Biomimetic synthesis of metal–hydroxyapatite (Au-HAp, Ag-HAp, Au-Ag-HAp): Structural analysis, spectroscopic characterization and biomedical application

Kim, Hyehyun,Mondal, Sudip,Jang, Bian,Manivasagan, Panchanathan,Moorthy, Madhappan Santha,Oh, Junghwan Elsevier 2018 Ceramics international Vol.44 No.16

<P><B>Abstract</B></P> <P>An innovative biomimetic approach has been employed for the synthesis of human and environmental friendly nanomaterials for biomedical application. The aim of this research is to study the structural analysis of biomimetic-synthesized gold (Au) and silver (Ag) nanoparticles loaded on pristine hydroxyapatite (HAp) and their potential advances in biomedical applications. The synthesized metal–hydroxyapatite nanoparticles’ structural and morphological characteristics were studied using X-ray diffraction (XRD), different spectroscopies (UV–vis, DRS, FTIR, zeta potential), BET surface area and pore size analyzer and electron microscopy (FE-TEM, FE-SEM). Biological activity was established using osteoblast-like MG-63 cell line and antibacterial tests with <I>Escherichia coli</I> (<I>E. coli</I>), which is one of the most common bacteria in the human body. Cell cytotoxicity test (MTT assay and fluorescence imaging with AO/PI staining) was conducted with MG-63 cells to study the toxicity of Au-HAp, Ag-HAp, and Au-Ag-HAp (bimetallic) nanoparticles. Antimicrobial studies have shown that all Ag-HAp nanoparticles have excellent in vitro antibacterial activity with <I>E. coli</I>. The present research investigates the structural stability and biocompatibility of Au-HAp, Ag-HAp, and Au-Ag-HAp nanoparticles, which may be the best materials to repair bone infection (osteomyelitis) and could be useful as a potential scaffold material to prevent postoperative infections.</P>

An autodriven, solar fuel collection for a highly compact, biomimetic-modified artificial leaf without membrane

Kim, Sangkuk,Han, Kiduk,Kim, Wuseok,Jeon, Sangmin,Yong, Kijung Elsevier 2019 Nano energy Vol.58 No.-

<P><B>Abstract</B></P> <P>Hydrogen fuel generation from water splitting has recently attracted much attention due to its high potential as a clean, renewable energy source. To obtain pure H<SUB>2</SUB> fuel, it is inevitably required to separate the H<SUB>2</SUB>/O<SUB>2</SUB> product gas mixture, mainly relying on a membrane system at the current stage. However, this process has inherent durability and cost issues due to contamination, corrosion and its complex configuration. In our current work, we invented a highly compact gas separation and collection method in a water electrolysis system, which is set onto a biomimetically modified electrode without the use of a membrane or external convective flow. A key idea of this smart, compact and self-driven system is gas bubble manipulation by buoyant force and a slippery liquid infused porous surface (SLIPS). With the critical help of the biomimetic SLIPS wall by blocking bubble leakage, H<SUB>2</SUB> and O<SUB>2</SUB> product gases can be separately collected at the corresponding collection port. As a result, we achieved a remarkably improved H<SUB>2</SUB> collection value of over 90% with high purity using this membrane-free electrolysis system in which the product gases are separated only by their intrinsic buoyancy. This simple but effective gas separation/collection system is also applied to a highly compact, monolithic artificial leaf, in which the solar water splitting is practicably and conveniently conducted in a compact, floatable design.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A membrane-free gas separation method is invented for monolithic artificial leaf. </LI> <LI> Buoyance force and biomimetic surface design is combined for gas bubble manipulation. </LI> <LI> The collection efficiency of H<SUB>2</SUB> gas records over 90% with its high purity. </LI> <LI> O<SUB>2</SUB> gas, counter product of water electrolysis shows very low cross-over with high purity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A membrane-free, compact solar fuel collection system employing the biomimetic SLIPS of the pitcher plant with water splitting electrodes, showing its mechanism and performance in its gas separation/collection.</P> <P>[DISPLAY OMISSION]</P>

