Properties Of Biological Materials Research Articles

Review of the Low-Temperature Acoustic Properties of Water, Aqueous Solutions, Lipids, and Soft Biological Tissues.

Existing data on the acoustic properties of low-temperature biological materials is limited and widely dispersed across fields. This makes it difficult to employ this information in the development of ultrasound applications in the medical field, such as cryosurgery and rewarming of cryopreserved tissues. In this review, the low-temperature acoustic properties of biological materials, and the measurement methods used to acquire them were collected from a range of scientific fields. The measurements were reviewed from the acoustic setup to thermal methodologies for samples preparation, temperature monitoring, and system insulation. The collected data contain the longitudinal and shear velocity, and attenuation coefficient of biological soft tissues and biologically relevant substances-water, aqueous solutions, and lipids-in the temperature range down to -50 °C and in the frequency range from 108 kHz to 25 MHz. The multiple reflection method (MRM) was found to be the preferred method for low-temperature samples, with a buffer rod inserted between the transducer and sample to avoid direct contact. Longitudinal velocity changes are observed through the phase transition zone, which is sharp in pure water, and occurs more slowly and at lower temperatures with added solutes. Lipids show longer transition zones with smaller sound velocity changes; with the longitudinal velocity changes observed during phase transition in tissues lying between these two extremes. More general conclusions on the shear velocity and attenuation coefficient at low-temperatures are restricted by the limited data. This review enhance knowledge guiding for further development of ultrasound applications in low-temperature biomedical fields, and may help to increase the precision and standardization of low-temperature acoustic property measurements.

Principal component analysis in application to Brillouin microscopy data

Brillouin microscopy has recently emerged as a new bio-imaging modality that provides information on the microscale mechanical properties of biological materials, cells and tissues. The data collected in a typical Brillouin microscopy experiment represents the high-dimensional set of spectral information, i.e. each pixel within a 2D/3D Brillouin image is associated with hundreds of points of spectral data. Its analysis requires non-trivial approaches due to subtlety in spectral variations as well as spatial and spectral overlaps of measured features. This article offers a guide to the application of Principal Component Analysis (PCA) for processing Brillouin imaging data. Being unsupervised multivariate analysis, PCA is well-suited to tackle processing of complex Brillouin spectra from heterogeneous biological samples with minimal a priori information requirements. We point out the importance of data pre-processing steps in order to improve outcomes of PCA. We also present a strategy where PCA combined with k-means clustering method can provide a working solution to data reconstruction and deeper insights into sample composition, structure and mechanics.

Quantifying local stiffness and forces in soft biological tissues using droplet optical microcavities

Mechanical properties of biological tissues fundamentally underlie various biological processes and noncontact, local, and microscopic methods can provide fundamental insights. Here, we present an approach for quantifying the local mechanical properties of biological materials at the microscale, based on measuring the spectral shifts of the optical resonances in droplet microcavities. Specifically, the developed method allows for measurements of deformations in dye-doped oil droplets embedded in soft materials or biological tissues with an error of only 1 nm, which in turn enables measurements of anisotropic stress inside tissues as small as a few pN/μm2. Furthermore, by applying an external strain, Young's modulus can be measured in the range from 1 Pa to 35 kPa, which covers most human soft tissues. Using multiple droplet microcavities, our approach could enable mapping of stiffness and forces in inhomogeneous soft tissues and could also be applied to in vivo and single-cell experiments. The developed method can potentially lead to insights into the mechanics of biological tissues.

Effect of Ultrasonic-Assisted Enzymolysis on Protein, Phenolic Content, and Antioxidant Activity of Chlorella sp. Crude Extract

