta-(F)eOOH layer exhibits efficient photocatalytic activity for degrading dyes through the photo-Fenton reaction in the presence of hydrogen peroxide, endowing the NFM concurrently with effective nanofiltration performance and self-cleaning capability. Moreover, the mineralized NFMs exhibit satisfactory stability under simultaneous filtration and photocatalysis processing, showing great potential in advanced wastewater treatment.

Effect of feed flow pattern on the distribution of permeate fluxes in desalination by direct contact membrane distillation

KAUST Repository

Soukane, Sofiane; Naceur, Mohamed W.; Francis, Lijo; Alsaadi, Ahmad Salem; Ghaffour, NorEddine

2017-01-01

The current study aims to highlight the effect of flow pattern on the variations of permeate fluxes over the membrane surface during desalination in a direct contact membrane distillation (DCMD) flat module. To do so, a three dimensional (3D

Local elasticity and adhesion of nanostructures on Drosophila melanogaster wing membrane studied using atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Wagner, Ryan, E-mail: rbwagner@purdue.edu [School of Mechanical Engineering, Purdue University, West Lafayette (United States); Brick Nanotechnology Center, Purdue University, West Lafayette (United States); Pittendrigh, Barry R. [Department of Entomology, University of Illinois, Champaign (United States); Raman, Arvind, E-mail: raman@purdue.edu [School of Mechanical Engineering, Purdue University, West Lafayette (United States); Brick Nanotechnology Center, Purdue University, West Lafayette (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer We studied the wing membrane of Drosophila melanogaster with atomic force microscopy. Black-Right-Pointing-Pointer We report the structure, elasticity, and adhesion on the wing membrane in air and nitrogen environments. Black-Right-Pointing-Pointer Results provide insight into the nature of the wing membrane enabling the development of biomimetic surface and micro air vehicles. - Abstract: Insect wings have a naturally occurring, complex, functional, hierarchical microstructure and nanostructure, which enable a remarkably water-resistant and self-cleaning surface. Insect wings are used as a basis for engineering biomimetic materials; however, the material properties of these nanostructures such as local elastic modulus and adhesion are poorly understood. We studied the wings of the Canton-S strain of Drosophila melanogaster (hereafter referred to as Drosophila) with atomic force microscopy (AFM) to quantify the local material properties of Drosophila wing surface nanostructures. The wings are found to have a hierarchical structure of 10-20 {mu}m long, 0.5-1 {mu}m diameter hair, and at a much smaller scale, 100 nm diameter and 30-60 nm high bumps. The local properties of these nanoscale bumps were studied under ambient and dry conditions with force-volume AFM. The wing membrane was found to have a elastic modulus on the order of 1000 MPa and the work of adhesion between the probe and wing membrane surface was found to be on the order of 100 mJ/m{sup 2}, these properties are the same order of magnitude as common thermoplastic polymers such as polyethylene. The difference in work of adhesion between the nanoscale bump and membrane does not change significantly between ambient (relative humidity of 30%) or dry conditions. This suggests that the nanoscale bumps and the surrounding membrane are chemically similar and only work to increase hydrophobicity though surface roughening or the geometric lotus effect.

Local elasticity and adhesion of nanostructures on Drosophila melanogaster wing membrane studied using atomic force microscopy

International Nuclear Information System (INIS)

Wagner, Ryan; Pittendrigh, Barry R.; Raman, Arvind

2012-01-01

Highlights: ► We studied the wing membrane of Drosophila melanogaster with atomic force microscopy. ► We report the structure, elasticity, and adhesion on the wing membrane in air and nitrogen environments. ► Results provide insight into the nature of the wing membrane enabling the development of biomimetic surface and micro air vehicles. - Abstract: Insect wings have a naturally occurring, complex, functional, hierarchical microstructure and nanostructure, which enable a remarkably water-resistant and self-cleaning surface. Insect wings are used as a basis for engineering biomimetic materials; however, the material properties of these nanostructures such as local elastic modulus and adhesion are poorly understood. We studied the wings of the Canton-S strain of Drosophila melanogaster (hereafter referred to as Drosophila) with atomic force microscopy (AFM) to quantify the local material properties of Drosophila wing surface nanostructures. The wings are found to have a hierarchical structure of 10–20 μm long, 0.5–1 μm diameter hair, and at a much smaller scale, 100 nm diameter and 30–60 nm high bumps. The local properties of these nanoscale bumps were studied under ambient and dry conditions with force-volume AFM. The wing membrane was found to have a elastic modulus on the order of 1000 MPa and the work of adhesion between the probe and wing membrane surface was found to be on the order of 100 mJ/m 2 , these properties are the same order of magnitude as common thermoplastic polymers such as polyethylene. The difference in work of adhesion between the nanoscale bump and membrane does not change significantly between ambient (relative humidity of 30%) or dry conditions. This suggests that the nanoscale bumps and the surrounding membrane are chemically similar and only work to increase hydrophobicity though surface roughening or the geometric lotus effect.

An efficient biomimetic coating methodology for a prosthetic alloy

International Nuclear Information System (INIS)

Adawy, Alaa; Abdel-Fattah, Wafa I.

2013-01-01

The combination of the load-bearing metallic implants with the bioactive materials in the design of synthetic implants is an important aspect in the biomaterials research. Biomimetic coating of bioinert alloys with calcium phosphate phases provides a good alternative to the prerequisite for the continual replacement of implants because of the failure of bone-implant integration. We attempted to accelerate the biomimetic coating process of stainless steel alloy (316L) with biomimetic apatite. In addition, we investigated the incorporation of functioning minerals such as strontianite and smithsonite into the deposited layer. In order to develop a highly mature apatite coating, our method requires soaking of the pre-treated alloy in highly concentrated synthetic body fluid for only few hours. Surface characterizations were performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Also, the deposited apatitic layers were analysed by powder diffraction X-ray analysis (XRD). 316L surface showed the growth of highly crystalline, low carbonated hydroxyapatite, after only 6 h of the whole soaking process. Highlights: ► The manuscript describes a fast and efficient biomimetic coating methodology. ► This methodology can be used for metallic implants. ► 316L was coated with crystalline hydroxyapatite. ► Addition of strontium and zinc lead to the deposition of brushite. ► Coating of all synthetic solutions is highly crystalline

Biomimetic fabrication of a three-level hierarchical calcium phosphate/collagen/hydroxyapatite scaffold for bone tissue engineering

International Nuclear Information System (INIS)

Zhou, Changchun; Ye, Xingjiang; Fan, Yujiang; Tan, Yanfei; Qing, Fangzu; Zhang, Xingdong; Ma, Liang

2014-01-01

A three-level hierarchical calcium phosphate/collagen/hydroxyapatite (CaP/Col/HAp) scaffold for bone tissue engineering was developed using biomimetic synthesis. Porous CaP ceramics were first prepared as substrate materials to mimic the porous bone structure. A second-level Col network was then composited into porous CaP ceramics by vacuum infusion. Finally, a third-level HAp layer was achieved by biomimetic mineralization. The three-level hierarchical biomimetic scaffold was characterized using scanning electron microscopy, energy-dispersive x-ray spectra, x-ray diffraction and Fourier transform infrared spectroscopy, and the mechanical properties of the scaffold were evaluated using dynamic mechanical analysis. The results show that this scaffold exhibits a similar structure and composition to natural bone tissues. Furthermore, this three-level hierarchical biomimetic scaffold showed enhanced mechanical strength compared with pure porous CaP scaffolds. The biocompatibility and osteoinductivity of the biomimetic scaffolds were evaluated using in vitro and in vivo tests. Cell culture results indicated the good biocompatibility of this biomimetic scaffold. Faster and increased bone formation was observed in these scaffolds following a six-month implantation in the dorsal muscles of rabbits, indicating that this biomimetic scaffold exhibits better osteoinductivity than common CaP scaffolds. (papers)

FIB patterning of dielectric, metallized and graphene membranes: A comparative study

International Nuclear Information System (INIS)

Hemamouche, A.; Morin, A.; Bourhis, E.; Madouri, A.; Lafosse, X.; Ulysse, C.; Guilet, S.; Patriarche, G.; Gierak, J.; Toury, B.; Tarnaud, E.; Mathe, J.; Guegan, P.; Auvray, L.; Montel, F.; Wilmart, Q.; Placais, B.; Yates, J.

2014-01-01

Fabrication of nano-pores and nano-masks has recently emerged as an area of considerable interest for research applications ranging from optics, to electronics and to biophysics. In this work we evaluate and compare the fabrication of nano-pores, using a finely focused gallium beam, in free-standing membranes/films made of Si, SiN, and SiO 2 (having thicknesses of a few tens of nanometers) and also in graphene and hexagonal boron nitride (h-BN) atomically thin suspended sheets. Mechanical resistance, charging effects and patterning performances are evaluated and compared. In spite of the very different properties of the membranes we report that reproducible nano-pore fabrication in the sub-10 nm range can be achieved in both amorphous and atomically thin sheets using Ga + focused ion beams (FIB). (authors)

Biological activity of lactoferrin-functionalized biomimetic hydroxyapatite nanocrystals

Directory of Open Access Journals (Sweden)

Nocerino N

2014-03-01

Full Text Available Nunzia Nocerino,1 Andrea Fulgione,1 Marco Iannaccone,1 Laura Tomasetta,1 Flora Ianniello,1 Francesca Martora,1 Marco Lelli,2 Norberto Roveri,2 Federico Capuano,3 Rosanna Capparelli1 1Department of Agriculture Special Biotechnology Center Federico II, CeBIOTEC Biotechnology, University of Naples Federico II, Naples, 2Department of Chemistry, G Ciamician, Alma Mater Studiorum, University of Bologna, Bologna, 3Department of Food Inspection IZS ME, Naples, Italy Abstract: The emergence of bacterial strains resistant to antibiotics is a general public health problem. Progress in developing new molecules with antimicrobial properties has been made. In this study, we evaluated the biological activity of a hybrid nanocomposite composed of synthetic biomimetic hydroxyapatite surface-functionalized by lactoferrin (LF-HA. We evaluated the antimicrobial, anti-inflammatory, and antioxidant properties of LF-HA and found that the composite was active against both Gram-positive and Gram-negative bacteria, and that it modulated proinflammatory and anti-inflammatory responses and enhanced antioxidant properties as compared with LF alone. These results indicate the possibility of using LF-HA as an antimicrobial system and biomimetic hydroxyapatite as a candidate for innovative biomedical applications. Keywords: lactoferrin, hydroxyapatite nanocrystals, biomimetism, biological activity, drug delivery

Biomimetic nanocrystalline apatite coatings synthesized by Matrix Assisted Pulsed Laser Evaporation for medical applications

Energy Technology Data Exchange (ETDEWEB)

Visan, A. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Grossin, D. [CIRIMAT – Carnot Institute, University of Toulouse, ENSIACET, 4 Allée Emile Monso, 31030 Toulouse Cedex 4 (France); Stefan, N.; Duta, L.; Miroiu, F.M. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Stan, G.E. [National Institute of Materials Physics, RO-077125, Magurele-Ilfov (Romania); Sopronyi, M.; Luculescu, C. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Freche, M.; Marsan, O.; Charvilat, C. [CIRIMAT – Carnot Institute, University of Toulouse, ENSIACET, 4 Allée Emile Monso, 31030 Toulouse Cedex 4 (France); Ciuca, S. [Politehnica University of Bucharest, Faculty of Materials Science and Engineering, Bucharest (Romania); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania)

2014-02-15

Highlights: • We report the deposition by MAPLE of biomimetic apatite coatings on Ti substrates. • This is the first report of MAPLE deposition of hydrated biomimetic apatite films. • Biomimetic apatite powder was synthesized by double decomposition process. • Non-apatitic environments, of high surface reactivity, are preserved post-deposition. • We got the MAPLE complete transfer as thin film of a hydrated, delicate material. -- Abstract: We report the deposition by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique of biomimetic nanocrystalline apatite coatings on titanium substrates, with potential application in tissue engineering. The targets were prepared from metastable, nanometric, poorly crystalline apatite powders, analogous to mineral bone, synthesized through a biomimetic approach by double decomposition process. For the deposition of thin films, a KrF* excimer laser source was used (λ = 248 nm, τ{sub FWHM} ≤ 25 ns). The analyses revealed the existence, in synthesized powders, of labile non-apatitic mineral ions, associated with the formation of a hydrated layer at the surface of the nanocrystals. The thin film analyses showed that the structural and chemical nature of the nanocrystalline apatite was prevalently preserved. The perpetuation of the non-apatitic environments was also observed. The study indicated that MAPLE is a suitable technique for the congruent transfer of a delicate material, such as the biomimetic hydrated nanohydroxyapatite.

Biomimetic nanocrystalline apatite coatings synthesized by Matrix Assisted Pulsed Laser Evaporation for medical applications

International Nuclear Information System (INIS)

Visan, A.; Grossin, D.; Stefan, N.; Duta, L.; Miroiu, F.M.; Stan, G.E.; Sopronyi, M.; Luculescu, C.; Freche, M.; Marsan, O.; Charvilat, C.; Ciuca, S.; Mihailescu, I.N.

2014-01-01

Highlights: • We report the deposition by MAPLE of biomimetic apatite coatings on Ti substrates. • This is the first report of MAPLE deposition of hydrated biomimetic apatite films. • Biomimetic apatite powder was synthesized by double decomposition process. • Non-apatitic environments, of high surface reactivity, are preserved post-deposition. • We got the MAPLE complete transfer as thin film of a hydrated, delicate material. -- Abstract: We report the deposition by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique of biomimetic nanocrystalline apatite coatings on titanium substrates, with potential application in tissue engineering. The targets were prepared from metastable, nanometric, poorly crystalline apatite powders, analogous to mineral bone, synthesized through a biomimetic approach by double decomposition process. For the deposition of thin films, a KrF* excimer laser source was used (λ = 248 nm, τ FWHM ≤ 25 ns). The analyses revealed the existence, in synthesized powders, of labile non-apatitic mineral ions, associated with the formation of a hydrated layer at the surface of the nanocrystals. The thin film analyses showed that the structural and chemical nature of the nanocrystalline apatite was prevalently preserved. The perpetuation of the non-apatitic environments was also observed. The study indicated that MAPLE is a suitable technique for the congruent transfer of a delicate material, such as the biomimetic hydrated nanohydroxyapatite

Structure and stability of the spinach aquaporin SoPIP2;1 in detergent micelles and lipid membranes.

Directory of Open Access Journals (Sweden)

Inés Plasencia

Full Text Available BACKGROUND: SoPIP2;1 constitutes one of the major integral proteins in spinach leaf plasma membranes and belongs to the aquaporin family. SoPIP2;1 is a highly permeable and selective water channel that has been successfully overexpressed and purified with high yields. In order to optimize reconstitution of the purified protein into biomimetic systems, we have here for the first time characterized the structural stability of SoPIP2;1. METHODOLOGY/PRINCIPAL FINDING: We have characterized the protein structural stability after purification and after reconstitution into detergent micelles and proteoliposomes using circular dichroism and fluorescence spectroscopy techniques. The structure of SoPIP2;1 was analyzed either with the protein solubilized with octyl-β-D-glucopyranoside (OG or reconstituted into lipid membranes formed by E. coli lipids, diphytanoylphosphatidylcholine (DPhPC, or reconstituted into lipid membranes formed from mixtures of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPE, 1-palmitoyl-2oleoyl-phosphatidylethanolamine (POPE, 1-palmitoyl-2-oleoyl-phosphatidylserine (POPS, and ergosterol. Generally, SoPIP2;1 secondary structure was found to be predominantly α-helical in accordance with crystallographic data. The protein has a high thermal structural stability in detergent solutions, with an irreversible thermal unfolding occurring at a melting temperature of 58°C. Incorporation of the protein into lipid membranes increases the structural stability as evidenced by an increased melting temperature of up to 70°C. CONCLUSION/SIGNIFICANCE: The results of this study provide insights into SoPIP2;1 stability in various host membranes and suggest suitable choices of detergent and lipid composition for reconstitution of SoPIP2;1 into biomimetic membranes for biotechnological applications.

Biomimetic nanoparticles: preparation, characterization and biomedical applications

Directory of Open Access Journals (Sweden)

Ana Maria Carmona-Ribeiro

2010-04-01

Full Text Available Ana Maria Carmona-RibeiroBiocolloids Lab, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, BrazilAbstract: Mimicking nature is a powerful approach for developing novel lipid-based devices for drug and vaccine delivery. In this review, biomimetic assemblies based on natural or synthetic lipids by themselves or associated to silica, latex or drug particles will be discussed. In water, self-assembly of lipid molecules into supramolecular structures is fairly well understood. However, their self-assembly on a solid surface or at an interface remains poorly understood. In certain cases, hydrophobic drug granules can be dispersed in aqueous solution via lipid adsorption surrounding the drug particles as nanocapsules. In other instances, hydrophobic drug molecules attach as monomers to borders of lipid bilayer fragments providing drug formulations that are effective in vivo at low drug-to-lipid-molar ratio. Cationic biomimetic particles offer suitable interfacial environment for adsorption, presentation and targeting of biomolecules in vivo. Thereby antigens can effectively be presented by tailored biomimetic particles for development of vaccines over a range of defined and controllable particle sizes. Biomolecular recognition between receptor and ligand can be reconstituted by means of receptor immobilization into supported lipidic bilayers allowing isolation and characterization of signal transduction steps.Keywords: cationic lipid, phospholipids, bilayer fragments, vesicles, silica, polymeric particles, antigens, novel cationic immunoadjuvants, drugs

A bio-inspired spatial patterning circuit.

Science.gov (United States)

Chen, Kai-Yuan; Joe, Danial J; Shealy, James B; Land, Bruce R; Shen, Xiling

2014-01-01

Lateral Inhibition (LI) is a widely conserved patterning mechanism in biological systems across species. Distinct from better-known Turing patterns, LI depend on cell-cell contact rather than diffusion. We built an in silico genetic circuit model to analyze the dynamic properties of LI. The model revealed that LI amplifies differences between neighboring cells to push them into opposite states, hence forming stable 2-D patterns. Inspired by this insight, we designed and implemented an electronic circuit that recapitulates LI patterning dynamics. This biomimetic system serve as a physical model to elucidate the design principle of generating robust patterning through spatial feedback, regardless of the underlying devices being biological or electrical.

Biomimetic micromechanical adaptive flow-sensor arrays

NARCIS (Netherlands)

Krijnen, Gijsbertus J.M.; Floris, J.; Dijkstra, Marcel; Lammerink, Theodorus S.J.; Wiegerink, Remco J.

2007-01-01

We report current developments in biomimetic flow-sensors based on flow sensitive mechano-sensors of crickets. Crickets have one form of acoustic sensing evolved in the form of mechanoreceptive sensory hairs. These filiform hairs are highly perceptive to low-frequency sound with energy sensitivities

Bottom-Up Synthesis and Sensor Applications of Biomimetic Nanostructures

Directory of Open Access Journals (Sweden)

Li Wang

2016-01-01

Full Text Available The combination of nanotechnology, biology, and bioengineering greatly improved the developments of nanomaterials with unique functions and properties. Biomolecules as the nanoscale building blocks play very important roles for the final formation of functional nanostructures. Many kinds of novel nanostructures have been created by using the bioinspired self-assembly and subsequent binding with various nanoparticles. In this review, we summarized the studies on the fabrications and sensor applications of biomimetic nanostructures. The strategies for creating different bottom-up nanostructures by using biomolecules like DNA, protein, peptide, and virus, as well as microorganisms like bacteria and plant leaf are introduced. In addition, the potential applications of the synthesized biomimetic nanostructures for colorimetry, fluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrical resistance, electrochemistry, and quartz crystal microbalance sensors are presented. This review will promote the understanding of relationships between biomolecules/microorganisms and functional nanomaterials in one way, and in another way it will guide the design and synthesis of biomimetic nanomaterials with unique properties in the future.

Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion.

Science.gov (United States)

Marras, Stefano; Porfiri, Maurizio

2012-08-07

The integration of biomimetic robots in a fish school may enable a better understanding of collective behaviour, offering a new experimental method to test group feedback in response to behavioural modulations of its 'engineered' member. Here, we analyse a robotic fish and individual golden shiners (Notemigonus crysoleucas) swimming together in a water tunnel at different flow velocities. We determine the positional preference of fish with respect to the robot, and we study the flow structure using a digital particle image velocimetry system. We find that biomimetic locomotion is a determinant of fish preference as fish are more attracted towards the robot when its tail is beating rather than when it is statically immersed in the water as a 'dummy'. At specific conditions, the fish hold station behind the robot, which may be due to the hydrodynamic advantage obtained by swimming in the robot's wake. This work makes a compelling case for the need of biomimetic locomotion in promoting robot-animal interactions and it strengthens the hypothesis that biomimetic robots can be used to study and modulate collective animal behaviour.

The Relationship between Respiration-Related Membrane Potential Slow Oscillations and Discharge Patterns in Mitral/Tufted Cells: What Are the Rules?

Science.gov (United States)

Briffaud, Virginie; Fourcaud-Trocmé, Nicolas; Messaoudi, Belkacem; Buonviso, Nathalie; Amat, Corine

2012-01-01

Background A slow respiration-related rhythm strongly shapes the activity of the olfactory bulb. This rhythm appears as a slow oscillation that is detectable in the membrane potential, the respiration-related spike discharge of the mitral/tufted cells and the bulbar local field potential. Here, we investigated the rules that govern the manifestation of membrane potential slow oscillations (MPSOs) and respiration-related discharge activities under various afferent input conditions and cellular excitability states. Methodology and Principal Findings We recorded the intracellular membrane potential signals in the mitral/tufted cells of freely breathing anesthetized rats. We first demonstrated the existence of multiple types of MPSOs, which were influenced by odor stimulation and discharge activity patterns. Complementary studies using changes in the intracellular excitability state and a computational model of the mitral cell demonstrated that slow oscillations in the mitral/tufted cell membrane potential were also modulated by the intracellular excitability state, whereas the respiration-related spike activity primarily reflected the afferent input. Based on our data regarding MPSOs and spike patterns, we found that cells exhibiting an unsynchronized discharge pattern never exhibited an MPSO. In contrast, cells with a respiration-synchronized discharge pattern always exhibited an MPSO. In addition, we demonstrated that the association between spike patterns and MPSO types appeared complex. Conclusion We propose that both the intracellular excitability state and input strength underlie specific MPSOs, which, in turn, constrain the types of spike patterns exhibited. PMID:22952828

Molecular motor assembly of a biomimetic system

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

@@ Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.

Biomimetic mineralization of CaCO3 on a phospholipid monolayer: from an amorphous calcium carbonate precursor to calcite via vaterite.

Science.gov (United States)

Xiao, Junwu; Wang, Zhining; Tang, Yecang; Yang, Shihe

2010-04-06

A phospholipid monolayer, approximately half the bilayer structure of a biological membrane, can be regarded as an ideal model for investigating biomineralization on biological membranes. In this work on the biomimetic mineralization of CaCO(3) under a phospholipid monolayer, we show the initial heterogeneous nucleation of amorphous calcium carbonate precursor (ACC) nanoparticles at the air-water interface, their subsequent transformation into the metastable vaterite phase instead of the most thermodynamically stable calcite phase, and the ultimate phase transformation to calcite. Furthermore, the spontaneity of the transformation from vaterite to calcite was found to be closely related to the surface tension; high surface pressure could inhibit the process, highlighting the determinant of surface energy. To understand better the mechanisms for ACC formation and the transformation from ACC to vaterite and to calcite, in situ Brewster angle microscopy (BAM), ex situ scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray diffraction analysis were employed. This work has clarified the crystallization process of calcium carbonate under phospholipid monolayers and therefore may further our understanding of the biomineralization processes induced by cellular membranes.

Biomimetic Designs Inspired by Seashells-Seashells Helping ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 6. Biomimetic Designs Inspired by Seashells - Seashells Helping Engineers Design Better Ceramics. Kiran Akella. General Article Volume 17 Issue 6 June 2012 pp 573-591 ...

Bioinspired porous membranes containing polymer nanoparticles for wound healing.

Science.gov (United States)

Ferreira, Ana M; Mattu, Clara; Ranzato, Elia; Ciardelli, Gianluca

2014-12-01

Skin damages covering a surface larger than 4 cm(2) require a regenerative strategy based on the use of appropriate wound dressing supports to facilitate the rapid tissue replacement and efficient self-healing of the lost or damaged tissue. In the present work, A novel biomimetic approach is proposed for the design of a therapeutic porous construct made of poly(L-lactic acid) (PLLA) fabricated by thermally induced phase separation (TIPS). Biomimicry of ECM was achieved by immobilization of type I collagen through a two-step plasma treatment for wound healing. Anti-inflammatory (indomethacin)-containing polymeric nanoparticles (nps) were loaded within the porous membranes in order to minimize undesired cell response caused by post-operative inflammation. The biological response to the scaffold was analyzed by using human keratinocytes cell cultures. In this work, a promising biomimetic construct for wound healing and soft tissue regeneration with drug-release properties was fabricated since it shows (i) proper porosity, pore size, and mechanical properties, (ii) biomimicry of ECM, and (iii) therapeutic potential. © 2014 Wiley Periodicals, Inc.

Biomimetic engineering of colloidal nanoarchitectures with "in vitro" and "in vivo" functionality

OpenAIRE

Einfalt, Tomaž

2017-01-01

Biomimetic engineering opens unprecedented possibilities of combining biomolecules (i.e. proteins, DNA, polysaccharides) with synthetic materials (i.e. synthetic polymers). This combination results in unique hybrid systems with functionalities that mimic processes in living organisms. While the translational value of functional biomimetically engineered structures is of exceptional importance in fields such as technology, engineering, chemistry, biology and medicine, due to the properties the...

A Biomimetic Haptic Sensor

OpenAIRE

Ben Mitchinson; Ian Gilhespy; Chris Melhuish; Mokhtar Nibouche; Tony J. Prescott; Anthony G. Pipe; Martin J. Pearson

2008-01-01

The design and implementation of the periphery of an artificial whisker sensory system is presented. It has been developed by adopting a biomimetic approach to model the structure and function of rodent facial vibrissae. The artificial vibrissae have been formed using composite materials and have the ability to be actively moved or whisked. The sensory structures at the root of real vibrissae has been modelled and implemented using micro strain gauges and Digital Signal Processors. The primar...

Wear Behavior of Medium Carbon Steel with Biomimetic Surface Under Starved Lubricated Conditions

Science.gov (United States)

Zhang, Zhihui; Shao, Feixian; Liang, Yunhong; Lin, Pengyu; Tong, Xin; Ren, Luquan

2017-07-01

Friction and wear under starved lubrication condition are both key life-related factors for mechanical performance of many structural parts. In this paper, different surface morphologies on medium carbon steel were fabricated using laser, inspired by the surface coupling effect of biological system. The friction and sliding wear behaviors of biomimetic specimens (characterized by convex and concave units on the specimen surface) were studied under starved lubrication condition. The stress distribution on different sliding surfaces under sliding friction was studied using finite element method. The results showed that the tribological performance of studied surfaces under starved lubrication condition depended not only on the surface morphology but also on the structure of biomimetic units below surface (subsurface structure). The friction coefficient of biomimetic surface was effectively reduced by the concave unit depth, while the refined microstructure with higher hardness led to the much better wear resistance. In addition to lubricant reserving and wear debris trapping effect derived from the surface concave morphology, it was believed that the well-formed subsurface structure of biomimetic units could carry much heavy loads against tribopair, which enhanced the function of surface topography and resulted in complementary lubrication in the wear contact area. The uniform stress distribution on the entire biomimetic surface also played an important role in stabilizing the friction coefficient and reducing the wear cracks.

Green Tribology Biomimetics, Energy Conservation and Sustainability

CERN Document Server

Bhushan, Bharat

2012-01-01

Tribology is the study of friction, wear and lubrication. Recently, the concept of “green tribology” as “the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts” was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment.

Biomimetics in the design of a robotic exoskeleton for upper limb therapy

Science.gov (United States)

Baniqued, Paul Dominick E.; Dungao, Jade R.; Manguerra, Michael V.; Baldovino, Renann G.; Abad, Alexander C.; Bugtai, Nilo T.

2018-02-01

Current methodologies in designing robotic exoskeletons for upper limb therapy simplify the complex requirements of the human anatomy. As a result, such devices tend to compromise safety and biocompatibility with the intended user. However, a new design methodology uses biological analogues as inspiration to address these technical issues. This approach follows that of biomimetics, a design principle that uses the extraction and transfer of useful information from natural morphologies and processes to solve technical design issues. In this study, a biomimetic approach in the design of a 5-degree-of-freedom robotic exoskeleton for upper limb therapy was performed. A review of biomimetics was first discussed along with its current contribution to the design of rehabilitation robots. With a proposed methodological framework, the design for an upper limb robotic exoskeleton was generated using CATIA software. The design was inspired by the morphology of the bones and the muscle force transmission of the upper limbs. Finally, a full design assembly presented had integrated features extracted from the biological analogue. The successful execution of a biomimetic design methodology made a case in providing safer and more biocompatible robots for rehabilitation.

Design of Self-Oscillating Gels and Application to Biomimetic Actuators

Directory of Open Access Journals (Sweden)

Ryo Yoshida

2010-03-01

Full Text Available As a novel biomimetic polymer, we have developed polymer gels with an autonomous self-oscillating function. This was achieved by utilizing oscillating chemical reactions, called the Belousov-Zhabotinsky (BZ reaction, which is recognized as a chemical model for understanding several autonomous phenomena in biological systems. Under the coexistence of the reactants, the polymer gel undergoes spontaneous swelling-deswelling changes without any on-off switching by external stimuli. In this review, our recent studies on the self-oscillating polymer gels and application to biomimetic actuators are summarized.

Fabrication of highly porous biodegradable biomimetic nanocomposite as advanced bone tissue scaffold

OpenAIRE

Abdalla Abdal-hay; Khalil Abdelrazek Khalil; Abdel Salam Hamdy; Fawzi F. Al-Jassir

2017-01-01

Development of bioinspired or biomimetic materials is currently a challenge in the field of tissue regeneration. In-situ 3D biomimetic microporous nanocomposite scaffold has been developed using a simple lyophilization post hydrothermal reaction for bone healing applications. The fabricated 3D porous scaffold possesses advantages of good bonelike apatite particles distribution, thermal properties and high porous interconnected network structure. High dispersion bonelike apatite nanoparticles ...

Biomimetic actuators using electroactive polymers (EAP) as artificial muscles

Science.gov (United States)

Bar-Cohen, Yoseph

2006-01-01

Evolution has resolved many of nature's challenges leading to lasting solutions with maximal performance and effective use of resources. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems and many other benefits. The field of mimicking nature is known as Biomimetics and one of its topics includes electroactive polymers that gain the moniker artificial muscles. Integrating EAP with embedded sensors, self-repair and many other capabilities that are used in composite materials can add greatly to the capability of smart biomimetic systems. Such development would enable fascinating possibilities potentially turning science fiction ideas into engineering reality.

Selected papers from the 7th International Conference on Biomimetics, Artificial Muscles and Nano-bio (BAMN2013)

Science.gov (United States)

Shahinpoor, Mohsen; Oh, Ilkwon

2014-07-01

The 7th International Congress on Biomimetics, Artificial Muscles and Nano-Bio was held on the magnificent and beautiful Jeju Island in Korea on 26-30 August 2013. In June 2007, the volcanic island and lava tube cave systems were designated as UNESCO World Natural Heritage Sites for their natural beauty and unique geographical values. The aim of the congress was to offer high-level lectures, extensive discussions and communications covering the state-of-the-art on biomimetics, artificial muscles, and nano-bio technologies providing an overview of their potential applications in the industrial, biomedical, scientific and robotic fields. This conference provided a necessary platform for an ongoing dialogue between researchers from different areas (chemistry, physics, biology, medicine, engineering, robotics, etc) within biomimetics, artificial muscle and nano-bio technologies. This special issue of Smart Materials and Structures is devoted to a selected number of research papers that were presented at BAMN2013. Of the 400 or so papers and over 220 posters presented at this international congress, 15 papers were finally received, reviewed and accepted for this special issue, following the regular peer review procedures of the journal. The special issue covers polymeric artificial muscles, electroactive polymers, multifunctional nanocomposites, and their applications. In particular, electromechanical performance and other characteristics of ionic polymer-metal composites (IPMCs) fabricated with various commercially available ion exchange membranes are discussed. Additionally, the control of free-edge interlaminar stresses in composite laminates using piezoelectric actuators is elaborated on. Further, the electrode effects of a cellulose-based electroactive paper energy harvester are described. Next, a flexible tactile-feedback touch screen using transparent ferroelectric polymer film vibrators is discussed. A broad coverage of bio-applications of IPMC transducers is

Elasticity-based patterning of red blood cells on undulated lipid membranes supported on porous topographic substrates.

Science.gov (United States)

Lee, Sang-Wook; Jeong, Cherlhyun; Lee, Sin-Doo

2009-03-26

We describe elasticity-based patterning of human red blood cells (RBCs) into a microarray form on supported lipid membranes (SLMs) prepared on a solid substrate having two types of topographic patterns, porous and flat regions. The underlying concept is to precisely control the interplay between adhesion and the bending rigidity of the RBCs that interact with the SLMs. Attachment of the RBCs on highly undulated SLMs formed on the porous region is not energetically favorable, since membrane bending of the RBCs costs a high curvature elastic energy which exceeds adhesion. The RBCs are thus selectively confined within relatively flat regions of the SLMs without causing considerable elastic distortions. It was found that the population of the RBCs in a single corral is linearly proportional to the area of one element in our microarray.

Bile acids modulate signaling by functional perturbation of plasma membrane domains.

Science.gov (United States)

Zhou, Yong; Maxwell, Kelsey N; Sezgin, Erdinc; Lu, Maryia; Liang, Hong; Hancock, John F; Dial, Elizabeth J; Lichtenberger, Lenard M; Levental, Ilya

2013-12-13

Eukaryotic cell membranes are organized into functional lipid and protein domains, the most widely studied being membrane rafts. Although rafts have been associated with numerous plasma membrane functions, the mechanisms by which these domains themselves are regulated remain undefined. Bile acids (BAs), whose primary function is the solubilization of dietary lipids for digestion and absorption, can affect cells by interacting directly with membranes. To investigate whether these interactions affected domain organization in biological membranes, we assayed the effects of BAs on biomimetic synthetic liposomes, isolated plasma membranes, and live cells. At cytotoxic concentrations, BAs dissolved synthetic and cell-derived membranes and disrupted live cell plasma membranes, implicating plasma membrane damage as the mechanism for BA cellular toxicity. At subtoxic concentrations, BAs dramatically stabilized domain separation in Giant Plasma Membrane Vesicles without affecting protein partitioning between coexisting domains. Domain stabilization was the result of BA binding to and disordering the nonraft domain, thus promoting separation by enhancing domain immiscibility. Consistent with the physical changes observed in synthetic and isolated biological membranes, BAs reorganized intact cell membranes, as evaluated by the spatial distribution of membrane-anchored Ras isoforms. Nanoclustering of K-Ras, related to nonraft membrane domains, was enhanced in intact plasma membranes, whereas the organization of H-Ras was unaffected. BA-induced changes in Ras lateral segregation potentiated EGF-induced signaling through MAPK, confirming the ability of BAs to influence cell signal transduction by altering the physical properties of the plasma membrane. These observations suggest general, membrane-mediated mechanisms by which biological amphiphiles can produce their cellular effects.

Effect of medium on friction and wear properties of compacted graphite cast iron processed by biomimetic coupling laser remelting process

International Nuclear Information System (INIS)

Guo Qingchun; Zhou Hong; Wang Chengtao; Zhang Wei; Lin Pengyu; Sun Na; Ren Luquan

2009-01-01

Stimulated by the cuticles of soil animals, an attempt to improve the wear resistance of compact graphite cast iron (CGI) with biomimetic units on the surface was made by using a biomimetic coupled laser remelting process in air and various thicknesses water film, respectively. The microstructures of biomimetic units were examined by scanning electron microscope and X-ray diffraction was used to describe the microstructure and identify the phases in the melted zone. Microhardness was measured and the wear behaviors of biomimetic specimens as functions of different mediums as well as various water film thicknesses were investigated under dry sliding condition, respectively. The results indicated that the microstructure zones in the biomimetic specimens processed with water film are refined compared with that processed in air and had better wear resistance increased by 60%, the microhardness of biomimetic units has been improved significantly. The application of water film provided finer microstructures and much more regular grain shape in biomimetic units, which played a key role in improving the friction properties and wear resistance of CGI.

