Natural Biological Materials Research Articles

Bioinspired Design

Bioinspired design involves the use of concepts observed in natural biological materials in engineering design. The hope is that the leveraging of biological materials in the engineering domain can lead to many technological innovations and novel products. This work presents the initial material characterization of kinixys erosa tortoise shell using a combination of x-ray diffraction, optical/scanning electron microscopy and micro-mechanical testing. The results were used in the analytical/computational modelling of shell structures. The potential implications or the results were then discussed to give fundamental understanding of deformation and stress responses of shell structures

天然树木和竹子纤维材料的力学性能及仿生研究进展

Natural bio-fiber composites have the characteristics of simple elements and sophisticated structure, superior mechanical properties of high strength, high toughness and low coefficient of friction, and are the inspirational sources for the design of new materials. Biomimetic fiber composites have been widely used in modern industry. At present, studies of learning from the natural biological material structure-functional characteristics to manufacturing biomimetic structure—Functional integration material have originated lots of results, such as imitating wood porous ceramic material, imitating shell multi-layer composite materials and imitating bone porous scaffolds, etc. However, a lot of problems still exist, such as fiber is brittle and easy to be pulled out, the size selection of the whisker is difficult, the choice of ceramic matrix composite toughening methods is difficult, etc. To guide advanced biomimetic materials designs, it is important to reveal the relationships between the distribution, angle and density of cellulose, structure and binding mode of interface and the mechanical and frictional properties of the biological fiber composites. Wood and bamboo are the most common natural biological fiber composites which have excellent mechanical properties. They have been widely used in a variety of traditional architectural and ship parts. In this manuscript, recent researches on the mechanical properties of the wood and bamboo as the typical representatives of the natural biological fiber composites have been reviewed. The biomimetic composites of natural fiber materials have been briefly summarized. This tentative review might provide a reference for the design and preparation of biomimetic high strength, wear-resistant fiber composites. Trees and bamboo with excellent tribological properties relies not only on its internal structure, but also on its biological activity. If purely from a mechanical point of view to achieve the purpose of the bionic, it is difficult to obtain satisfactory results. Modern fiber composites in the rapid development process, often there is a big fiber brittle, difficult to interface design, easy to pull the fibers lead to enhanced failure whisker size selection difficult to choose the difficulty of ceramic matrix composites toughened approach the problem. Therefore, the application of bionic fiber reinforced composites toughened functional design principle, simulate biological fiber composite materials and structures excellent interface characteristics, is expected to further address the interface of chemical and physical properties of stability and strength of fiber composites tough problem, has important academic significance and application value.

Epoxy and succinic anhydride functionalized soybean oil for wood protection against UV light action

Wood is a versatile composite material consisting of natural macromolecules, including carbohydrates (cellulose, hemicelluloses) and lignin. As a natural biological material, wood undergoes photooxidation phenomena under environmental factors action. Colour modification of wood surface is a primary consequence of the photooxidation phenomena. One way to prevent wood photodegradation consists in coating it with protective layers by chemical modification of the surface. The aim of this study is related to the photostability evaluation of chemically modified softwood by successive treatment stages with succinic anhydride and epoxidized soybean oil, respectively, during exposure to UV radiation with wavelength above 280 nm. Wood and wood coated materials photooxidation was monitored in terms of colour and structural modification as functions of irradiation time and dose. Chromatic coordinates values exhibited a slow increase with irradiation time and dose compared to the values of unmodified wood. Lignin exhibited stronger photodegradation tendencies, leading mainly to an increase of redness feature of wood samples surface. The coating layer consisting of epoxidized soybean oil protected the modified wood surface against photooxidation reactions by a screening effect.

Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties.

Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials.

Remarkable shape memory effect of a natural biopolymer in aqueous environment

Remarkable water-stimulated shape memory effect was revealed in a natural biopolymer of peacock's tail covert feathers of which the innate shape can almost be fully recovered after severe deformation by a short hydration step. The shape memory effect manifests a good stability of high recovery rate and ratio during cycles of deformation and subsequent recovery. Both strength and energy absorption efficiency of medullary foam can be recovered despite the apparent decrease in the first deformation stroke caused by structural damage. A kinetic model developed from non-equilibrium thermodynamic fluctuation theory was adopted to describe the shape recovery process by considering the viscoelastic relaxation. The effects of hydration on mechanical properties, recovery kinetics, activation process and dynamic mechanical behaviors were also evaluated. Mechanisms were explored based on the lubrication, swelling effect and structural changes of macromolecular chains or segments in terms of their mobility. This study is expected to aid in understanding the responses of natural biological materials to environmental stimuli and to provide useful information for synthetic shape memory materials from the bio-inspiration perspective.