Biomimetic-inspired highly sensitive flexible capacitive pressure sensor with high-aspect-ratio microstructures

Zhao Le,Yu Shihui,Li Junjun,Song Zichen,Wu Muying,Wang Xiuyu,Wang Xiaohu 한국물리학회 2021 Current Applied Physics Vol.31 No.-

The high sensitivity flexible capacitive pressure sensor (FCPS) manufactured in a fast and efficient way has friendly man-machine interaction function. In this paper, a high-sensitivity FCPS is developed by using a twostep template method to reproduce biomimetic microtower polydimethylsiloxane (PDMS) from the lotus leaf surface. The capacitive sensor is composed of a PDMS dielectric layer and the Cu nanowire electrodes sandwiching in the middle, with a high sensitivity of ~1.207 kPa 1, a low detection limit of less than 0.02 kPa and a fast response time of 61.6 ms. Particularly, the sensing performance can be kept basically unchanged when bent at a 5 mm radius. Moreover, the FCPS can withstand 4000 repeated tests and maintain stable performance, and the sensitivity is almost the same in the process of loading and unloading, suggesting the high robustness. These results demonstrates the FCPSs have potential applications in electronic wearables, human health monitoring and uneven surface applications.

Self assembly of biomimetic hydroxyapatite on the surface of different polymer thin films

M. Petrovic 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.4

The role of the process of designing a scaffold in bone tissue engineering is to provide optimal conditions for new bone tissue growth. The primary concern of such engineering is to create an adequate nanotopology of the scaffold inner walls, which can initiate the growth and activity of bone cells. Here, we present a completely new scaffold designing process based on a biomimetic approach in order to improve the nanostructure of pore walls of previously-made calcium hydroxyapatite (CHA) porous scaffolds. CHA porous scaffolds were covered with different polymer thin films (alginate, cellulose and PLGA) and exposed to simulated body fluid (SBF) for 42 days. SBF induced in situ formation of “bone-like” apatite phases on the surface of CHA/polymer composites. Fourier Transformed Infrared (FTIR) spectroscopy showed that the biomimetically-assembled phase is CHA of slightly shifted stoichiometry. X-ray diffraction confirmed that CHA is self-assembled on the surface of all investigated thin films. The calculation of crystallite sizes showed small differences in the degree of crystallinity between different samples. Scanning electron microscopy revealed a dominant blow-ball morphology of CHA particles (size 1 - 5 µm) with nano-sized branches on their surfaces.

A study on improving the surface structure of solar cell and increasing the light absorbing efficiency - Applying the structure of leaves' surface -

김태민(Kim, Taemin),홍주표(Hong, Joopyo) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.11

Biomimetc is a new domain of learning that proposes a solution getting clues from nature. There seems to be a sign of this phenomenon in fields of Renewable Energy. Foe example, Wind power was imitate the whale's fin that was improve efficiency of generating energy. This study focused on the photovoltaic generation as the instance of applying biomimetic. Efficiency is the most important factor in field of Photovoltaic generation. When given solar cell taking the sun light, most important fields of the study are absorb more light and increase the quantity of generation. For improving efficiency, the solar cell were builded up textures of taking a pyramid form, such a surface structure taking a role for remaining the light. This effects do the role as increasing absorbing efficiency. Such phenomenon calls Light Trapping, locking up the light on the surface of solar cell for a long time. Light is a vital factor to plants in the nature. Plants grow up through the photosynthesis that absorbing light for growth and propagation. So, plants make a effort how can absorb more the light in poor surroundings. This study set up a goal that imitates the minute surface structure of plants and applies to the existing solar cells's surface structure, so it can improve the efficiency of absorbing light. We used Light Tools software analyzing geometrical optics to analyze efficiency about new designed textures on the computer. We made a comparison between existing textures and new designed textures. Consequently, new designed textures were advanced efficiency, absorbing rates of light increasing about 7 percent. In comparison with existing and new textures, advancing about 20 percent in the efficient aspect.