Effect of medium on friction and wear properties of compacted graphite cast iron processed by biomimetic coupling laser remelting process

Science.gov (United States)

Guo, Qing-chun; Zhou, Hong; Wang, Cheng-tao; Zhang, Wei; Lin, Peng-yu; Sun, Na; Ren, Luquan

2009-04-01

Stimulated by the cuticles of soil animals, an attempt to improve the wear resistance of compact graphite cast iron (CGI) with biomimetic units on the surface was made by using a biomimetic coupled laser remelting process in air and various thicknesses water film, respectively. The microstructures of biomimetic units were examined by scanning electron microscope and X-ray diffraction was used to describe the microstructure and identify the phases in the melted zone. Microhardness was measured and the wear behaviors of biomimetic specimens as functions of different mediums as well as various water film thicknesses were investigated under dry sliding condition, respectively. The results indicated that the microstructure zones in the biomimetic specimens processed with water film are refined compared with that processed in air and had better wear resistance increased by 60%, the microhardness of biomimetic units has been improved significantly. The application of water film provided finer microstructures and much more regular grain shape in biomimetic units, which played a key role in improving the friction properties and wear resistance of CGI.

Biomimetic synthesis and characterization of semiconducting hybrid

Indian Academy of Sciences (India)

Triple hybrid materials based on polyaniline-polyethylene glycol and cadmium sulphide have been prepared by the duffusion–limited biomimetic route and characterized by a number of spectroscopic, XRD, SEM, thermal and electrical measurements. These hybrid materials have been prepared by controlled precipitation of ...

Developing the ultimate biomimetic flow-sensor array

NARCIS (Netherlands)

Bruinink, C.M.; Jaganatharaja, R.K.; de Boer, Meint J.; Berenschot, Johan W.; Kolster, M.L.; Lammerink, Theodorus S.J.; Wiegerink, Remco J.; Krijnen, Gijsbertus J.M.

2009-01-01

This contribution reports on the major developments and achievements in our group on fabricating highly sensitive biomimetic flow-sensor arrays. The mechanoreceptive sensory hairs of crickets are taken as a model system for their ability to perceive flow signals at thermal noise levels and,

Voltage-Gated Transport of Nanoparticles across Free-Standing All-Carbon-Nanotube-Based Hollow-Fiber Membranes.

Science.gov (United States)

Wei, Gaoliang; Quan, Xie; Chen, Shuo; Fan, Xinfei; Yu, Hongtao; Zhao, Huimin

2015-07-15

Understanding the mechanism underlying controllable transmembrane transport observed in biological membranes benefits the development of next-generation separation membranes for a variety of important applications. In this work, on the basis of common structural features of cell membranes, a very simple biomimetic membrane system exhibiting gated transmembrane performance has been constructed using all-carbon-nanotube (CNT)-based hollow-fiber membranes. The conductive CNT membranes with hydrophobic pore channels can be positively or negatively charged and are consequently capable of regulating the transport of nanoparticles across their pore channels by their "opening" or "closing". The switch between penetration and rejection of nanoparticles through/by CNT membranes is of high efficiency and especially allows dynamic control. The underlying mechanism is that CNT pore channels with different polarities can prompt or prevent the formation of their noncovalent interactions with charged nanoparticles, resulting in their rejection or penetration by/through the CNT membranes. The theory about noncovalent interactions and charged pore channels may provide new insight into understanding the complicated ionically and bimolecularly gated transport across cell membranes and can contribute to many other important applications beyond the water purification and resource recovery demonstrated in this study.

Characterization and expression patterns of a membrane-bound trehalase from Spodoptera exigua

Directory of Open Access Journals (Sweden)

Xu Weihua

2008-05-01

Full Text Available Abstract Background The chitin biosynthesis pathway starts with trehalose in insects and the main functions of trehalases are hydrolysis of trehalose to glucose. Although insects possess two types, soluble trehalase (Tre-1 and membrane-bound trehalase (Tre-2, very little is known about Tre-2 and the difference in function between Tre-1 and Tre-2. Results To gain an insight into trehalase functions in insects, we investigated a putative membrane-bound trehalase from Spodoptera exigua (SeTre-2 cloned from the fat body. The deduced amino acid sequence of SeTre-2 contains 645 residues and has a predicted molecular weight of ~74 kDa and pI of 6.01. Alignment of SeTre-2 with other insect trehalases showed that it contains two trehalase signature motifs and a putative transmembrane domain, which is an important characteristic of Tre-2. Comparison of the genomic DNA and cDNA sequences demonstrated that SeTre-2 comprises 13 exons and 12 introns. Southern blot analysis revealed that S. exigua has two trehalase genes and that SeTre-2 is a single-copy gene. Northern blot analyses showed that the SeTre-2 transcript is expressed not only in the midgut, as previously reported for Bombyx mori, but also in the fat body and Malpighian tubules, although expression patterns differed between the midgut and fat body. SeTre-2 transcripts were detected in the midgut of feeding stage larvae, but not in pupae, whereas SeTre-2 mRNA was detected in the fat body of fifth instar larvae and pupae. Conclusion These findings provide new data on the tissue distribution, expression patterns and potential function of membrane-bound trehalase. The results suggest that the SeTre-2 gene may have different functions in the midgut and fat body.

Antinuclear antibodies giving the 'multiple nuclear dots' or the 'rim-like/membranous' patterns: diagnostic accuracy for primary biliary cirrhosis.

Science.gov (United States)

Granito, A; Muratori, P; Muratori, L; Pappas, G; Cassani, F; Worthington, J; Guidi, M; Ferri, S; DE Molo, C; Lenzi, M; Chapman, R W; Bianchi, F B

2006-12-01

Serum antinuclear antibodies giving the 'multiple nuclear dots' or the 'rim-like/membranous' patterns are frequently detected by indirect immunofluorescence on HEp-2 cells in patients with primary biliary cirrhosis. To assess the accuracy of multiple nuclear dot and rim-like/membranous antinuclear antibodies for the diagnosis of primary biliary cirrhosis. Sera from 4371 consecutive patients referred to our laboratory were analysed under code for antinuclear antibodies testing by indirect immunofluorescence on HEp-2 cells. Review of the clinical records of the 4371 patients allowed identification of 101 patients with antimitochondrial antibody-positive primary biliary cirrhosis and 22 with antimitochondrial antibody-negative variant. Multiple nuclear dot and/or rim-like/membranous patterns were found in 59 (1.3%) of the 4371 patients: 31 antimitochondrial antibody-positive primary biliary cirrhosis, 17 antimitochondrial antibody-negative primary biliary cirrhosis and 11 non-primary biliary cirrhosis. The specificity for primary biliary cirrhosis of both the antinuclear antibodies pattern was 99%. Positive predictive value and likelihood ratio for a positive test were 86% (95% CI: 72.7-94) and 221 (95% CI: 91.7-544) for multiple nuclear dot, 79% (95% CI: 62.2-90.1) and 132 (95% CI: 56.8-312.7) for rim-like/membranous, respectively. Multiple nuclear dot and rim-like/membranous antinuclear antibodies are rare findings. Their positivity strongly suggests the diagnosis of primary biliary cirrhosis, irrespective of antimitochondrial antibody status. The high specificity for primary biliary cirrhosis makes them a useful diagnostic tool especially in antimitochondrial antibody-negative patients.

The state of the art in biomimetics

International Nuclear Information System (INIS)

Lepora, Nathan F; Prescott, Tony J; Verschure, Paul

2013-01-01

Biomimetics is a research field that is achieving particular prominence through an explosion of new discoveries in biology and engineering. The field concerns novel technologies developed through the transfer of function from biological systems. To analyze the impact of this field within engineering and related sciences, we compiled an extensive database of publications for study with network-based information analysis techniques. Criteria included publications by year and journal or conference, and subject areas judged by popular and common terms in titles. Our results reveal that this research area has expanded rapidly from less than 100 papers per year in the 1990s to several thousand papers per year in the first decade of this century. Moreover, this research is having impact across a variety of research themes, spanning robotics, computer science and bioengineering. In consequence, biomimetics is becoming a leading paradigm for the development of new technologies that will potentially lead to significant scientific, societal and economic impact in the near future. (perspective)

The state of the art in biomimetics.

Science.gov (United States)

Lepora, Nathan F; Verschure, Paul; Prescott, Tony J

2013-03-01

Biomimetics is a research field that is achieving particular prominence through an explosion of new discoveries in biology and engineering. The field concerns novel technologies developed through the transfer of function from biological systems. To analyze the impact of this field within engineering and related sciences, we compiled an extensive database of publications for study with network-based information analysis techniques. Criteria included publications by year and journal or conference, and subject areas judged by popular and common terms in titles. Our results reveal that this research area has expanded rapidly from less than 100 papers per year in the 1990s to several thousand papers per year in the first decade of this century. Moreover, this research is having impact across a variety of research themes, spanning robotics, computer science and bioengineering. In consequence, biomimetics is becoming a leading paradigm for the development of new technologies that will potentially lead to significant scientific, societal and economic impact in the near future.

Biomimetic catalysts responsive to specific chemical signals

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yan [Iowa State Univ., Ames, IA (United States)

2015-03-04

Part 1. Design of Biomimetic Catalysts Based on Amphiphilic Systems The overall objective of our research is to create biomimetic catalysts from amphiphilic molecules. More specifically, we aim to create supramolecular systems that can be used to control the microenvironment around a catalytic center in a biomimetic fashion and apply the learning to construct supramolecular catalysts with novel functions found in enzymatic catalysts. We have prepared synthetic molecules (i.e., foldamers) that could fold into helical structures with nanometer-sized internal hydrophilic cavities. Cavities of this size are typically observed only in the tertiary and quaternary structures of proteins but were formed in our foldamer prepared in just a few steps from the monomer. Similar to many proteins, our foldamers displayed cooperativity in the folding/unfolding equilibrium and followed a two-state conformational transition. In addition, their conformational change could be triggered by solvent polarity, pH, or presence of metal ions and certain organic molecules. We studied their environmentally dependent conformational changes in solutions, surfactant micelles, and lipid bilayer membranes. Unlike conventional rigid supramolecular host, a foldamer undergoes conformational change during guest binding. Our study in the molecular recognition of an oligocholate host yielded some extremely exciting results. Cooperativity between host conformation and host–guest interactions was found to “magnify” weak binding interactions. In other words, since binding affinity is determined by the overall change of free energy during the binding, guest-induced conformational change of the host, whether near or far from the binding site, affects the binding. This study has strong implications in catalysis because enzymes have been hypothesized to harvest similar intramolecular forces to strengthen their binding with the transition state of an enzyme-catalyzed reaction. The supramolecular and

Couple of biomimetic surfaces with different morphologies for remanufacturing nonuniform wear rail surface

Science.gov (United States)

Sui, Qi; Zhou, Hong; Yang, Lin; Zhang, Haifeng; Feng, Li; Zhang, Peng

2018-02-01

In this work, biomimetic laser treatment was performed on repairing and remanufacturing the nonuniform worn rail surface. The wearing depth distribution of three work regions of a failure rail surface was discussed, and different thickness hardening layers with different microstructure, microhardness and wear resistances were detected from the worm surfaces. Varying wear resistances of the surfaces with different biomimetic morphologies were obtained by biomimetic laser treatments, and the corresponding effect on the lubrication sliding wear of treated and untreated surfaces were studied for comparative study. In addition, the relationship between wear resistance and the spacing of units was also provided, which can lay the important theoretical foundation for avoiding the wear resistance of the serious worn surface is less than that of the slight worn surface in the future practical applications.

The Effects of Alkyl Chain Combinations on the Structural and Mechanical Properties of Biomimetic Ion Pair Amphiphile Bilayers

Directory of Open Access Journals (Sweden)

Cheng-hao Chen

2017-10-01

Full Text Available Ion pair amphiphile (IPA, a lipid-like complex composed of a pair of cationic and anionic surfactants, has great potentials in various pharmaceutical applications. In this work, we utilized molecular dynamics (MD simulation to systematically examine the structural and mechanical properties of the biomimetic bilayers consist of alkyltrimethyl-ammonium-alkylsulfate (CmTMA+-CnS− IPAs with various alkyl chain combinations. Our simulations show an intrinsic one-atom offset for the CmTMA+ and CnS− alignment, leading to the asymmetric index definition of ΔC = m − (n + 1. Larger |ΔC| gives rise to higher conformational fluctuations of the alkyl chains with the reduced packing order and mechanical strength. In contrast, increasing the IPA chain length enhances the van der Waals interactions within the bilayer and thus improves the bilayer packing order and mechanical properties. Further elongating the CmTMA+-CnS− alkyl chains to m and n ≥ 12 causes the liquid disorder to gel phase transition of the bilayer at 298 K, with the threshold membrane properties of 0.45 nm2 molecular area, deuterium order parameter value of 0.31, and effective bending rigidity of 20 kBT, etc. The combined results provide molecular insights into the design of biomimetic IPA bilayers with wide structural and mechanical characteristics for various applications.

A review paper on biomimetic calcium phosphate coatings

NARCIS (Netherlands)

Lin, X.; de Groot, K.; Wang, D.; Hu, Q.; Wismeijer, D.; Liu, Y.

2015-01-01

Biomimetic calcium phosphate coatings have been developed for bone regeneration and repair because of their biocompatibility, osteoconductivity, and easy preparation. They can be rendered osteoinductive by incorporating an osteogenic agent, such as bone morphogenetic protein 2 (BMP-2), into the

Inkjet printing for direct micropatterning of a superhydrophobic surface: Toward biomimetic fog harvesting surfaces

KAUST Repository

Zhang, Lianbin

2015-01-01

The preparation of biomimetic superhydrophobic surfaces with hydrophilic micro-sized patterns is highly desirable, but a one-step, mask-free method to produce such surfaces has not previously been reported. We have developed a direct method to produce superhydrophilic micropatterns on superhydrophobic surfaces based on inkjet printing technology. This work was inspired by the efficient fog-harvesting behavior of Stenocara beetles in the Namib Desert. A mussel-inspired ink consisting of an optimized solution of dopamine was applied directly by inkjet printing to superhydrophobic surfaces. Stable Wenzel\\'s microdroplets of the dopamine solution with well-defined micropatterns were obtained on these surfaces. Superhydrophilic micropatterns with well-controlled dimensions were then readily achieved on the superhydrophobic surfaces by the formation of polydopamine via in situ polymerization. The micropatterned superhydrophobic surfaces prepared by this inkjet printing method showed enhanced water collection efficiency compared with uniform superhydrophilic and superhydrophobic surfaces. This method can be used for the facile large-scale patterning of superhydrophobic surfaces with high precision and superior pattern stability and is therefore a key step toward patterning superhydrophobic surfaces for practical applications. This journal is

A small-scale, rolled-membrane microfluidic artificial lung designed towards future large area manufacturing.

Science.gov (United States)

Thompson, A J; Marks, L H; Goudie, M J; Rojas-Pena, A; Handa, H; Potkay, J A

2017-03-01

Artificial lungs have been used in the clinic for multiple decades to supplement patient pulmonary function. Recently, small-scale microfluidic artificial lungs (μAL) have been demonstrated with large surface area to blood volume ratios, biomimetic blood flow paths, and pressure drops compatible with pumpless operation. Initial small-scale microfluidic devices with blood flow rates in the μ l/min to ml/min range have exhibited excellent gas transfer efficiencies; however, current manufacturing techniques may not be suitable for scaling up to human applications. Here, we present a new manufacturing technology for a microfluidic artificial lung in which the structure is assembled via a continuous "rolling" and bonding procedure from a single, patterned layer of polydimethyl siloxane (PDMS). This method is demonstrated in a small-scale four-layer device, but is expected to easily scale to larger area devices. The presented devices have a biomimetic branching blood flow network, 10  μ m tall artificial capillaries, and a 66  μ m thick gas transfer membrane. Gas transfer efficiency in blood was evaluated over a range of blood flow rates (0.1-1.25 ml/min) for two different sweep gases (pure O 2 , atmospheric air). The achieved gas transfer data closely follow predicted theoretical values for oxygenation and CO 2 removal, while pressure drop is marginally higher than predicted. This work is the first step in developing a scalable method for creating large area microfluidic artificial lungs. Although designed for microfluidic artificial lungs, the presented technique is expected to result in the first manufacturing method capable of simply and easily creating large area microfluidic devices from PDMS.

Engineering zonal cartilage through bioprinting collagen type II hydrogel constructs with biomimetic chondrocyte density gradient.

Science.gov (United States)

Ren, Xiang; Wang, Fuyou; Chen, Cheng; Gong, Xiaoyuan; Yin, Li; Yang, Liu

2016-07-20

Cartilage tissue engineering is a promising approach for repairing and regenerating cartilage tissue. To date, attempts have been made to construct zonal cartilage that mimics the cartilaginous matrix in different zones. However, little attention has been paid to the chondrocyte density gradient within the articular cartilage. We hypothesized that the chondrocyte density gradient plays an important role in forming the zonal distribution of extracellular matrix (ECM). In this study, collagen type II hydrogel/chondrocyte constructs were fabricated using a bioprinter. Three groups were created according to the total cell seeding density in collagen type II pre-gel: Group A, 2 × 10(7) cells/mL; Group B, 1 × 10(7) cells/mL; and Group C, 0.5 × 10(7) cells/mL. Each group included two types of construct: one with a biomimetic chondrocyte density gradient and the other with a single cell density. The constructs were cultured in vitro and harvested at 0, 1, 2, and 3 weeks for cell viability testing, reverse-transcription quantitative PCR (RT-qPCR), biochemical assays, and histological analysis. We found that total ECM production was positively correlated with the total cell density in the early culture stage, that the cell density gradient distribution resulted in a gradient distribution of ECM, and that the chondrocytes' biosynthetic ability was affected by both the total cell density and the cell distribution pattern. Our results suggested that zonal engineered cartilage could be fabricated by bioprinting collagen type II hydrogel constructs with a biomimetic cell density gradient. Both the total cell density and the cell distribution pattern should be optimized to achieve synergistic biological effects.

Biomimetic calcium phosphate coatings: : Physicochemistry and biological activity

NARCIS (Netherlands)

Barrère, F.

2002-01-01

Plasma-sprayed hydroxylapatite coatings on metallic prosthesis significantly increased the success rate of hip arthroplasty, namely from about 90% after 10 years for cemented hip stems to 98% for HA coated ones. Nowadays, the biomimetic approach has received increased interest because of the

Water Activated Graphene Oxide Transfer Using Wax Printed Membranes for Fast Patterning of a Touch Sensitive Device.

Science.gov (United States)

Baptista-Pires, Luis; Mayorga-Martínez, Carmen C; Medina-Sánchez, Mariana; Montón, Helena; Merkoçi, Arben

2016-01-26

We demonstrate a graphene oxide printing technology using wax printed membranes for the fast patterning and water activation transfer using pressure based mechanisms. The wax printed membranes have 50 μm resolution, longtime stability and infinite shaping capability. The use of these membranes complemented with the vacuum filtration of graphene oxide provides the control over the thickness. Our demonstration provides a solvent free methodology for printing graphene oxide devices in all shapes and all substrates using the roll-to-roll automatized mechanism present in the wax printing machine. Graphene oxide was transferred over a wide variety of substrates as textile or PET in between others. Finally, we developed a touch switch sensing device integrated in a LED electronic circuit.

Biomimetic structures for fluid drag reduction in laminar and turbulent flows

International Nuclear Information System (INIS)

Jung, Yong Chae; Bhushan, Bharat

2010-01-01

Biomimetics allows one to mimic nature to develop materials and devices of commercial interest for engineers. Drag reduction in fluid flow is one of the examples found in nature. In this study, nano, micro, and hierarchical structures found in lotus plant surfaces, as well as shark skin replica and a rib patterned surface to simulate shark skin structure were fabricated. Drag reduction efficiency studies on the surfaces were systematically carried out using water flow. An experimental flow channel was used to measure the pressure drop in laminar and turbulent flows, and the trends were explained in terms of the measured and predicted values by using fluid dynamics models. The slip length for various surfaces in laminar flow was also investigated based on the measured pressure drop. For comparison, the pressure drop for various surfaces was also measured using air flow.

Biomimetic Moth-eye Nanofabrication: Enhanced Antireflection with Superior Self-cleaning Characteristic.

Science.gov (United States)

Sun, Jingyao; Wang, Xiaobing; Wu, Jinghua; Jiang, Chong; Shen, Jingjing; Cooper, Merideth A; Zheng, Xiuting; Liu, Ying; Yang, Zhaogang; Wu, Daming

2018-04-03

Sub-wavelength antireflection moth-eye structures were fabricated with Nickel mold using Roll-to-Plate (R2P) ultraviolet nanoimprint lithography (UV-NIL) on transparent polycarbonate (PC) substrates. Samples with well replicated patterns established an average reflection of 1.21% in the visible light range, 380 to 760 nm, at normal incidence. An excellent antireflection property of a wide range of incidence angles was shown with the average reflection below 4% at 50°. Compared with the unpatterned ultraviolet-curable resin coating, the resulting sub-wavelength moth-eye structure also exhibited increased hydrophobicity in addition to antireflection. This R2P method is especially suitable for large-area product preparation and the biomimetic moth-eye structure with multiple performances can be applied to optical devices such as display screens, solar cells, or light emitting diodes.

Biomimetic Composite Scaffold for Breast Reconstruction Following Tumor Resection

National Research Council Canada - National Science Library

Patrick, Jr, Charles W

2005-01-01

... of life and outcomes are markedly improved. We hypothesized that a novel composite material consisting of silk fibroin and chitosan will act as a biomimetic scaffold amenable to in vivo adipogenesis. The specific aims (SAs...

Effect of distribution of striated laser hardening tracks on dry sliding wear resistance of biomimetic surface

Science.gov (United States)

Su, Wei; Zhou, Ti; Zhang, Peng; Zhou, Hong; Li, Hui

2018-01-01

Some biological surfaces were proved to have excellent anti-wear performance. Being inspired, Nd:YAG pulsed laser was used to create striated biomimetic laser hardening tracks on medium carbon steel samples. Dry sliding wear tests biomimetic samples were performed to investigate specific influence of distribution of laser hardening tracks on sliding wear resistance of biomimetic samples. After comparing wear weight loss of biomimetic samples, quenched sample and untreated sample, it can be suggested that the sample covered with dense laser tracks (3.5 mm spacing) has lower wear weight loss than the one covered with sparse laser tracks (4.5 mm spacing); samples distributed with only dense laser tracks or sparse laser tracks (even distribution) were proved to have better wear resistance than samples distributed with both dense and sparse tracks (uneven distribution). Wear mechanisms indicate that laser track and exposed substrate of biomimetic sample can be regarded as hard zone and soft zone respectively. Inconsecutive striated hard regions, on the one hand, can disperse load into small branches, on the other hand, will hinder sliding abrasives during wear. Soft regions with small range are beneficial in consuming mechanical energy and storing lubricative oxides, however, soft zone with large width (>0.5 mm) will be harmful to abrasion resistance of biomimetic sample because damages and material loss are more obvious on surface of soft phase. As for the reason why samples with even distributed bionic laser tracks have better wear resistance, it can be explained by the fact that even distributed laser hardening tracks can inhibit severe worn of local regions, thus sliding process can be more stable and wear extent can be alleviated as well.

Biomimetic synthesis of hybrid nanocomposite scaffolds by freeze

Indian Academy of Sciences (India)

The aim of this study is to biomimetically synthesize hydroxyapatite–hydrophilic polymer scaffolds for biomedical applications. This organic–inorganic hybrid has been structurally characterized and reveals a good microstructural control as seen by the SEM analysis and the nanosize of the particulates is confirmed by AFM ...

Enhanced Critical Size Defect Repair in Rabbit Mandible by Electrospun Gelatin/β-TCP Composite Nanofibrous Membranes

Directory of Open Access Journals (Sweden)

Mingming Xu

2015-01-01

Full Text Available The design and fabrication of biodegradable barrier membranes with satisfactory structure and composition remain a considerable challenge for periodontal tissue regeneration. We have developed a biomimetic nanofibrous membrane made from a composite of gelatin and β-tricalcium phosphate (β-TCP. We previously confirmed the in vitro biological performance of the membrane material, but the efficacy of the membranes in promoting bone repair in situ has not yet been examined. Gelatin/β-TCP composite nanofibers were fabricated by incorporation of 20 wt.% β-TCP nanoparticles into electrospun gelatin nanofibers. Electron microscopy showed that the composite membranes presented a nonwoven structure with an interconnected porous network and had a rough surface due to the β-TCP nanoparticles, which were distributed widely and uniformly throughout the gelatin-fiber matrix. The repair efficacy of rabbit mandible defects implanted with bone substitute (Bio-Oss and covered with the gelatin/β-TCP composite nanofibrous membrane was evaluated in comparison with pure gelatin nanofibrous membrane. Gross observation, histological examination, and immunohistochemical analysis showed that new bone formation and defect closure were significantly enhanced by the composite membranes compared to the pure gelatin ones. From these results, we conclude that nanofibrous gelatin/β-TCP composite membranes could serve as effective barrier membranes for guided tissue regeneration.

Biomimetic calcium phosphate coating of additively manufactured porous CoCr implants

Energy Technology Data Exchange (ETDEWEB)

Lindahl, Carl [BIOMATCELL Vinn Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Department of Engineering Sciences, Ångstrom Laboratory, Uppsala University, Uppsala (Sweden); Xia, Wei, E-mail: wei.xia@angstrom.uu.se [BIOMATCELL Vinn Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Department of Engineering Sciences, Ångstrom Laboratory, Uppsala University, Uppsala (Sweden); Engqvist, Håkan [BIOMATCELL Vinn Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Department of Engineering Sciences, Ångstrom Laboratory, Uppsala University, Uppsala (Sweden); Snis, Anders [BIOMATCELL Vinn Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Arcam AB, Krokslätts Fabriker 27 A, SE-431 37 Mölndal (Sweden); Lausmaa, Jukka [BIOMATCELL Vinn Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Department of Chemistry, Materials and Surfaces, SP Technical Research Institute of Sweden, Borås (Sweden); Palmquist, Anders [BIOMATCELL Vinn Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Department of Biomaterials, Sahlgrenska Academy at the University of Gothenburg, Gothenburg (Sweden)

2015-10-30

Highlights: • A route for coating complex shaped electron beam melted implants is presented. • Biomimetic HA coatings were deposited on CoCr alloys using a solution method. • Deposited biomimetic coating was partially crystalline, slightly calcium deficient. • Coating morphology was plate-like with crystallites forming roundish flowers. • Present coating procedure could be useful for porous implants made by EBM. - Abstract: The aim of this work was to study the feasibility to use a biomimetic method to prepare biomimetic hydroxyapatite (HA) coatings on CoCr substrates with short soaking times and to characterize the properties of such coatings. A second objective was to investigate if the coatings could be applied to porous CoCr implants manufactured by electron beam melting (EBM). The coating was prepared by immersing the pretreated CoCr substrates and EBM implants into the phosphate-buffered solution with Ca{sup 2+} in sealed plastic bottles, kept at 60 °C for 3 days. The formed coating was partially crystalline, slightly calcium deficient and composed of plate-like crystallites forming roundish flowers in the size range of 300–500 nm. Cross-section imaging showed a thickness of 300–500 nm. In addition, dissolution tests in Tris–HCl up to 28 days showed that a substantial amount of the coating had dissolved, however, undergoing only minor morphological changes. A uniform coating was formed within the porous network of the additive manufactured implants having similar thickness and morphology as for the flat samples. In conclusion, the present coating procedure allows coatings to be formed on CoCr and could be used for complex shaped, porous implants made by additive manufacturing.

Biomimetic calcium phosphate coating of additively manufactured porous CoCr implants

International Nuclear Information System (INIS)

Lindahl, Carl; Xia, Wei; Engqvist, Håkan; Snis, Anders; Lausmaa, Jukka; Palmquist, Anders

2015-01-01

Highlights: • A route for coating complex shaped electron beam melted implants is presented. • Biomimetic HA coatings were deposited on CoCr alloys using a solution method. • Deposited biomimetic coating was partially crystalline, slightly calcium deficient. • Coating morphology was plate-like with crystallites forming roundish flowers. • Present coating procedure could be useful for porous implants made by EBM. - Abstract: The aim of this work was to study the feasibility to use a biomimetic method to prepare biomimetic hydroxyapatite (HA) coatings on CoCr substrates with short soaking times and to characterize the properties of such coatings. A second objective was to investigate if the coatings could be applied to porous CoCr implants manufactured by electron beam melting (EBM). The coating was prepared by immersing the pretreated CoCr substrates and EBM implants into the phosphate-buffered solution with Ca"2"+ in sealed plastic bottles, kept at 60 °C for 3 days. The formed coating was partially crystalline, slightly calcium deficient and composed of plate-like crystallites forming roundish flowers in the size range of 300–500 nm. Cross-section imaging showed a thickness of 300–500 nm. In addition, dissolution tests in Tris–HCl up to 28 days showed that a substantial amount of the coating had dissolved, however, undergoing only minor morphological changes. A uniform coating was formed within the porous network of the additive manufactured implants having similar thickness and morphology as for the flat samples. In conclusion, the present coating procedure allows coatings to be formed on CoCr and could be used for complex shaped, porous implants made by additive manufacturing.

Biomimetically Reinforced Polyvinyl Alcohol-Based Hybrid Scaffolds for Cartilage Tissue Engineering

Directory of Open Access Journals (Sweden)

Hwan D. Kim

2017-11-01

Full Text Available Articular cartilage has a very limited regeneration capacity. Therefore, injury or degeneration of articular cartilage results in an inferior mechanical stability, load-bearing capacity, and lubrication capability. Here, we developed a biomimetic scaffold consisting of macroporous polyvinyl alcohol (PVA sponges as a platform material for the incorporation of cell-embedded photocrosslinkable poly(ethylene glycol diacrylate (PEGDA, PEGDA-methacrylated chondroitin sulfate (PEGDA-MeCS; PCS, or PEGDA-methacrylated hyaluronic acid (PEGDA-MeHA; PHA within its pores to improve in vitro chondrocyte functions and subsequent in vivo ectopic cartilage tissue formation. Our findings demonstrated that chondrocytes encapsulated in PCS or PHA and loaded into macroporous PVA hybrid scaffolds maintained their physiological phenotypes during in vitro culture, as shown by the upregulation of various chondrogenic genes. Further, the cell-secreted extracellular matrix (ECM improved the mechanical properties of the PVA-PCS and PVA-PHA hybrid scaffolds by 83.30% and 73.76%, respectively, compared to their acellular counterparts. After subcutaneous transplantation in vivo, chondrocytes on both PVA-PCS and PVA-PHA hybrid scaffolds significantly promoted ectopic cartilage tissue formation, which was confirmed by detecting cells positively stained with Safranin-O and for type II collagen. Consequently, the mechanical properties of the hybrid scaffolds were biomimetically reinforced by 80.53% and 210.74%, respectively, compared to their acellular counterparts. By enabling the recapitulation of biomimetically relevant structural and functional properties of articular cartilage and the regulation of in vivo mechanical reinforcement mediated by cell–matrix interactions, this biomimetic material offers an opportunity to control the desired mechanical properties of cell-laden scaffolds for cartilage tissue regeneration.

Advances in immobilized artificial membrane (IAM) chromatography for novel drug discovery.

Science.gov (United States)

Tsopelas, Fotios; Vallianatou, Theodosia; Tsantili-Kakoulidou, Anna

2016-01-01

The development of immobilized artificial membrane (IAM) chromatography has unfolded new perspectives for the use of chromatographic techniques in drug discovery, combining simulation of the environment of cell membranes with rapid measurements. The present review describes the characteristics of phosphatidylcholine-based stationary phases and analyses the molecular factors governing IAM retention in comparison to n-octanol-water and liposomes partitioning systems as well as to reversed phase chromatography. Other biomimetic stationary phases are also briefly discussed. The potential of IAM chromatography to model permeability through the main physiological barriers and drug membrane interactions is outlined. Further applications to calculate complex pharmacokinetic properties, related to tissue binding, and to screen drug candidates for phospholipidosis, as well as to estimate cell accumulation/retention are surveyed. The ambivalent nature of IAM chromatography, as a border case between passive diffusion and binding, defines its multiple potential applications. However, despite its successful performance in many permeability and drug-membrane interactions studies, IAM chromatography is still used as a supportive and not a stand-alone technique. Further studies looking at IAM chromatography in different biological processes are still required if this technique is to have a more focused and consistent application in drug discovery.

Methane hydroxylation: a biomimetic approach

International Nuclear Information System (INIS)

Shilov, Aleksandr E; Shteinman, Al'bert A

2012-01-01

The review addresses direct methane oxidation — an important fundamental problem, which has attracted much attention of researchers in recent years. Analysis of the available results on biomimetic and bio-inspired methane oxygenation has demonstrated that assimilating of the experience of Nature on oxidation of methane and other alkanes significantly enriches the arsenal of chemistry and can radically change the character of the entire chemical production, as well as enables the solution of many material, energetic and environmental problems. The bibliography includes 310 references.

Evolution and development of model membranes for physicochemical and functional studies of the membrane lateral heterogeneity.

Science.gov (United States)

Morigaki, Kenichi; Tanimoto, Yasushi

2018-03-14

One of the main questions in the membrane biology is the functional roles of membrane heterogeneity and molecular localization. Although segregation and local enrichment of protein/lipid components (rafts) have been extensively studied, the presence and functions of such membrane domains still remain elusive. Along with biochemical, cell observation, and simulation studies, model membranes are emerging as an important tool for understanding the biological membrane, providing quantitative information on the physicochemical properties of membrane proteins and lipids. Segregation of fluid lipid bilayer into liquid-ordered (Lo) and liquid-disordered (Ld) phases has been studied as a simplified model of raft in model membranes, including giant unilamellar vesicles (GUVs), giant plasma membrane vesicles (GPMVs), and supported lipid bilayers (SLB). Partition coefficients of membrane proteins between Lo and Ld phases were measured to gauze their affinities to lipid rafts (raftophilicity). One important development in model membrane is patterned SLB based on the microfabrication technology. Patterned Lo/Ld phases have been applied to study the partition and function of membrane-bound molecules. Quantitative information of individual molecular species attained by model membranes is critical for elucidating the molecular functions in the complex web of molecular interactions. The present review gives a short account of the model membranes developed for studying the lateral heterogeneity, especially focusing on patterned model membranes on solid substrates. Copyright © 2018 Elsevier B.V. All rights reserved.

Placental histologic patterns and neonatal seizure, in preterm premature rupture of membrane.

Science.gov (United States)

Ko, Hyun Sun; Cheon, Ju Young; Choi, Sae Kyung; Lee, Hye Won; Lee, Ahwon; Park, In Yang; Shin, Jong Chul

2017-04-01

To investigate the relationship between placenta and perinatal outcomes, in preterm infants born to mothers with preterm premature rupture of fetal membrane (PPROM). We report detailed histology of placentas and perinatal outcomes of infants from 79 PPROM pregnancies. Placental histologic pattern and adverse perinatal outcomes were assessed by logistic regression, adjusting for gestational age at birth, birth weight and interval from rupture of membrane to delivery. Mean gestational age at membrane rupture was 29.5 ± 3.4 weeks. The incidence of histologic chorioamnionitis (HCA), fetal inflammatory response (FIR) and vascular thrombotic abnormalities in placental histologic examination were 63.3, 25.3 and 78.5%, respectively. Neonates with FIR showed significantly higher incidence of periventricular leukomalacia (PVL) (85% versus 59.3%, p = 0.0364) at brain ultrasonography, than neonates without FIR, in univariate analysis, but not in logistic regression analysis. In logistic regression analysis, the odds ratio of low Apgar score at 1 min in the neonates with clinical chorioamnionitis was 5.009 (95% CI, 1.242-20.195). The odds ratio of neonatal seizure in the neonates with FIR and vascular thrombotic problem was 7.486 (95% CI, 1.617-34.653). Our findings support the association between FIR with vascular thrombotic problem in placenta and neonatal seizure, in pregnancies with PPROM.