Chlorella sp. microalgae is a potential source of natural antioxidants and other bioactive compounds used in the food and pharmaceutical industries. Ultrasound pretreatments followed by enzymolysis are widely used to improve the functional properties of biological materials. This work aimed to investigate the effects of ultrasound pretreatments followed by bromelain hydrolysis on the proteins, phenolic content, and antioxidant activity of Chlorella sp. crude extract. The experimental design for the study involved two factors: ultrasound pretreatment time (0, 5, and 10 min) and bromelain hydrolysis time (0, 2, 4, and 6 hours). The protein was measured using Lowry assay while the total phenolic content was measured using a Folin–Ciocalteu assay. The highest protein content (7.09 ± 0.44 mg/mL) and phenolic concentrations (0.28 ± 0.01 ìg/mL) were obtained at 5 min ultrasound pretreatment and 6 hours enzymolysis. For antioxidant activity, 5 min ultrasound pretreatment followed by 4 hours of enzymolysis resulted in the highest DPPH (1,1-diphenyl-2-picrylhydrazyl radical) inhibitory activity (81.74%). Meanwhile, ultrasound pretreatment for 10 min followed by 6 hours of enzymolysis resulted in the highest ABTS (2,20 azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) inhibitory activity (94.10%). This study showed that variation in ultrasound pretreatments followed by bromelain hydrolysis could be used to improve the protein content, phenolic content, and antioxidant activity of Chlorella sp. crude extract.

Principle and applications of near‐infrared imaging for fruit quality assessment—An overview

SummaryThe quality (i.e. the degree of excellence and acceptance to the consumer) evaluation and safety of fruit and other agricultural products is by far the main challenging task in the food industries. Hence, the development of efficient non‐invasive, real‐time and rapid‐quality assessment tools and techniques is the need of the hour. This review paper aims to provide the basic or fundamental knowledge regarding the principle, potential and application of near‐infrared imaging‐based computer vision systems. Non‐invasive technologies, based on optical properties, are the most applicable and important for real‐time quality assessment. Absorption, reflection and scattering before the transmission of incident light are phenomenon properties of biological materials. The principle and application of NIR imaging (i.e. medical imaging) in agriculture for quality detection were studied from various published research papers. Thus, collected pieces of information are summarised, concluded and discussed in a unique way in this report. The NIR spectrum of electromagnetic waves has some basic benefits of light penetration into the upper layer and makes visualisation of the targeted area of objects. Several studies have proved that the non‐destructive system based on visible and non‐visible imaging in combination has a significant role in quality defect detection in fruits. In NIR imaging, the artefacts caused by light illumination can be reduced and it will help in the visualisation of biological tissues and hidden defects just below the peel.

The Mechanical, Thermal, and Biological Properties of Materials Intended for Dental Implants: A Comparison of Three Types of Poly(aryl-ether-ketones) (PEEK and PEKK).

Regarding the dynamic development of 3D printing technology, as well as its application in a growing part of industries, i.e., in the automotive industry, construction industry, medical industry, etc., there is a notable opportunity for its application in producing dental implants, which presents a promising alternative to traditional implant manufacturing methods. The medical industry is very restrictive regarding the applied materials, and it is necessary to use materials that exhibit very good mechanical and thermal parameters, show clinical indifference and biocompatibility, are non-allergenic and non-cancerous, and are likely to sterilize. Such materials are poly(aryl-ether-ketone)s (PAEK)s, mainly poly(ether-ether-ketone) (PEEK) and poly(ether-ketone-ketone) (PEKK), that are found to be high-performance polymers and can be defined as materials that retain their functionality even in extreme conditions. In the present paper, two types of PEEKs and PEKK were compared regarding their structural, mechanical, and thermal properties along with the biological activity toward selected strains. The tested samples were obtained with Fused Deposition Modeling (FDM) technology. The PEKK, after heat treatment, exhibits the most promising mechanical properties as well as less bacterial adhesion on its surface when compared to both PEEKs. Consequently, among the evaluated materials, PEKK after heat treatment stands out as the optimal selection for a dental prosthesis.

The energy dissipation property in bioinspired staggered composites with the viscoelastic matrix

Many biological materials, such as bone and nacre, exhibit remarkable combinations of stiffness, strength, toughness, and impact resistance over millions of years of evolution. They provide prototypes for designing high-performance artificial composites. However, the dynamic properties of biological materials under impact loading are still not clear. In this study, we establish a dynamic shear-lag model to explore the dynamic response and the energy dissipation capacity of bioinspired staggered composites with a viscoelastic matrix under impact loading. The time domain solution of the dynamic shear-lag model is derived. Then, the model is verified by comparing it with the results from the finite element method. The results demonstrate that matrix viscosity plays a significant role in dissipating the impact energy and enhances the wave transformation between adjacent tablets. Furthermore, there exists an optimal viscosity coefficient to achieve an excellent balance between the rate and efficiency of energy dissipation. The model and the results can not only reveal the energy dissipation property of biological materials but also provide guidelines for the design and optimization of high-performance composites.