Biomimetic apatite formed on cobalt-chromium alloy: A polymer-free carrier for drug eluting stent

Chen, Cen,Yao, Chenxue,Yang, Jingxin,Luo, Dandan,Kong, Xiangdong,Chung, Sung-Min,Lee, In-Seop Elsevier 2017 Colloids and surfaces Biointerfaces Vol.151 No.-

<P><B>Abstract</B></P> <P>In this study, sirolimus (SRL) was loaded within biomimetic apatite formed on cobalt-chromium (Co-Cr) alloy, which has been reported for the first time, to inhibit the in-stent restenosis. Two different groups of loading SRL within biomimetic apatite were prepared: Group A (mono-layer of apatite/SRL) and Group B (bi-layer of apatite/SRL). Group A and Group B showed the biphasic pattern of SRL release up to 40 and 90days, respectively. The attachment of human artery smooth muscle cell (HASMC) for both Group A and Group B was significantly inhibited, and proliferation dramatically decreased with the release of SRL. Noteworthily, biomimetic apatite alone also suppressed the SMC proliferation. The porous biomimetic apatite uniformly covered Co-Cr stent without crack or webbings. After balloon expansion, the integrity of biomimetic apatite was sufficient to resist delamination or destruction. Thus, this study demonstrated that biomimetic apatite is a promising drug carrier for potential use in stents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biomimetic apatite is formed on Co-Cr alloy as a polymer-free drug carrier. </LI> <LI> To inhibit in-stent restenosis, sirolimus is loaded within apatite in two ways. </LI> <LI> Porous and biodegradable biomimetic apatite releases of sirolimus over 40days. </LI> <LI> Integrity of biomimetic apatite is sufficient for clamping and balloon expansion. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Allometric Scaling of Insects and Animals for Biomimetic Robot Design Considerations

Taejae Lee,Seohyeong Jang,Mingi Jeong,Dong-Il “Dan” Cho 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

Recently, biomimetic robots have received great attention as an alternative to overcome the limit of conventional robots. However, there is no standardized methodology to design and determine the specifications of biomimetic robots. In this paper, the concept of allometric scaling and its application to biomimetic robot design considerations are discussed. Also, characteristics of motion data of small insects and animals, which are eight species of crawling and eight species of flying creatures, all with less than 400 g in weight, are investigated. These are used to compare with those of recently presented biomimetic robots as a function of the body mass in several categories, including the velocity, angular velocity, acceleration, stride frequency, and wing beat frequency. The results show that the characteristics of most of the small biomimetic robots approximately fit in the allometric scaling of insects and animals. However, it is found that some small robots have characteristics which are quite different to those predictable from the allometric scaling law. Learning from nature may be a solution to design and determine the specifications of biomimetic robots, and the allometric scaling can be the one of the methods that can help define the achievable performance envelope.

Biomimetic membranes as potential tools for water purification: Preceding and future avenues

Fuwad, Ahmed,Ryu, Hyunil,Malmstadt, Noah,Kim, Sun Min,Jeon, Tae-Joon Elsevier 2019 Desalination Vol.458 No.-

<P><B>Abstract</B></P> <P>Industrialization and urbanization lead to increased generation of wastewater causing serious environmental pollution and deterioration of water quality. Membrane-based water treatment represents a major technological approach to addressing global water scarcity and environmental pollution issues. However, there has been relatively little progress in membrane technologies for water treatment mainly due to the inherent limitations of membrane materials and membrane fabrication techniques. In recent years, biomimetic membranes, such as the aquaporin membrane, have emerged as strong candidates for membrane-based water purification technology. Biomimetic approaches have the potential to overcome the problems associated with existing membranes including limited permeability, low selectivity, and excessive energy consumption. But industrial-scale defect-free biomimetic membrane fabrication remains a major challenge. Key factors that must be addressed to overcome this challenge include protein stability, membrane housing materials, and the surface chemistry and structural characteristics of the substrate. This paper reviews the state-of-the-art of membrane-based water purification technologies, summarizing the role and limitations of conventional membrane materials while evaluating the latest progress in the field of biomimetic membrane fabrication. We conclude that a thorough understanding of the relationship between substrate structure-surface properties and membrane performance is necessary for the further development and commercialization of aquaporin biomimetic membranes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A broad thematic view of membrane technology for water purification is discussed. </LI> <LI> The inherent problems associated with conventional membranes limit their function. </LI> <LI> Conventional membranes technologies and the fundamental problems associated with them are discussed. </LI> <LI> Aquaporin biomimetic membranes have been emerging as a potential “all-in-one” solution for overcoming current obstacles. </LI> <LI> Practical challenges associated with the implementation of biomimetic membranes are discussed. </LI> </UL> </P>