Sensing in nature: using biomimetics for design of sensors

DEFF Research Database (Denmark)

Lenau, Torben Anker; Cheong, Hyunmin; Shu, Li

2008-01-01

limitations/implications – Biomimetics can be a challenge to engineers due to the terminology from another scientific discipline. Practical implications – Using a formalised search method is a way of solving the problem of finding the relevant biological analogies. Originality/value – The paper is of value...... of sense organs in animals and illustrates how a formal search method developed at University of Toronto can be applied to sensor design. Design/methodology/approach – Using biomimetics involves a search for relevant cases, a proper analysis of the biological solutions, identification of design principles...... and design of the desired artefact. The present search method is based on formulation of relevant keywords and search for occurrences in a standard university biology textbook. Most often a simple formulation of keywords and a following search is not enough to generate a sufficient amount of useful ideas...

Models and prototypes of biomimetic devices to architectural purposes

Directory of Open Access Journals (Sweden)

Silvia Titotto

2014-12-01

Full Text Available This paper presents some results of an ongoing interdisciplinary research about models and prototypes of biomimetic devices via installations and the focus of this paper is to outline this research role in architectural purposes as it perpasses the cultural and heritage contexts by being a way of understanding and living in the world as well as taking place in the world as devices or environments that pass on to future generations to use, learn from and be inspired by. Both the theoretical and the experimental work done so far point out that installations built with association of laser cutting and rapid prototyping techniques might be on the best feasible ways for developing and testing new technologies involved in biomimetic devices to architectural purposes that put both tectonics and nature as their central theme. 

Experimental parametric study of a biomimetic fish robot actuated by piezoelectric actuators

Science.gov (United States)

Wiguna, T.; Park, Hoon C.; Heo, S.; Goo, Nam S.

2007-04-01

This paper presents an experiment and parametric study of a biomimetic fish robot actuated by the Lightweight Piezocomposite Actuator (LIPCA). The biomimetic aspects in this work are the oscillating tail beat motion and shape of caudal fin. Caudal fins that resemble fins of BCF (Body and Caudal Fin) mode fish were made in order to perform parametric study concerning the effect of caudal fin characteristics on thrust production at an operating frequency range. The observed caudal fin characteristics are the shape, stiffness, area, and aspect ratio. It is found that a high aspect ratio caudal fin contributes to high swimming speed. The robotic fish propelled by artificial caudal fins shaped after thunniform-fish and mackerel caudal fins, which have relatively high aspect ratio, produced swimming speed as high as 2.364 cm/s and 2.519 cm/s, respectively, for a 300 V p-p input voltage excited at 0.9 Hz. Thrust performance of the biomimetic fish robot is examined by calculating Strouhal number, Froude number, Reynolds number, and power consumption.

Case Study in Biomimetic Design: Handling and Assembly of Microparts

DEFF Research Database (Denmark)

Shu, Li; Hansen, Hans Nørgaard; Gegeckaite, Asta

2006-01-01

This paper describes the application of the biomimetic design process to the development of automated gripping devices for microparts. Handling and assembly of micromechanical parts is complicated by size effects that occur when part dimensions are scaled down. A common complication involves stic...... and the abscission process in plants inspired concepts of new automated handling devices for microobjects. The design, development and testing of a gripping device based on biological principles for the automated handling and assembly of a microscrew is presented.......This paper describes the application of the biomimetic design process to the development of automated gripping devices for microparts. Handling and assembly of micromechanical parts is complicated by size effects that occur when part dimensions are scaled down. A common complication involves...

Growth of hydroxyapatite on the cellular membrane of the bacterium Bacillus thuringiensis for the preparation of hybrid biomaterials

Energy Technology Data Exchange (ETDEWEB)

Cervantes, Eric Reyes, E-mail: onomaeric@hotmail.com [Centro de Investigación en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Prolongación de la 24 Sur y Ave San Claudio, Ciudad Universitaria, Col San Manuel, C.P. 72570 Puebla, Pue (Mexico); Torres, Maykel González, E-mail: mikegcu@fata.unam.mx [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro C.P. 76230 (Mexico); Muñoz, Susana Vargas, E-mail: vmsu@unam.mx [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro C.P. 76230 (Mexico); Rosas, Efraín Rubio, E-mail: efrainrubio@yahoo.com [Centro de Investigación en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Prolongación de la 24 Sur y Ave San Claudio, Ciudad Universitaria, Col San Manuel, C.P. 72570 Puebla, Pue (Mexico); and others

2016-01-01

This study aimed to grow hydroxyapatite (HAp) crystals on the cellular wall of the Gram-positive bacterium Bacillus thuringiensis using a bio-mimetic method. Several strains were phenotypically and genotypically characterized using multilocus sequence typing (MLST) gene markers to differentiate the strains and confirm the identity of the isolated species to guarantee that the selected species was not harmful to human health or the environment. Three of the analyzed strains were selected because they exhibited the best nucleation and growth of HAp on the bacterial surface. This innovative method to grow HAp crystals on a cellular membrane helps to elucidate the mechanisms by which osseous tissue is formed in nature. The optimum concentration for the simulated physiological fluid (SPF) was 1.5 ×. The hybrid materials were characterized by optical microscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). - Highlights: • HAp crystals are grown on the cellular wall of a GP bacteria Bacillus thuringiensis. • The growing was carried out by using a bio-mimetic method. • Hybrid materials were characterized with morphological and spectroscopic techniques. • The reported method allows understanding the mechanisms to produce osseous tissue. • The membrane of Bacillus thuringiensis can grow more HAp than Bacillus halodurans.

Lactoferrin Adsorbed onto Biomimetic Hydroxyapatite Nanocrystals Controlling - In Vivo - the Helicobacter pylori Infection

Science.gov (United States)

Fulgione, Andrea; Nocerino, Nunzia; Iannaccone, Marco; Roperto, Sante; Capuano, Federico; Roveri, Norberto; Lelli, Marco; Crasto, Antonio; Calogero, Armando; Pilloni, Argenia Paola; Capparelli, Rosanna

2016-01-01

Background The resistance of Helicobacter pylori to the antibiotic therapy poses the problem to discover new therapeutic approaches. Recently it has been stated that antibacterial, immunomodulatory, and antioxidant properties of lactoferrin are increased when this protein is surface-linked to biomimetic hydroxyapatite nanocrystals. Objective Based on these knowledge, the aim of the study was to investigate the efficacy of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles with cell free supernatant from probiotic Lactobacillus paracasei as an alternative therapy against Helicobacter pylori infection. Methods Antibacterial and antinflammatory properties, humoral antibody induction, histopathological analysis and absence of side effects were evaluated in both in vitro and in vivo studies. Results The tests carried out have been demonstrated better performance of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles combined with cell free supernatant from probiotic Lactobacillus paracasei compared to both lactoferrin and probiotic alone or pooled. Conclusion These findings indicate the effectiveness and safety of our proposed therapy as alternative treatment for Helicobacter pylori infection. PMID:27384186

Forearm interosseous membrane trauma: MRI diagnostic criteria and injury patterns

Energy Technology Data Exchange (ETDEWEB)

McGinley, Joseph C. [Stanford University Medical Center, Department of Radiology, Stanford, CA (United States); Roach, Neil [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Hopgood, Brendon C. [Albert Einstein Medical Center, Department of Surgery, Philadelphia, PA (United States); Limmer, Karl [Temple University School of Medicine, Philadelphia, PA (United States); Kozin, Scott H. [Shriners Hospital for Children, Temple University and Pediatric Hand and Upper Extremity Surgeon, Philadelphia, PA (United States)

2006-05-15

Define criteria for interosseous membrane (IOM) injury diagnosis using MRI, and characterize patterns of IOM disruption following forearm trauma. Our hypothesis is that most IOM injuries occur along the ulnar insertion, and MRI should be obtained following forearm trauma to assess IOM competency. Sixteen cadaver forearms were subjected to longitudinal impact trauma. Prior to and following injury, MR images were examined by a board-certified musculoskeletal radiologist using pre-defined criteria for determining IOM integrity. Each specimen was dissected and the viability/pattern of injury examined. The MRI and dissection results were compared using a double-blinded methodology. Eight of the 16 specimens demonstrated IOM trauma. Seven specimens demonstrated complete IOM disruption from the ulnar insertion, and one revealed a mid-substance tear with intact origin and insertion. The dorsal oblique bundle was disrupted in four specimens. MRI analysis identified IOM injury in seven of the eight forearms. The injury location was correctly identified in six specimens when compared to dissection observations. MRI determination of IOM injury demonstrated a positive predictive value of 100%, a negative predictive value of 89%, a sensitivity of 87.5% and a specificity of 100%. (orig.)

Forearm interosseous membrane trauma: MRI diagnostic criteria and injury patterns

International Nuclear Information System (INIS)

McGinley, Joseph C.; Roach, Neil; Hopgood, Brendon C.; Limmer, Karl; Kozin, Scott H.

2006-01-01

Define criteria for interosseous membrane (IOM) injury diagnosis using MRI, and characterize patterns of IOM disruption following forearm trauma. Our hypothesis is that most IOM injuries occur along the ulnar insertion, and MRI should be obtained following forearm trauma to assess IOM competency. Sixteen cadaver forearms were subjected to longitudinal impact trauma. Prior to and following injury, MR images were examined by a board-certified musculoskeletal radiologist using pre-defined criteria for determining IOM integrity. Each specimen was dissected and the viability/pattern of injury examined. The MRI and dissection results were compared using a double-blinded methodology. Eight of the 16 specimens demonstrated IOM trauma. Seven specimens demonstrated complete IOM disruption from the ulnar insertion, and one revealed a mid-substance tear with intact origin and insertion. The dorsal oblique bundle was disrupted in four specimens. MRI analysis identified IOM injury in seven of the eight forearms. The injury location was correctly identified in six specimens when compared to dissection observations. MRI determination of IOM injury demonstrated a positive predictive value of 100%, a negative predictive value of 89%, a sensitivity of 87.5% and a specificity of 100%. (orig.)

Biomimetic syntheses of phenols from polyketones.

Science.gov (United States)

Evans, G E; Garson, M J; Griffin, D A; Leeper, F J; Stauton, J

1978-01-01

As a result of speculation that many enzymes control polyketone cyclization in vivo by converting a key carbonyl group to a cis-enol ether derivative, we describe two novel biomimetic cyclizations. The first involves condensation of two C6 units derived from triacetic lactone to form an arylpyrone related to aloenin. In the second a naphthapyrone of the rubrofusarin type is formed by condensation of an orsellinic acid derivative with the ether of triacetic lactone.

Characterization of complementary patterned metallic membranes produced simultaneously by a dual fabrication process

Science.gov (United States)

Hao, Qingzhen; Zeng, Yong; Wang, Xiande; Zhao, Yanhui; Wang, Bei; Chiang, I.-Kao; Werner, Douglas H.; Crespi, Vincent; Huang, Tony Jun

2010-11-01

An efficient technique is developed to fabricate optically thin metallic films with subwavelength patterns and their complements simultaneously. By comparing the spectra of the complementary films, we show that Babinet's principle nearly holds for these structures in the optical domain. Rigorous full-wave simulations are employed to verify the experimental observations. It is further demonstrated that a discrete-dipole approximation can qualitatively describe the spectral dependence of the metallic membranes on the geometry of the constituent particles as well as the illuminating polarization.

A Biomimetic Structural Form: Developing a Paradigm to Attain Vital Sustainability in Tall Architecture

OpenAIRE

Osama Al-Sehail

2017-01-01

This paper argues for sustainability as a necessity in the evolution of tall architecture. It provides a different mode for dealing with sustainability in tall architecture, taking into consideration the speciality of its typology. To this end, the article develops a Biomimetic Structural Form as a paradigm to attain Vital Sustainability. A Biomimetic Structural Form, which is derived from the amalgamation of biomimicry as an approach for sustainability defining nature as source of knowledge ...

Synthetic biology and biomimetic chemistry as converging technologies fostering a new generation of smart biosensors.

Science.gov (United States)

Scognamiglio, Viviana; Antonacci, Amina; Lambreva, Maya D; Litescu, Simona C; Rea, Giuseppina

2015-12-15

Biosensors are powerful tunable systems able to switch between an ON/OFF status in response to an external stimulus. This extraordinary property could be engineered by adopting synthetic biology or biomimetic chemistry to obtain tailor-made biosensors having the desired requirements of robustness, sensitivity and detection range. Recent advances in both disciplines, in fact, allow to re-design the configuration of the sensing elements - either by modifying toggle switches and gene networks, or by producing synthetic entities mimicking key properties of natural molecules. The present review considered the role of synthetic biology in sustaining biosensor technology, reporting examples from the literature and reflecting on the features that make it a useful tool for designing and constructing engineered biological systems for sensing application. Besides, a section dedicated to bioinspired synthetic molecules as powerful tools to enhance biosensor potential is reported, and treated as an extension of the concept of biomimetic chemistry, where organic synthesis is used to generate artificial molecules that mimic natural molecules. Thus, the design of synthetic molecules, such as aptamers, biomimetics, molecular imprinting polymers, peptide nucleic acids, and ribozymes were encompassed as "products" of biomimetic chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

Engineering anisotropic biomimetic fibrocartilage microenvironment by bioprinting mesenchymal stem cells in nanoliter gel droplets.

Science.gov (United States)

Gurkan, Umut A; El Assal, Rami; Yildiz, Simin E; Sung, Yuree; Trachtenberg, Alexander J; Kuo, Winston P; Demirci, Utkan

2014-07-07

Over the past decade, bioprinting has emerged as a promising patterning strategy to organize cells and extracellular components both in two and three dimensions (2D and 3D) to engineer functional tissue mimicking constructs. So far, tissue printing has neither been used for 3D patterning of mesenchymal stem cells (MSCs) in multiphase growth factor embedded 3D hydrogels nor been investigated phenotypically in terms of simultaneous differentiation into different cell types within the same micropatterned 3D tissue constructs. Accordingly, we demonstrated a biochemical gradient by bioprinting nanoliter droplets encapsulating human MSCs, bone morphogenetic protein 2 (BMP-2), and transforming growth factor β1 (TGF- β1), engineering an anisotropic biomimetic fibrocartilage microenvironment. Assessment of the model tissue construct displayed multiphasic anisotropy of the incorporated biochemical factors after patterning. Quantitative real time polymerase chain reaction (qRT-PCR) results suggested genomic expression patterns leading to simultaneous differentiation of MSC populations into osteogenic and chondrogenic phenotype within the multiphasic construct, evidenced by upregulation of osteogenesis and condrogenesis related genes during in vitro culture. Comprehensive phenotypic network and pathway analysis results, which were based on genomic expression data, indicated activation of differentiation related mechanisms, via signaling pathways, including TGF, BMP, and vascular endothelial growth factor.

Engineering Anisotropic Biomimetic Fibrocartilage Microenvironment by Bioprinting Mesenchymal Stem Cells in Nanoliter Gel Droplets

Science.gov (United States)

2015-01-01

Over the past decade, bioprinting has emerged as a promising patterning strategy to organize cells and extracellular components both in two and three dimensions (2D and 3D) to engineer functional tissue mimicking constructs. So far, tissue printing has neither been used for 3D patterning of mesenchymal stem cells (MSCs) in multiphase growth factor embedded 3D hydrogels nor been investigated phenotypically in terms of simultaneous differentiation into different cell types within the same micropatterned 3D tissue constructs. Accordingly, we demonstrated a biochemical gradient by bioprinting nanoliter droplets encapsulating human MSCs, bone morphogenetic protein 2 (BMP-2), and transforming growth factor β1 (TGF- β1), engineering an anisotropic biomimetic fibrocartilage microenvironment. Assessment of the model tissue construct displayed multiphasic anisotropy of the incorporated biochemical factors after patterning. Quantitative real time polymerase chain reaction (qRT-PCR) results suggested genomic expression patterns leading to simultaneous differentiation of MSC populations into osteogenic and chondrogenic phenotype within the multiphasic construct, evidenced by upregulation of osteogenesis and condrogenesis related genes during in vitro culture. Comprehensive phenotypic network and pathway analysis results, which were based on genomic expression data, indicated activation of differentiation related mechanisms, via signaling pathways, including TGF, BMP, and vascular endothelial growth factor. PMID:24495169

Hydroxyapatite coating by biomimetic method on titanium alloy ...

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 28; Issue 6. Hydroxyapatite coating by biomimetic method on titanium alloy using concentrated SBF. S Bharati M K Sinha ... Optical microscopic and SEM observations revealed the deposition of Ca–P layer on the titanium alloy by both the methods. Thickness of coating ...

Inhomogeneity Based Characterization of Distribution Patterns on the Plasma Membrane.

Directory of Open Access Journals (Sweden)

Laura Paparelli

2016-09-01

Full Text Available Cell surface protein and lipid molecules are organized in various patterns: randomly, along gradients, or clustered when segregated into discrete micro- and nano-domains. Their distribution is tightly coupled to events such as polarization, endocytosis, and intracellular signaling, but challenging to quantify using traditional techniques. Here we present a novel approach to quantify the distribution of plasma membrane proteins and lipids. This approach describes spatial patterns in degrees of inhomogeneity and incorporates an intensity-based correction to analyze images with a wide range of resolutions; we have termed it Quantitative Analysis of the Spatial distributions in Images using Mosaic segmentation and Dual parameter Optimization in Histograms (QuASIMoDOH. We tested its applicability using simulated microscopy images and images acquired by widefield microscopy, total internal reflection microscopy, structured illumination microscopy, and photoactivated localization microscopy. We validated QuASIMoDOH, successfully quantifying the distribution of protein and lipid molecules detected with several labeling techniques, in different cell model systems. We also used this method to characterize the reorganization of cell surface lipids in response to disrupted endosomal trafficking and to detect dynamic changes in the global and local organization of epidermal growth factor receptors across the cell surface. Our findings demonstrate that QuASIMoDOH can be used to assess protein and lipid patterns, quantifying distribution changes and spatial reorganization at the cell surface. An ImageJ/Fiji plugin of this analysis tool is provided.

Aloe vera Induced Biomimetic Assemblage of Nucleobase into Nanosized Particles

Science.gov (United States)

Chauhan, Arun; Zubair, Swaleha; Sherwani, Asif; Owais, Mohammad

2012-01-01

Aim Biomimetic nano-assembly formation offers a convenient and bio friendly approach to fabricate complex structures from simple components with sub-nanometer precision. Recently, biomimetic (employing microorganism/plants) synthesis of metal and inorganic materials nano-particles has emerged as a simple and viable strategy. In the present study, we have extended biological synthesis of nano-particles to organic molecules, namely the anticancer agent 5-fluorouracil (5-FU), using Aloe vera leaf extract. Methodology The 5-FU nano- particles synthesized by using Aloe vera leaf extract were characterized by UV, FT-IR and fluorescence spectroscopic techniques. The size and shape of the synthesized nanoparticles were determined by TEM, while crystalline nature of 5-FU particles was established by X-ray diffraction study. The cytotoxic effects of 5-FU nanoparticles were assessed against HT-29 and Caco-2 (human adenocarcinoma colorectal) cell lines. Results Transmission electron microscopy and atomic force microscopic techniques confirmed nano-size of the synthesized particles. Importantly, the nano-assembled 5-FU retained its anticancer action against various cancerous cell lines. Conclusion In the present study, we have explored the potential of biomimetic synthesis of nanoparticles employing organic molecules with the hope that such developments will be helpful to introduce novel nano-particle formulations that will not only be more effective but would also be devoid of nano-particle associated putative toxicity constraints. PMID:22403622

Plasma lipid pattern and red cell membrane structure in β-thalassemia patients in Jakarta

Directory of Open Access Journals (Sweden)

Seruni K.U. Freisleben

2011-08-01

Full Text Available Background: Over the last 10 years, we have investigated thalassemia patients in Jakarta to obtain a comprehensive picture of iron overload, oxidative stress, and cell damage.Methods: In blood samples from 15 transfusion-dependent patients (group T, 5 non-transfused patients (group N and 10 controls (group C, plasma lipids and lipoproteins, lipid-soluble vitamin E, malondialdehyde (MDA and thiol status were measured. Isolated eryhtrocyte membranes were investigated with electron paramagnetic resonance (EPR spectroscopy using doxyl-stearic acid and maleimido-proxyl spin lables. Data were analyzed statistically with ANOVA.Results: Plasma triglycerides were higher and cholesterol levels were lower in thalassemic patients compared to controls. Vitamin E, group C: 21.8 vs T: 6.2 μmol/L and reactive thiols (C: 144 vs. T: 61 μmol/L were considerably lower in transfused patients, who exert clear signs of oxidative stress (MDA, C: 1.96 vs T: 9.2 μmol/L and of tissue cell damage, i.e., high transaminases plasma levels. Non-transfused thalassemia patients have slight signs of oxidative stress, but no significant indication of cell damage. Erythrocyte membrane parameters from EPR spectroscopy differ considerably between all groups. In transfusion-dependent patients the structure of the erythrocyte membrane and the gradients of polarity and fluidity are destroyed in lipid domains; binding capacity of protein thiols in the membrane is lower and immobilized.Conclusion: In tranfusion-dependent thalassemic patients, plasma lipid pattern and oxidative stress are associated with structural damage of isolated erythrocyte membranes as measured by EPR spectroscopy with lipid and proteinthiol spin labels. (Med J Indones 2011; 20:178-84Keywords: electron paramagnetic resonance spectroscopy, erythrocyte membrane, lipoproteins, oxidative stress, thalassemia, plasma lipids.

A biomimetic accelerometer inspired by the cricket's clavate hair

NARCIS (Netherlands)

Droogendijk, H.; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

2014-01-01

Crickets use so-called clavate hairs to sense (gravitational) acceleration to obtain information on their orientation. Inspired by this clavate hair system, a one-axis biomimetic accelerometer has been developed and fabricated using surface micromachining and SU-8 lithography. An analytical model

Modeling of dielectric elastomer oscillators for soft biomimetic applications.

Science.gov (United States)

Henke, E-F M; Wilson, Katherine E; Anderson, I A

2018-06-26

Biomimetic, entirely soft robots with animal-like behavior and integrated artificial nervous systems will open up totally new perspectives and applications. However, until now, most presented studies on soft robots were limited to only partly soft designs, since all solutions at least needed conventional, stiff electronics to sense, process signals and activate actuators. We present a novel approach for a set up and the experimental validation of an artificial pace maker that is able to drive basic robotic structures and act as artificial central pattern generator. The structure is based on multi-functional dielectric elastomers (DEs). DE actuators, DE switches and DE resistors are combined to create complex DE oscillators (DEOs). Supplied with only one external DC voltage, the DEO autonomously generates oscillating signals that can be used to clock a robotic structure, control the cyclic motion of artificial muscles in bionic robots or make a whole robotic structure move. We present the basic functionality, derive a mathematical model for predicting the generated signal waveform and verify the model experimentally.

Progress on bioinspired, biomimetic, and bioreplication routes to harvest solar energy

Science.gov (United States)

Martín-Palma, Raúl J.; Lakhtakia, Akhlesh

2017-06-01

Although humans have long been imitating biological structures to serve their particular purposes, only a few decades ago engineered biomimicry began to be considered a technoscientific discipline with a great problem-solving potential. The three methodologies of engineered biomimicry-viz., bioinspiration, biomimetic, and bioreplication-employ and impact numerous technoscientific fields. For producing fuels and electricity by artificial photosynthesis, both processes and porous surfaces inspired by plants and certain marine animals are under active investigation. Biomimetically textured surfaces on the subwavelength scale have been shown to reduce the reflectance of photovoltaic solar cells over the visible and the near-infrared regimes. Lenticular compound lenses bioreplicated from insect eyes by an industrially scalable technique offer a similar promise.

Effects of PEGylation on biomimetic synthesis of magnetoferritin nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Yang, Caiyun, E-mail: ycy@mail.iggcas.ac.cn; Cao, Changqian, E-mail: changqiancao@mail.iggcas.ac.cn; Cai, Yao, E-mail: caiyao@mail.iggcas.ac.cn; Xu, Huangtao, E-mail: xuhuangtao@mail.iggcas.ac.cn; Zhang, Tongwei, E-mail: ztw@mail.iggcas.ac.cn; Pan, Yongxin, E-mail: yxpan@mail.iggcas.ac.cn [Institute of Geology and Geophysics, Chinese Academy of Sciences, Key Laboratory of Earth and Planetary Physics (China)

2017-03-15

Recent studies have demonstrated that ferrimagnetic magnetoferritin nanoparticles are a promising novel magnetic nanomaterial in biomedical applications, including biocatalysis, imaging, diagnostics, and tumor therapy. Here we investigated the PEGylation of human H-ferritin (HFn) proteins and the possible influence on biomimetic synthesis of magnetoferritin nanoparticles. The outer surface of HFn proteins was chemically modified with different PEG molecular weights (PEG10K and PEG20K) and different modification ratios (HFn subunit:PEG20K = 1:1, 1:2, 1:4). The PEGylated HFn proteins were used for biomimetic synthesis of ferrimagnetic magnetoferritin nanoparticles. We found that, compared with magnetoferritin using non-PEGylated HFn protein templates, the synthesized magnetoferritin using the PEGylated HFn protein templates possessed larger magnetite cores, higher magnetization and relaxivity values, and improved thermal stability. These results suggest that the PEGylation of H-ferritin may improve the biomineralization of magnetoferritin nanoparticles and enhance their biomedical applications.

Interactions des antibiotiques ituriniques avec la membrane plasmique. Apport des systèmes biomimétiques des membranes (synthèse bibliographique

Directory of Open Access Journals (Sweden)

Nasir, MN.

2013-01-01

Full Text Available Interactions of iturinic antibiotics with plasma membrane. Contribution of biomimetic membranes. Iturinic antibiotics are produced by Bacillus subtilis strains and constitute a family including iturin A, mycosubtilin and bacillomycins D, F and Lc. These are cyclic lipopeptides with β-amino fatty acids linked up to a peptide constituted by seven α-aminoacids with an invariable LDDLLDL chiral sequence. The first three α-aminoacids containing the tyrosyl residue are the same for all members. They are well known for their strong antifungal activities but they also have antibacterial and hemolytic properties. These biological properties are due to their amphiphilic nature, allowing interactions with different membrane components. Sterols found in plasma membranes are the privileged interaction partners of these lipopeptides. Moreover, the tyrosyl residue of the iturinic antibiotics seems to play an important role during their fixation to the plasma membrane, the result of which is often cellular lysis. Within plasma membranes, there are particular regions with a high sterol content. These microdomains have a different composition compared to the rest of the membrane; they are rich in certain lipids and proteins and are involved in many key cellular processes. The perturbation of these microdomains could therefore have an important impact on the cell. Due to their composition, these microdomains may constitute the preferential target of iturin antibiotics. This review aims to summarize the studies relating to the biological activities of iturinic antibiotics. It focuses in particular on the existing knowledge regarding iturin antibiotics at the molecular level and discusses both the key chemical groups of these drugs and the potentiality of microdomains to constitute a target for these molecules.

Biomimetics Bioinspired Hierarchical-Structured Surfaces for Green Science and Technology

CERN Document Server

Bhushan, Bharat

2012-01-01

This book presents an overview of the general field of biomimetics - lessons from nature. It presents various examples of biomimetics, including roughness-induced superomniphobic surfaces which provide functionality of commercial interest. The major focus in the book is on lotus effect, rose petal effect, shark skin effect, and gecko adhesion.  For each example, the book first presents characterization of an object to understand how a natural object provides functionality, followed by modeling and then fabrication of structures in the lab using nature’s route to verify one’s understanding of nature and provide guidance for development of optimum structures. Once it is understood how nature does it, examples of fabrication of optimum structures using smart materials and fabrication techniques, are presented. Examples of nature inspired objects are also presented throughout.

Biomimetic supercontainers for size-selective electrochemical sensing of molecular ions

Science.gov (United States)

Netzer, Nathan L.; Must, Indrek; Qiao, Yupu; Zhang, Shi-Li; Wang, Zhenqiang; Zhang, Zhen

2017-04-01

New ionophores are essential for advancing the art of selective ion sensing. Metal-organic supercontainers (MOSCs), a new family of biomimetic coordination capsules designed using sulfonylcalix[4]arenes as container precursors, are known for their tunable molecular recognition capabilities towards an array of guests. Herein, we demonstrate the use of MOSCs as a new class of size-selective ionophores dedicated to electrochemical sensing of molecular ions. Specifically, a MOSC molecule with its cavities matching the size of methylene blue (MB+), a versatile organic molecule used for bio-recognition, was incorporated into a polymeric mixed-matrix membrane and used as an ion-selective electrode. This MOSC-incorporated electrode showed a near-Nernstian potentiometric response to MB+ in the nano- to micro-molar range. The exceptional size-selectivity was also evident through contrast studies. To demonstrate the practical utility of our approach, a simulated wastewater experiment was conducted using water from the Fyris River (Sweden). It not only showed a near-Nernstian response to MB+ but also revealed a possible method for potentiometric titration of the redox indicator. Our study thus represents a new paradigm for the rational design of ionophores that can rapidly and precisely monitor molecular ions relevant to environmental, biomedical, and other related areas.

Membrane Interactions of Phytochemicals as Their Molecular Mechanism Applicable to the Discovery of Drug Leads from Plants

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Hironori Tsuchiya

2015-10-01

Full Text Available In addition to interacting with functional proteins such as receptors, ion channels, and enzymes, a variety of drugs mechanistically act on membrane lipids to change the physicochemical properties of biomembranes as reported for anesthetic, adrenergic, cholinergic, non-steroidal anti-inflammatory, analgesic, antitumor, antiplatelet, antimicrobial, and antioxidant drugs. As well as these membrane-acting drugs, bioactive plant components, phytochemicals, with amphiphilic or hydrophobic structures, are presumed to interact with biological membranes and biomimetic membranes prepared with phospholipids and cholesterol, resulting in the modification of membrane fluidity, microviscosity, order, elasticity, and permeability with the potencies being consistent with their pharmacological effects. A novel mechanistic point of view of phytochemicals would lead to a better understanding of their bioactivities, an insight into their medicinal benefits, and a strategic implication for discovering drug leads from plants. This article reviews the membrane interactions of different classes of phytochemicals by highlighting their induced changes in membrane property. The phytochemicals to be reviewed include membrane-interactive flavonoids, terpenoids, stilbenoids, capsaicinoids, phloroglucinols, naphthodianthrones, organosulfur compounds, alkaloids, anthraquinonoids, ginsenosides, pentacyclic triterpene acids, and curcuminoids. The membrane interaction’s applicability to the discovery of phytochemical drug leads is also discussed while referring to previous screening and isolating studies.

The importance of the biomimetic composites components for recreating the optical properties and molecular composition of intact dental tissues.

Science.gov (United States)

Seredin, P. V.; Goloshchapov, D. L.; Gushchin, M. S.; Ippolitov, Y. A.; Prutskij, T.

2017-11-01

The objective of this paper was to investigate whether it is possible to obtain biomimetic materials recreating the luminescent properties and molecular composition of intact dental tissues. Biomimetic materials were produced and their properties compared with native dental tissues. In addition, the overall contribution of the organic and non-organic components in the photoluminescence band was investigated. The results showed that it is possible to develop biomimetic materials with similar molecular composition and optical properties to native dental tissues for the early identification of dental caries.

Bipolar Plasma Membrane Distribution of Phosphoinositides and Their Requirement for Auxin-Mediated Cell Polarity and Patterning in Arabidopsis

NARCIS (Netherlands)

Tejos, R.; Sauer, M.; Vanneste, S.; Palacios-Gomez, M.; Li, H.; Heilmann, M.; van Wijk, R.; Vermeer, J.E.M.; Heilmann, I.; Munnik, T.; Friml, J.

2014-01-01

Cell polarity manifested by asymmetric distribution of cargoes, such as receptors and transporters, within the plasma membrane (PM) is crucial for essential functions in multicellular organisms. In plants, cell polarity (re)establishment is intimately linked to patterning processes. Despite the

Biomimetic Receptors for Bioanalyte Detection by Quartz Crystal Microbalances — From Molecules to Cells

Directory of Open Access Journals (Sweden)

Usman Latif

2014-12-01

Full Text Available A universal label-free detection of bioanalytes can be performed with biomimetic quartz crystal microbalance (QCM coatings prepared by imprinting strategies. Bulk imprinting was used to detect the endocrine disrupting chemicals (EDCs known as estradiols. The estrogen 17β-estradiol is one of the most potent EDCs, even at very low concentrations. A highly sensitive, selective and robust QCM sensor was fabricated for real time monitoring of 17β-estradiol in water samples by using molecular imprinted polyurethane. Optimization of porogen (pyrene and cross-linker (phloroglucinol levels leads to improved sensitivity, selectivity and response time of the estradiol sensor. Surface imprinting of polyurethane as sensor coating also allowed us to generate interaction sites for the selective recognition of bacteria, even in a very complex mixture of interfering compounds, while they were growing from their spores in nutrient solution. A double molecular imprinting approach was followed to transfer the geometrical features of natural bacteria onto the synthetic polymer to generate biomimetic bacteria. The use of biomimetic bacteria as template makes it possible to prepare multiple sensor coatings with similar sensitivity and selectivity. Thus, cell typing, e.g., differentiation of bacteria strains, bacteria growth profile and extent of their nutrition, can be monitored by biomimetic mass sensors. Obviously, this leads to controlled cell growth in bioreactors.

Hydrogen Production by a Hyperthermophilic Membrane-Bound Hydrogenase in Soluble Nanolipoprotein Particles

Energy Technology Data Exchange (ETDEWEB)

Baker, S E; Hopkins, R C; Blanchette, C; Walsworth, V; Sumbad, R; Fischer, N; Kuhn, E; Coleman, M; Chromy, B; Letant, S; Hoeprich, P; Adams, M W; Henderson, P T

2008-10-22

Hydrogenases constitute a promising class of enzymes for ex vivo hydrogen production. Implementation of such applications is currently hindered by oxygen sensitivity and, in the case of membrane-bound hydrogenases (MBH), poor water solubility. Nanolipoprotein particles (NLPs), formed from apolipoproteins and phospholipids, offer a novel means to incorporate MBH into in a well-defined water-soluble matrix that maintains the enzymatic activity and is amenable to incorporation into more complex architectures. We report the synthesis, hydrogen-evolving activity and physical characterization of the first MBH-NLP assembly. This may ultimately lead to the development of biomimetic hydrogen production devices.

Investigation of patterned and non-patterned poly(2,6-dimethyl 1,4-phenylene) oxide based anion exchange membranes for enhanced desalination and power generation in a microbial desalination cell.

Science.gov (United States)

Moruno, Francisco Lopez; Rubio, Juan E; Santoro, Carlo; Atanassov, Plamen; Cerrato, José M; Arges, Christopher G

2018-01-01

Quaternary ammonium poly(2,6-dimethyl 1,4-phenylene oxide) (QAPPO) anion exchange membranes (AEMs) with topographically patterned surfaces were assessed in a microbial desalination cell (MDC) system. The MDC results with these QAPPO AEMs were benchmarked against a commercially available AEM. The MDC with the non-patterned QAPPO AEM (Q1) displayed the best desalination rate (a reduction of salinity by 53 ± 2.7%) and power generation (189 ± 5 mW m - 2 ) when compared against the commercially available AEM and the patterned AEMs. The enhanced performance with the Q1 AEM was attributed to its higher ionic conductivity and smaller thickness leading to a reduced area specific resistance. It is important to note that Real Pacific Ocean seawater and activated sludge were used into the desalination chamber and anode chamber respectively for the MDC - which mimicked realistic conditions. Although the non-patterned QAPPO AEM displayed better performance over the patterned QAPPO AEMs, it was observed that the anodic overpotential was smaller when the MDCs featured QAPPO AEMs with larger lateral feature sizes. The results from this study have important implications for the continuous improvements necessary for developing cheaper and better performing membranes in order to optimize the MDC.

Hydroxyapatite coating by biomimetic method on titanium alloy ...

Indian Academy of Sciences (India)

Unknown

Abstract. This article reports a biomimetic approach for coating hydroxyapatite on titanium alloy at ambient temperature. In the present study, coating was obtained by soaking the substrate in a 5 times concentrated simulated body fluid (5XSBF) solution for different periods of time with and without the use of CaO–SiO2.

Helicoidal microstructure of Scarabaei cuticle and biomimetic research

International Nuclear Information System (INIS)

Chen, B.; Peng, X.; Cai, C.; Niu, H.; Wu, X.