Construction of Wearable Touch Sensors by Mimicking the Properties of Materials and Structures in Nature.

Wearable touch sensors, which can convert force or pressure signals into quantitative electronic signals, have emerged as essential smart sensing devices and play an important role in various cutting-edge fields, including wearable health monitoring, soft robots, electronic skin, artificial prosthetics, AR/VR, and the Internet of Things. Flexible touch sensors have made significant advancements, while the construction of novel touch sensors by mimicking the unique properties of biological materials and biogenetic structures always remains a hot research topic and significant technological pathway. This review provides a comprehensive summary of the research status of wearable touch sensors constructed by imitating the material and structural characteristics in nature and summarizes the scientific challenges and development tendencies of this aspect. First, the research status for constructing flexible touch sensors based on biomimetic materials is summarized, including hydrogel materials, self-healing materials, and other bio-inspired or biomimetic materials with extraordinary properties. Then, the design and fabrication of flexible touch sensors based on bionic structures for performance enhancement are fully discussed. These bionic structures include special structures in plants, special structures in insects/animals, and special structures in the human body. Moreover, a summary of the current issues and future prospects for developing wearable sensors based on bio-inspired materials and structures is discussed.

Particle Network Self-Assembly of Similar Size Sub-Micron Calcium Alginate and Polystyrene Particles Atop Glass.

Particle-mediated self-assembly, such as nanocomposites, microstructure formation in materials, and core-shell coating of biological particles, offers precise control over the properties of biological materials for applications in drug delivery, tissue engineering, and biosensing. The assembly of similar-sized calcium alginate (CAG) and polystyrene sub-micron particles is studied in an aqueous sodium nitrate solution as a model for particle-mediated self-assembly of biological and synthetic mixed particle species. The objective is to reinforce biological matrices by incorporating synthetic particles to form hybrid particulate networks with tailored properties. By varying the ionic strength of the suspension, the authorsalter the energy barriers for particle attachment to each other and to a glass substrate that result from colloidal surface forces. The particles do not show monotonic adsorption trend to glass with ionic strength. Hence, apart from DLVO theory-van der Waals and electrostatic interactions-the authors further consider solvation and bridging interactions in the analysis of the particulate adsorption-coagulation system. CAG particles, which support lower energy barriers to attachment relative to their counterpart polystyrene particles, accumulate as dense aggregates on the glass substrate. Polystyrene particles adsorb simultaneously as detached particles. At high electrolyte concentrations, where electrostatic repulsion is largely screened, the mixture of particles covers most of the glass substrate; the CAG particles form a continuous network throughout the glass substrate with pockets of polystyrene particles. The particulate structure is correlated with the adjustable energy barriers for particle attachment in thesuspension.

In Situ Nanoindentation at Elevated Humidities

AbstractNanoindentation is one of the most widespread methods to measure the mechanical performance of complex materials systems. As it allows for local characterization of composite architectures with sub‐micron spatial features and a large range of properties, nanoindentation is commonly used to measure the properties of biological materials. In situ nanoindentation, a further development of the approach, is a powerful tool for the analysis of plastic deformation and failure of materials. Here, samples can be mechanically manipulated using the indenter, while their behavior is monitored with the resolution of a scanning electron microscope (SEM). Indeed, numerous studies demonstrate the potential of this approach for studying the most fundamental material characteristics. However, so far, these measurements are performed in high‐vacuum conditions inherent to the conventional electron microscopy method, which are irrelevant when studying biological structures that evolved to perform in hydrated conditions. In this work, the ability to conduct nanoindentation experiments under controlled humidity and temperature inside an environmental SEM is developed. This technique has the potential to become crucial for materials design and characterization in many domains where humidity has a significant impact on performance. These include organic/polymer systems, microelectronic and optoelectronic devices, materials for catalysis, batteries, and many more.