Laminin functionalized biomimetic apatite to regulate the adhesion and proliferation behaviors of neural stem cells

Luo, Dandan,Ruan, Shichao,Liu, Aiping,Kong, Xiangdong,Lee, In-Seop,Chen, Cen Dove Medical Press 2018 International journal of nanomedicine Vol.13 No.-

<P><B>Background</B></P><P>Functionalizing biomaterial substrates with biological signals shows promise in regulating neural stem cell (NSC) behaviors through mimicking cellular microenvironment. However, diverse methods for immobilizing biological molecules yields promising results but with many problems. Biomimetic apatite is an excellent carrier due to its non-toxicity, good biocompatibility, biodegradability, and favorable affinity to plenty of molecules. Therefore, it may provide a promising alternative in regulating NSC behaviors.</P><P><B>Methods</B></P><P>Biomimetic apatite immobilized with the extracellular protein – laminin (LN) was prepared through coprecipitation process in modified Dulbecco’s phosphate-buffered saline (DPBS) containing LN. The amount of coprecipitated LN and their release kinetics were examined. The adhesion and proliferation behaviors of NSC on biomimetic apatite immobilized with LN were investigated.</P><P><B>Results</B></P><P>The coprecipitation approach provided well retention of LN within biomimetic apatite up to 28 days, and supported the adhesion and proliferation of NSCs without cytotoxicity. For long-term cultivation, NSCs formed neurosphere-like aggregates on non-functionalized biomimetic apatite. A monolayer of proliferated NSCs on biomimetic apatite with coprecipitated LN was observed and even more stable than the positive control of LN coated tissue-culture treated polystyrene (TCP).</P><P><B>Conclusion</B></P><P>The simple and reproducible method of coprecipitation suggests that biomimetic apatite is an ideal carrier to functionalize materials with biological molecules for neural-related applications.</P>

Biomimetic Scaffolds for Tissue Engineering

Kim, Taek Gyoung,Shin, Heungsoo,Lim, Dong Woo WILEY‐VCH Verlag 2012 Advanced functional materials Vol.22 No.12

<P>Biomimetic scaffolds mimic important features of the extracellular matrix (ECM) architecture and can be finely controlled at the nano- or microscale for tissue engineering. Rational design of biomimetic scaffolds is based on consideration of the ECM as a natural scaffold; the ECM provides cells with a variety of physical, chemical, and biological cues that affect cell growth and function. There are a number of approaches available to create 3D biomimetic scaffolds with control over their physical and mechanical properties, cell adhesion, and the temporal and spatial release of growth factors. Here, an overview of some biological features of the natural ECM is presented and a variety of original engineering methods that are currently used to produce synthetic polymer-based scaffolds in pre-fabricated form before implantation, to modify their surfaces with biochemical ligands, to incorporate growth factors, and to control their nano- and microscale geometry to create biomimetic scaffolds are discussed. Finally, in contrast to pre-fabricated scaffolds composed of synthetic polymers, injectable biomimetic scaffolds based on either genetically engineered- or chemically synthesized-peptides of which sequences are derived from the natural ECM are discussed. The presence of defined peptide sequences can trigger in situ hydrogelation via molecular self-assembly and chemical crosslinking. A basic understanding of the entire spectrum of biomimetic scaffolds provides insight into how they can potentially be used in diverse tissue engineering, regenerative medicine, and drug delivery applications.</P>