2006-01-01

Insect cuticles as a natural biocomposite include many favorable microstructures which have been refined over centuries and endow the cuticles excellent mechanical and physical properties, such as light weight, high strength and toughness, etc. The various microstructures of a Scarabaei cuticle are investigated with a scanning electronic microscope and reported in this paper. It is found that the cuticle is a kind of fiber-reinforced biocomposite composed of chitin-fiber layers and sclerous protein matrixes. Different chitin-fiber layers have different orientations, composed of crossed and helicoidal structures at different location. In the helicoidal structure, each fiber layer rotates with an almost fixed angle against its neighboring layer. The maximum pullout energy of the helicoidal structure is analyzed based on the representative model of the structure. The result shows that the pullout energy of the helicoidal structure is markedly larger than that of the conventional 0 o -structure. A biomimetic composite with the observed helicoidal structure is designed and fabricated. A comparative test shows that the fracture toughness of the biomimetic composite is markedly larger than that of the 0 o -layer composite

9-Fluorenylmethyl (Fm) Disulfides: Biomimetic Precursors for Persulfides

Energy Technology Data Exchange (ETDEWEB)

Park, Chung-Min; Johnson, Brett A.; Duan, Jicheng; Park, Jeong-Jin; Day, Jacob J.; Gang, David; Qian, Wei-Jun; Xian, Ming

2016-03-04

Protein S-sulfhydration has been recognized as an important post-translational modification that regulates H2S signals. However, the reactivity and biological implications of the products of S-sulfhydration, i.e. persulfides, are still unclear. This is mainly due to the instability of persulfides and difficulty to access these molecules. Under physiological conditions persulfides mainly exist in anionic forms because of their low pKa values. However, current methods do not allow for the direct generation of persulfide anions under biomimetic and non-H2S conditions. Herein we report the development of a functional disulfide, FmSSPy-A (Fm =9-fluorenylmethyl; Py = pyridinyl). This reagent can effectively convert both small molecule and protein thiols (-SH) to form –S-SFm adducts under mild conditions. It allows for a H2S-free and biomimetic protocol to generate highly reactive persulfides (in their anionic forms). We also demonstrated the high nucleophilicity of persulfides toward a number of thiol-blocking reagents. This method holds promise for further understanding the chemical biology of persulfides and S-sulfhydration.

3D Printing of Lotus Root-Like Biomimetic Materials for Cell Delivery and Tissue Regeneration.

Science.gov (United States)

Feng, Chun; Zhang, Wenjie; Deng, Cuijun; Li, Guanglong; Chang, Jiang; Zhang, Zhiyuan; Jiang, Xinquan; Wu, Chengtie

2017-12-01

Biomimetic materials have drawn more and more attention in recent years. Regeneration of large bone defects is still a major clinical challenge. In addition, vascularization plays an important role in the process of large bone regeneration and microchannel structure can induce endothelial cells to form rudimentary vasculature. In recent years, 3D printing scaffolds are major materials for large bone defect repair. However, these traditional 3D scaffolds have low porosity and nonchannel structure, which impede angiogenesis and osteogenesis. In this study, inspired by the microstructure of natural plant lotus root, biomimetic materials with lotus root-like structures are successfully prepared via a modified 3D printing strategy. Compared with traditional 3D materials, these biomimetic materials can significantly improve in vitro cell attachment and proliferation as well as promote in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration.

Induction of Chondrogenic Differentiation of Human Mesenchymal Stem Cells by Biomimetic Gold Nanoparticles with Tunable RGD Density.

Science.gov (United States)

Li, Jingchao; Li, Xiaomeng; Zhang, Jing; Kawazoe, Naoki; Chen, Guoping

2017-07-01

Nanostructured materials have drawn a broad attention for their applications in biomedical fields. Ligand-modified nanomaterials can well mimic the dynamic extracellular matrix (ECM) microenvironments to regulate cell functions and fates. Herein, ECM mimetic gold nanoparticles (Au NPs) with tunable surface arginine-glycine-aspartate (RGD) density are designed and synthesized to induce the chondrogenic differentiation of human mesenchymal stem cells (hMSCs). The biomimetic Au NPs with an average size of 40 nm shows good biocompatibility without affecting the cell proliferation in the studied concentration range. The RGD motifs on Au NPs surface facilitate cellular uptake of NPs into monolayer hMSCs through integrin-mediated endocytosis. The biomimetic NPs have a promotive effect on cartilaginous matrix production and marker gene expression in cell pellet culture, especially for the biomimetic Au NPs with high surface RGD density. This study provides a novel strategy for fabricating biomimetic NPs to regulate cell differentiation, which holds great potentials in tissue engineering and biomedical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

Science.gov (United States)

Nguyen, Canh Toan; Phung, Hoa; Dat Nguyen, Tien; Lee, Choonghan; Kim, Uikyum; Lee, Donghyouk; Moon, Hyungpil; Koo, Jachoon; Nam, Jae-do; Ryeol Choi, Hyouk

2014-06-01

A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators.

A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

International Nuclear Information System (INIS)

Nguyen, Canh Toan; Phung, Hoa; Nguyen, Tien Dat; Lee, Choonghan; Kim, Uikyum; Lee, Donghyouk; Moon, Hyungpil; Koo, Jachoon; Choi, Hyouk Ryeol; Nam, Jae-do

2014-01-01

A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators. (paper)

Biomimetic design processes in architecture: morphogenetic and evolutionary computational design

International Nuclear Information System (INIS)

Menges, Achim

2012-01-01

Design computation has profound impact on architectural design methods. This paper explains how computational design enables the development of biomimetic design processes specific to architecture, and how they need to be significantly different from established biomimetic processes in engineering disciplines. The paper first explains the fundamental difference between computer-aided and computational design in architecture, as the understanding of this distinction is of critical importance for the research presented. Thereafter, the conceptual relation and possible transfer of principles from natural morphogenesis to design computation are introduced and the related developments of generative, feature-based, constraint-based, process-based and feedback-based computational design methods are presented. This morphogenetic design research is then related to exploratory evolutionary computation, followed by the presentation of two case studies focusing on the exemplary development of spatial envelope morphologies and urban block morphologies. (paper)

Effect of feed flow pattern on the distribution of permeate fluxes in desalination by direct contact membrane distillation

KAUST Repository

Soukane, Sofiane

2017-05-31

The current study aims to highlight the effect of flow pattern on the variations of permeate fluxes over the membrane surface during desalination in a direct contact membrane distillation (DCMD) flat module. To do so, a three dimensional (3D) Computational Fluid Dynamics (CFD) model with embedded pore scale calculations is implemented to predict flow, heat and mass transfer in the DCMD module. Model validation is carried out in terms of average permeate fluxes with experimental data of seawater desalination using two commercially available PTFE membranes. Average permeate fluxes agree within 6% and less with experimental values without fitting parameters. Simulation results show that the distribution of permeate fluxes and seawater salinity over the membrane surface are strongly dependent on momentum and heat transport and that temperature and concentration polarization follow closely the flow distribution. The analysis reveals a drastic effect of recirculation loops and dead zones on module performance and recommendations to improve MD flat module design are drawn consequently.

Induction of bone formation by smart biphasic hydroxyapatite tricalcium phosphate biomimetic matrices in the non-human primate Papio ursinus

CSIR Research Space (South Africa)

Ripamonti, U

2008-01-01

Full Text Available Long-term studies in the non-human primate Chacma baboon Papio ursinus were set to investigate the induction of bone formation by biphasic hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) biomimetic matrices. HA/β-TCP biomimetic matrices in a pre...

Active Gating, Molecular Pumping, and Turnover Determination in Biomimetic Lipidic Cubic Mesophases with Reconstituted Membrane Proteins.

Science.gov (United States)

Speziale, Chiara; Zabara, Alexandru Florian; Drummond, Calum John; Mezzenga, Raffaele

2017-11-28

Understanding the mechanisms controlling molecular transport in bioinspired materials is a central topic in many branches of nanotechnology. In this work, we show that biomolecules of fundamental importance in biological processes, such as glucose, can be transported in an active, controlled, and selective manner across macroscopic lipidic cubic mesophases, by correctly reconstituting within them their corresponding membrane protein transporters, such as Staphylococcus epidermidis (GlcP Se ). Importantly, by duly exploiting the symporter properties of GlcP Se of coupled glucose/H + transport, the diffusion of glucose can further be tuned by independent physiological stimuli, such as parallel or antiparallel pH gradients, offering an important model to study molecular exchange processes in cellular machinery. We finally show that by measuring the transport properties of the lipidic mesophases with and without the GlcP Se membrane protein reconstituted within, it becomes possible to determine its intrinsic conductance. We generalize these findings to other membrane proteins from the antiporters family, such as the bacterial ClC exchanger from Escherichia coli (EcClC), providing a robust method for evaluating the turnover rate of the membrane proteins in general.

3D Printing of Lotus Root‐Like Biomimetic Materials for Cell Delivery and Tissue Regeneration

Science.gov (United States)

Feng, Chun; Zhang, Wenjie; Deng, Cuijun; Li, Guanglong; Chang, Jiang; Zhang, Zhiyuan

2017-01-01

Abstract Biomimetic materials have drawn more and more attention in recent years. Regeneration of large bone defects is still a major clinical challenge. In addition, vascularization plays an important role in the process of large bone regeneration and microchannel structure can induce endothelial cells to form rudimentary vasculature. In recent years, 3D printing scaffolds are major materials for large bone defect repair. However, these traditional 3D scaffolds have low porosity and nonchannel structure, which impede angiogenesis and osteogenesis. In this study, inspired by the microstructure of natural plant lotus root, biomimetic materials with lotus root‐like structures are successfully prepared via a modified 3D printing strategy. Compared with traditional 3D materials, these biomimetic materials can significantly improve in vitro cell attachment and proliferation as well as promote in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration. PMID:29270348

UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

Directory of Open Access Journals (Sweden)

Saita M

2016-01-01

Full Text Available Makiko Saita,1 Takayuki Ikeda,1,2 Masahiro Yamada,1,3 Katsuhiko Kimoto,4 Masaichi Chang-Il Lee,5 Takahiro Ogawa1 1Division of Advanced Prosthodontics, Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, CA, USA; 2Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Yokosuka, Japan; 3Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan; 4Department of Prosthodontics and Oral Rehabilitation, 5Yokosuka-Shonan Disaster Health Emergency Research Center and ESR Laboratories, Kanagawa Dental University Graduate School of Dentistry, Yokosuka, Japan Background: Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability.Methods and results: Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light were immersed in simulated body fluid (SBF for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition

Towards a real-time interface between a biomimetic model of sensorimotor cortex and a robotic arm

OpenAIRE

Dura-Bernal, Salvador; Chadderdon, George L; Neymotin, Samuel A; Francis, Joseph T; Lytton, William W

2014-01-01

Brain-machine interfaces can greatly improve the performance of prosthetics. Utilizing biomimetic neuronal modeling in brain machine interfaces (BMI) offers the possibility of providing naturalistic motor-control algorithms for control of a robotic limb. This will allow finer control of a robot, while also giving us new tools to better understand the brain’s use of electrical signals. However, the biomimetic approach presents challenges in integrating technologies across multiple hardware and...

A review of selected pumping systems in nature and engineering--potential biomimetic concepts for improving displacement pumps and pulsation damping.

Science.gov (United States)

Bach, D; Schmich, F; Masselter, T; Speck, T

2015-09-03

The active transport of fluids by pumps plays an essential role in engineering and biology. Due to increasing energy costs and environmental issues, topics like noise reduction, increase of efficiency and enhanced robustness are of high importance in the development of pumps in engineering. The study compares pumps in biology and engineering and assesses biomimetic potentials for improving man-made pumping systems. To this aim, examples of common challenges, applications and current biomimetic research for state-of-the art pumps are presented. The biomimetic research is helped by the similar configuration of many positive displacement pumping systems in biology and engineering. In contrast, the configuration and underlying pumping principles for fluid dynamic pumps (FDPs) differ to a greater extent in biology and engineering. However, progress has been made for positive displacement as well as for FDPs by developing biomimetic devices with artificial muscles and cilia that improve energetic efficiency and fail-safe operation or reduce noise. The circulatory system of vertebrates holds a high biomimetic potential for the damping of pressure pulsations, a common challenge in engineering. Damping of blood pressure pulsation results from a nonlinear viscoelastic behavior of the artery walls which represent a complex composite material. The transfer of the underlying functional principle could lead to an improvement of existing technical solutions and be used to develop novel biomimetic damping solutions. To enhance efficiency or thrust of man-made fluid transportation systems, research on jet propulsion in biology has shown that a pulsed jet can be tuned to either maximize thrust or efficiency. The underlying principle has already been transferred into biomimetic applications in open channel water systems. Overall there is a high potential to learn from nature in order to improve pumping systems for challenges like the reduction of pressure pulsations, increase of jet

Biocompatible and Biomimetic Self-Assembly of Functional Nanostructures

Science.gov (United States)

2017-03-15

cells, biomolecularinterfaces and bio-mimetic processes to direct the formation of new classes of complex, symbiotic, hierarchical materials with life...like structure and functionality. This aim is predicated on two principal goals: 1) use of living/fixed cells to direct the formation of new classes...self-sensing, repair and replication; simultaneously hard , tough, and strong protection systems. Natural materials exhibit well optimized property

Layer-by-Layer Assembled Nanotubes as Biomimetic Nanoreactors for Calcium Carbonate Deposition.

Science.gov (United States)

He, Qiang; Möhwald, Helmuth; Li, Junbai

2009-09-17

Enzyme-loaded magnetic polyelectrolyte multilayer nanotubes prepared by layer-by-layer assembly combined with the porous template could be used as biomimetic nanoreactors. It is demonstrated that calcium carbonate can be biomimetically synthesized inside the cavities of the polyelectrolyte nanotubes by the catalysis of urease, and the size of the calcium carbonate precipitates was controlled by the cavity dimensions. The metastable structure of the calcium carbonate precipitates inside the nanotubes was protected by the outer shell of the polyelectrolyte multilayers. These features may allow polyelectrolyte nanotubes to be applied in the fields of nanomaterials synthesis, controlled release, and drug delivery. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic approaches to modulate cellular adhesion in biomaterials: A review.

Science.gov (United States)

Rahmany, Maria B; Van Dyke, Mark

2013-03-01

Natural extracellular matrix (ECM) proteins possess critical biological characteristics that provide a platform for cellular adhesion and activation of highly regulated signaling pathways. However, ECM-based biomaterials can have several limitations, including poor mechanical properties and risk of immunogenicity. Synthetic biomaterials alleviate the risks associated with natural biomaterials but often lack the robust biological activity necessary to direct cell function beyond initial adhesion. A thorough understanding of receptor-mediated cellular adhesion to the ECM and subsequent signaling activation has facilitated development of techniques that functionalize inert biomaterials to provide a biologically active surface. Here we review a range of approaches used to modify biomaterial surfaces for optimal receptor-mediated cell interactions, as well as provide insights into specific mechanisms of downstream signaling activation. In addition to a brief overview of integrin receptor-mediated cell function, so-called "biomimetic" techniques reviewed here include (i) surface modification of biomaterials with bioadhesive ECM macromolecules or specific binding motifs, (ii) nanoscale patterning of the materials and (iii) the use of "natural-like" biomaterials. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Rapid fabrication of microfluidic polymer electrolyte membrane fuel cell in PDMS by surface patterning of perfluorinated ion-exchange resin

Energy Technology Data Exchange (ETDEWEB)

Song, Yong-Ak; Han, Jongyoon [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Batista, Candy [Roxbury Community College, 1234 Columbus Ave., Roxbury Crossing, MA 02120 (United States); Sarpeshkar, Rahul [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

2008-09-01

In this paper we demonstrate a simple and rapid fabrication method for a microfluidic polymer electrolyte membrane (PEM) fuel cell using polydimethylsiloxane (PDMS), which has become the de facto standard material in BioMEMS. Instead of integrating a Nafion sheet film between two layers of a PDMS device in a traditional ''sandwich format,'' we pattern a perfluorinated ion-exchange resin such as a Nafion resin on a glass substrate using a reversibly bonded PDMS microchannel to generate an ion-selective membrane between the fuel-cell electrodes. After this patterning step, the assembly of the microfluidic fuel cell is accomplished by simple oxygen plasma bonding between the PDMS chip and the glass substrate. In an example implementation, the planar PEM microfluidic fuel cell generates an open circuit voltage of 600-800 mV and delivers a maximum current output of nearly 4 {mu}A. To enhance the power output of the fuel cell we utilize self-assembled colloidal arrays as a support matrix for the Nafion resin. Such arrays allow us to increase the thickness of the ion-selective membrane to 20 {mu}m and increase the current output by 166%. Our novel fabrication method enables rapid prototyping of microfluidic fuel cells to study various ion-exchange resins for the polymer electrolyte membrane. Our work will facilitate the development of miniature, implantable, on-chip power sources for biomedical applications. (author)

A highly sensitive pressure sensor using a Au-patterned polydimethylsiloxane membrane for biosensing applications

International Nuclear Information System (INIS)

Liu, Xinchuan; Zhu, Yihao; Nomani, Md W; Koley, Goutam; Wen, Xuejun; Hsia, Tain-Yen

2013-01-01

We report on the fabrication and characterization of a highly sensitive pressure sensor using a Au film patterned on a polydimethylsiloxane (PDMS) membrane. The strain-induced change in the film resistance was utilized to perform the quantitative measurement of absolute pressure. The highest sensitivity obtained for a 200 µm thick PDMS film sensor was 0.23/KPa with a range of 50 mm Hg, which is the best result reported so far, over that range, for any pressure sensor on a flexible membrane. The noise-limited pressure resolution was found to be 0.9 Pa (0.007 mm Hg), and a response time of ∼200 ms, are the best reported results for these sensors. The ultrahigh sensitivity is attributed to the strain-induced formation of microcracks, the effect of which on the resistance change was found to be highly reversible within a certain pressure range. A physical model correlating the sensitivity with the sensor parameters and crack geometry has been proposed. (paper)

Synthesis of chitosan/hydroxyapatite membranes coated with hydroxycarbonate apatite for guided tissue regeneration purposes

Energy Technology Data Exchange (ETDEWEB)

Fraga, Alexandre Felix [Federal University of Sao Carlos, Department of Materials Engineering, DEMa, UFSCar, Sao Carlos, SP (Brazil); Almeida Filho, Edson de, E-mail: edsonafilho@yahoo.com.br [University Estadual Paulista, Department of Physical Chemistry - IQ, Araraquara, SP (Brazil); Silva Rigo, Eliana Cristina da [University of Sao Paulo, Department of Basic Science - FZEA-ZAB, Pirassununga, SP (Brazil); Ortega Boschi, Anselmo [Federal University of Sao Carlos, Department of Materials Engineering, DEMa, UFSCar, Sao Carlos, SP (Brazil)

2011-02-15

Chitosan, which is a non-toxic, biodegradable and biocompatible biopolymer, has been widely researched for several applications in the field of biomaterials. Calcium phosphate ceramics stand out among the so-called bioceramics for their absence of local or systemic toxicity, their non-response to foreign bodies or inflammations, and their apparent ability to bond to the host tissue. Hydroxyapatite (HA) is one of the most important bioceramics because it is the main component of the mineral phase of bone. The aim of this work was to produce chitosan membranes coated with hydroxyapatite using the modified biomimetic method. Membranes were synthesized from a solution containing 2% of chitosan in acetic acid (weight/volume) via the solvent evaporation method. Specimens were immersed in a sodium silicate solution and then in a 1.5 SBF (simulated body fluid) solution. The crystallinity of the HA formed over the membranes was correlated to the use of the nucleation agent (the sodium silicate solution itself). Coated membranes were characterized by means of scanning electron microscopy - SEM, X-ray diffraction - XRD, and Fourier transform infrared spectroscopy - FTIR. The results indicate a homogeneous coating covering the entire surface of the membrane and the production of a semi-crystalline hydroxyapatite layer similar to the mineral phase of human bone.

Synthetic Hydroxyapatite as a Biomimetic Oral Care Agent.

Science.gov (United States)

Enax, Joachim; Epple, Matthias

Human tooth enamel consists mostly of minerals, primarily hydroxyapatite, Ca10(PO4)6(OH)2, and thus synthetic hydroxyapatite can be used as a biomimetic oral care agent. This review describes the synthesis and characterization of hydroxyapatite from a chemist's perspective and provides an overview of its current use in oral care, with a focus on dentin hypersensitivity, caries, biofilm management, erosion, and enamel lesions. Reviews and original research papers published in English and German were included. The efficiency of synthetic hydroxyapatite in occluding open dentin tubules, resulting in a protection for sensitive teeth, has been well documented in a number of clinical studies. The first corresponding studies on caries, biofilm management and erosion have provided evidence for a positive effect of hydroxyapatite either as a main or synergistic agent in oral care products. However, more in situ and in vivo studies are needed due to the complexity of the oral milieu and to further clarify existing results. Due to its biocompatibility and similarity to biologically formed hydroxyapatite in natural tooth enamel, synthetic hydroxyapatite is a promising biomimetic oral care ingredient that may extend the scope of preventive dentistry.

Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

Directory of Open Access Journals (Sweden)

Ievgen Volodymyrovych PYLYPCHUK

2014-09-01

Full Text Available Hydroxyapatite (HA has long been used as a coating material in the implant industry for orthopedic implant applications. HA is the natural inorganic constituent of bone and teeth. By coating titanium (base material of implant engineering because of its lightness and durability with hydroxyapatite, we can provide higher biocompatibility of titanium implants, according to HA ability to form a direct biochemical bond with living tissues. This article reports a biomimetic approach for coating hydroxyapatite with titanium A method of modifying the surface of titanium by organic modifiers (for creating functional groups on the surface, followed by formation "self-assembled" layer of biomimetic hydroxyapatite in simulated body fluid (SBF. FTIR and XPS confirmed the formation of hydroxyapatite coatings on titanium surface. Comparative study of the formation of HA on the surface of titanium plates modified by different functional groups: Ti(≡OH, Ti/(≡Si-OH and Ti/(≡COOH is conducted. It was found that the closest to natural stoichiometric hydroxyapatite Ca/P ratio was obtained on Ti/(≡COOH samples. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4974

Biomimetic mineralization of calcium carbonate/carboxymethylcellulose microspheres for lysozyme immobilization

International Nuclear Information System (INIS)

Lu Zheng; Zhang Juan; Ma Yunzi; Song Siyue; Gu Wei

2012-01-01

Porous calcium carbonate/carboxymethylcellulose (CaCO 3 /CMC) microspheres were prepared by the biomimetic mineralization method for lysozyme immobilization via adsorption. The size and morphology of CaCO 3 /CMC microspheres were characterized by transmitted electron microscopy (TEM) and zeta potential measurement. The lysozyme immobilization was verified by Fourier transform infrared (FTIR) spectroscopy. The effects of pHs and temperatures on lysozyme adsorption were investigated as well. It was revealed that CaCO 3 /CMC microspheres could immobilize lysozyme efficiently via electrostatic interactions and a maximum adsorption capacity of 450 mg/g was achieved at pH 9.2 and 25 °C. Moreover, it was found that the adsorption process fitted well with the Langmuir isothermal model. In addition, UV, fluorescence, and circular dichroism (CD) spectroscopic studies showed that lysozyme maintained its original secondary structure during the adsorption/desorption process. Our study therefore demonstrated that CaCO 3 /CMC microsphere can be used as a cost-effective and efficient support for lysozyme immobilization. - Graphical abstract: CaCO 3 /CMC microsphere was prepared by a facile biomimetic mineralization method and can be used as an efficient and cost-effective support for lysozyme immobilization. Highlights: ► CaCO 3 /CMC microspheres were prepared by the biomimetic mineralization method. ► Lysozyme was efficiently immobilized to CaCO 3 /CMC microspheres via adsorption. ► A maximum adsorption capacity of 450 mg/g was obtained at pH 9.2 and 25 °C. ► The original secondary structure of lysozyme was maintained upon immobilization.

Erythrocyte membrane-coated gold nanocages for targeted photothermal and chemical cancer therapy

Science.gov (United States)

Zhu, Dao-Ming; Xie, Wei; Xiao, Yu-Sha; Suo, Meng; Zan, Ming-Hui; Liao, Qing-Quan; Hu, Xue-Jia; Chen, Li-Ben; Chen, Bei; Wu, Wen-Tao; Ji, Li-Wei; Huang, Hui-Ming; Guo, Shi-Shang; Zhao, Xing-Zhong; Liu, Quan-Yan; Liu, Wei

2018-02-01

Recently, red blood cell (RBC) membrane-coated nanoparticles have attracted much attention because of their excellent immune escapability; meanwhile, gold nanocages (AuNs) have been extensively used for cancer therapy due to their photothermal effect and drug delivery capability. The combination of the RBC membrane coating and AuNs may provide an effective approach for targeted cancer therapy. However, few reports have shown the utilization of combining these two technologies. Here, we design erythrocyte membrane-coated gold nanocages for targeted photothermal and chemical cancer therapy. First, anti-EpCam antibodies were used to modify the RBC membranes to target 4T1 cancer cells. Second, the antitumor drug paclitaxel (PTX) was encapsulated into AuNs. Then, the AuNs were coated with the modified RBC membranes. These new nanoparticles were termed EpCam-RPAuNs. We characterized the capability of the EpCam-RPAuNs for selective tumor targeting via exposure to near-infrared irradiation. The experimental results demonstrate that EpCam-RPAuNs can effectively generate hyperthermia and precisely deliver the antitumor drug PTX to targeted cells. We also validated the biocompatibility of the EpCam-RAuNs in vitro. By combining the molecularly modified targeting RBC membrane and AuNs, our approach provides a new way to design biomimetic nanoparticles to enhance the surface functionality of nanoparticles. We believe that EpCam-RPAuNs can be potentially applied for cancer diagnoses and therapies.

Stabilization of Phenylalanine Ammonia Lyase from Rhodotorula glutinis by Encapsulation in Polyethyleneimine-Mediated Biomimetic Silica.

Science.gov (United States)

Cui, Jiandong; Liang, Longhao; Han, Cong; Lin Liu, Rong

2015-06-01

Phenylalanine ammonia lyase (PAL) from Rhodotorula glutinis was encapsulated within polyethyleneimine-mediated biomimetic silica. The main factors in the preparation of biomimetic silica were optimized by response surface methodology (RSM). Compared to free PAL (about 2 U), the encapsulated PAL retained more than 43 % of their initial activity after 1 h of incubation time at 60 °C, whereas free PAL lost most of activity in the same conditions. It was clearly indicated that the thermal stability of PAL was improved by encapsulation. Moreover, the encapsulated PAL exhibited the excellent stability of the enzyme against denaturants and storage stability, and pH stability was improved by encapsulation. Operational stability of 7 reaction cycles showed that the encapsulated PAL was stable. Nevertheless, the K m value of encapsulated PAL in biomimetic silica was higher than that of the free PAL due to lower total surface area and increased mass transfer resistance.

Adipose Stem Cell Coating of Biomimetic β-TCP Macrospheres by Use of Laboratory Centrifuge.

Science.gov (United States)

Chou, Joshua; Green, David W; Singh, Krishneel; Hao, Jia; Ben-Nissan, Besim; Milthorpe, Bruce

2013-02-01

Biomimetic materials such as coral exoskeletons possess unique architectural structures with a uniform and interconnected porous network that can be beneficial as a scaffold material. In addition, these marine structures can be hydrothermally converted to calcium phosphates, while retaining the original structural properties. The ability of biomaterials to stimulate the local microenvironment is one of the main focuses in tissue engineering, and directly coating the scaffold with stem cells facilitates future potential applications in therapeutics and regenerative medicine. In this article we describe a new and simple method that uses a laboratory centrifuge to coat hydrothermally derived beta-tricalcium phosphate macrospheres from coral exoskeleton with stem cells. In this research the optimal seeding duration and speed were determined to be 1 min and 700 g. Scanning electron micrographs showed complete surface coverage by stem cells within 7 days of seeding. This study constitutes an important step toward achieving functional tissue-engineered implants by increasing our understanding of the influence of dynamic parameters on the efficiency and distribution of stem cell attachment to biomimetic materials and how stem cells interact with biomimetic materials.

Industrial-scale spray layer-by-layer assembly for production of biomimetic photonic systems.

Science.gov (United States)

Krogman, K C; Cohen, R E; Hammond, P T; Rubner, M F; Wang, B N

2013-12-01

Layer-by-layer assembly is a powerful and flexible thin film process that has successfully reproduced biomimetic photonic systems such as structural colour. While most of the seminal work has been carried out using slow and ultimately unscalable immersion assembly, recent developments using spray layer-by-layer assembly provide a platform for addressing challenges to scale-up and manufacturability. A series of manufacturing systems has been developed to increase production throughput by orders of magnitude, making commercialized structural colour possible. Inspired by biomimetic photonic structures we developed and demonstrated a heat management system that relies on constructive reflection of near infrared radiation to bring about dramatic reductions in heat content.

Introducing Membrane Charge and Membrane Potential to T Cell Signaling

Directory of Open Access Journals (Sweden)

Yuanqing Ma

2017-11-01

Full Text Available While membrane models now include the heterogeneous distribution of lipids, the impact of membrane charges on regulating the association of proteins with the plasma membrane is often overlooked. Charged lipids are asymmetrically distributed between the two leaflets of the plasma membrane, resulting in the inner leaflet being negatively charged and a surface potential that attracts and binds positively charged ions, proteins, and peptide motifs. These interactions not only create a transmembrane potential but they can also facilitate the formation of charged membrane domains. Here, we reference fields outside of immunology in which consequences of membrane charge are better characterized to highlight important mechanisms. We then focus on T cell receptor (TCR signaling, reviewing the evidence that membrane charges and membrane-associated calcium regulate phosphorylation of the TCR–CD3 complex and discuss how the immunological synapse exhibits distinct patterns of membrane charge distribution. We propose that charged lipids, ions in solution, and transient protein interactions form a dynamic equilibrium during T cell activation.

A biomimetic approach toward artificial bone-like materials

OpenAIRE

Bertozzi, Carolyn R.

2001-01-01

Bone consists of microcrystalline hydroxyapatite and collagen, an elastic protein matrix that is decorated with mineral-nucleating phosphoproteins. Our rational design of artificial bone-like material uses natural bone as a guide. Hydrogel and self-assembling polymers that possess anionic groups suitably positioned for nucleating biominerals, and therefore mimic the natural function of the collagen-phosphoprotein matrix in bone, were designed to direct template-driven biomimetic mineralizatio...

Upper Limb-Hand 3D Display System for Biomimetic Myoelectric Hand Simulator

National Research Council Canada - National Science Library

Jimenez, Gonzalo

2001-01-01

A graphics system displaying both upper limb posture and opening-closing of a prosthetic hand was developed for realtime operation of our biomimetic myoelectric hand simulator, Posture of the upper...

In vitro evaluation of biomimetic chitosan–calcium phosphate scaffolds with potential application in bone tissue engineering

International Nuclear Information System (INIS)

Tanase, C E; Popa, M I; Sartoris, A; Unger, R E; Kirkpatrick, C J; Verestiuc, L

2013-01-01

This work reports on the physicochemical properties and in vitro cytotoxicity assessment of chitosan–calcium phosphate (Cs–CP) scaffolds for bone tissue engineering, which were synthesized by a novel biomimetic co-precipitation method. X-ray diffraction (XRD) along with scanning electron microscopy (SEM) analysis confirmed the porous morphology of the scaffolds and the amorphous nature of the inorganic phase with different crystallite sizes and the formation of various forms of calcium phosphate. Compressive mechanical testing revealed that the Young's modulus of the biomaterials is in the range of human trabecular bone. In vitro tests were performed on the biomaterials for up to 14 days to study the behavior of the osteoblast-like human cell line (MG63), primary human osteoblasts (HOS) and human dermal microvascular endothelial cells (HDMEC). The cytotoxicity was evaluated by the MTS assay for cell metabolism and the detection of membrane integrity (lactate dehydrogenase-LDH release). An expression of the vascular endothelial growth factor (VEGF) in the cell supernatants was quantified by ELISA. Cell viability gave values close to untreated controls for MG63 and HOS, while in the case of HDMEC the viability after 2 weeks in the cell culture was between 80–90%. The cytotoxicity induced by the Cs–CP scaffolds on MG63, HOS and HDMEC in vitro was evaluated by the amount of LDH released, which is a sensitive and accurate marker for cellular toxicity. The increased levels of VEGF obtained in the osteoblast culture highlights its important role in the regulation of vascularization and bone remodeling. The biological responses of the Cs–CP scaffolds demonstrate a similar proliferation and differentiation characteristics of the cells comparable to the controls. These results reveal that biomimetic Cs–CP composite scaffolds are promising biomaterials for bone tissue engineering; their in vivo response remains to be tested. (paper)

A water-forming NADH oxidase from Lactobacillus pentosus and its potential application in the regeneration of synthetic biomimetic cofactors

Directory of Open Access Journals (Sweden)

Claudia eNowak

2015-09-01

Full Text Available The cell-free biocatalytic production of fine chemicals by oxidoreductases has continuously grown over the past years. Since especially dehydrogenases depend on the stoichiometric use of nicotinamide pyridine cofactors, an integrated efficient recycling system is crucial to allow process operation under economic conditions. Lately, the variety of cofactors for biocatalysis was broadened by the utilization of totally synthetic and cheap biomimetics. Though, to date the regeneration has been limited to chemical or electrochemical methods. Here, we report an enzymatic recycling by the flavoprotein NADH-oxidase from Lactobacillus pentosus (LpNox. Since this enzyme has not been described before, we first characterized it in regard to its optimal reaction parameters. We found that the heterologously overexpressed enzyme only contained 13 % FAD. In vitro loading of the enzyme with FAD, resulted in a higher specific activity towards its natural cofactor NADH as well as different nicotinamide derived biomimetics. Apart from the enzymatic recycling, which gives water as a by-product by transferring four electrons onto oxygen, unbound FAD can also catalyse the oxidation of biomimetic cofactors. Here a two electron process takes place yielding H2O2 instead. The enzymatic and chemical recycling was compared in regard to reaction kinetics for the natural and biomimetic cofactors. With LpNox and FAD, two recycling strategies for biomimetic cofactors are described with either water or hydrogen peroxide as a by-product.

Proliferation and differentiation of osteoblast-like MC3T3-E1 cells ons biomimetically and electrolytically deposited calcium phosphate coatings

NARCIS (Netherlands)

Wang, J.; de Boer, Jan; de Groot, K.

2009-01-01

Biomimetic and electrolytic deposition are versatile methods to prepare calcium phosphate coatings. In this article, we compared the effects of biomimetically deposited octacalcium phosphate and carbonate apatite coatings as well as electrolytically deposited carbonate apatite coating on the

Biomimetic synthesis of cellular SiC based ceramics from plant ...

Indian Academy of Sciences (India)

Unknown

SiC based materials so derived can be used in structural applications and in designing high temperature filters and catalyst supports. Keywords. Biomimetic synthesis; carbonaceous biopreform; biomorphic Si–SiC ceramic composites; porous cellular SiC ceramics. 1. Introduction. In recent years, there has been tremendous ...

WO3/Pt nanoparticles are NADPH oxidase biomimetics that mimic effector cells in vitro and in vivo

International Nuclear Information System (INIS)

Clark, Andrea J; Coury, Emma L; Meilhac, Alexandra M; Petty, Howard R

2016-01-01

To provide a means of delivering an artificial immune effector cell-like attack on tumor cells, we report the tumoricidal ability of inorganic WO 3 /Pt nanoparticles that mimic a leukocyte’s functional abilities. These nanoparticles route electrons from organic structures and electron carriers to form hydroxyl radicals within tumor cells. During visible light exposure, WO 3 /Pt nanoparticles manufacture hydroxyl radicals, degrade organic compounds, use NADPH, trigger lipid peroxidation, promote lysosomal membrane disruption, promote the loss of reduced glutathione, and activate apoptosis. In a model of advanced breast cancer metastasis to the eye’s anterior chamber, we show that WO 3 /Pt nanoparticles prolong the survival of 4T1 tumor-bearing Balb/c mice. This new generation of inorganic photosensitizers do not photobleach, and therefore should provide an important therapeutic advance in photodynamic therapy. As biomimetic nanoparticles destroy targeted cells, they may be useful in treating ocular and other forms of cancer. (paper)

WO3/Pt nanoparticles are NADPH oxidase biomimetics that mimic effector cells in vitro and in vivo

Science.gov (United States)

Clark, Andrea J.; Coury, Emma L.; Meilhac, Alexandra M.; Petty, Howard R.