Nuclear-physical analysis methods in medical geology: Assessment of the impact of environmental factors on human health

The procedure for geomedical studies is outlined, and the niche occupied by the nuclear-physical analysis methods in these studies is pointed out. The necessity of construction of an efficient complex of the most modern analytical methods is demonstrated. The metrological parameters of methods applied in the analysis of natural environments and biological materials are evaluated. The current state of pollution of natural environments with heavy and toxic metals is characterized in two specific industrial hubs: the towns of Gus-Khrustalny and Podolsk. The levels of pollution of diagnostic biological materials (hair and blood) from children living in various urban districts are studied in the light of specific features of the manufacturing industry in these towns and the life environment of child population. The results of studies focused on evaluating the effect of environment on the health of child population are detailed. The actual damage to child health, their neuropsychic development and behavior, and the effect of socioeconomic factors are determined. Preventive problems among the child population exposed to lead and other toxic metals are evaluated, and ways to solve them are proposed. A system of early diagnosis and preventive measures for the mitigation of adverse effect of toxic metals (Pb, Cu, Mn, Zn, Cr, Ni, As, etc.) on the neuropsychic development of children is developed based on an actual ecogeochemical estimation of the state of the region under study.

Hydrogel Scaffold Fabricated by 3D Printing & Ultrasonic Spraying

This paper presents a novel strategy for fabricating hydrogel scaffold at ambient temperature by 3D printing supplemented with an ultrasonic spraying which involves crosslink reaction. The contradictory between the rheological properties and solidification of natural biological material for machinability and formability respectively at ambient temperature was solved. The gelled fraction and porosity were measured respectively to study the influence of crosslinking agent. The results showed that the two subjects appear a parabolic trend with the concentration of CaCl2 from 2% to 4%, but the tolerance of aperture decreases monotone.

The Application of Tissue Engineering and Biological Materials on Exercise-Induced Meniscus Injury

The development of tissue engineering provides a new way for the repair and reconstruction of meniscal injury. Using this technology to build a functional meniscus in the prevention of complications after meniscectomy has important significance. Because of the blood supply characteristics of the meniscus, meniscal injury caused no blood flow region do not have the ability to heal. The development of tissue engineering provides a new way for the repair and reconstruction of meniscal injury. The repair of meniscal scaffold materials more reports mainly include natural biological materials, synthetic materials, nanomaterials etc. The study of tissue engineering meniscus has achieved initial results, but are in the experimental stage of the scaffold material, there is no an ideal material. Therefore, the search for a good cell compatibility, controllable degradation rate and hot research has certain mechanical strength of scaffold materials is still the meniscus tissue engineering.

Anti-wear properties of the molluscan shell Scapharca subcrenata: Influence of surface morphology, structure and organic material on the elementary wear process

As a typical natural biological mineralisation material, molluscan shells have excellent wear-resistance properties that result from the interactions amongst biological coupling elements such as morphology, structure and material. The in-depth study of the wear-resistance performance of shells and the contribution made by each coupling element may help to promote the development of new bionic wear-resistant devices. The objective of this study was to investigate the influence of surface morphology (rib distribution on the shell), structure (rib coupled with nodules) and material (organic matter) on the anti-wear performance of the molluscan Scapharca subcrenata shell. The effect and contribution of each of these biological coupling elements were systematically investigated using the comparative experiment method. All three were found to exert significant effects on the shell's wear-resistance ability, and their individual contributions to that ability were revealed. Organic material can be classified as the principal coupling element, rib morphology as the secondary coupling element and the combined rib-nodule structure as the general coupling element.

Engineering Technology for Increasing Soybean Production And to Control Damping-off Disease using Biological Fertilization Mixture

Fall seedling diseases (damping-off) caused by Sclerotium rolfsii is one factor in low productivity of soybean in Indonesia, which may cause loss results achieved 30-75% depending on the level of attacks. Given the character of soil borne diseases (soil borne), then all control efforts through many obstacles, either because the pathogen can survive for decades in the form resistant propagules ( Sclerotium ) although there is no host for the development. This study aimed to find ways to control the disease by utilizing the potential of natural biological materials and find ways to get control for effective results. For this purpose the various steps of research has been conducted both in laboratory and greenhouse using experimental research design (completely randomized design) and F test to see the difference. The results show that in the first year of research proven to provide results tuba root extract is effective in controlling pathogens. Streptomyces isolates proved to be antagonistic to Sclerotium rolfsii , and when combined with mycorrhizae (AM) will be able to increase its effectiveness. Introduction of inoculum will likely increase their effectiveness when mixed directly into cropping land that can be done as a biological fertilizer just before planting. There is a tendency that the combination treatment between biopesticide will help the effectiveness of its control, though not necessarily affect the production, so the increase in soybean production is due to the protection of soybean from the dead early in the seedling that can suppress up to 50 percent compared with the control.