2016-02-01

To provide a means of delivering an artificial immune effector cell-like attack on tumor cells, we report the tumoricidal ability of inorganic WO3/Pt nanoparticles that mimic a leukocyte’s functional abilities. These nanoparticles route electrons from organic structures and electron carriers to form hydroxyl radicals within tumor cells. During visible light exposure, WO3/Pt nanoparticles manufacture hydroxyl radicals, degrade organic compounds, use NADPH, trigger lipid peroxidation, promote lysosomal membrane disruption, promote the loss of reduced glutathione, and activate apoptosis. In a model of advanced breast cancer metastasis to the eye’s anterior chamber, we show that WO3/Pt nanoparticles prolong the survival of 4T1 tumor-bearing Balb/c mice. This new generation of inorganic photosensitizers do not photobleach, and therefore should provide an important therapeutic advance in photodynamic therapy. As biomimetic nanoparticles destroy targeted cells, they may be useful in treating ocular and other forms of cancer.

Diffraction from relief gratings on a biomimetic elastomer cast

International Nuclear Information System (INIS)

Guerrero, Raphael A.; Aranas, Erika B.

2010-01-01

Biomimetic optical elements combine the optimized designs of nature with the versatility of materials engineering. We employ a beetle carapace as the template for fabricating relief gratings on an elastomer substrate. Biological surface features are successfully replicated by a direct casting procedure. Far-field diffraction effects are discussed in terms of the Fraunhofer approximation in Fourier space.

Positron annihilation lifetime spectroscopy (PALS): a probe for molecular organisation in self-assembled biomimetic systems.

Science.gov (United States)

Fong, Celesta; Dong, Aurelia W; Hill, Anita J; Boyd, Ben J; Drummond, Calum J

2015-07-21

Positron annihilation lifetime spectroscopy (PALS) has been shown to be highly sensitive to conformational, structural and microenvironmental transformations arising from subtle geometric changes in molecular geometry in self-assembling biomimetic systems. The ortho-positronium (oPs) may be considered an active probe that can provide information on intrinsic packing and mobility within low molecular weight solids, viscous liquids, and soft matter systems. In this perspective we provide a critical overview of the literature in this field, including the evolution of analysis software and experimental protocols with commentary upon the practical utility of PALS. In particular, we discuss how PALS can provide unique insight into the macroscopic transport properties of several porous biomembrane-like nanostructures and suggest how this insight may provide information on the release of drugs from these matrices to aid in developing therapeutic interventions. We discuss the potentially exciting and fruitful application of this technique to membrane dynamics, diffusion and permeability. We propose that PALS can provide novel molecular level information that is complementary to conventional characterisation techniques.

Application of biomimetic HPLC to estimate lipophilicity, protein and phospholipid binding of potential peptide therapeutics

Directory of Open Access Journals (Sweden)

Klara Livia Valko

2018-06-01

Full Text Available Peptide therapeutics are new modalities offering several challenges to drug discovery. They are generally less stable and permeable in vivo. The characterization of their lipophilicity cannot be carried out using the traditional in silico or wet octanol/water partition coefficients. The prediction of their in vivo distribution and permeability is also challenging. In this paper, it is demonstrated that the biomimetic properties such as lipophilicity, protein and phospholipid binding can be easily assessed by HPLC using chemically bonded protein and immobilized artificial membrane (IAM stationary phases. The obtained properties for a set of potential therapeutic peptides with 3 to 33 amino acids have been analysed and it was found that similar characteristics of the properties could be observed as for small molecule drugs. The albumin binding showed correlation with their measured lipophilicity on the C-18 stationary phase with acidic peptides showing stronger than expected albumin binding. The (IAM chromatography revealed peptide membrane affinity, which was stronger for positively charged peptides (containing arginine and showed correlation to the alpha-1-acid glycoprotein (AGP binding, which was also stronger for positively charged compounds. The in vivo volume of distribution and drug efficiency of the peptides have been estimated using the models developed for small molecules. One of the candidate linear peptides has been assessed in various cellular and in vivo assays and the results have confirmed the estimated cell partition and brain to plasma ratio. It can be demonstrated, that up to 21 amino acids, the peaks of the peptides obtained on the protein phase were symmetrical and narrow. The interaction of larger peptides with the protein stationary phases resulted in wide peaks showing multiple equilibrium processes with slow kinetics during chromatography. The larger peptides showed narrow and symmetrical peaks on the IAM column enabling

Structure and Stability of the Spinach Aquaporin SoPIP2;1 in Detergent Micelles and Lipid Membranes

DEFF Research Database (Denmark)

Plasencia, Ines; Survery, Sabeen; Ibragimova, Sania

2011-01-01

Background: SoPIP2;1 constitutes one of the major integral proteins in spinach leaf plasma membranes and belongs to the aquaporin family. SoPIP2;1 is a highly permeable and selective water channel that has been successfully overexpressed and purified with high yields. In order to optimize...... reconstitution of the purified protein into biomimetic systems, we have here for the first time characterized the structural stability of SoPIP2;1. Methodology/Principal Finding: We have characterized the protein structural stability after purification and after reconstitution into detergent micelles...... and proteoliposomes using circular dichroism and fluorescence spectroscopy techniques. The structure of SoPIP2;1 was analyzed either with the protein solubilized with octyl-beta-D-glucopyranoside (OG) or reconstituted into lipid membranes formed by E. coli lipids, diphytanoylphosphatidylcholine (DPh...

Computational optimization of synthetic water channels.

Energy Technology Data Exchange (ETDEWEB)

Rogers, David Michael; Rempe, Susan L. B.

2012-12-01

Membranes for liquid and gas separations and ion transport are critical to water purification, osmotic energy generation, fuel cells, batteries, supercapacitors, and catalysis. Often these membranes lack pore uniformity and robustness under operating conditions, which can lead to a decrease in performance. The lack of uniformity means that many pores are non-functional. Traditional membranes overcome these limitations by using thick membrane materials that impede transport and selectivity, which results in decreased performance and increased operating costs. For example, limitations in membrane performance demand high applied pressures to deionize water using reverse osmosis. In contrast, cellular membranes combine high flux and selective transport using membrane-bound protein channels operating at small pressure differences. Pore size and chemistry in the cellular channels is defined uniformly and with sub-nanometer precision through protein folding. The thickness of these cellular membranes is limited to that of the cellular membrane bilayer, about 4 nm thick, which enhances transport. Pores in the cellular membranes are robust under operating conditions in the body. Recent efforts to mimic cellular water channels for efficient water deionization produced a significant advance in membrane function. The novel biomimetic design achieved a 10-fold increase in membrane permeability to water flow compared to commercial membranes and still maintained high salt rejection. Despite this success, there is a lack of understanding about why this membrane performs so well. To address this lack of knowledge, we used highperformance computing to interrogate the structural and chemical environments experienced by water and electrolytes in the newly created biomimetic membranes. We also compared the solvation environments between the biomimetic membrane and cellular water channels. These results will help inform future efforts to optimize and tune the performance of synthetic

Cell membrane-inspired polymeric micelles as carriers for drug delivery.

Science.gov (United States)

Liu, Gongyan; Luo, Quanqing; Gao, Haiqi; Chen, Yuan; Wei, Xing; Dai, Hong; Zhang, Zongcai; Ji, Jian

2015-03-01

In cancer therapy, surface engineering of drug delivery systems plays an essential role in their colloidal stability, biocompatibility and prolonged blood circulation. Inspired by the cell membrane consisting of phospholipids and glycolipids, a zwitterionic phosphorylcholine functionalized chitosan oligosaccharide (PC-CSO) was first synthesized to mimic the hydrophilic head groups of those amphipathic lipids. Then hydrophobic stearic acid (SA) similar to lipid fatty acids was grafted onto PC-CSO to form amphiphilic PC-CSO-SA copolymers. Cell membrane-mimetic micelles with a zwitterionic surface and a hydrophobic SA core were prepared by the self-assembly of PC-CSO-SA copolymers, showing excellent stability under extreme conditions including protein containing media, high salt content or a wide pH range. Doxorubicin (DOX) was successfully entrapped into polymeric micelles through the hydrophobic interaction between DOX and SA segments. After fast internalization by cancer cells, sustained drug release from micelles to the cytoplasm and nucleus was achieved. This result suggests that these biomimetic polymeric micelles may be promising drug delivery systems in cancer therapy.

Contact kinematics of biomimetic scales

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Ranajay; Ebrahimi, Hamid; Vaziri, Ashkan, E-mail: vaziri@coe.neu.edu [Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115 (United States)

2014-12-08

Dermal scales, prevalent across biological groups, considerably boost survival by providing multifunctional advantages. Here, we investigate the nonlinear mechanical effects of biomimetic scale like attachments on the behavior of an elastic substrate brought about by the contact interaction of scales in pure bending using qualitative experiments, analytical models, and detailed finite element (FE) analysis. Our results reveal the existence of three distinct kinematic phases of operation spanning linear, nonlinear, and rigid behavior driven by kinematic interactions of scales. The response of the modified elastic beam strongly depends on the size and spatial overlap of rigid scales. The nonlinearity is perceptible even in relatively small strain regime and without invoking material level complexities of either the scales or the substrate.

Biotechnologies and biomimetics for civil engineering

CERN Document Server

Labrincha, J; Diamanti, M; Yu, C-P; Lee, H

2015-01-01

Putting forward an innovative approach to solving current technological problems faced by human society, this book encompasses a holistic way of perceiving the potential of natural systems. Nature has developed several materials and processes which both maintain an optimal performance and are also totally biodegradable, properties which can be used in civil engineering. Delivering the latest research findings to building industry professionals and other practitioners, as well as containing information useful to the public, ‘Biotechnologies and Biomimetics for Civil Engineering’ serves as an important tool to tackle the challenges of a more sustainable construction industry and the future of buildings.

Patterning of super-hydrophobic structures on permeable sensor membranes

NARCIS (Netherlands)

Pelt, van S.; Eggermont, J.; Frijns, A.J.H.; Dietzel, A.H.; Colin, S; Morini, GL; Brandner, JJ

2012-01-01

For a disposable smart food monitoring system, a gas sensor membrane is needed that isolates the sensor surface from (dust) particles water droplets. At the same time, this membrane must have a high permeability, a sufficiently fast response times and should be water repellent to avoid blocking of

Characterization of a biomimetic coating on dense and porous titanium substrates

Energy Technology Data Exchange (ETDEWEB)

Rocha, M.N. da; Pereira, L.C. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEMM/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Metalurgica e de Materiais; Ribeiro, A.A.; Oliveira, M.V. de, E-mail: marize.varella@int.gov.b [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil); Andrade, M.C. de [Universidade do Estado do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico

2010-07-01

Bioactive materials have been studied as coatings on bioinert subtracts. Thus, it is possible to combine the bioactivity of materials such as calcium phosphate with the excellent mechanical properties of metals. Titanium (Ti) implants can be bioactivated by a biomimetic precipitation method. This study introduces a biomimetic method under a simplified solution (SS) with calcium and phosphorus ions. As substrates, commercially pure Ti sheet and micro-porous Ti samples produced by powder metallurgy were used. The substrates were submitted to chemical and heat treating and then immersed in the SS for 7, 14, 21 days. Surface roughness was evaluated by confocal scanning optical microscopy. Coating characterization was performed by scanning electron microscopy and high resolution X-ray diffraction (XRD). The results showed calcium phosphate crystal morphologies observed in all samples, which was confirmed by XRD phase identifications. These results reveal the solution potential for coating Ti substrates. (author)

Foundation of the Outstanding Toughness in Biomimetic and Natural Spider Silk.

Science.gov (United States)

Anton, Arthur Markus; Heidebrecht, Aniela; Mahmood, Nasir; Beiner, Mario; Scheibel, Thomas; Kremer, Friedrich

2017-12-11

Spider dragline silk is distinguished through the highest toughness of all natural as well as artificial fiber materials. To unravel the toughness's molecular foundation and to enable manufacturing biomimetic analogues, we investigated the morphological and functional structure of recombinant fibers, which exhibit toughness similar to that of the natural template, on the molecular scale by means of vibrational spectroscopy and on the mesoscale by X-ray scattering. Whereas the former was used to identify protein secondary structures and their alignment in the natural as well as artificial silks, the latter revealed nanometer-sized crystallites on the higher structural level. Furthermore, a spectral red shift of a crystal-specific absorption band demonstrated that macroscopically applied stress is directly transferred to the molecular scale, where it is finally dissipated. Concerning this feature, both the natural as well as the biomimetic fibers are almost indistinguishable, giving rise to the toughness of both fiber materials.

Characterization of a biomimetic coating on dense and porous titanium substrates

International Nuclear Information System (INIS)

Rocha, M.N. da; Pereira, L.C.; Andrade, M.C. de

2010-01-01

Bioactive materials have been studied as coatings on bioinert subtracts. Thus, it is possible to combine the bioactivity of materials such as calcium phosphate with the excellent mechanical properties of metals. Titanium (Ti) implants can be bioactivated by a biomimetic precipitation method. This study introduces a biomimetic method under a simplified solution (SS) with calcium and phosphorus ions. As substrates, commercially pure Ti sheet and micro-porous Ti samples produced by powder metallurgy were used. The substrates were submitted to chemical and heat treating and then immersed in the SS for 7, 14, 21 days. Surface roughness was evaluated by confocal scanning optical microscopy. Coating characterization was performed by scanning electron microscopy and high resolution X-ray diffraction (XRD). The results showed calcium phosphate crystal morphologies observed in all samples, which was confirmed by XRD phase identifications. These results reveal the solution potential for coating Ti substrates. (author)

Biomimetic Nanoarchitectures for the Study of T Cell Activation with Single-Molecule Control

Science.gov (United States)

Cai, Haogang

Physical factors in the environment of a cell affect its function and behavior in a variety of ways. There is increasing evidence that, among these factors, the geometric arrangement of receptor ligands plays an important role in setting the conditions for critical cellular processes. The goal of this thesis is to develop new techniques for probing the role of extracellular ligand geometry, with a focus on T cell activation. In this work, top-down molecular-scale nanofabrication and bottom-up selective self-assembly were combined in order to present functional nanomaterials (primarily biomolecules) on a surface with precise spatial control and single-molecule resolution. Such biomolecule nanoarrays are becoming an increasingly important tool in surface-based in vitro assays for biosensing, molecular and cellular studies. The nanoarrays consist of metallic nanodots patterned on glass coverslips using electron beam and nanoimprint lithography, combined with self-aligned pattern transfer. The nanodots were then used as anchors for the immobilization of biological ligands, and backfilled with a protein-repellent passivation layer of polyethylene glycol. The passivation efficiency was improved to minimize nonspecific adsorption. In order to ensure true single-molecule control, we developed an on-chip protocol to measure the molecular occupancy of nanodot arrays based on fluorescence photobleaching, while accounting for quenching effects by plasmonic absorption. We found that the molecular occupancy can be interpreted as a packing problem, with the solution depending on the nanodot size and the concentration of self-assembly reagents, where the latter can be easily adjusted to control the molecular occupancy according to the dot size. The optimized nanoarrays were used as biomimetic architectures for the study of T cell activation with single-molecule control. T cell activation involves an elaborate arrangement of signaling, adhesion, and costimulatory molecules

Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

Science.gov (United States)

Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2016-08-01

Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

Human serum albumin supported lipid patterns for the targeted recognition of microspheres coated by membrane based on ss-DNA hybridization

International Nuclear Information System (INIS)

Zhang Xiaoming; He Qiang; Cui Yue; Duan Li; Li Junbai

2006-01-01

Human serum albumin (HSA) patterns have been successfully fabricated for the deposition of lipid bilayer, 1,2-dimyristoyl-sglycerophosphate (DMPA), by making use of the micro-contact printing (μCP) technique and liposome fusion. Confocal laser scanning microscopy (CLSM) results indicate that lipid bilayer has been assembled in HSA patterns with a good stability. Such well-defined lipid patterns formed on HSA surface create possibility to incorporate specific components like channels or receptors for specific recognition. In view of this, microspheres coated with lipid membranes were immobilized in HSA-supported lipid patterns via the hybridization of complementary ss-DNAs. This procedure enables to transfer solid materials to a soft surface through a specific recognition

Biomimetic processing of oriented crystalline ceramic layers

Energy Technology Data Exchange (ETDEWEB)

Cesarano, J.; Shelnutt, J.A.

1997-10-01

The aim of this project was to develop the capabilities for Sandia to fabricate self assembled Langmuir-Blodgett (LB) films of various materials and to exploit their two-dimensional crystalline structure to promote the growth of oriented thin films of inorganic materials at room temperature. This includes the design and synthesis of Langmuir-active (amphiphilic) organic molecules with end groups offering high nucleation potential for various ceramics. A longer range goal is that of understanding the underlying principles, making it feasible to use the techniques presented in this report to fabricate unique oriented films of various materials for electronic, sensor, and membrane applications. Therefore, whenever possible, work completed in this report was completed with the intention of addressing the fundamental phenomena underlying the growth of crystalline, inorganic films on template layers of highly organized organic molecules. This problem was inspired by biological processes, which often produce exquisitely engineered structures via templated growth on polymeric layers. Seashells, for example, exhibit great toughness owing to their fine brick-and-mortar structure that results from templated growth of calcium carbonate on top of layers of ordered organic proteins. A key goal in this work, therefore, is to demonstrate a positive correlation between the order and orientation of the template layer and that of the crystalline ceramic material grown upon it. The work completed was comprised of several parallel efforts that encompassed the entire spectrum of biomimetic growth from solution. Studies were completed on seashells and the mechanisms of growth for calcium carbonate. Studies were completed on the characterization of LB films and the capability developed for the in-house fabrication of these films. Standard films of fatty acids were studied as well as novel polypeptides and porphyrins that were synthesized.

Membrane tension regulates clathrin-coated pit dynamics

Science.gov (United States)

Liu, Allen

2014-03-01

Intracellular organization depends on close communication between the extracellular environment and a network of cytoskeleton filaments. The interactions between cytoskeletal filaments and the plasma membrane lead to changes in membrane tension that in turns help regulate biological processes. Endocytosis is thought to be stimulated by low membrane tension and the removal of membrane increases membrane tension. While it is appreciated that the opposing effects of exocytosis and endocytosis have on keeping plasma membrane tension to a set point, it is not clear how membrane tension affects the dynamics of clathrin-coated pits (CCPs), the individual functional units of clathrin-mediated endocytosis. Furthermore, although it was recently shown that actin dynamics counteracts membrane tension during CCP formation, it is not clear what roles plasma membrane tension plays during CCP initiation. Based on the notion that plasma membrane tension is increased when the membrane area increases during cell spreading, we designed micro-patterned surfaces of different sizes to control the cell spreading sizes. Total internal reflection fluorescence microscopy of living cells and high content image analysis were used to quantify the dynamics of CCPs. We found that there is an increased proportion of CCPs with short (<20s) lifetime for cells on larger patterns. Interestingly, cells on larger patterns have higher CCP initiation density, an effect unexpected based on the conventional view of decreasing endocytosis with increasing membrane tension. Furthermore, by analyzing the intensity profiles of CCPs that were longer-lived, we found CCP intensity decreases with increasing cell size, indicating that the CCPs are smaller with increasing membrane tension. Finally, disruption of actin dynamics significantly increased the number of short-lived CCPs, but also decreased CCP initiation rate. Together, our study reveals new mechanistic insights into how plasma membrane tension regulates

Biomimetic Spider Leg Joints: A Review from Biomechanical Research to Compliant Robotic Actuators

Directory of Open Access Journals (Sweden)

Stefan Landkammer

2016-07-01

Full Text Available Due to their inherent compliance, soft actuated joints are becoming increasingly important for robotic applications, especially when human-robot-interactions are expected. Several of these flexible actuators are inspired by biological models. One perfect showpiece for biomimetic robots is the spider leg, because it combines lightweight design and graceful movements with powerful and dynamic actuation. Building on this motivation, the review article focuses on compliant robotic joints inspired by the function principle of the spider leg. The mechanism is introduced by an overview of existing biological and biomechanical research. Thereupon a classification of robots that are bio-inspired by spider joints is presented. Based on this, the biomimetic robot applications referring to the spider principle are identified and discussed.

Pyro-electrification of polymer membranes for cell patterning

Energy Technology Data Exchange (ETDEWEB)

Rega, R.; Gennari, O.; Mecozzia, L.; Grilli, S.; Pagliarulo, V.; Ferraro, P. [National Council of Research, Institute of Applied Science & Intelligent Systems (ISASI) ‘E. Caianiello’, Via Campi Flegrei 34, 80078 Pozzuoli (Italy)

2016-05-18

In the recent years, much attention has been devoted to the possibility of charging polymer-based materials, due to their potential in developing large-scale and inexpensive flexible thin-film technology. The availability of localized electrostatic fields is in of great interest for a huge amount of applications such as distribution of biomolecules and cells from the liquid phase. Here we report a voltage-free pyro-electrification (PE) process able to induce permanent dipoles into polymer layers; the lithium niobate (LN) crystal is the key component that plays the multi-purpose role of sustaining, heating and poling the polymer layer that is then peeled-off easily in order to have a free-standing charged membrane. The results show the fascinating application for the living cell patterning. It well known that cell behaviour is affected by chemical and topographical cues of substrate. In fact, polymers, such as polystyrene (PS) and poly(methyl methacrylate) (PMMA), are naturally cytophobic and require specific functionalization treatments in order to promote cell adhesion. Through our proposal technique, it’s possible to obtain spontaneous organization and a driven growth of SH-SY5Y cells that is solely dictated by the nature of the charge polymer surface, opening, in this way, the innovative chance to manipulate and transfer biological samples on a free-standing polymer layer [1].

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications.

Science.gov (United States)

Barthlott, W; Mail, M; Neinhuis, C

2016-08-06

A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications

Science.gov (United States)

Mail, M.; Neinhuis, C.

2016-01-01

A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’. PMID:27354736

Tunable hydrodynamic characteristics in microchannels with biomimetic superhydrophobic (lotus leaf replica) walls.

Science.gov (United States)

Dey, Ranabir; Raj M, Kiran; Bhandaru, Nandini; Mukherjee, Rabibrata; Chakraborty, Suman

2014-05-21

The present work comprehensively addresses the hydrodynamic characteristics through microchannels with lotus leaf replica (exhibiting low adhesion and superhydrophobic properties) walls. The lotus leaf replica is fabricated following an efficient, two-step, soft-molding process and is then integrated with rectangular microchannels. The inherent biomimetic, superhydrophobic surface-liquid interfacial hydrodynamics, and the consequential bulk flow characteristics, are critically analyzed by the micro-particle image velocimetry technique. It is observed that the lotus leaf replica mediated microscale hydrodynamics comprise of two distinct flow regimes even within the low Reynolds number paradigm, unlike the commonly perceived solely apparent slip-stick dominated flows over superhydrophobic surfaces. While the first flow regime is characterized by an apparent slip-stick flow culminating in an enhanced bulk throughput rate, the second flow regime exhibits a complete breakdown of the aforementioned laminar and uni-axial flow model, leading to a predominantly no-slip flow. Interestingly, the critical flow condition dictating the transition between the two hydrodynamic regimes is intrinsically dependent on the micro-confinement effect. In this regard, an energetically consistent theoretical model is also proposed to predict the alterations in the critical flow condition with varying microchannel configurations, by addressing the underlying biomimetic surface-liquid interfacial conditions. Hence, the present research endeavour provides a new design-guiding paradigm for developing multi-functional microfluidic devices involving biomimetic, superhydrophobic surfaces, by judicious exploitation of the tunable hydrodynamic characteristics in the two regimes.

Patterning Multi-Nanostructured Poly(l-lactic acid) Fibrous Matrices to Manipulate Biomolecule Distribution and Functions.

Science.gov (United States)

Xiao, Wenwu; Li, Qingtao; He, Huimin; Li, Wenxiu; Cao, Xiaodong; Dong, Hua

2018-03-14

Precise manipulation of biomolecule distribution and functions via biomolecule-matrix interaction is very important and challenging for tissue engineering and regenerative medicine. As a well-known biomimetic matrix, electrospun fibers often lack the unique spatial complexity compared to their natural counterparts in vivo and thus cannot deliver fully the regulatory cues to biomolecules. In this paper, we report a facile and reliable method to fabricate micro- and nanostructured poly(l-lactic acid) (PLLA) fibrous matrices with spatial complexity by a combination of advanced electrospinning and agarose hydrogel stamp-based micropatterning. Specifically, advanced electrospinning is used to construct multi-nanostructures of fibrous matrices while solvent-loaded agarose hydrogel stamps are used to create microstructures. Compared with other methods, our method shows extreme simplicity and flexibility originated from the mono-/multi-spinneret conversion and limitless micropatterns of agarose hydrogel stamps. Three types of PLLA fibrous matrices including patterned nano-Ag/PLLA hybrid fibers, patterned bicompartment polyethylene terephthalate/PLLA fibers, and patterned hollow PLLA fibers are fabricated and their capability to manipulate biomolecule distribution and functions, that is, bacterial distribution and antibacterial performance, cell patterning and adhesion/spreading behaviors, and protein adsorption and delivery, is demonstrated in detail. The method described in our paper provides a powerful tool to restore spatial complexity in biomimetic matrices and would have promising applications in the field of biomedical engineering.

A Novel Soft Biomimetic Microrobot with Two Motion Attitudes

Directory of Open Access Journals (Sweden)

Liwei Shi

2012-12-01

Full Text Available  A variety of microrobots have commonly been used in the fields of biomedical engineering and underwater operations during the last few years. Thanks to their compact structure, low driving power, and simple control systems, microrobots can complete a variety of underwater tasks, even in limited spaces. To accomplish our objectives, we previously designed several bio-inspired underwater microrobots with compact structure, flexibility, and multi-functionality, using ionic polymer metal composite (IPMC actuators. To implement high-position precision for IPMC legs, in the present research, we proposed an electromechanical model of an IPMC actuator and analysed the deformation and actuating force of an equivalent IPMC cantilever beam, which could be used to design biomimetic legs, fingers, or fins for an underwater microrobot. We then evaluated the tip displacement of an IPMC actuator experimentally. The experimental deflections fit the theoretical values very well when the driving frequency was larger than 1 Hz. To realise the necessary multi-functionality for adapting to complex underwater environments, we introduced a walking biomimetic microrobot with two kinds of motion attitudes: a lying state and a standing state. The microrobot uses eleven IPMC actuators to move and two shape memory alloy (SMA actuators to change its motion attitude. In the lying state, the microrobot implements stick-insect-inspired walking/rotating motion, fish-like swimming motion, horizontal grasping motion, and floating motion. In the standing state, it implements inchworm-inspired crawling motion in two horizontal directions and grasping motion in the vertical direction. We constructed a prototype of this biomimetic microrobot and evaluated its walking, rotating, and floating speeds experimentally. The experimental results indicated that the robot could attain a maximum walking speed of 3.6 mm/s, a maximum rotational speed of 9°/s, and a maximum floating speed of 7

A crude protective film on historic stones and its artificial preparation through biomimetic synthesis

Science.gov (United States)

Liu, Qiang; Zhang, Bingjian; Shen, Zhongyue; Lu, Huanming

2006-12-01

A biomimetic film has been found on the surface of the historic stone buildings and monuments. The stone inscriptions under the film are preserved so well that has not been damaged for more than 1000 years. Samples of the crude film have been analyzed by XRD, FTIR, PLM, EDA, SEM and TEM. The results show that it consists mainly of calcium oxalate monohydrate. On the basis of the existence of the organism debris, it is concluded that the film should be a product of biomineralization. According to this hypothesis, a similar film has been prepared on the stone surface through biomimetic synthesis in our laboratory. The preliminary analysis shows that the artificial protective film functions well.

Polypropylene non-woven fabric membrane via surface modification with biomimetic phosphorylcholine in Ce(IV)/HNO{sub 3} redox system

Energy Technology Data Exchange (ETDEWEB)

Zhao Jie; Shi Qiang; Luan Shifang; Song Lingjie; Yang Huawei [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2012-10-01

Surface modification of polypropylene non-woven fabric membrane (NWF) for improving its hemocompatibility was developed by grafting a biomimic monomer, 2-methacryloyloxyethyl phosphorycholine (MPC). The NWF membrane surface was first activated by potassium peroxydisulfate to form hydroxyl groups, and then grafted with MPC using ceric (IV) ammonium nitrate as the redox initiator. The surface chemical changes before and after modification were confirmed by Fourier transform infrared spectroscopy with an ATR unit (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS); the water contact angle results showed the gradual changes in wettability from hydrophobic to hydrophilic surface. Meanwhile, the hemocompatibility of these samples was also evaluated by protein adsorption and platelet adhesion. These experimental results exhibited that the introduction of poly(MPC) onto the NWF membrane surfaces substantially improved their hemocompatibility. The feasibility and simplicity of this procedure may lead to potential applications of NWF membranes in biomedical separation and blood purification. - Graphical abstract: 2-methacryloyloxyethyl phosphorycholine (MPC), was grafted onto non-woven fabric (NWF) membrane surface by Ce(IV)/HNO{sub 3} redox system. The protein adsorption and platelet adhesion were substantially suppressed by the introduction of poly(MPC). Highlights: Black-Right-Pointing-Pointer MPC was successfully grafted onto NWF PP membrane surface. Black-Right-Pointing-Pointer Obviously enhanced hemocompatibility was acquired by the modified samples. Black-Right-Pointing-Pointer A facile redox grafting was adopted in the whole process.

A Biomimetic Haptic Sensor

Directory of Open Access Journals (Sweden)

Ben Mitchinson

2008-11-01

Full Text Available The design and implementation of the periphery of an artificial whisker sensory system is presented. It has been developed by adopting a biomimetic approach to model the structure and function of rodent facial vibrissae. The artificial vibrissae have been formed using composite materials and have the ability to be actively moved or whisked. The sensory structures at the root of real vibrissae has been modelled and implemented using micro strain gauges and Digital Signal Processors. The primary afferents and vibrissal trigeminal ganglion have been modelled using empirical data taken from electrophysiological measurements, and implemented in real-time using a Field Programmable Gate Array. Pipelining techniques were employed to maximise the utility of the FPGA hardware. The system is to be integrated into a more complete whisker sensory model, including neural structures within the central nervous system, which can be used to orient a mobile robot.

A Biomimetic Haptic Sensor

Directory of Open Access Journals (Sweden)

Martin J. Pearson

2005-12-01

Full Text Available The design and implementation of the periphery of an artificial whisker sensory system is presented. It has been developed by adopting a biomimetic approach to model the structure and function of rodent facial vibrissae. The artificial vibrissae have been formed using composite materials and have the ability to be actively moved or whisked. The sensory structures at the root of real vibrissae has been modelled and implemented using micro strain gauges and Digital Signal Processors. The primary afferents and vibrissal trigeminal ganglion have been modelled using empirical data taken from electrophysiological measurements, and implemented in real-time using a Field Programmable Gate Array. Pipelining techniques were employed to maximise the utility of the FPGA hardware. The system is to be integrated into a more complete whisker sensory model, including neural structures within the central nervous system, which can be used to orient a mobile robot.

Biomimetic coprecipitation of calcium phosphate and bovine serum albumin on titanium alloy

NARCIS (Netherlands)

Liu, Yuelian; Layrolle, Pierre; de Bruijn, Joost Dick; van Blitterswijk, Clemens; de Groot, K.

2001-01-01

Titanium alloy implants were precoated biomimetically with a thin and dense layer of calcium phosphate and then incubated either in a supersaturated solution of calcium phosphate or in phosphate-buffered saline, each containing bovine serum albumin (BSA) at various concentrations, under

Enhanced performance of a biomimetic membrane for Na2CO3 crystallization in the scenario of CO₂ capture

DEFF Research Database (Denmark)

Ye, Wenyuan; Lin, Jiuyang; Tækker Madsen, Henrik

2016-01-01

membrane (0.21Lm-2h-1 in FO mode and 0.16Lm-2h-1 in PRO mode) and a porous hydrophobic hollow fiber membrane (0.08Lm-2h-1) under the same operating conditions.Crystallization utilizing the AIM60 membrane in an osmotic crystallizer was achieved without noticeable membrane scaling or degradation. Furthermore...

Enzymatic pH control for biomimetic depostion of calcium phosphate coatings

NARCIS (Netherlands)

Nijhuis, A.W.G.; Nejadnik, M.R.; Nudelman, F.; Walboomers, X.F.; Riet, te J.; Habibovic, P.; Birgani, Z.T.; Li, Y.B.; Bomans, P.H.H.; Jansen, J.A.; Sommerdijk, N.A.J.M.; Leeuwenburgh, S.C.G.

2014-01-01

The current study examines the enzymatic decomposition of urea into carbon dioxide and ammonia as a means to increase the pH during biomimetic deposition of calcium phospate (CaP) onto implant surfaces. The kinetics of the enzymatically induced pH increase were studied by monitoring pH, calcium

Enzymatic pH control for biomimetic deposition of calcium phosphate coatings

NARCIS (Netherlands)

Nijhuis, A.W.G.; Nejadnik, M.R.; Nudelman, F.; Walboomers, X.F.; Riet, J. te; Habibovic, P.; Tahmasebi Birgani, Z.; Li, Y.; Bomans, P.H.; Jansen, J.A.; Sommerdijk, N.A.; Leeuwenburgh, S.C.G.

2014-01-01

The current study examines the enzymatic decomposition of urea into carbon dioxide and ammonia as a means to increase the pH during biomimetic deposition of calcium phosphate (CaP) onto implant surfaces. The kinetics of the enzymatically induced pH increase were studied by monitoring pH, calcium

Enzymatic pH Control for Biomimetic Deposition of Calcium Phosphate Coatings

NARCIS (Netherlands)

Nijhuis, A.W.; Reza Nejadnik, M.; Nudelman, F.; Walboomers, X.F.; te Riet, J.; Habibovic, Pamela; Tahmasebi Birgani, Zeinab; Yubao, L.; Bomans, P.H.H.; Jansen, J.A.; Sommerdijk, N.A.J.M.; Leeuwenburgh, S.C.G.

2014-01-01

The current study has focused on enzymatic decomposition of urea into carbon dioxide and ammonia as a means to increase the pH during biomimetic deposition of Calcium Phospate (CaP) onto implant surfaces. The kinetics of the enzymatically induced pH increase were studied by monitoring pH, calcium

Design of biomimetic cellular scaffolds for co-culture system and their application

Science.gov (United States)

Kook, Yun-Min; Jeong, Yoon; Lee, Kangwon; Koh, Won-Gun

2017-01-01

The extracellular matrix of most natural tissues comprises various types of cells, including fibroblasts, stem cells, and endothelial cells, which communicate with each other directly or indirectly to regulate matrix production and cell functionality. To engineer multicellular interactions in vitro, co-culture systems have achieved tremendous success achieving a more realistic microenvironment of in vivo metabolism than monoculture system in the past several decades. Recently, the fields of tissue engineering and regenerative medicine have primarily focused on three-dimensional co-culture systems using cellular scaffolds, because of their physical and biological relevance to the extracellular matrix of actual tissues. This review discusses several materials and methods to create co-culture systems, including hydrogels, electrospun fibers, microfluidic devices, and patterning for biomimetic co-culture system and their applications for specific tissue regeneration. Consequently, we believe that culture systems with appropriate physical and biochemical properties should be developed, and direct or indirect cell–cell interactions in the remodeled tissue must be considered to obtain an optimal tissue-specific microenvironment. PMID:29081966

Biomimetic artificial sphincter muscles: status and challenges

Science.gov (United States)

Leung, Vanessa; Fattorini, Elisa; Karapetkova, Maria; Osmani, Bekim; Töpper, Tino; Weiss, Florian; Müller, Bert

2016-04-01

Fecal incontinence is the involuntary loss of bowel content and affects more than 12% of the adult population, including 45% of retirement home residents. Severe fecal incontinence is often treated by implanting an artificial sphincter. Currently available implants, however, have long-term reoperation rates of 95% and definitive explantation rates of 40%. These statistics show that the implants fail to reproduce the capabilities of the natural sphincter and that the development of an adaptive, biologically inspired implant is required. Dielectric elastomer actuators (DEA) are being developed as artificial muscles for a biomimetic sphincter, due to their suitable response time, reaction forces, and energy consumption. However, at present the operation voltage of DEAs is too high for artificial muscles implanted in the human body. To reduce the operating voltage to tens of volts, we are using microfabrication to reduce the thickness of the elastomer layer to the nanometer level. Two microfabrication methods are being investigated: molecular beam deposition and electrospray deposition. This communication covers the current status and a perspective on the way forward, including the long-term prospects of constructing a smart sphincter from low-voltage sensors and actuators based on nanometer-thin dielectric elastomer films. As DEA can also provide sensory feedback, a biomimetic sphincter can be designed in accordance with the geometrical and mechanical parameters of its natural counterpart. The availability of such technology will enable fast pressure adaption comparable to the natural feedback mechanism, so that tissue atrophy and erosion can be avoided while maintaining continence du ring daily activities.