Water-responsive rapid recovery of natural cellular material

Insight into the stimuli–responsive behaviour of biological materials with hierarchical microstructures is essential for designing new sustainable materials and structures. Shape memory, self-healing and self-repairing will become valuable characteristics of advanced materials. Here we report the water-triggered shape recovery of a natural biological material, the luffa sponge. The longitudinally crushed luffa sponge column can recover up to 98% of its original shape after it is immersed in water. The mechanical properties of the luffa sponge can also be recovered, to a large extent, after a subsequent drying process. The effects of strain rate, crushing strains, loading cycles, and temperature/duration of water treatment of the drying process on the shape recovery ratio and the energy dissipation recovery ratio have been investigated. The results from this study have demonstrated that the luffa sponge material possesses remarkable shape memory effects and mechanical recovery features which could be exploited or biomimicked for the design of water-responsive smart materials undergoing large deformations.

Comparisons of Microstructures and Hardness Distribution between Clinocardium Californiense and Veined Rapa Whelk Shells

Abstract. Microstructures, phase compositions and microhardness distribution of two kinds of natural biological materials called Burnt-end Ark and Veined rapa whelk shells were studied and discussed for comparisons. It was found that the both shells present a hierarchical structure comprising three layers in thickness, i.e., inner, middle and outer layers. The inner and middle layers of the two kinds of shells exhibit cross-lamellar structures with somewhat of differences in the morphology and dimension. The outer layer presents a porous blocky structure for Burnt-end Ark shell and a layered structure for Veined rapa whelk shell. The X-ray diffraction (XRD) analyses show that all the layers of Burnt-end Ark shell as well as the inner and middle layers of Veined rapa whelk consist of crystalline aragonite CaCO3, while the out layer of Veined rapa whelk consists of crystalline calcite CaCO3. The microhardness measurements on the cross sections perpendicular to the growth lines of the shells demonstrate that the hardness of the both shells decreases gradually from the inner layer to the outer layer, strongly depending upon their microstructures.

Nanoscale Characterization of Reed Stalk Fiber Cell Walls

Reed (Phragmites australis) is a natural biological material that has great potential as reinforcing material in bio-composites. In order to evaluate the potential of reed stalk for reinforcement, the microstructure, elemental composition, microfibril angle (MFA), and mechanical properties of fiber cell walls were investigated by means of scanning probe microscopy (SPM), energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), and nanoindentation, respectively. The effects of elemental composition and microfibril angle of reed fibers on the mechanical properties were also considered. The results indicated that reed fiber cells have a multilayered structure. The observed increase in lignin content and decrease in MFA may contribute to the increase of mechanical properties. The elastic modulus and hardness of fibers in the upper part of the reed stalk were higher than those of the lower part. Based on nanoindentation results found in the literature, reed fibers have higher elastic modulus and hardness than poplar and spruce fibers.

Effect of Microstructure of Spongy Bone in Different Parts of Woodpecker’s Skull on Resistance to Impact Injury

Natural biological materials such as bone, teeth and nacre are nano‐composites of protein and mineral frequently exhibit highly superior strength for self‐assembly and nanofabrication. Mineral mass and microstructure/nanostructure of bone are susceptible to stimulation by mechanical loads, ensuring that its mechanical behavior and strength are adapted to environmental changes. Woodpeckers repeatedly drum tree trunks at a speed of 6‐7 m s−1 and acceleration of ~1000 g with no head injuries. The uneven distribution of spongy bone has been founded on woodpecker′s skull in our previous study. More knowledge of the distribution of the shock‐absorbing spongy bone could be incorporated into the design of new safety helmets, sports products, and other devices that need to be able to resist the impact. In this study, the effect of microstructure of spongy bone in different parts on woodpecker’s skull compared with other birds was observed and analyzed. It was found that the unique coordinate ability of micro‐parameters in different parts of woodpecker’s skull could be one of the most important roles of its resistance to impact injury. Better understanding of the materials would provide new inspirations of shock‐absorbing composite materials in engineering.

Manufacture and Mechanical Properties of Biocomposite Made of Reed and Silvergrass

Reed and sivergrass are natural biological materials, the process parameters of being used as raw materials of biocomposite were determined. Microscopic structure of reed and silvergrass was characterized by environment scanning electron microscopy. Best reed-silvergrass particleboard process parameters were drawn from orthogonal test, that adhesive addition is 14%, press temperature is 1800C, and press time is 7min. The effects of reed/silvergrass particles mixing ratio on mechanical properties of reed-sivergrass particleboard were also discussed, mechanical properties of reed-silvergrass particleboard reached the maximum value at reed/silvergrass particles mixing ratio 3/2.