Determination of catechin in green tea using a catechol oxidase biomimetic sensor

International Nuclear Information System (INIS)

Fernandes, Suellen C.; Osorio, Renata El-Hage M. de Barros; Anjos, Ademir dos; Neves, Ademir; Micke, Gustavo Amadeu; Vieira, Iolanda C.

2008-01-01

A catechol oxidase biomimetic sensor, based on a novel copper(II) complex, was developed for the determination of catechin in green tea and the results were compared with those obtained by capillary electrophoresis. The dinuclear copper(II) complex, [Cu 2 (HL)(μ-CH 3 COO)](ClO 4 ), containing the ligand N,N-[bis-(2-pyridylmethyl)]-N',N'-[(2-hydroxybenzyl)(2-hydroxy-3,5-di-tert - butylbenzyl)]-1,3-propanediamine-2-ol (H 3 L), was synthesized and characterized by IR, 1 H NMR and elemental analysis. The best conditions for the optimization of the biomimetic sensor were established by square wave voltammetry. The best performance for this sensor was obtained in 75:15:10% (m/m/m) of the graphite powder:nujol:copper(II) complex, 0.05 mol L -1 phosphate buffer solution (pH 7.5) and frequency, pulse amplitude, scan increment at 30 Hz, 80 mV, 3.3 mV, respectively. The analytical curve was linear in the concentration range 4.95 x 10 -6 to 3.27 x 10 -5 mol L -1 (r = 0.9993) with a detection limit of 2.8 x 10 -7 mol L -1 . This biomimetic sensor demonstrated long-term stability (9 months; 800 determinations) and reproducibility with a relative standard deviation of 3.5%. The recovery of catechin from green tea samples ranged from 93.8 to 106.9% and the determination, compared with that obtained using capillary electrophoresis, was found to be acceptable at the 95% confidence level. (author)

Biomimetic honeycomb-patterned surface as the tunable cell adhesion scaffold.

Science.gov (United States)

Chen, Shuangshuang; Lu, Xuemin; Hu, Ying; Lu, Qinghua

2015-01-01

Inspired by the typically adhesive behaviors of fish skin and Parthenocissus tricuspidata, two different decorations of polystyrene honeycomb membrane (PSHCM) prepared by the breath figure approach were carried out with poly(N-(3-Sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine)(polySBMA) to explore controllable bioadhesive surfaces. Casting and dip-coating were employed to graft polySBMA onto the plasma treated PSHCM. The polySBMA casted PSHCM showed a uniform covering layer on the PSHCM similar to the mucus layer of fish skin, presenting excellent antifouling properties. On the contrary, a dip-coated one showed the polySBMA aggregating on the honeycomb pore walls forming a large number of sucking disks such as the adhesive disks of the tendrils of P. tricuspidata, which remarkably boosts cell adhesion on substrates. Thus, bioadhesion could be regulated as desired by tuning the distribution of zwitterionic polymer on the honeycomb surface. The results may provide a new approach for the design of biomaterial surfaces.

Nanobiotechnology of Biomimetic Membranes

CERN Document Server

Martin, Donald K

2007-01-01

About the Series: Fundamental Biomedical Technologies features titles in multidisciplinary, technology-driven areas, providing the foundations for breakthrough advances in medicine and biology. The term technology refers, in a vigorously unrestrictive sense, to a broad array of engineering disciplines, the sciences of computation and informatics, mathematical models exploiting and advancing methods of mathematical physics, and the development of novel, experimental discovery devices. Titles in this series are designed and selected to provide high-level visionary input for specialists, while presenting overviews of emerging fields for those in related areas. Volumes in this series aim to provide technologists with the material to gain competent entry into biomedical research and biomedical researchers to understand and embrace novel technological foundations and tools. About the Series Editor: Mauro Ferrari is a professor in the Brown Institute of Molecular Medicine, a professor of internal medicine in the div...

Design and fabrication of a biomimetic gyroscope inspired by the fly's haltere

NARCIS (Netherlands)

Droogendijk, H.; Brookhuis, Robert Anton; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

2012-01-01

We report on the design and fabrication of a MEMS-based gyroscopic system inspired by the fly's haltere system. Two types of so-called biomimetic gyroscopes have been designed, fabricated and their drive mode has been characterized. First measurements indicate excitable gyropscopes with natural

Proteoliposomes as matrix vesicles' biomimetics to study the initiation of skeletal mineralization

Directory of Open Access Journals (Sweden)

A.M.S. Simão

2010-03-01

Full Text Available During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite (HA seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs. Ion transporters control the availability of phosphate and calcium needed for HA deposition. The lipidic microenvironment in which MV-associated enzymes and transporters function plays a crucial physiological role and must be taken into account when attempting to elucidate their interplay during the initiation of biomineralization. In this short mini-review, we discuss the potential use of proteoliposome systems as chondrocyte- and osteoblast-derived MVs biomimetics, as a means of reconstituting a phospholipid microenvironment in a manner that recapitulates the native functional MV microenvironment. Such a system can be used to elucidate the interplay of MV enzymes during catalysis of biomineralization substrates and in modulating in vitro calcification. As such, the enzymatic defects associated with disease-causing mutations in MV enzymes could be studied in an artificial vesicular environment that better mimics their in vivo biological milieu. These artificial systems could also be used for the screening of small molecule compounds able to modulate the activity of MV enzymes for potential therapeutic uses. Such a nanovesicular system could also prove useful for the repair/treatment of craniofacial and other skeletal defects and to facilitate the mineralization of titanium-based tooth implants.

Motoneurons have different membrane resistance during fictive scratching and weight support

DEFF Research Database (Denmark)

Perreault, Marie-Claude

2002-01-01

locomotion; central pattern generator; spinal cord; synaptic integration; membrane conductance; glycine; postsynaptic inhibition; chloride......locomotion; central pattern generator; spinal cord; synaptic integration; membrane conductance; glycine; postsynaptic inhibition; chloride...

Adaptation of Salmonella enterica Hadar under static magnetic field: effects on outer membrane protein pattern

Directory of Open Access Journals (Sweden)

Snoussi Sarra

2012-02-01

Full Text Available Abstract Background Salmonella enterica serovar Hadar (S. Hadar is a highly prevalent foodborne pathogen and therefore a major cause of human gastroenteritis worldwide. Outer membrane proteins whose production is often regulated by environmental conditions also play important roles in the adaptability of bacterial pathogens to various environments. Results The present study investigated the adaptation of S. Hadar under the effect of acute static magnetic field exposure (200 mT, 9 h and the impact on the outer membrane protein pattern. Via two-dimensional electrophoresis (2-DE and LC-MS/MS spectrometry, we compared the proteome of enriched-outer membrane fraction before and after exposure to a magnetic field. A total of 11 proteins, displaying more than a two-fold change, were differentially expressed in exposed cells, among which 7 were up-regulated and 4 down-regulated. These proteins were involved in the integrity of cell envelope (TolB, Pal, in the response to oxidative stress (OmpW, dihydrolipoamide dehydrogenase, UspF, in the oxidative stress status (bacterioferritin, in virulence (OmpX, Yfgl or in motility (FlgE and UspF. Complementary experiments associated the down-regulation of FlgE and UspF with an alteration of swarming, a flagella-driven motility, under SMF. Furthermore, the antibiotic disc diffusion method confirmed a decrease of gentamicin susceptibility in exposed cells. This decrease could be partly associated with the up-regulation of TolC, outer membrane component of an efflux pump. OmpA, a multifunctional protein, was up-regulated. Conclusions SMF (200 mT seems to maintain the cell envelope integrity and to submit the exposed cells to an oxidative stress. Some alterations suggest an increase of the ability of exposed cells to form biofilms.

[Modification of the pattern of fatty acids of erythrocytes’ membranes due to the acetone intoxication].

Science.gov (United States)

Momot, T V; Kushnerova, N F; Rakhmanin, Yu A

Results of the study of the impact of acetone intoxication on the fatty acids pattern of the general lipids of erythrocytes’ membranes in rats are presented. The inhalation exposure of acetone was carried out in the inoculation chamber with the volume of 100 liters. The chamber was designed for the type of B.A. Kurlyandsky with self-contained system of purification and air regeneration and specified parameters of temperature (20-22С) and air humidity. The flow rate of the air and aerosolized acetone passed through the chamber accounted of 10 liters/min. Concentration of acetone in the chamber was sustained at the level of 206 ± 3,9 mg/m that corresponds to maximum permissible concentration for acetone vapor in the air of a working area. The time of exposure was 6 hours per day for 3 weeks in a monotonous mode, excluding weekend, and was based upon specific parameters of environment simulation in industry. The acetone impact was shown to be accompanied by the gain in the quantity of all kinds of saturated fatty acids and the fall of unsaturated fatty acids in general lipids of erythrocytes ’ membranes in rats and in the structure ofphospholipid fractions. In the content of phosphatydilcholine and phosphatydilethanolamine, as a basic structural phospholipids of biological membranes, there was noted the increase in palmitic and stearic acids. In the range offatty acids of the n-6 family the amount of linoleic and arachidonic acids decreased. In the array of fatty acids of the n-3 family the content of linolenic, eicosapentaenoic and docosahexaenoic acids (n-3 family) declined. Redistribution of fatty acids in the erythrocytes membrane towards to such alteration in quantity as the increasing of saturation and decreasing of the unsaturated fatty acids supposes the change of its physical and chemical properties, permeability, lability and complexity of passing erythrocyte via microcircular channels.

Framing biomimetics in a strategic orientation perspective (biopreneuring)

DEFF Research Database (Denmark)

Ulhøi, John Parm

2015-01-01

somewhat overlooked. This paper fills some of that void. Business orientation literature is applied to identify some of the key strategic aspects associated with commercial translations. In closing, this paper briefly sketches out some key implications for business research and for affected decision-makers.......This paper discusses how design originally rooted in biology can be translated into applications outside its original domain (biomimetics), and thus become strategically important for commercial organisations. This paper will also discuss how concepts from organisation and management theory can...

A novel catalyst layer structure based surface-patterned Nafion® membrane for high-performance direct methanol fuel cell

DEFF Research Database (Denmark)

Chen, Ming; Wang, Meng; Ding, Xianan

2018-01-01

.5% respectively, compared with the conventional catalyst layer. Performance improvement is attributed to the fact that the novel catalyst layer structure optimizes the electrolyte membrane/catalyst layer and gas diffusion layer/catalyst layer interfacial structure, which increases the electrochemical reaction......Conventional catalyst layer with a smooth surface exists the larger area of“catalytic dead zone” and reduces the utilization of catalyst. Based on this, a novel catalyst layer structure based surface-patterned Nafion® membrane was designed to achieve more efficient electrochemical reaction...... to prepare the novel catalyst layer, and the effect of pressure on the performance of MEA was investigated. The results suggested that the peak power density of DMFC with optimal novel catalyst layer structure increased by 28.84%, the charge transfer resistances of anode and cathode reduced by 28.8% and 26...

Interplay of static and dynamic features in biomimetic smart ears.

Science.gov (United States)

Pannala, Mittu; Meymand, Sajjad Zeinoddini; Müller, Rolf

2013-06-01

Horseshoe bats (family Rhinolophidae) have sophisticated biosonar systems with outer ears (pinnae) that are characterized by static local shape features as well as dynamic non-rigid changes to their overall shapes. Here, biomimetic prototypes fabricated from elastic rubber sheets have been used to study the impact of these static and dynamic features on the acoustic device characteristics. The basic shape of the prototypes was an obliquely truncated horn augmented with three static local shape features: vertical ridge, pinna-rim incision and frontal flap (antitragus). The prototype shape was deformed dynamically using a one-point actuation mechanism to produce a biomimetic bending of the prototype's tip. In isolation, the local shape features had little impact on the device beampattern. However, strong interactions were observed between these features and the overall deformation. The further the prototype tip was bent down, the stronger the beampatterns associated with combinations of multiple features differed from the upright configuration in the prominence of sidelobes. This behavior was qualitatively similar to numerical predictions for horseshoe bats. Hence, the interplay between static and dynamic features could be a bioinspired principle for affecting large changes through the dynamic manipulations of interactions that are sensitive to small geometrical changes.

Characterization of biomimetically synthesized Hap-Gel nanocomposites as bone substitute

International Nuclear Information System (INIS)

Bera, Tanmay; Vivek, A N; Saraf, S K; Ramachandrarao, P

2008-01-01

There is an increasing demand for an affordable and easy-to-fabricate material to help patients having a long bone gap. In this paper, we describe the biomimetic synthesis of Hap-Gel in situ nanocomposite powders with varied proportions. Their biocompatibility and bone regeneration abilities were assessed on a rabbit model. The use of Hap crystals and Gel molecule, the soluble form of bone protein, makes the nanocomposites comparable to natural bone in constituents. The application of biomimetic principles improves crystal morphology and the interaction of Hap crystals with the Gel molecules as seen through in vitro characterizations. Out of the various compositions studied, one with 80:20 proportions of Hap to Gel proved to be closest to the characteristics of natural bone. The immunological response to this composite, assessed through intradermal inoculation, did not reveal any reaction. The in vivo implantation studies in the femoral condyle of the animals, as assessed by serial post-operative follow-up radiography and the histological evaluation, revealed a good biocompatibility and bone-regeneration ability of the material. Thus, nanocomposites of Hap-Gel have a great potential for serving as an effective and affordable biomaterial for bone grafting applications

Membrane-Mimic Nanoparticles for Drug and Gene Delivery

KAUST Repository

Alamoudi, Kholod

2017-12-01

Nanoscale organic particles have gained a prominent role in drug and gene delivery field. As the nature of the nanoparticle’s (NPs) surface plays a major role in their targeting efficiency, bioavailability, and cytotoxicity, membrane-mimic nanoparticles are considered highly attractive materials for in vivo and in vitro applications. Synthetic membrane vesicles (liposomes) and nanoconstructs built with native cancer cellular membrane are excellent scaffolds to improve cellular delivery. Liposomes have been extensively used due to their high loading capacity, biocompatibility and biodegradability. However, modifications with stimuli responsive materials are highly needed to improve their stability and turn them active participants in controlled delivery. Towards a nature inspired approach, reconstructed bilayers from cell membrane are a good candidate to enhance NP’s targeting ability and biocompatibility. The primary focus of this research is to develop smart responsive (lipid) membrane coated NPs with surface modifications for controlled and targeted drug and/or gene delivery for application in cancer therapy. Three approaches have been developed, namely i) liposomes as thermoresponsive nanocarriers for the delivery of genetic material; ii) magnetically photosensitive liposome hybrids and iii) biomimetic periodic mesoporous organo silica engineered for better a biocompatibility and targeting capabilities. In the first project synthetic liposomes were loaded with ammonium bicarbonate salt (ABC) and siRNA. The combination of lipids chosen and the relative ratios allowed the rapid release of the genetic material to the multi drug resistant cancer cells studied, upon external heat trigger. This design has improved the gene silencing efficiency via successful endosomal escape. In the second project, SPIO@Au nanoparticles were imbedded in the lipid bilayer to produce a photo/thermal responsive carrier that could be also used in cell imaging besides gene transfection

VEGF-incorporated biomimetic poly(lactide-co-glycolide) sintered microsphere scaffolds for bone tissue engineering.

Science.gov (United States)

Jabbarzadeh, Ehsan; Deng, Meng; Lv, Qing; Jiang, Tao; Khan, Yusuf M; Nair, Lakshmi S; Laurencin, Cato T

2012-11-01

Regenerative engineering approaches utilizing biomimetic synthetic scaffolds provide alternative strategies to repair and restore damaged bone. The efficacy of the scaffolds for functional bone regeneration critically depends on their ability to induce and support vascular infiltration. In the present study, three-dimensional (3D) biomimetic poly(lactide-co-glycolide) (PLAGA) sintered microsphere scaffolds were developed by sintering together PLAGA microspheres followed by nucleation of minerals in a simulated body fluid. Further, the angiogenic potential of vascular endothelial growth factor (VEGF)-incorporated mineralized PLAGA scaffolds were examined by monitoring the growth and phenotypic expression of endothelial cells on scaffolds. Scanning electron microscopy micrographs confirmed the growth of bone-like mineral layers on the surface of microspheres. The mineralized PLAGA scaffolds possessed interconnectivity and a compressive modulus of 402 ± 61 MPa and compressive strength of 14.6 ± 2.9 MPa. Mineralized scaffolds supported the attachment and growth and normal phenotypic expression of endothelial cells. Further, precipitation of apatite layer on PLAGA scaffolds resulted in an enhanced VEGF adsorption and prolonged release compared to nonmineralized PLAGA and, thus, a significant increase in endothelial cell proliferation. Together, these results demonstrated the potential of VEGF-incorporated biomimetic PLAGA sintered microsphere scaffolds for bone tissue engineering as they possess the combined effects of osteointegrativity and angiogenesis. Copyright © 2012 Wiley Periodicals, Inc.

Changes in 3D Midfacial Parameters after Biomimetic Oral Appliance Therapy in Adults

Directory of Open Access Journals (Sweden)

G Dave Singh

2014-01-01

Conclusion: These data support the notion that maxillary bone width and volume can be changed in nongrowing adults. Furthermore, midfacial redevelopment may provide a potentially-useful method of managing adults diagnosed with obstructive sleep apnea, using biomimetic, oral appliances.

Influence of the Chemical Design on the Coherent Photoisomerization of Biomimetic Molecular Switches

Directory of Open Access Journals (Sweden)

Olivucci Massimo

2013-03-01

Full Text Available Ultrafast transient absorption spectroscopy reveals the effect of chemical substitutions on the photoreaction kinetics of biomimetic photoswitches displaying coherent dynamics. Ground state vibrational coherences are no longer observed when the excited state lifetime exceeds 300fs.

Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia

Energy Technology Data Exchange (ETDEWEB)

Alcaraz, Jordi; Xu, Ren; Mori, Hidetoshi; Nelson, Celeste M.; Mroue, Rana; Spencer, Virginia A.; Brownfield, Doug; Radisky, Derek C.; Bustamante, Carlos; Bissell, Mina J.

2008-10-20

In the mammary gland, epithelial cells are embedded in a 'soft' environment and become functionally differentiated in culture when exposed to a laminin-rich extracellular matrix gel. Here, we define the processes by which mammary epithelial cells integrate biochemical and mechanical extracellular cues to maintain their differentiated phenotype. We used single cells cultured on top of gels in conditions permissive for {beta}-casein expression using atomic force microscopy to measure the elasticity of the cells and their underlying substrata. We found that maintenance of {beta}-casein expression required both laminin signalling and a 'soft' extracellular matrix, as is the case in normal tissues in vivo, and biomimetic intracellular elasticity, as is the case in primary mammary epithelial organoids. Conversely, two hallmarks of breast cancer development, stiffening of the extracellular matrix and loss of laminin signalling, led to the loss of {beta}-casein expression and non-biomimetic intracellular elasticity. Our data indicate that tissue-specific gene expression is controlled by both the tissues unique biochemical milieu and mechanical properties, processes involved in maintenance of tissue integrity and protection against tumorigenesis.

Biomimetic photo-actuation: sensing, control and actuation in sun-tracking plants

International Nuclear Information System (INIS)

Dicker, M P M; Bond, I P; Weaver, P M; Rossiter, J M

2014-01-01

Although the actuation mechanisms that drive plant movement have been investigated from a biomimetic perspective, few studies have looked at the wider sensing and control systems that regulate this motion. This paper examines photo-actuation—actuation induced by, and controlled with light—through a review of the sun-tracking functions of the Cornish Mallow. The sun-tracking movement of the Cornish Mallow leaf results from an extraordinarily complex—yet extremely elegant—process of signal perception, generation, filtering and control. Inspired by this process, a concept for a simplified biomimetic analogue of this leaf is proposed: a multifunctional structure employing chemical sensing, signal transmission, and control of composite hydrogel actuators. We present this multifunctional structure, and show that the success of the concept will require improved selection of materials and structural design. This device has application in the solar-tracking of photovoltaic panels for increased energy yield. More broadly it is envisaged that the concept of chemical sensing and control can be expanded beyond photo-actuation to many other stimuli, resulting in new classes of robust solid-state devices. (paper)

Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

Science.gov (United States)

Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

2015-12-22

In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

Biomimetic hierarchical growth and self-assembly of hydroxyapatite/titania nanocomposite coatings and their biomedical applications

International Nuclear Information System (INIS)

Nathanael, A. Joseph; Im, Young Min; Oh, Tae Hwan; Yuvakkumar, R.; Mangalaraj, D.

2015-01-01

Graphical abstract: - Highlights: • Novel ‘bowtie’ like biomimetic HA/TiO 2 nanocomposite coatings were prepared. • Simple sol–gel method was used to achieve this novel structure. • Details analysis confirms the formation of bowtie like structure in many ways. • Their functional analysis showed their enhanced activity for biomedical application. - Abstract: This article describes a systematic study of the biomimetic hierarchical growth of hydroxyapatite (HA)/titania (TiO 2 ) nanocomposite layered coatings applied by a simple sol–gel dip coating method. Highly stable HA and TiO 2 sols were prepared prior to inducing biomimetic hierarchical growth. Initially, the samples formed a small leaf like structure; however, increasing the dipping cycle resulted in formation of an elongated seed-like structure. Increasing the number of dipping cycles further resulted in a ‘bowtie’ or straw-bale like nanowire structure with a length of 500 nm and a width of 100 nm. Each nanowire like structure had a width of very few nanometers. The crystalline structures, micro/nano structures and surface properties of the coatings were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy respectively. In vitro cellular assays revealed that the growth of the cells in the ‘bowtie’ like structure improved over other samples

Biomimetic hierarchical growth and self-assembly of hydroxyapatite/titania nanocomposite coatings and their biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Nathanael, A. Joseph, E-mail: ajosephnc@yahoo.com [Department of Nano, Medical and Polymer Materials, Yeungnam University, Gyeongsan (Korea, Republic of); Im, Young Min [Department of Nano, Medical and Polymer Materials, Yeungnam University, Gyeongsan (Korea, Republic of); Oh, Tae Hwan, E-mail: taehwanoh@ynu.ac.kr [Department of Nano, Medical and Polymer Materials, Yeungnam University, Gyeongsan (Korea, Republic of); Yuvakkumar, R. [Department of Nanomaterials Engineering, Chungnam National University, Daejeon (Korea, Republic of); Mangalaraj, D. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore (India)

2015-03-30

Graphical abstract: - Highlights: • Novel ‘bowtie’ like biomimetic HA/TiO{sub 2} nanocomposite coatings were prepared. • Simple sol–gel method was used to achieve this novel structure. • Details analysis confirms the formation of bowtie like structure in many ways. • Their functional analysis showed their enhanced activity for biomedical application. - Abstract: This article describes a systematic study of the biomimetic hierarchical growth of hydroxyapatite (HA)/titania (TiO{sub 2}) nanocomposite layered coatings applied by a simple sol–gel dip coating method. Highly stable HA and TiO{sub 2} sols were prepared prior to inducing biomimetic hierarchical growth. Initially, the samples formed a small leaf like structure; however, increasing the dipping cycle resulted in formation of an elongated seed-like structure. Increasing the number of dipping cycles further resulted in a ‘bowtie’ or straw-bale like nanowire structure with a length of 500 nm and a width of 100 nm. Each nanowire like structure had a width of very few nanometers. The crystalline structures, micro/nano structures and surface properties of the coatings were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy respectively. In vitro cellular assays revealed that the growth of the cells in the ‘bowtie’ like structure improved over other samples.

Bioinspired, biomimetic, double-enzymatic mineralization of hydrogels for bone regeneration with calcium carbonate

DEFF Research Database (Denmark)

Lopez-Heredia, Marco A.; Łapa, Agata; Mendes, Ana Carina Loureiro

2017-01-01

Hydrogels are popular materials for tissue regeneration. Incorporation of biologically active substances, e.g. enzymes, is straightforward. Hydrogel mineralization is desirable for bone regeneration. Here, hydrogels of Gellan Gum (GG), a biocompatible polysaccharide, were mineralized biomimetically...... of osteoblast-like cells....

Colorimetric biomimetic sensor systems based on molecularly imprinted polymer membranes for highly-selective detection of phenol in environmental samples

Directory of Open Access Journals (Sweden)

Sergeyeva T. A.

2014-05-01

Full Text Available Aim. Development of an easy-to-use colorimetric sensor system for fast and accurate detection of phenol in envi- ronmental samples. Methods. Technique of molecular imprinting, method of in situ polymerization of molecularly imprinted polymer membranes. Results. The proposed sensor is based on free-standing molecularly imprinted polymer (MIP membranes, synthesized by in situ polymerization, and having in their structure artificial binding sites capable of selective phenol recognition. The quantitative detection of phenol, selectively adsorbed by the MIP membranes, is based on its reaction with 4-aminoantipyrine, which gives a pink-colored product. The intensity of staining of the MIP membrane is proportional to phenol concentration in the analyzed sample. Phenol can be detected within the range 50 nM–10 mM with limit of detection 50 nM, which corresponds to the concentrations that have to be detected in natural and waste waters in accordance with environmental protection standards. Stability of the MIP-membrane-based sensors was assessed during 12 months storage at room temperature. Conclusions. The sensor system provides highly-selective and sensitive detection of phenol in both mo- del and real (drinking, natural, and waste water samples. As compared to traditional methods of phenol detection, the proposed system is characterized by simplicity of operation and can be used in non-laboratory conditions.

Biomimetic hydrogels for biosensor implant biocompatibility: electrochemical characterization using micro-disc electrode arrays (MDEAs).

Science.gov (United States)

Justin, Gusphyl; Finley, Stephen; Abdur Rahman, Abdur Rub; Guiseppi-Elie, Anthony

2009-02-01

Our interest is in the development of engineered microdevices for continuous remote monitoring of intramuscular lactate, glucose, pH and temperature during post-traumatic hemorrhaging. Two important design considerations in the development of such devices for in vivo diagnostics are discussed; the utility of micro-disc electrode arrays (MDEAs) for electrochemical biosensing and the application of biomimetic, bioactive poly(HEMA)-based hydrogel composites for implant biocompatibility. A poly(HEMA)-based hydrogel membrane containing polyethylene glycol (PEG) was UV cross-linked with tetraethyleneglycol diacrylate following application to MDEAs (50 mum discs) and to 250 mum diameter gold electrodes within 8-well culture ware. Cyclic voltammetry (CV) of the MDEAs revealed a reduction in the apparent diffusion coefficient of ferrocenemonocarboxylic acid (FcCO(2)H), from 6.68 x 10(-5) to 6.74 x 10(-6) cm(2)/s for the uncoated and 6 mum thick hydrogel coated devices, respectively. Single frequency (4 kHz) temporal impedance measurements of the hydrogels in the 8-well culture ware showed a reversible 5% change in the absolute impedance of the hydrogels when exposed to a pH change between 6.1 to 7.2 and a 20% drop between pH 6.1 and 8.8.

Improving electromechanical output of IPMC by high surface area Pd-Pt electrodes and tailored ionomer membrane thickness

Directory of Open Access Journals (Sweden)

Viljar Palmre

2014-04-01

Full Text Available In this study, we attempt to improve the electromechanical performance of ionic polymer–metal composites (IPMCs by developing high surface area Pd-Pt electrodes and tailoring the ionomer membrane thickness. With proper electroless plating techniques, a high dispersion of palladium particles is achieved deep in the ionomer membrane, thereby increasing notably the interfacial surface area of electrodes. The membrane thickness is increased using 0.5 and 1 mm thick ionomer films. For comparison, IPMCs with the same ionomer membranes, but conventional Pt electrodes, are also prepared and studied. The electromechanical, mechanoelectrical, electrochemical and mechanical properties of different IPMCs are characterized and discussed. Scanning electron microscopy-energy dispersive X-ray (SEM-EDS is used to investigate the distribution of deposited electrode metals in the cross section of Pd-Pt IPMCs. Our experiments demonstrate that IPMCs assembled with millimeter thick ionomer membranes and newly developed Pd-Pt electrodes are superior in mechanoelectrical transduction, and show significantly higher blocking force compared to conventional type of IPMCs. The blocking forces of more than 0.3 N were measured at 4V DC input, exceeding the force output of typical Nafion® 117-based Pt IPMCs more than two orders of magnitude. The newly designed Pd-Pt IPMCs can be useful in more demanding applications, e.g., in biomimetic underwater robotics, where high stress and drag forces are encountered.

Biomimetic Growth of Hydroxyapatite on Kenaf Fibers

Directory of Open Access Journals (Sweden)

Saiful Izwan Abd Razak

2016-01-01

Full Text Available Biomimetic hydroxyapatite (HA growth on mercerized kenaf fiber (KF was achieved by immersion in a simulated body fluid (SBF solution with the addition of a chelating agent. An electron micrograph revealed uniform HA layers on the KF within 14 days of immersion with significant vibrational peaks of HA components. The tensile tests showed no significant drops in the unit break of the modified fibers. This new bone-like apatite coating on KF can be useful in the field of bone tissue engineering. The key motivation for this new approach was that it utilizes the abundantly available kenaf plant resource as the biobased template.

Biomimetic synthesis and antiproliferative properties of racemic natural(-) and unnnatural(+) glyceollin I

Science.gov (United States)

A 14-step biomimetic synthetic route to glyceollin I in ca. 1.5% overall yield has been developed. In addition to being useful for the elaboration of analogs that can contribute to SAR, this route provides practical access to analytical standards that may be used for quality control purposes when gl...

Potential transducers based man-tailored biomimetic sensors for selective recognition of dextromethorphan as an antitussive drug.

Science.gov (United States)

El-Naby, Eman H; Kamel, Ayman H

2015-09-01

A biomimetic potentiometric sensor for specific recognition of dextromethorphan (DXM), a drug classified according to the Drug Enforcement Administration (DEA) as a "drug of concern", is designed and characterized. A molecularly imprinted polymer (MIP), with special molecular recognition properties of DXM, was prepared by thermal polymerization in which DXM acted as template molecule, methacrylic acid (MAA) and acrylonitrile (AN) acted as functional monomers in the presence of ethylene glycol dimethacrylate (EGDMA) as crosslinker. The sensors showed a high selectivity and a sensitive response to the template in aqueous system. Electrochemical evaluation of these sensors revealed near-Nernstian response with slopes of 49.6±0.5 and 53.4±0.5 mV decade(-1) with a detection limit of 1.9×10(-6), and 1.0×10(-6) mol L(-1) DXM with MIP/MAA and MIP/AN membrane based sensors, respectively. Significantly improved accuracy, precision, response time, stability, selectivity and sensitivity were offered by these simple and cost-effective potentiometric sensors compared with other standard techniques. The method has the requisite accuracy, sensitivity and precision to assay DXM in pharmaceutical products. Copyright © 2015 Elsevier B.V. All rights reserved.

AFM imaging and analysis of local mechanical properties for detection of surface pattern of functional groups

Energy Technology Data Exchange (ETDEWEB)

Knotek, Petr, E-mail: petr.knotek@upce.cz [University of Pardubice, Faculty of Chemical Technology, Joint Laboratory of Solid State Chemistry of IMC ASCR and University of Pardubice, Studentska 573, 532 10 Pardubice (Czech Republic); Chanova, Eliska; Rypacek, Frantisek [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovskeho sq. 2, 162 06 Prague (Czech Republic)

2013-05-01

In this work we evaluate the applicability of different atomic force microscopy (AFM) modes, such as Phase Shift Imaging, Atomic Force Acoustic Microscopy (AFAM) and Force Spectroscopy, for mapping of the distribution pattern of low-molecular-weight biomimetic groups on polymer biomaterial surfaces. Patterns with either random or clustered spatial distribution of bioactive peptide group derived from fibronectin were prepared by surface deposition of functional block copolymer nano-colloids and grafted with RGDS peptide containing the sequence of amino acids arginine–glycine–aspartic acid–serine (conventionally labeled as RGDS) and carrying biotin as a tag. The biotin-tagged peptides were labeled with 40 nm streptavidin-modified Au nanospheres. The peptide molecules were localized through the detection of bound Au nanospheres by AFM, and thus, the surface distribution of peptides was revealed. AFM techniques capable of monitoring local mechanical properties of the surface were proved to be the most efficient for identification of Au nano-markers. The efficiency was successfully demonstrated on two different patterns, i.e. random and clustered distribution of RGDS peptides on structured surface of the polymer biomaterial. Highlights: ► Bioactive peptides for cell adhesion on PLA-b-PEO biomimetic surface were visualized. ► The biotin-tagged RGDS peptides were labeled with streptavidin-Au nanospheres. ► The RGDS pattern was detected using different atomic force microscopy (AFM) modes. ► Phase Shift Image was proved to be suitable method for studying peptide distribution.

Optimization of a biomimetic bone cement: role of DCPD.

Science.gov (United States)

Panzavolta, Silvia; Bracci, Barbara; Rubini, Katia; Bigi, Adriana

2011-08-01

We previously proposed a biomimetic α-tricalcium phosphate (α-TCP) bone cement where gelatin controls the transformation of α-TCP into calcium deficient hydroxyapatite (CDHA), leading to improved mechanical properties. In this study we investigated the setting and hardening processes of biomimetic cements containing increasing amounts of CaHPO(4)·2H2O (DCPD) (0, 2.5, 5, 10, 15 wt.%), with the aim to optimize composition. Both initial and final setting times increased significantly when DCPD content accounts for 10 wt.%, whereas cements containing 15 wt.% DCPD did not set at all. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetry (TG) and scanning electron microscopy (SEM) investigations were performed on samples maintained in physiological solution for different times. DCPD dissolution starts soon after cement preparation, but the rate of transformation decreases on increasing DCPD initial content in the samples. The rate of α-TCP to CDHA conversion during hardening decreases on increasing DCPD initial content. Moreover, the presence of DCPD prevents gelatin release during hardening. The combined effects of gelatin and DCPD on the rate of CDHA formation and porosity lead to significantly improved mechanical properties, with the best composition displaying a compressive strength of 35 MPa and a Young modulus of 1600 MPa. Copyright © 2011 Elsevier Inc. All rights reserved.

Biomimetic molecular design tools that learn, evolve, and adapt

Science.gov (United States)

2017-01-01

A dominant hallmark of living systems is their ability to adapt to changes in the environment by learning and evolving. Nature does this so superbly that intensive research efforts are now attempting to mimic biological processes. Initially this biomimicry involved developing synthetic methods to generate complex bioactive natural products. Recent work is attempting to understand how molecular machines operate so their principles can be copied, and learning how to employ biomimetic evolution and learning methods to solve complex problems in science, medicine and engineering. Automation, robotics, artificial intelligence, and evolutionary algorithms are now converging to generate what might broadly be called in silico-based adaptive evolution of materials. These methods are being applied to organic chemistry to systematize reactions, create synthesis robots to carry out unit operations, and to devise closed loop flow self-optimizing chemical synthesis systems. Most scientific innovations and technologies pass through the well-known “S curve”, with slow beginning, an almost exponential growth in capability, and a stable applications period. Adaptive, evolving, machine learning-based molecular design and optimization methods are approaching the period of very rapid growth and their impact is already being described as potentially disruptive. This paper describes new developments in biomimetic adaptive, evolving, learning computational molecular design methods and their potential impacts in chemistry, engineering, and medicine. PMID:28694872

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

Directory of Open Access Journals (Sweden)

Bharat Bhushan

2011-02-01

Full Text Available The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biological and organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on various superoleophobic surfaces created in the lab.

Biomimetic molecular design tools that learn, evolve, and adapt

Directory of Open Access Journals (Sweden)

David A Winkler

2017-06-01

Full Text Available A dominant hallmark of living systems is their ability to adapt to changes in the environment by learning and evolving. Nature does this so superbly that intensive research efforts are now attempting to mimic biological processes. Initially this biomimicry involved developing synthetic methods to generate complex bioactive natural products. Recent work is attempting to understand how molecular machines operate so their principles can be copied, and learning how to employ biomimetic evolution and learning methods to solve complex problems in science, medicine and engineering. Automation, robotics, artificial intelligence, and evolutionary algorithms are now converging to generate what might broadly be called in silico-based adaptive evolution of materials. These methods are being applied to organic chemistry to systematize reactions, create synthesis robots to carry out unit operations, and to devise closed loop flow self-optimizing chemical synthesis systems. Most scientific innovations and technologies pass through the well-known “S curve”, with slow beginning, an almost exponential growth in capability, and a stable applications period. Adaptive, evolving, machine learning-based molecular design and optimization methods are approaching the period of very rapid growth and their impact is already being described as potentially disruptive. This paper describes new developments in biomimetic adaptive, evolving, learning computational molecular design methods and their potential impacts in chemistry, engineering, and medicine.

Triangular prism-shaped β-peptoid helices as unique biomimetic scaffolds

DEFF Research Database (Denmark)

Laursen, Jonas Striegler; Harris, Pernille; Fristrup, Peter

2015-01-01

β-Peptoids are peptidomimetics based on N-alkylated β-aminopropionic acid residues (or N-alkyl-β-alanines). This type of peptide mimic has previously been incorporated in biologically active ligands and has been hypothesized to be able to exhibit foldamer properties. Here we show, for the first t...... of novel biomimetics that display functional groups with high accuracy in three dimensions, which has potential for development of new functional materials....

Reductive debromination of polybrominated diphenyl ethers in anaerobic sediment and a biomimetic system.

Science.gov (United States)

Tokarz, John A; Ahn, Mi-Youn; Leng, June; Filley, Timothy R; Nies, Loring

2008-02-15

Because of the bioaccumulation of penta- and tetrapolybrominated diphenyl ether (PBDE) flame retardants in biota,the environmental biotransformation of decabromodiphenyl ether (BDE-209) is of interest. BDE-209 accounts for more than 80% by mass of PBDE production and is the dominant PBDE in sediments. Most sediments are anaerobic and reports of microbial reductive dehalogenation of hydrophobic persistent organohalogen pollutants are numerous. Reductive debromination of BDE-209 in the environment could provide a significant source of lesser-brominated PBDEs to biota. Moreover, a recent study showed that BDE-209 debrominates in sewage sludge, and another demonstrated that some halorespiring bacteria will debrominate BDE-209. To determine whether reductive debromination of BDE-209 occurs in sediments, parallel experiments were conducted using anaerobic sediment microcosms and a cosolvent-enhanced biomimetic system. In the biomimetic system, reductive debromination occurred at rates corresponding to bromine substitution levels with a BDE-209 half-life of only 18 s compared with a halflife of almost 60 days for 2,2',4,4'-tetrabromodiphenyl ether. In sediment, the measured debromination half-life of BDE-209 was well over a decade and was in good agreement with the predicted value obtained from the biomimetic experiment. Product congeners were predominantly double para-substituted. BDE-209 debrominated in sediment with a corresponding increase in nona-, octa-, hepta-, and hexa-PBDEs. Nine new PBDE congeners appeared in sediment from reductive debromination. Given the very large BDE-209 burden already in sediments globally, it is important to determine whether this transformation is a significant source of lesser-brominated PBDEs to the environment.

Electrospun biomimetic scaffold of hydroxyapatite/chitosan supports enhanced osteogenic differentiation of mMSCs

International Nuclear Information System (INIS)

Peng Hongju; Feng Bei; Yuan Huihua; Zhang Yanzhong; Yin Zi; Liu Huanhuan; Chen Xiao; Ouyang Hongwei; Su Bo

2012-01-01

Engaging functional biomaterial scaffolds to regulate stem cell differentiation has drawn a great deal of attention in the tissue engineering and regenerative medicine community. In this study, biomimetic composite nanofibrous scaffolds of hydroxyapatite/chitosan (HAp/CTS) were prepared to investigate their capacity for inducing murine mesenchymal stem cells (mMSCs) to differentiate into the osteogenic lineage, in the absence and presence of an osteogenic supplementation (i.e., ascorbic acid, β-glycerol phosphate, and dexamethasone), respectively. Using electrospun chitosan (CTS) nanofibrous scaffolds as the control, cell morphology, growth, specific osteogenic genes expression, and quantified proteins secretion on the HAp/CTS scaffolds were sequentially examined and assessed. It appeared that the HAp/CTS scaffolds supported better attachment and proliferation of the mMSCs. Most noteworthy was that in the absence of the osteogenic supplementation, expression of osteogenic genes including collagen I (Col I), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and osteocalcin (OCN) were significantly upregulated in mMSCs cultured on the HAp/CTS nanofibrous scaffolds. Also increased secretion of the osteogenesis protein markers of alkaline phosphatase and collagen confirmed that the HAp/CTS nanofibrous scaffold markedly promoted the osteogenic commitment in the mMSCs. Moreover, the presence of osteogenic supplementation proved an enhanced efficacy of mMSC osteogenesis on the HAp/CTS nanofibrous scaffolds. Collectively, this study demonstrated that the biomimetic nanofibrous HAp/CTS scaffolds could support and enhance the adhesion, proliferation, and particularly osteogenic differentiation of the mMSCs. It also substantiated the potential of using biomimetic nanofibrous scaffolds of HAp/CTS for functional bone repair and regeneration applications. (paper)

A membrane actuator based on an ionic polymer network and carbon nanotubes: the synergy of ionic transport and mechanical properties

International Nuclear Information System (INIS)

Dai, Chi-An; Hsiao, Chih-Chun; Weng, Shih-Chun; Kao, An-Cheng; Liu, Chien-Pan; Tsai, Wei-Bor; Chen, Wen-Shiang; Liu, Wei-Ming; Shih, Wen-Pin; Ma, Chien-Ching

2009-01-01

There is a growing interest in the development of ionic polymer–metal composites (IPMC) as sensors and actuators for biomedical applications due to their large deformation under low driving voltage. In this study, we employed poly(vinyl alcohol)/poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PVA/PAMPS) blend membranes as semi-interpenetrating polymer networks for ion exchange in IPMC construction. To improve the mechanical and electrical properties of the IPMC, multi-walled carbon nanotubes (MWNT) were added into PVA/PAMPS membranes. The actuator performance of the membranes was measured as a function of their water uptake, ion exchange capacity, ionic conductivity and the amount of MWNT in the membrane. The dispersion quality of the modified MWNT in the PVA/PAMPS membrane was measured using transmission electron microscopy. The cantilever-type IPMC actuator bends under applied voltage and its bending angle and the generative tip force were measured. Under an applied voltage, IPMC with ∼1 wt% MWNT showed the largest deflection and generated the largest blocking tip force compared with those of IPMC with other various amounts of MWNT. These results show that a small addition of MWNT can optimize the actuation performance of IPMC. The result indicates that IPMC with MWNT shows potential for use as biomimetic artificial muscle

Design and fabrication of a biomimetic gyroscope inspired by the fly’s haltere

NARCIS (Netherlands)

Droogendijk, H.; Brookhuis, Robert Anton; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

2013-01-01

We report on the design and fabrication of a MEMS-based gyroscopic system inspired by the fly’s haltere system. Two types of so-called biomimetic gyroscopes have been designed, fabricated and partially characterized. First measurements indicate excitable gyropscopes with natural frequencies in the

The Design and Implementation of a Biomimetic Robot Fish

OpenAIRE

Chao Zhou; Min Tan; Nong Gu; Zhiqiang Cao; Shuo Wang; Long Wang

2008-01-01

In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. I...

Biomimetic "Cactus Spine" with Hierarchical Groove Structure for Efficient Fog Collection.

Science.gov (United States)

Bai, Fan; Wu, Juntao; Gong, Guangming; Guo, Lin

2015-07-01

A biomimetic "cactus spine" with hierarchical groove structure is designed and fabricated using simple electrospinning. This novel artificial cactus spine possesses excellent fog collection and water transportation ability. A model cactus equipped with artificial spines also shows a great water storage capacity. The results can be helpful in the development of water collectors and may make a contribution to the world water crisis.

“Click & seed” approach to the biomimetic modification of material surfaces

Czech Academy of Sciences Publication Activity Database

Proks, Vladimír; Jaroš, J.; Pop-Georgievski, Ognen; Kučka, Jan; Popelka, Štěpán; Dvořák, P.; Hampl, A.; Rypáček, František

2012-01-01

Roč. 12, č. 9 (2012), s. 1232-1242 ISSN 1616-5187 R&D Projects: GA AV ČR KJB400500904; GA ČR GAP108/11/1857; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505 Keywords : biomimetic modifications * click chemistry * peptide radiolabeling Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.742, year: 2012

Plastic deformation in nano-scale multilayer materials — A biomimetic approach based on nacre

Energy Technology Data Exchange (ETDEWEB)

Lackner, Juergen M., E-mail: juergen.lackner@joanneum.at [JOANNEUM RESEARCH Forschungsges.m.b.H., Institute for Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf (Austria); Waldhauser, Wolfgang [JOANNEUM RESEARCH Forschungsges.m.b.H., Institute for Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf (Austria); Major, Boguslaw; Major, Lukasz [Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences, IMIM-PAN, ul. Reymonta 25, PL-30059 Krakow (Poland); Kot, Marcin [University of Science and Technology, AGH, Aleja Adama Mickiewicza 30, 30-059 Krakow (Poland)

2013-05-01

The paper reports about a biomimetic based comparison of deformation in magnetron sputtered multilayer coatings based on titanium (Ti), titanium nitride (TiN) and diamond-like carbon (DLC) layers and the deformation mechanisms in nacre of mollusc shells. Nacre as highly mineralized tissue combines high stiffness and hardness with high toughness, enabling resistance to fracture and crack propagation during tensile loading. Such behaviour is based on a combination of load transmission by tensile stressed aragonite tablets and shearing in layers between the tablets. Shearing in these polysaccharide and protein interlayers demands hydrated conditions. Otherwise, nacre has similar brittle behaviour to aragonite. To prevent shear failure, shear hardening occurs by progressive tablet locking due to wavy dovetail-like surface geometry of the tablets. Similar effects by shearing and strain hardening mechanisms were found for Ti interlayers between TiN and DLC layers in high-resolution transmission electron microscopy studies, performed in deformed zones beneath spherical indentations. 7 nm thin Ti films are sufficient for strong toughening of the whole multi-layered coating structure, providing a barrier for propagation of cracks, starting from tensile-stressed, hard, brittle TiN or DLC layers. - Highlights: • Biomimetic approach to TiN-diamond-like carbon (DLC) multilayers by sputtering • Investigation of deformation in/around hardness indents by HR-TEM • Plastic deformation with shearing in 7-nm thick Ti interlayers in TiN–DLC multilayers • Biomimetically comparable to nacre deformation.

Fabrication of cell outer membrane mimetic polymer brush on polysulfone surface via RAFT technique

International Nuclear Information System (INIS)

Ma Qian; Zhang Hui; Zhao Jiang; Gong Yongkuan

2012-01-01

Highlights: ► Cell membrane mimetic antifouling polymer brush was grown on polysulfone surface. ► Graft density and polymerization degree were calculated from XPS results. ► Water contact angle measurements showed an extremely hydrophilic surface. ► Platelet adhesion and protein adsorption results suggested excellent antifouling ability. - Abstract: Cell membrane mimetic antifouling polymer brush was grown on polysulfone (PSF) membrane by surface-induced reversible addition–fragmentation chain transfer (RAFT) polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC). The RAFT agent immobilized PSF substrate was prepared by successive chloromethylation, amination with ethylenediamine (EDA) and amidation of the amine group of grafted EDA with the carboxylic group of 4-cyanopentanoic acid dithiobenzoate (CPAD). The surface RAFT polymerization of MPC was initiated in aqueous solution by 4,4′-azobis-4-cyanopentanoic acid (ACPA). The formation of PMPC brush coating is evidenced by X-ray photoelectron spectroscopy and water contact angle measurements. The degree of polymerization of PMPC and the polymer grafting density were calculated from the high resolution XPS spectra. The platelet adhesion and protein adsorption results showed that the PMPC-grafted PSF surface has excellent antifouling ability to resist platelet adhesion completely and suppress protein adsorption significantly. This biomimetic and bio-friendly surface RAFT polymerization strategy could be promising for a variety of biomedical applications.

Adhesion of mesenchymal stem cells to biomimetic polymers: A review

Energy Technology Data Exchange (ETDEWEB)

Shotorbani, Behnaz Banimohamad [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Alizadeh, Effat, E-mail: Alizadehe@tbzmed.ac.ir [Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Drug Applied Research Center and Faculty of advanced Medical Science, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); The Umbilical Cord Stem Cell Research Center (UCSRC), Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Salehi, Roya [Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Drug Applied Research Center and Faculty of advanced Medical Science, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); The Umbilical Cord Stem Cell Research Center (UCSRC), Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Barzegar, Abolfazl [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of)

2017-02-01

The mesenchymal stem cells (MSCs) are promising candidates for cell therapy due to the self-renewal, multi-potency, ethically approved state and suitability for autologous transplantation. However, key issue for isolation and manipulation of MSCs is adhesion in ex-vivo culture systems. Biomaterials engineered for mimicking natural extracellular matrix (ECM) conditions which support stem cell adhesion, proliferation and differentiation represent a main area of research in tissue engineering. Some of them successfully enhanced cells adhesion and proliferation because of their biocompatibility, biomimetic texture, and chemistry. However, it is still in its infancy, therefore intensification and optimization of in vitro, in vivo, and preclinical studies is needed to clarify efficacies as well as applicability of those bioengineered constructs. The aim of this review is to discuss mechanisms related to the in-vitro adhesion of MSCs, surfaces biochemical, biophysical, and other factors (of cell's natural and artificial micro-environment) which could affect it and a review of previous research attempting for its bio-chemo-optimization. - Highlights: • The main materials utilized for fabrication of biomimetic polymers are presented. • MSCs cell-material adhesion mechanism and involved molecules are reviewed. • Surface modifications of polymers in terms of MSC adhesion improving are discussed.

Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

Science.gov (United States)

Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

2015-12-01

The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements-including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth-were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light-tissue interactions and characterizing biophotonic system performance.

Adhesion of mesenchymal stem cells to biomimetic polymers: A review

International Nuclear Information System (INIS)

Shotorbani, Behnaz Banimohamad; Alizadeh, Effat; Salehi, Roya; Barzegar, Abolfazl

2017-01-01

The mesenchymal stem cells (MSCs) are promising candidates for cell therapy due to the self-renewal, multi-potency, ethically approved state and suitability for autologous transplantation. However, key issue for isolation and manipulation of MSCs is adhesion in ex-vivo culture systems. Biomaterials engineered for mimicking natural extracellular matrix (ECM) conditions which support stem cell adhesion, proliferation and differentiation represent a main area of research in tissue engineering. Some of them successfully enhanced cells adhesion and proliferation because of their biocompatibility, biomimetic texture, and chemistry. However, it is still in its infancy, therefore intensification and optimization of in vitro, in vivo, and preclinical studies is needed to clarify efficacies as well as applicability of those bioengineered constructs. The aim of this review is to discuss mechanisms related to the in-vitro adhesion of MSCs, surfaces biochemical, biophysical, and other factors (of cell's natural and artificial micro-environment) which could affect it and a review of previous research attempting for its bio-chemo-optimization. - Highlights: • The main materials utilized for fabrication of biomimetic polymers are presented. • MSCs cell-material adhesion mechanism and involved molecules are reviewed. • Surface modifications of polymers in terms of MSC adhesion improving are discussed.

Alkaline fuel cell with nitride membrane

Science.gov (United States)

Sun, Shen-Huei; Pilaski, Moritz; Wartmann, Jens; Letzkus, Florian; Funke, Benedikt; Dura, Georg; Heinzel, Angelika

2017-06-01

The aim of this work is to fabricate patterned nitride membranes with Si-MEMS-technology as a platform to build up new membrane-electrode-assemblies (MEA) for alkaline fuel cell applications. Two 6-inch wafer processes based on chemical vapor deposition (CVD) were developed for the fabrication of separated nitride membranes with a nitride thickness up to 1 μm. The mechanical stability of the perforated nitride membrane has been adjusted in both processes either by embedding of subsequent ion implantation step or by optimizing the deposition process parameters. A nearly 100% yield of separated membranes of each deposition process was achieved with layer thickness from 150 nm to 1 μm and micro-channel pattern width of 1μm at a pitch of 3 μm. The process for membrane coating with electrolyte materials could be verified to build up MEA. Uniform membrane coating with channel filling was achieved after the optimization of speed controlled dip-coating method and the selection of dimethylsulfoxide (DMSO) as electrolyte solvent. Finally, silver as conductive material was defined for printing a conductive layer onto the MEA by Ink-Technology. With the established IR-thermography setup, characterizations of MEAs in terms of catalytic conversion were performed successfully. The results of this work show promise for build up a platform on wafer-level for high throughput experiments.

A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

Science.gov (United States)

Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

2014-01-01

Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

Detection, recognition, identification, and tracking of military vehicles using biomimetic intelligence

Science.gov (United States)

Pace, Paul W.; Sutherland, John

2001-10-01

This project is aimed at analyzing EO/IR images to provide automatic target detection/recognition/identification (ATR/D/I) of militarily relevant land targets. An increase in performance was accomplished using a biomimetic intelligence system functioning on low-cost, commercially available processing chips. Biomimetic intelligence has demonstrated advanced capabilities in the areas of hand- printed character recognition, real-time detection/identification of multiple faces in full 3D perspectives in cluttered environments, advanced capabilities in classification of ground-based military vehicles from SAR, and real-time ATR/D/I of ground-based military vehicles from EO/IR/HRR data in cluttered environments. The investigation applied these tools to real data sets and examined the parameters such as the minimum resolution for target recognition, the effect of target size, rotation, line-of-sight changes, contrast, partial obscuring, background clutter etc. The results demonstrated a real-time ATR/D/I capability against a subset of militarily relevant land targets operating in a realistic scenario. Typical results on the initial EO/IR data indicate probabilities of correct classification of resolved targets to be greater than 95 percent.

Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

Science.gov (United States)

Liu, Ying; Liu, Xiaoheng; Wang, Xin

2011-12-01

Herein, the generation of gold, silver, and silver-gold (Ag-Au) bimetallic nanoparticles was carried out in collagen (gelatin) solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV-visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure) into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device.

Design, preparation and preliminary use of a novel biomimetic agent rFN/CAD

Directory of Open Access Journals (Sweden)

Hong KUANG

2012-12-01

Full Text Available Objective 　To prepare a novel biomimetic agent with adhesive and osteoinduction capabilities, and provide a new approach for improving seeding cell adhesion and osteoblastic differentiation on a scaffold surface. Methods 　A novel bifunctional recombinant protein was engineered and prepared by bioinformatics, standard molecular cloning, protein expression and purification techniques. A centrifugal cell adhesive assay and an osteoinduction assay were employed to determine the biofunction ex vivo. Results 　A 1954bp long DNA chimera of FN Ⅲ7-10/CAD11 EC1-2 and recombinant FN Ⅲ7-10/CAD11 EC1-2 of 641 amino acids were obtained. Polystyrene surface coated with this protein significantly increased the adhesive property and osteodifferentiation of human bone marrow mesenchymal stem cells. Conclusion 　rFN/CAD possesses dual biofunctions of osteoblastic adhesion and differentiation, which can be further applied as an ideal biomimetic molecule for surface modification.

Fabrication of Biomimetic Fog-Collecting Superhydrophilic-Superhydrophobic Surface Micropatterns Using Femtosecond Lasers.

Science.gov (United States)

Kostal, Elisabeth; Stroj, Sandra; Kasemann, Stephan; Matylitsky, Victor; Domke, Matthias

2018-03-06

The exciting functionalities of natural superhydrophilic and superhydrophobic surfaces served as inspiration for a variety of biomimetic designs. In particular, the combination of both extreme wetting states to micropatterns opens up interesting applications, as the example of the fog-collecting Namib Desert beetle shows. In this paper, the beetle's elytra were mimicked by a novel three-step fabrication method to increase the fog-collection efficiency of glasses. In the first step, a double-hierarchical surface structure was generated on Pyrex wafers using femtosecond laser structuring, which amplified the intrinsic wetting property of the surface and made it superhydrophilic (water contact angle 150°). In the last step, the Teflon-like coating was selectively removed by fs-laser ablation to uncover superhydrophilic spots below the superhydrophobic surface, following the example of the Namib Desert beetle's fog-collecting elytra. To investigate the influence on the fog-collection behavior, (super)hydrophilic, (super)hydrophobic, and low and high contrast wetting patterns were fabricated on glass wafers using selected combinations of these three processing steps and were exposed to fog in an artificial nebulizer setup. This experiment revealed that high-contrast wetting patterns collected the highest amount of fog and enhanced the fog-collection efficiency by nearly 60% compared to pristine Pyrex glass. The comparison of the fog-collection behavior of the six samples showed that the superior fog-collection efficiency of surface patterns with extreme wetting contrast is due to the combination of water attraction and water repellency: the superhydrophilic spots act as drop accumulation areas, whereas the surrounding superhydrophobic areas allow a fast water transportation caused by gravity. The presented method enables a fast and flexible surface functionalization of a broad range of materials including transparent substrates, which offers exciting possibilities for

Surface functionalization of a polymeric lipid bilayer for coupling a model biological membrane with molecules, cells, and microstructures.

Science.gov (United States)

Morigaki, Kenichi; Mizutani, Kazuyuki; Saito, Makoto; Okazaki, Takashi; Nakajima, Yoshihiro; Tatsu, Yoshiro; Imaishi, Hiromasa

2013-02-26

We describe a stable and functional model biological membrane based on a polymerized lipid bilayer with a chemically modified surface. A polymerized lipid bilayer was formed from a mixture of two diacetylene-containing phospholipids, 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DiynePC) and 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphoethanolamine (DiynePE). DiynePC formed a stable bilayer structure, whereas the ethanolamine headgroup of DiynePE enabled functional molecules to be grafted onto the membrane surface. Copolymerization of DiynePC and DiynePE resulted in a robust bilayer. Functionalization of the polymeric bilayer provided a route to a robust and biomimetic surface that can be linked with biomolecules, cells, and three-dimensional (3D) microstructures. Biotin and peptides were grafted onto the polymeric bilayer for attaching streptavidin and cultured mammalian cells by molecular recognition, respectively. Nonspecific adsorption of proteins and cells on polymeric bilayers was minimum. DiynePE was also used to attach a microstructure made of an elastomer (polydimethylsiloxan: PDMS) onto the membrane, forming a confined aqueous solution between the two surfaces. The microcompartment enabled us to assay the activity of a membrane-bound enzyme (cyochrome P450). Natural (fluid) lipid bilayers were incorporated together with membrane-bound proteins by lithographically polymerizing DiynePC/DiynePE bilayers. The hybrid membrane of functionalized polymeric bilayers and fluid bilayers offers a novel platform for a wide range of biomedical applications including biosensor, bioassay, cell culture, and cell-based assay.

Optical Biosensors to Explore Biological Systems

DEFF Research Database (Denmark)

Palanco, Marta Espina; Mogensen, Klaus Bo; Andersen, Nils H. Skovgaard

2016-01-01

their capability to work in biosensor devices. For example, Raman spectroscopy can be non-invasive and can provide 1 μm of spatial resolution in 1 second of collection time, well suited for sensing. Moreover, it may give information at the single cell and even approaching the single molecule scale. Here we present...... protein may be used as an efficient sensor in an organic environment via a biomimetic membrane model. The combination of both biomimetic membranes and protein membranes as a signal transduction medium has interesting applications in biology and medicine. It is crucial that the matrix where a protein...

Photonic crystal and photonic quasicrystal patterned in PDMS surfaces and their effect on LED radiation properties

Energy Technology Data Exchange (ETDEWEB)

Suslik, Lubos [Dept. of Physics, Faculty of Electrical Engineering, University of Zilina, Univerzitna 1, 010 26, Zilina (Slovakia); Pudis, Dusan, E-mail: pudis@fyzika.uniza.sk [Dept. of Physics, Faculty of Electrical Engineering, University of Zilina, Univerzitna 1, 010 26, Zilina (Slovakia); Goraus, Matej [Dept. of Physics, Faculty of Electrical Engineering, University of Zilina, Univerzitna 1, 010 26, Zilina (Slovakia); Nolte, Rainer [Fakultät für Maschinenbau FG Lichttechnik Ilmenau University of Technology, Ilmenau (Germany); Kovac, Jaroslav [Inst. of Electronics and Photonics, Slovak University of Technology, Ilkovicova 3, 812 19, Bratislava (Slovakia); Durisova, Jana; Gaso, Peter [Dept. of Physics, Faculty of Electrical Engineering, University of Zilina, Univerzitna 1, 010 26, Zilina (Slovakia); Hronec, Pavol [Inst. of Electronics and Photonics, Slovak University of Technology, Ilkovicova 3, 812 19, Bratislava (Slovakia); Schaaf, Peter [Chair Materials for Electronics, Institute of Materials Engineering and Institute of Micro- and Nanotechnologies MacroNano, TU Ilmenau, Gustav-Kirchhoff-Str. 5, 98693 Ilmenau (Germany)

2017-02-15

Graphical abstract: Photonic quasicrystal patterned in the surface of polydimethylsiloxane membrane (left) and radiation pattern of light emitting diode with patterned membrane applied in the surface (right). - Highlights: • We presented fabrication technique of PDMS membranes with patterned surface by photonic crystal (PhC) and photonic quasi-crystal (PQC). • Presented technique is effective for preparation PhC and PQC PDMS membranes easily implementing in the LED chip. • From the goniophotometer measurements, the membranes document effective angular emission due to the diffraction on patterned surfaces. • 12 fold symmetry PQC structure shows homogeneous radiation pattern, while the 2 fold symmetry of square PhC shows evident diffraction lobes. - Abstract: We present results of fabrication and implementation of thin polydimethylsiloxane (PDMS) membranes with patterned surface for the light emitting diode (LED). PDMS membranes were patterned by using the interference lithography in combination with embossing technique. Two-dimensional photonic crystal and photonic quasicrystal structures with different period were patterned in the surface of thin PDMS membranes with depth up to 550 nm. Patterned PDMS membranes placed on the LED chip effectively diffracted light and increased angular emission of LED radiation pattern. We presented effective technique for fabrication of patterned PDMS membranes, which could modify the emission properties of optoelectronic devices and can be applied directly on surface LEDs and small optical devices.

Design, fabrication and characterisation of a biomimetic accelerometer inspired by the cricket's clavate hair

NARCIS (Netherlands)

Droogendijk, H.; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

2013-01-01

Crickets use so-called clavate hairs to sense (gravitational) acceleration to obtain information on their orientation. Inspired by this clavate hair system, a biomimetic accelerometer has been developed and fabricated using surface micromachining and SU-8 lithography. First measurements indicate

A Biomimetic Approach for Designing a Full External Breast Prosthesis: Post-Mastectomy

Directory of Open Access Journals (Sweden)

Pedro Cruz

2018-03-01

Full Text Available This work presents the design of a new breast prosthesis using the biomimetic technique for cases of complete mastectomy to address the problem of the increasing number of women diagnosed with breast cancer in Mexico who are candidates for a mastectomy. The designed prosthesis considers the morphology of a real breast regarding its internal structure to obtain authentic mobility and feel. In order to accomplish this, a model was obtained in 3D CAD using a coordinate measuring machine (CMM that can be scalable without losing its qualities, and which can be used in any type of patient; afterwards, a finite element model was developed and a static analysis performed with suggested load cases to evaluate the sensitivity and naturalness of the prosthesis; and finally, a modal analysis was conducted. The results obtained in displacements and in distribution of stress for the load cases assessed are consistent with those of a real breast: there were smooth contours and there was natural mobility in the prosthesis designed by means of the biomimetic technique.

In vivo remineralization of dentin using an agarose hydrogel biomimetic mineralization system

Science.gov (United States)

Han, Min; Li, Quan-Li; Cao, Ying; Fang, Hui; Xia, Rong; Zhang, Zhi-Hong

2017-02-01

A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits’ incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.

Biomimetic oral mucin from polymer micelle networks

Science.gov (United States)

Authimoolam, Sundar Prasanth

Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated using affinity-based interactions on synthetic and biological surfaces. Unlike conventional polyelectrolyte-based LBL methods, pre-assembled biotin-functionalized filamentous (worm-like) micelles was utilized as the network building block, which from complementary additions of streptavidin generated synthetic networks of desired thickness. The biomimetic nature in those synthetic networks are studied by evaluating its structural and bio-functional properties. Structurally, synthetic networks formed a nanoporous mesh. The networks demonstrated excellent surface hydration property and were able capable of microbial capture. Those functional properties are akin to that of natural mucin networks. Further, the role of synthetic mucin as a drug delivery vehicle, capable of providing localized and tunable release was demonstrated. By incorporating antibacterial curcumin drug loading within synthetic networks, bacterial growth inhibition was also demonstrated. Thus, such bioactive interfaces can serve as a model for independently characterizing mucin network properties and through its role as a drug carrier vehicle it presents exciting future opportunities for localized drug delivery, in regenerative applications and as bio

Biomimetic and microbial approaches to solar fuel generation.

Science.gov (United States)

Magnuson, Ann; Anderlund, Magnus; Johansson, Olof; Lindblad, Peter; Lomoth, Reiner; Polivka, Tomas; Ott, Sascha; Stensjö, Karin; Styring, Stenbjörn; Sundström, Villy; Hammarström, Leif

2009-12-21

Photosynthesis is performed by a multitude of organisms, but in nearly all cases, it is variations on a common theme: absorption of light followed by energy transfer to a reaction center where charge separation takes place. This initial form of chemical energy is stabilized by the biosynthesis of carbohydrates. To produce these energy-rich products, a substrate is needed that feeds in reductive equivalents. When photosynthetic microorganisms learned to use water as a substrate some 2 billion years ago, a fundamental barrier against unlimited use of solar energy was overcome. The possibility of solar energy use has inspired researchers to construct artificial photosynthetic systems that show analogy to parts of the intricate molecular machinery of photosynthesis. Recent years have seen a reorientation of efforts toward creating integrated light-to-fuel systems that can use solar energy for direct synthesis of energy-rich compounds, so-called solar fuels. Sustainable production of solar fuels is a long awaited development that promises extensive solar energy use combined with long-term storage. The stoichiometry of water splitting into molecular oxygen, protons, and electrons is deceptively simple; achieving it by chemical catalysis has proven remarkably difficult. The reaction center Photosystem II couples light-induced charge separation to an efficient molecular water-splitting catalyst, a Mn(4)Ca complex, and is thus an important template for biomimetic chemistry. In our aims to design biomimetic manganese complexes for light-driven water oxidation, we link photosensitizers and charge-separation motifs to potential catalysts in supramolecular assemblies. In photosynthesis, production of carbohydrates demands the delivery of multiple reducing equivalents to CO(2). In contrast, the two-electron reduction of protons to molecular hydrogen is much less demanding. Virtually all microorganisms have enzymes called hydrogenases that convert protons to hydrogen, many of

Photolabeling of brain membrane proteins by lysergic acid diethylamide

International Nuclear Information System (INIS)

Mahon, A.C.; Hartig, P.R.

1982-01-01

3 H-Lysergic acid diethylamide ( 3 H-LSD) is irreversibly incorporated into bovine caudate membranes during ultraviolet light illumination. The incorporated radioligand apparently forms a covalent bond with a sub-population of the membrane proteins. Although the photolabeling pattern differs significantly from the Coomassie blue staining pattern on SDS gels, the photolabeling is apparently not specific for LSD binding sites associated with neurotransmitter receptors. 3 H-LSD photolabeling can occur during prolonged exposure of membrane samples to room lighting and thus may introduce artifacts into receptor binding assays

Evaluation in vitro and in vivo of biomimetic hydroxyapatite coated on titanium dental implants

International Nuclear Information System (INIS)

Rigo, E.C.S.; Boschi, A.O.; Yoshimoto, M.; Allegrini, S.; Konig, B.; Carbonari, M.J.

2004-01-01

Among several materials used as dental implants, metals present relatively high tensile strengths. Although metals are biotolerable, they do not adhere to bone tissues. On the other hand, bioactive ceramics are known to chemically bind to bone tissues, but they are not enough mechanically resistant to tension stresses. To overcome this drawback, biotolerable metals can be coated with bioactive ceramics. Various methods can be employed for coating ceramic layers on metal substrates, among them ion sputtering, plasma spray, sol-gel, electrodeposition and a biomimetic process [E.C.S. Rigo, L.C. Oliveira, L.A. Santos, A.O. Boschi, R.G. Carrodeguas. Implantes metalicos recobertos com hidroxiapatita. Revista de Engenharia Biomedica, vol. 15 (1999), numeros 1-2, 21-29. Rio de Janeiro]. The aim of this work was to study the effect of the substitution of G glass, employed in the conventional biomimetic method during the nucleation stage, by a solution of sodium silicate (SS) on the chemical and morphological characteristics, and the adhesion of biomimetic coatings deposited on Ti implants. The obtained coatings were analyzed by diffuse reflectance FTIR spectroscopy (DRIFT) and scanning electron microscopy (SEM). Titanium implants were immersed in synthetic body fluid (SBF) and SS. All implants were left inside an incubator at 37 deg. C for 7 days, followed by immersion in 1.5 SBF and taken back to the incubator for additional 6 days at 37 deg. C. The 1.5 SBF were refreshed every 2 days. At the end of the treatment, the implants were washed in distilled and deionized water and dried at room temperature. To check the osseointegration, titanium implants coated with biomimetic method were inserted in rabbit's tibia, remaining there for 8 weeks. During the healing period, polyfluorochrome sequential labeling was inoculated in the rabbits to determine the period of bone remodeling. Results from DRIFT and SEM showed that, for all processing variants employed, a HA coating was

Bio-mimetic mineralization potential of collagen hydrolysate obtained from chromium tanned leather waste

International Nuclear Information System (INIS)

Banerjee, Pradipta; Madhu, S.; Chandra Babu, N.K.; Shanthi, C.

2015-01-01

Hydroxyapatite (HA) ceramics serve as an alternative to autogenous-free bone grafting by virtue of their excellent biocompatibility. However, chemically synthesized HA lacks the strong load-bearing capacity as required by bone. The bio-mimetic growth of HA crystals on collagen surface provides a feasible solution for synthesizing bone substitutes with the desired properties. This study deals with the utilization of the collagen hydrolysate recovered from leather waste as a substrate for promoting HA crystal growth. Bio-mimetic growth of HA was induced by subjecting the hydrolysate to various mineralization conditions. Parameters that would have a direct effect on crystal growth were varied to determine the optimal conditions necessary. Maximum mineralization was achieved with a combination of 10 mM of CaCl 2 , 5 mM of Na 2 HPO 4 , 100 mM of NaCl and 0.575% glutaraldehyde at a pH of 7.4. The metal–protein interactions leading to formation of HA were identified through Fourier-transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD) studies. The crystal dimensions were determined to be in the nanoscale range by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The size and crystallinity of bio-mimetically grown HA indicate that hydrolysate from leather waste can be used as an ideal alternative substrate for bone growth. - Highlights: • Collagen hydrolysate, extracted from leather industry waste is subjected to biomineralization. • Optimal conditions required for HA growth are identified. • FTIR studies reveal higher Ca−COO − and low C−N stretch with higher HA formation. • AFM and SEM studies reveal nanometer ranged HA crystals

Magnetic biodegradable Fe3O4/CS/PVA nanofibrous membranes for bone regeneration

International Nuclear Information System (INIS)

Wei Yan; Zhang Xuehui; Hu Xiaoyang; Deng Xuliang; Song Yu; Lin Yuanhua; Han Bing; Wang Xinzhi

2011-01-01

In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. The aim of this study is to develop magnetic biodegradable fibrous materials with potential use in bone regeneration. Magnetic biodegradable Fe 3 O 4 /chitosan (CS)/poly vinyl alcohol (PVA) nanofibrous membranes were achieved by electrospinning with average fiber diameters ranging from 230 to 380 nm and porosity of 83.9-85.1%. The influences of polymer concentration, applied voltage and Fe 3 O 4 nanoparticles loading on the fabrication of nanofibers were investigated. The polymer concentration of 4.5 wt%, applied voltage of 20 kV and Fe 3 O 4 nanoparticles loading of lower than 5 wt% could produce homogeneous, smooth and continuous Fe 3 O 4 /CS/PVA nanofibrous membranes. X-ray diffraction (XRD) data confirmed that the crystalline structure of the Fe 3 O 4 , CS and PVA were maintained during electrospinning process. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the Fe 3 O 4 loading up to 5 wt% did not change the functional groups of CS/PVA greatly. Transmission electron microscopy (TEM) showed islets of Fe 3 O 4 nanoparticles evenly distributed in the fibers. Weak ferrimagnetic behaviors of membranes were revealed by vibrating sample magnetometer (VSM) test. Tensile test exhibited Young's modulus of membranes that were gradually enhanced with the increase of Fe 3 O 4 nanoparticles loading, while ultimate tensile stress and ultimate strain were slightly reduced by Fe 3 O 4 nanoparticles loading of 5%. Additionally, MG63 human osteoblast-like cells were seeded on the magnetic nanofibrous membranes to evaluate their bone biocompatibility. Cell growth dynamics according to MTT assay and scanning electron microscopy (SEM) observation exhibited good cell adhesion and proliferation, suggesting that this magnetic biodegradable Fe 3 O 4 /CS/PVA nanofibrous membranes can be one of promising biomaterials for facilitation of osteogenesis.