Elemental Analysis of Reed and Manufacture of Composites Using Mixture of Reed and Poplar

Reed is a natural biological material and has great potential as reinforced material in bio-composites.The morphology and element contents of reed stem were investigated using scanning electronic microscopy equipped with energy dispersive spectrometer (SEM/EDS). And the effects of the mass mixing ratio of reed and poplar particles, dosage of water repellent on the physical and mechanical properties of reed/poplar composites were determined. Results indicated that the outside surface of reed stem has high silica content.The mass mixing ratio of 6:4 or 5:5 resulted in an optimum reed/poplar products. As the mass mixing ratio ranged from 4:6 to 10:0, the composites could be produced without adding additional water repellent. Therefore, it is possible to manufacture qualified reed/poplar composites by using urea-formaldehyde resin.

A modified analysis for thermal–mechanical properties of staggered structure in biomimetic materials

The thermal–mechanical stress distributions and equivalent coefficient of thermal expansion (CTE) of the staggered arrangement of mineral platelets wrapped by soft matrix are analyzed, which exist in numerous natural biological and biomimetic materials. Two analytical models, ‘Stress model’ and ‘Displacement model’, were established from the ways of stress and displacement solution based on the modification of classical shear-lag model. Complementary finite element analysis (FEA) was used to verify the analytical models. Results reveal that, compared to ‘Displacement model’, ‘Stress model’ gives a better prediction of the stress distributions within the staggered structure referring to FEA. The equivalent CTE predicted by both models reach constant as the aspect ratio and volume fraction of platelets exceeding the critical values. Nevertheless, the relative error between the results from different models increases with the increase of the ratio of overlap to length of platelets. These provide a benchmark to the optimum design of micro/nano-structure in bio-inspired materials suffering to temperature fluctuation and applied loading.

Preparation and certification of mussel reference material for organochlorine pesticides and polychlorinated biphenyls using isotope dilution-high resolution mass spectrometry

A method for the preparation and certification of the reference material of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in mussel tissue is described. The mussel tissue from Dalian Bay was frozen-dried, comminuted, sieved, homogenized, packaged, and sterilized by 60Co radiation sterilization in turn. The certified values for 18 OCPs and 16 PCBs were determined by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) using isotope dilution and internal standard quantitation techniques. The certified values were validated and given based on seven accredited laboratories, and these values are traceable to the SI (international system of units) through gravimetrically prepared standards of established purity and measurement intercomparisons. The certified values of PCBs and OCPs in mussel span 4 orders of magnitude with a relative uncertainty of about 10%. This material is a natural biological material with confirmed good homogeneity and stability, and it was approved as the grade "primary reference material" (GBW10069) in June 2012 in China. This reference material provided necessary quality control products for our country to implement the Stockholm Treaty on the monitoring of persistent organic pollutants (POPs). The material is intended to be used for the method validation and quality control in the determination of OCPs and PCBs in biota samples.

Research Progress on Tissue Engineering of Neural Stem Cells

Neural stem cells (NSCs), as therapeutic agents, play the key role in the treatment of central nervous system (CNS) disorders. It is a researching tendency for promote proliferation and differentiation of neural stem cells by using tissue engineering. It is discovered that joint use neural stem cells and NSCs-seeded scaffold may increase the cell survival state and better control cellular microenvironment. We find suitable material include natural biological materials, synthetic materials, compound materials, bio-derived materials and 3D-materials of neural stem cells tissue engineering by analyzing and summing up of the research which combine tissue engineering with NSCs transplant in past several years. It hold out a hope of the possibility of utilizing the treatment of neural stem cells transplantation with tissue engineering, and there has been a great quantity of achievements on the research of it to treat CNS disorders by promote proliferation and differentiate.

Biomaterials‐Based Electronics: Polymers and Interfaces for Biology and Medicine

Advanced polymeric biomaterials continue to serve as a cornerstone for new medical technologies and therapies. The vast majority of these materials, both natural and synthetic, interact with biological matter in the absence of direct electronic communication. However, biological systems have evolved to synthesize and utilize naturally-derived materials for the generation and modulation of electrical potentials, voltage gradients, and ion flows. Bioelectric phenomena can be translated into potent signaling cues for intra- and inter-cellular communication. These cues can serve as a gateway to link synthetic devices with biological systems. This progress report will provide an update on advances in the application of electronically active biomaterials for use in organic electronics and bio-interfaces. Specific focus will be granted to covering technologies where natural and synthetic biological materials serve as integral components such as thin film electronics, in vitro cell culture models, and implantable medical devices. Future perspectives and emerging challenges will also be highlighted.