Adaptation in the visual cortex: influence of membrane trajectory and neuronal firing pattern on slow afterpotentials.

Directory of Open Access Journals (Sweden)

Vanessa F Descalzo

Full Text Available The input/output relationship in primary visual cortex neurons is influenced by the history of the preceding activity. To understand the impact that membrane potential trajectory and firing pattern has on the activation of slow conductances in cortical neurons we compared the afterpotentials that followed responses to different stimuli evoking similar numbers of action potentials. In particular, we compared afterpotentials following the intracellular injection of either square or sinusoidal currents lasting 20 seconds. Both stimuli were intracellular surrogates of different neuronal responses to prolonged visual stimulation. Recordings from 99 neurons in slices of visual cortex revealed that for stimuli evoking an equivalent number of spikes, sinusoidal current injection activated a slow afterhyperpolarization of significantly larger amplitude (8.5 ± 3.3 mV and duration (33 ± 17 s than that evoked by a square pulse (6.4 ± 3.7 mV, 28 ± 17 s; p<0.05. Spike frequency adaptation had a faster time course and was larger during plateau (square pulse than during intermittent (sinusoidal depolarizations. Similar results were obtained in 17 neurons intracellularly recorded from the visual cortex in vivo. The differences in the afterpotentials evoked with both protocols were abolished by removing calcium from the extracellular medium or by application of the L-type calcium channel blocker nifedipine, suggesting that the activation of a calcium-dependent current is at the base of this afterpotential difference. These findings suggest that not only the spikes, but the membrane potential values and firing patterns evoked by a particular stimulation protocol determine the responses to any subsequent incoming input in a time window that spans for tens of seconds to even minutes.

Extreme biomimetic approach for synthesis of nanocrystalline chitin-(Ti,Zr)O2 multiphase composites

International Nuclear Information System (INIS)

Wysokowski, Marcin; Motylenko, Mykhaylo; Rafaja, David; Koltsov, Iwona; Stöcker, Hartmut; Szalaty, Tadeusz J.; Bazhenov, Vasilii V.; Stelling, Allison L.; Beyer, Jan; Heitmann, Johannes; Jesionowski, Teofil; Petovic, Slavica; Đurović, Mirko; Ehrlich, Hermann

2017-01-01

This work presents an extreme biomimetics route for the modification of the surface of fibre-based scaffolds of poriferan origin by the creation of novel nanostructured multiphase biocomposites. The exceptional thermal stability of the nanostructured sponge chitin allowed for the formation of a novel nanocrystalline chitin-(Ti,Zr)O 2 composite with a well-defined nanoscale structure under hydrothermal conditions (160 °C). Using a combination of experimental techniques, including X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, EDX mapping and near-edge electron loss spectroscopy (ELNES) in TEM and thermogravimetry/differential scanning calorimetry coupled with mass spectrometry; we showed that this bioorganic scaffold facilitates selective crystallization of TiO 2 , predominantly in form of anatase, over the monoclinic zirconium dioxide (baddeleyite). The control of the crystal morphology through the chitin templates is also demonstrated. Obtained samples were characterized in terms of their photoluminescent properties and photocatalytic performance. These data confirm the high potential of the extreme biomimetics approach for developing a new generation of multiphase biopolymer-based nanostructured materials. - Highlights: • Extreme biomimetically prepared chitin-(Ti,Zr)O 2 and (Ti,Zr)O 2 composites. • Chitin-(Ti,Zr)O 2 composite contains anatase as the most inorganic component. • The mean crystallite size is (31.7 ± 0.3) nm for chitin-(Ti,Zr)O 2 composite. • The mean crystallite size is (2.4 ± 0.5) nm for (Ti,Zr)O 2 composite. • (Ti,Zr)O 2 composite is 2 times more effective photocatalyst than chitin-(Ti,Zr)O 2 .

Wetting study of patterned surfaces for superhydrophobicity

Energy Technology Data Exchange (ETDEWEB)

Bhushan, Bharat [Nanotribology Laboratory for Information Storage and MEMS/NEMS (NLIM), 201 W. 19th Avenue, Ohio State University, Columbus, OH 43202-1107 (United States)], E-mail: Bhushan.2@osu.edu; Jung, Yong Chae [Nanotribology Laboratory for Information Storage and MEMS/NEMS (NLIM), 201 W. 19th Avenue, Ohio State University, Columbus, OH 43202-1107 (United States)

2007-10-15

Superhydrophobic surfaces have considerable technological potential for various applications due to their extreme water-repellent properties. A number of studies have been carried out to produce artificial biomimetic roughness-induced hydrophobic surfaces. In general, both homogeneous and composite interfaces are possible on the produced surface. Silicon surfaces patterned with pillars of two different diameters and heights with varying pitch values were fabricated. We show how static contact angles vary with different pitch values on the patterned silicon surfaces. Based on the experimental data and a numerical model, the trends are explained. We show that superhydrophobic surfaces have low hysteresis and tilt angle. Tribological properties play an important role in many applications requiring water-repellent properties. Therefore, it is important to study the adhesion and friction properties of these surfaces that mimic nature. An atomic/friction force microscope (AFM/FFM) is used for surface characterization and adhesion and friction measurements.

Graphene-based structure, method of suspending graphene membrane, and method of depositing material onto graphene membrane

Science.gov (United States)

Zettl, Alexander K.; Meyer, Jannik Christian

2013-04-02

An embodiment of a method of suspending a graphene membrane across a gap in a support structure includes attaching graphene to a substrate. A pre-fabricated support structure having the gap is attached to the graphene. The graphene and the pre-fabricated support structure are then separated from the substrate which leaves the graphene membrane suspended across the gap in the pre-fabricated support structure. An embodiment of a method of depositing material includes placing a support structure having a graphene membrane suspended across a gap under vacuum. A precursor is adsorbed to a surface of the graphene membrane. A portion of the graphene membrane is exposed to a focused electron beam which deposits a material from the precursor onto the graphene membrane. An embodiment of a graphene-based structure includes a support structure having a gap, a graphene membrane suspended across the gap, and a material deposited in a pattern on the graphene membrane.

Research trends in biomimetic medical materials for tissue engineering: 3D bioprinting, surface modification, nano/micro-technology and clinical aspects in tissue engineering of cartilage and bone.

Science.gov (United States)

Chen, Cen; Bang, Sumi; Cho, Younghak; Lee, Sahnghoon; Lee, Inseop; Zhang, ShengMin; Noh, Insup

2016-01-01

This review discusses about biomimetic medical materials for tissue engineering of bone and cartilage, after previous scientific commentary of the invitation-based, Korea-China joint symposium on biomimetic medical materials, which was held in Seoul, Korea, from October 22 to 26, 2015. The contents of this review were evolved from the presentations of that symposium. Four topics of biomimetic medical materials were discussed from different research groups here: 1) 3D bioprinting medical materials, 2) nano/micro-technology, 3) surface modification of biomaterials for their interactions with cells and 4) clinical aspects of biomaterials for cartilage focusing on cells, scaffolds and cytokines.

Enhancing Osteoconduction of PLLA-Based Nanocomposite Scaffolds for Bone Regeneration Using Different Biomimetic Signals to MSCs

Directory of Open Access Journals (Sweden)

Nicola Baldini

2012-02-01

Full Text Available In bone engineering, the adhesion, proliferation and differentiation of mesenchymal stromal cells rely on signaling from chemico-physical structure of the substrate, therefore prompting the design of mimetic “extracellular matrix”-like scaffolds. In this study, three-dimensional porous poly-L-lactic acid (PLLA-based scaffolds have been mixed with different components, including single walled carbon nanotubes (CNT, micro-hydroxyapatite particles (HA, and BMP2, and treated with plasma (PT, to obtain four different nanocomposites: PLLA + CNT, PLLA + CNTHA, PLLA + CNT + HA + BMP2 and PLLA + CNT + HA + PT. Adult bone marrow mesenchymal stromal cells (MSCs were derived from the femur of orthopaedic patients, seeded on the scaffolds and cultured under osteogenic induction up to differentiation and mineralization. The release of specific metabolites and temporal gene expression profiles of marrow-derived osteoprogenitors were analyzed at definite time points, relevant to in vitro culture as well as in vivo differentiation. As a result, the role of the different biomimetic components added to the PLLA matrix was deciphered, with BMP2-added scaffolds showing the highest biomimetic activity on cells differentiating to mature osteoblasts. The modification of a polymeric scaffold with reinforcing components which also work as biomimetic cues for cells can effectively direct osteoprogenitor cells differentiation, so as to shorten the time required for mineralization.

Thermal gelation and tissue adhesion of biomimetic hydrogels

International Nuclear Information System (INIS)

Burke, Sean A; Ritter-Jones, Marsha; Lee, Bruce P; Messersmith, Phillip B

2007-01-01

Marine and freshwater mussels are notorious foulers of natural and manmade surfaces, secreting specialized protein adhesives for rapid and durable attachment to wet substrates. Given the strong and water-resistant nature of mussel adhesive proteins, significant potential exists for mimicking their adhesive characteristics in bioinspired synthetic polymer materials. An important component of these proteins is L-3,4-dihydroxylphenylalanine (DOPA), an amino acid believed to contribute to mussel glue solidification through oxidation and crosslinking reactions. Synthetic polymers containing DOPA residues have previously been shown to crosslink into hydrogels upon the introduction of oxidizing reagents. Here we introduce a strategy for stimuli responsive gel formation of mussel adhesive protein mimetic polymers. Lipid vesicles with a bilayer melting transition of 37 0 C were designed from a mixture of dipalmitoyl and dimyristoyl phosphatidylcholines and exploited for the release of a sequestered oxidizing reagent upon heating from ambient to physiologic temperature. Colorimetric studies indicated that sodium-periodate-loaded liposomes released their cargo at the phase transition temperature, and when used in conjunction with a DOPA-functionalized poly(ethylene glycol) polymer gave rise to rapid solidification of a crosslinked polymer hydrogel. The tissue adhesive properties of this biomimetic system were determined by in situ thermal gelation of liposome/polymer hydrogel between two porcine dermal tissue surfaces. Bond strength measurements showed that the bond formed by the adhesive hydrogel (mean = 35.1 kPa, SD = 12.5 kPa, n = 11) was several times stronger than a fibrin glue control tested under the same conditions. The results suggest a possible use of this biomimetic strategy for repair of soft tissues

Recent advances on gradient hydrogels in biomimetic cartilage tissue engineering [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Ivana Gadjanski

2017-12-01

Full Text Available Articular cartilage (AC is a seemingly simple tissue that has only one type of constituting cell and no blood vessels and nerves. In the early days of tissue engineering, cartilage appeared to be an easy and promising target for reconstruction and this was especially motivating because of widespread AC pathologies such as osteoarthritis and frequent sports-induced injuries. However, AC has proven to be anything but simple. Recreating the varying properties of its zonal structure is a challenge that has not yet been fully answered. This caused the shift in tissue engineering strategies toward bioinspired or biomimetic approaches that attempt to mimic and simulate as much as possible the structure and function of the native tissues. Hydrogels, particularly gradient hydrogels, have shown great potential as components of the biomimetic engineering of the cartilaginous tissue.

Toward a New Generation of Smart Biomimetic Actuators for Architecture.

Science.gov (United States)

Poppinga, Simon; Zollfrank, Cordt; Prucker, Oswald; Rühe, Jürgen; Menges, Achim; Cheng, Tiffany; Speck, Thomas

2017-10-24

Motile plant structures (e.g., leaves, petals, cone scales, and capsules) are functionally highly robust and resilient concept generators for the development of biomimetic actuators for architecture. Here, a concise review of the state-of-the-art of plant movement principles and derived biomimetic devices is provided. Achieving complex and higher-dimensional shape changes and passive-hydraulic actuation at a considerable time scale, as well as mechanical robustness of the motile technical structures, is challenging. For example, almost all currently available bioinspired hydraulic actuators show similar limitations due to the poroelastic time scale. Therefore, a major challenge is increasing the system size to the meter range, with actuation times of minutes or below. This means that response speed and flow rate need significant improvement for the systems, and the long-term performance degradation issue of hygroscopic materials needs to be addressed. A theoretical concept for "escaping" the poroelastic regime is proposed, and the possibilities for enhancing the mechanical properties of passive-hydraulic bilayer actuators are discussed. Furthermore, the promising aspects for further studies to implement tropistic movement behavior are presented, i.e., movement that depends on the direction of the triggering stimulus, which can finally lead to "smart building skins" that autonomously and self-sufficiently react to changing environmental stimuli in a direction-dependent manner. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

Science.gov (United States)

Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

2015-01-01

Abstract. The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements—including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth—were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light–tissue interactions and characterizing biophotonic system performance. PMID:26662064

Biomimetic flow-sensor arrays based on the filiform hairs on the cerci of crickets

NARCIS (Netherlands)

Wiegerink, Remco J.; Floris, J.; Jaganatharaja, R.K.; Izadi, N.; Lammerink, Theodorus S.J.; Krijnen, Gijsbertus J.M.

2007-01-01

In this paper we report on the latest developments in biomimetic flow-sensors based on the flow sensitive mechano-sensors of crickets. Crickets have one form of acoustic sensing evolved in the form of mechanoreceptive sensory hairs. These filiform hairs are highly perceptive to low-frequency sound

Influence of different temperatures on the thermal fatigue behavior and thermal stability of hot-work tool steel processed by a biomimetic couple laser technique

Science.gov (United States)

Meng, Chao; Zhou, Hong; Zhou, Ying; Gao, Ming; Tong, Xin; Cong, Dalong; Wang, Chuanwei; Chang, Fang; Ren, Luquan

2014-04-01

Three kinds of biomimetic non-smooth shapes (spot-shape, striation-shape and reticulation-shape) were fabricated on the surface of H13 hot-work tool steel by laser. We investigated the thermal fatigue behavior of biomimetic non-smooth samples with three kinds of shapes at different thermal cycle temperature. Moreover, the evolution of microstructure, as well as the variations of hardness of laser affected area and matrix were studied and compared. The results showed that biomimetic non-smooth samples had better thermal fatigue behavior compared to the untreated samples at different thermal cycle temperatures. For a given maximal temperature, the biomimetic non-smooth sample with reticulation-shape had the optimum thermal fatigue behavior, than with striation-shape which was better than that with the spot-shape. The microstructure observations indicated that at different thermal cycle temperatures the coarsening degrees of microstructures of laser affected area were different and the microstructures of laser affected area were still finer than that of the untreated samples. Although the resistance to thermal cycling softening of laser affected area was lower than that of the untreated sample, laser affected area had higher microhardness than the untreated sample at different thermal cycle temperature.

GSL-enriched membrane microdomains in innate immune responses.

Science.gov (United States)

Nakayama, Hitoshi; Ogawa, Hideoki; Takamori, Kenji; Iwabuchi, Kazuhisa

2013-06-01

Many pathogens target glycosphingolipids (GSLs), which, together with cholesterol, GPI-anchored proteins, and various signaling molecules, cluster on host cell membranes to form GSL-enriched membrane microdomains (lipid rafts). These GSL-enriched membrane microdomains may therefore be involved in host-pathogen interactions. Innate immune responses are triggered by the association of pathogens with phagocytes, such as neutrophils, macrophages and dendritic cells. Phagocytes express a diverse array of pattern-recognition receptors (PRRs), which sense invading microorganisms and trigger pathogen-specific signaling. PRRs can recognize highly conserved pathogen-associated molecular patterns expressed on microorganisms. The GSL lactosylceramide (LacCer, CDw17), which binds to various microorganisms, including Candida albicans, is expressed predominantly on the plasma membranes of human mature neutrophils and forms membrane microdomains together with the Src family tyrosine kinase Lyn. These LacCer-enriched membrane microdomains can mediate superoxide generation, migration, and phagocytosis, indicating that LacCer functions as a PRR in innate immunity. Moreover, the interactions of GSL-enriched membrane microdomains with membrane proteins, such as growth factor receptors, are important in mediating the physiological properties of these proteins. Similarly, we recently found that interactions between LacCer-enriched membrane microdomains and CD11b/CD18 (Mac-1, CR3, or αMβ2-integrin) are significant for neutrophil phagocytosis of non-opsonized microorganisms. This review describes the functional role of LacCer-enriched membrane microdomains and their interactions with CD11b/CD18.

Effects of Laser Energies on Wear and Tensile Properties of Biomimetic 7075 Aluminum Alloy

Science.gov (United States)

Yuan, Yuhuan; Zhang, Peng; Zhao, Guoping; Gao, Yang; Tao, Lixi; Chen, Heng; Zhang, Jianlong; Zhou, Hong

2018-03-01

Inspired by the non-smooth surface of certain animals, a biomimetic coupling unit with various sizes, microstructure, and hardness was prepared on the surface of 7075 aluminum alloy. Following experimental studies were conducted to investigate the wear and tensile properties with various laser energy inputs. The results demonstrated that the non-smooth surface with biomimetic coupling units had a positive effect on both the wear resistance and tensile property of 7075 aluminum alloy. In addition, the sample with the unit fabricated by the laser energy of 420.1 J/cm2 exhibited the most significant improvement on the wear and tensile properties owing to the minimum grain size and the highest microhardness. Also, the weight loss of the sample was one-third of the untreated one's, and the yield strength, the ultimate tensile strength, and the elongation improved by 20, 20, and 34% respectively. Moreover, the mechanisms of wear and tensile properties improvement were also analyzed.

Dense and porous titanium substrates with a biomimetic calcium phosphate coating

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, A.A., E-mail: aantunesr@yahoo.com.br [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil); Balestra, R.M. [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil); Rocha, M.N. [Metallurgical and Materials Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21941-972 Rio de Janeiro, RJ (Brazil); Peripolli, S.B. [Materials Metrology Division, National Institute of Metrology, Normalization and Quality, No. 50 Nossa Senhora das Gracas Street, Building 3, 25250-020 Duque de Caxias, RJ (Brazil); Andrade, M.C. [Polytechnic Institute of Rio de Janeiro, Rio de Janeiro State University, s/n, Alberto Rangel Street, 28630-050 Nova Friburgo, RJ (Brazil); Pereira, L.C. [Metallurgical and Materials Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21941-972 Rio de Janeiro, RJ (Brazil); Oliveira, M.V. [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil)

2013-01-15

Highlights: Black-Right-Pointing-Pointer A biomimetic coating method with simplified solution is proposed. Black-Right-Pointing-Pointer Titanium substrates are submitted to chemical and heat treatments. Black-Right-Pointing-Pointer Titanium substrates are coated with biocompatible calcium phosphate phases. Black-Right-Pointing-Pointer The simplified solution shows potential to be applied as a coating technique. - Abstract: The present work studied a biomimetic method using a simplified solution (SS) with calcium and phosphorus ions for coating titanium substrates, in order to improve their bioactivity. Commercially pure titanium dense sheet, microporous and macroporous titanium samples, both produced by powder metallurgy, were treated in NaOH solution followed by heat-treating and immersed in SS for 7, 14 or 21 days. The samples characterization was performed by quantitative metallographic analysis, confocal scanning optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and low angle X-ray diffraction. The results showed coatings with calcium phosphate precipitation in all samples, with globular or plate-like morphology, typical of hydroxyapatite and octacalcium phosphate, respectively, indicating that the solution (SS) has potential for coating titanium substrates. In addition, the different surfaces of substrates had an effect on the formed calcium phosphate phase and thickness of coatings, depending on the substrate type and imersion time in the simplified solution.

Biomimetic synthesized chiral mesoporous silica: Structures and controlled release functions as drug carrier

Energy Technology Data Exchange (ETDEWEB)

Li, Jing; Xu, Lu, E-mail: xl2013109@163.com; Yang, Baixue; Bao, Zhihong; Pan, Weisan; Li, Sanming, E-mail: li_sanming2013@163.com

2015-10-01

This work initially illustrated the formation mechanism of chiral mesoporous silica (CMS) in a brand new insight named biomimetic synthesis. Three kinds of biomimetic synthesized CMS (B-CMS, including B-CMS1, B-CMS2 and B-CMS3) were prepared using different pH or stirring rate condition, and their characteristics were tested with transmission electron microscope and small angle X-ray diffraction. The model drug indomethacin was loaded into B-CMS and drug loading content was measured using ultraviolet spectroscopy. The result suggested that pH condition influenced energetics of self-assembly process, mainly packing energetics of the surfactant, while stirring rate was the more dominant factor to determine particle length. In application, indomethacin loading content was measured to be 35.3%, 34.8% and 35.1% for indomethacin loaded B-CMS1, indomethacin loaded B-CMS2 and indomethacin loaded B-CMS3. After loading indomethacin into B-CMS carriers, surface area, pore volume and pore diameter of B-CMS carriers were reduced. B-CMS converted crystalline state of indomethacin to amorphous state, leading to the improved indomethacin dissolution. B-CMS1 controlled drug release without burst-release, while B-CMS2 and B-CMS3 released indomethacin faster than B-CMS1, demonstrating that the particle length, the ordered lever of multiple helixes, the curvature degree of helical channels and pore diameter greatly contributed to the release behavior of indomethacin loaded B-CMS. - Highlights: • Chiral mesoporous silica was synthesized using biomimetic method. • pH influenced energetics of self-assembly process of chiral mesoporous silica. • Stirring rate determined the particle length of chiral mesoporous silica. • Controlled release behaviors of chiral mesoporous silica varied based on structures.

Biomimetic synthesized chiral mesoporous silica: Structures and controlled release functions as drug carrier

International Nuclear Information System (INIS)

Li, Jing; Xu, Lu; Yang, Baixue; Bao, Zhihong; Pan, Weisan; Li, Sanming

2015-01-01

This work initially illustrated the formation mechanism of chiral mesoporous silica (CMS) in a brand new insight named biomimetic synthesis. Three kinds of biomimetic synthesized CMS (B-CMS, including B-CMS1, B-CMS2 and B-CMS3) were prepared using different pH or stirring rate condition, and their characteristics were tested with transmission electron microscope and small angle X-ray diffraction. The model drug indomethacin was loaded into B-CMS and drug loading content was measured using ultraviolet spectroscopy. The result suggested that pH condition influenced energetics of self-assembly process, mainly packing energetics of the surfactant, while stirring rate was the more dominant factor to determine particle length. In application, indomethacin loading content was measured to be 35.3%, 34.8% and 35.1% for indomethacin loaded B-CMS1, indomethacin loaded B-CMS2 and indomethacin loaded B-CMS3. After loading indomethacin into B-CMS carriers, surface area, pore volume and pore diameter of B-CMS carriers were reduced. B-CMS converted crystalline state of indomethacin to amorphous state, leading to the improved indomethacin dissolution. B-CMS1 controlled drug release without burst-release, while B-CMS2 and B-CMS3 released indomethacin faster than B-CMS1, demonstrating that the particle length, the ordered lever of multiple helixes, the curvature degree of helical channels and pore diameter greatly contributed to the release behavior of indomethacin loaded B-CMS. - Highlights: • Chiral mesoporous silica was synthesized using biomimetic method. • pH influenced energetics of self-assembly process of chiral mesoporous silica. • Stirring rate determined the particle length of chiral mesoporous silica. • Controlled release behaviors of chiral mesoporous silica varied based on structures

Molecular phospholipid films on solid supports

DEFF Research Database (Denmark)

Czolkos, Ilja; Jesorka, Aldo; Orwar, Owe

2011-01-01

Phospholipid membranes are versatile structures for mimicking biological surfaces. Bilayer and monolayer membranes can be formed on solid supports, leading to enhanced stability and accessibility of the biomimetic molecular film. This has facilitated functional studies of membrane proteins and ai...

Methods and Experimental Protocols to Design a Simulated Bio-Mimetic Quadruped Robot

Directory of Open Access Journals (Sweden)

Hadi El Daou

2013-05-01

Full Text Available Abstract This paper presents a bio-mimetic approach to design and simulate a tortoise-like virtual robot. This study takes a multidisciplinary approach: from in vivo and in vitro experiments on animals, data are collected and used to design, control and simulate a bio-mimetic virtual robot using MD ADAMS platform. From the in vitro experiments, the geometrical and inertial properties of body limbs are measured, and a model of tortoise kinematics is derived. From the in vivo experiments the contact forces between each limb and the ground are measured. The contributions of hind and forelimbs in the generation of propelling and braking forces are studied. The motion of the joints between limb segments are recorded and used to solve the inverse kinematics problem. A virtual model of a tortoise-like robot is built; it is a linkage of 15 rigid bodies articulated by 22 degrees of freedom. This model is referred to as TATOR II. It has the inertial and geometrical properties measured during the in vitro experiments. TATOR II motion is achieved using a Proportional-Derivative controller copying the joint angle trajectories calculated from the in vivo experiments.

Multilayered membranes with tuned well arrays to be used as regenerative patches.

Science.gov (United States)

Martins, Nádia I; Sousa, Maria P; Custódio, Catarina A; Pinto, Vânia C; Sousa, Paulo J; Minas, Graça; Cleymand, Franck; Mano, João F

2017-07-15

Membranes have been explored as patches in tissue repair and regeneration, most of them presenting a flat geometry or a patterned texture at the nano/micrometer scale. Herein, a new concept of a flexible membrane featuring well arrays forming pore-like environments to accommodate cell culture is proposed. The processing of such membranes using polysaccharides is based on the production of multilayers using the layer-by-layer methodology over a patterned PDMS substrate. The detached multilayered membrane exhibits a layer of open pores at one side and a total thickness of 38±2.2µm. The photolithography technology used to produce the molds allows obtaining wells on the final membranes with a tuned shape and micro-scale precision. The influence of post-processing procedures over chitosan/alginate films with 100 double layers, including crosslinking with genipin or fibronectin immobilization, on the adhesion and proliferation of human osteoblast-like cells is also investigated. The results suggest that the presence of patterned wells affects positively cell adhesion, morphology and proliferation. In particular, it is seen that cells colonized preferentially the well regions. The geometrical features with micro to sub-millimeter patterned wells, together with the nano-scale organization of the polymeric components along the thickness of the film will allow to engineer highly versatile multilayered membranes exhibiting a pore-like microstructure in just one of the sides, that could be adaptable in the regeneration of multiple tissues. Flexible multilayered membranes containing multiple micro-reservoirs are found as potential regenerative patches. Layer-by-layer (LbL) methodology over a featured PDMS substrate is used to produce patterned membranes, composed only by natural-based polymers, that can be easily detached from the PDMS substrate. The combination of nano-scale control of the polymeric organization along the thickness of the chitosan/alginate (CHT

Computational modelling of oxygenation processes in enzymes and biomimetic model complexes

OpenAIRE

de Visser, Sam P.; Quesne, Matthew G.; Martin, Bodo; Comba, Peter; Ryde, Ulf

2014-01-01

With computational resources becoming more efficient and more powerful and at the same time cheaper, computational methods have become more and more popular for studies on biochemical and biomimetic systems. Although large efforts from the scientific community have gone into exploring the possibilities of computational methods on large biochemical systems, such studies are not without pitfalls and often cannot be routinely done but require expert execution. In this review we summarize and hig...

The effect of channel flow pattern on internal properties distribution of a proton exchange membrane fuel cell for cathode starvation conditions

International Nuclear Information System (INIS)

Ko, Dong Soo; Kang, Young Min; Yang, Jang Sik; Jeong, Ji Hwan; Choi, Gyung Min; Kim, Duck Jool

2010-01-01

The effect of channel flow pattern on the internal properties distribution of a proton exchange membrane fuel cell (PEMFC) for cathode starvation conditions in a unit cell was investigated through numerical studies and experiments. The polarization curves of a lab-scale mixed serpentine PEMFC were measured with increasing current loads for different cell temperatures (40, 50, and 60 .deg. C) at a relative humidity of 100%. To study the local temperature on the membrane, the water content in the MEA, and the gas velocity in terms of the channel type of the PEMFC with operating characteristics, numerical studies using the es-pemfc module of STAR-CD, which have been matched to the experimental data, were conducted in detail. The water content and velocity at the cathode channel bend of the mixed serpentine channel were relatively higher than those at the single and double channels. Conversely, the local temperature and mean temperature on the membrane of a single serpentine channel were the highest among all channels. These results can be used to design the PEMFC system, the channel flow field, and the cooling device

Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

Science.gov (United States)

Green, David W.; Lee, Jung-Seok; Jung, Han-Sung

2016-01-01

The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a “water-tight” barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell–cell connections, cell–matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis. PMID:26903872

Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

Directory of Open Access Journals (Sweden)

David William Green

2016-02-01

Full Text Available The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a water-tight barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachement complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement.. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organising cell-cell connections, cell-matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis.

Precise and Arbitrary Deposition of Biomolecules onto Biomimetic Fibrous Matrices for Spatially Controlled Cell Distribution and Functions.

Science.gov (United States)

Jia, Chao; Luo, Bowen; Wang, Haoyu; Bian, Yongqian; Li, Xueyong; Li, Shaohua; Wang, Hongjun

2017-09-01

Advances in nano-/microfabrication allow the fabrication of biomimetic substrates for various biomedical applications. In particular, it would be beneficial to control the distribution of cells and relevant biomolecules on an extracellular matrix (ECM)-like substrate with arbitrary micropatterns. In this regard, the possibilities of patterning biomolecules and cells on nanofibrous matrices are explored here by combining inkjet printing and electrospinning. Upon investigation of key parameters for patterning accuracy and reproducibility, three independent studies are performed to demonstrate the potential of this platform for: i) transforming growth factor (TGF)-β1-induced spatial differentiation of fibroblasts, ii) spatiotemporal interactions between breast cancer cells and stromal cells, and iii) cancer-regulated angiogenesis. The results show that TGF-β1 induces local fibroblast-to-myofibroblast differentiation in a dose-dependent fashion, and breast cancer clusters recruit activated stromal cells and guide the sprouting of endothelial cells in a spatially resolved manner. The established platform not only provides strategies to fabricate ECM-like interfaces for medical devices, but also offers the capability of spatially controlling cell organization for fundamental studies, and for high-throughput screening of various biomolecules for stem cell differentiation and cancer therapeutics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A human endogenous protein exerts multi-role biomimetic chemistry in synthesis of paramagnetic gold nanostructures for tumor bimodal imaging.

Science.gov (United States)

Yang, Weitao; Wu, Xiaoli; Dou, Yan; Chang, Jin; Xiang, Chenyang; Yu, Jiani; Wang, Jun; Wang, Xiuli; Zhang, Bingbo

2018-04-01

Protein-mediated biomimetic nanoparticles because of simplicity of their synthesis, subdued nonspecific adsorption, improved pharmacokinetics, and biocompatibility have been receiving increasing attention recently. Nevertheless, only a handful of proteins have been developed for biomimetic synthesis. Worse still, most of them are constrained on single-function usages in chemistry. Exploring new functional proteins, especially those with multi-dentate moieties for multi-role biomimetic chemistry, still remains a substantial challenge. Here, we report on a human endogenous protein, glutathione S-transferase (GST), with favorable amino acid motifs, that has innate talents in incubating high quality gold nanoparticles without adding reducing agents at physiological temperature, and particularly can further anchor gadolinium ions without adding extra chelators. The resultant paramagnetic AuNPs@GST Gd exhibits highly crystallization and uniform size of ca. 10 nm. Compared with clinical contrast agents (Iopamidol, Magnevist), AuNPs@GST Gd shows better imaging performance (e.g. enhanced relaxivity and larger X-ray attenuation efficiency) with clear evidence from Monte Carlo simulation and in vitro experimental results. Further in vivo imaging demonstrates good tumor targeting and clearance of AuNPs@GST Gd without obvious systemic toxicity. Particularly, low immunogenicity of AuNPs@GST Gd is certified by immunological status evaluation of T cells after stimulated with them. This study for the first time demonstrates the manipulation of a human protein for multi-role biomimetic chemistry depending on its unique amino acid motifs and its incorporation into a synthetic agent for potentially addressing some critical issues in cancer nanotheranostics such as synthetic methodology, biocompatibility, function integration, targeting, and immunogenicity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Accelerating the design of biomimetic materials by integrating RNA-seq with proteomics and materials science.

Science.gov (United States)

Guerette, Paul A; Hoon, Shawn; Seow, Yiqi; Raida, Manfred; Masic, Admir; Wong, Fong T; Ho, Vincent H B; Kong, Kiat Whye; Demirel, Melik C; Pena-Francesch, Abdon; Amini, Shahrouz; Tay, Gavin Z; Ding, Dawei; Miserez, Ali

2013-10-01

Efforts to engineer new materials inspired by biological structures are hampered by the lack of genomic data from many model organisms studied in biomimetic research. Here we show that biomimetic engineering can be accelerated by integrating high-throughput RNA-seq with proteomics and advanced materials characterization. This approach can be applied to a broad range of systems, as we illustrate by investigating diverse high-performance biological materials involved in embryo protection, adhesion and predation. In one example, we rapidly engineer recombinant squid sucker ring teeth proteins into a range of structural and functional materials, including nanopatterned surfaces and photo-cross-linked films that exceed the mechanical properties of most natural and synthetic polymers. Integrating RNA-seq with proteomics and materials science facilitates the molecular characterization of natural materials and the effective translation of their molecular designs into a wide range of bio-inspired materials.

Biomimetic synthesis of noble metal nanocrystals

Science.gov (United States)

Chiu, Chin-Yi

At the nanometer scale, the physical and chemical properties of materials heavily depend on their sizes and shapes. This fact has triggered considerable efforts in developing controllable nanomaterial synthesis. The controlled growth of colloidal nanocrystal is a kinetic process, in which high-energy facets grow faster and then vanish, leading to a nanocrystal enclosed by low-energy facets. Identifying a surfactant that can selectively bind to a particular crystal facet and thus lower its surface energy, is critical and challenging in shape controlled synthesis of nanocrystals. Biomolecules exhibiting exquisite molecular recognition properties can be exploited to precisely engineer nanostructured materials. In the first part of my thesis, we employed the phage display technique to select a specific multifunctional peptide sequence which can bind on Pd surface and mediate Pd crystal nucleation and growth, achieving size controlled synthesis of Pd nanocrystals in aqueous solution. We further demonstrated a rational biomimetic approach to the predictable synthesis of nanocrystals enclosed by a particular facet in the case of Pt. Specifically, Pt {100} and Pt {111} facet-specific peptides were identified and used to synthesize Pt nanocubes and Pt nano-tetrahedrons, respectively. The mechanistic studies of Pt {111} facet-specific peptide had led us to study the facet-selective adsorption of aromatic molecules on noble metal surfaces. The discoveries had achieved the development of design strategies to select facet-selective molecules which can synthesize nanocrystals with expected shapes in both Pt and Pd system. At last, we exploited Pt facet-specific peptides and controlled the molecular interaction to produce one- and three- dimensional nanostructures composed of anisotropic nanoparticles in synthetic conditions without supramolecular pre-organization, demonstrating the full potential of biomolecules in mediating material formation process. My research on biomimetic

Effects of striated laser tracks on thermal fatigue resistance of cast iron samples with biomimetic non-smooth surface