Atomic Force Microscopy Methods to Measure Tumor Mechanical Properties

Atomic force microscopy (AFM) is a popular tool for evaluating the mechanical properties of biological materials (cells and tissues) at high resolution. This technique has become particularly attractive to cancer researchers seeking to bridge the gap between mechanobiology and cancer initiation, progression, and treatment resistance. The majority of AFM studies thus far have been extensively focused on the nanomechanical characterization of cells. However, these approaches fail to capture the complex and heterogeneous nature of a tumor and its host organ. Over the past decade, efforts have been made to characterize the mechanical properties of tumors and tumor-bearing tissues using AFM. This has led to novel insights regarding cancer mechanopathology at the tissue scale. In this Review, we first explain the principles of AFM nanoindentation for the general study of tissue mechanics. We next discuss key considerations when using this technique and preparing tissue samples for analysis. We then examine AFM application in characterizing the mechanical properties of cancer tissues. Finally, we provide an outlook on AFM in the field of cancer mechanobiology and its application in the clinic.

Surface quality investigation in surfactant-based EDM of Inconel 617 using deep cryogenically treated electrodes

Surface quality governs the physical, mechanical, tribological, physio-chemical, and biological properties of materials. Considering the excellent mechanical characteristics of Inconel 617 and the nature of its intended applications, electric discharge machining is generally engaged. However, there is still a need to uplift the surface quality of machined parts to improve their working life and performance. Therefore, this study revealed the potential of deep cryogenically treated (DCT) electrodes under dielectrics modified with span and tween in the said context using a full factorial experimental design. Experimental findings are deeply investigated by employing 3D surface profilometry, scanning electron, and optical microscopy. Cryogenically treated electrode(s) have demonstrated a better surface quality in comparison to the non-treated electrodes, such as DCT Cu has provided a 25.5% lower roughness value than non-treated Cu. Referring to the role of additives, there exists a reduction of 32.5% in roughness when DCT brass is used instead of typical brass using a mixture of span-20 (S-20) and kerosene as a dielectric. The surface finish given by the cryogenically treated brass is 18.99% better when compared to the average value given by all cryogenically treated electrodes considered in this study. It has also been revealed that tween-based dielectrics gave 83% better surface finish than span-based dielectrics with DCT electrodes.

Micropattern lamination improving piezoelectric coefficient of bio-membrane for multifunctional single-electrode devices

Natural bio-piezoelectric materials are of great concern as energy harvesters and sensors for their inherent nontoxicity, excellent biocompatiblility and biodegradability. Nevertheless, the piezoelectric coefficient of these materials are much lower than that of organic/inorganic piezoelectric material. Therefore, it is necessary to strengthen the research on improving the piezoelectric properties of biological materials to promote their practical application. In this study, the natural bio-membrane of hog casings composed of a large number of orderly layer-by layer collagen fibers were proposed as a bio-piezoelectric material for the multifunctional single-electrode devices, with emphasis on strengthening the piezoelectric coefficient of the bio-membrane from 5.3 to 13.1 pC N−1 based on a facile micropattern lamination method. The hog casings between different pieces formed interlock with the gaps between collagen fibers, and polypeptide chains were interconnected with hydrogen bonds by the surface functional groups, which made the lamination expand the accumulated stress and electric dipole moment. Moreover, the single-electrode mode adopted in the piezoelectric device could effectively avoid the risk of short circuit and kept on providing continuous power partially cracked, which was particularly important in power supply equipment in human body. The bio-membrane based piezoelectric device exhibited good piezoelectric performance, stability and durability in the explored applications.

Bioinspired Textiles; Observations from the Evaluation of a Novel Practice-Based Framework Linking Lessons on Sustainable/Circular Design from Biology to Textile Practice

This paper presents initial findings from the evaluation of the BIT design framework and potential impacts on the usage of resources (substance and energy) during the design and manufacture of textile products. The Bio-inspired Textile (BIT) design framework was created to understand if and how lessons from the structures and properties of biological materials could help textile designers enhance the efficiency, longevity, and recovery of resources within their practice. The framework’s key objective was to enable the flow of information on the function/structure relationship of biological materials, generated by material scientists, into guidance for textile designers on implementing these new perspectives into their practice. To test the BIT design framework, we recruited fourteen professional textile Makers to participate in a collaborative design project and help us study the impact of the BIT framework on their individual practice. We collected reflections and critical feedback at key points during the collaboration via surveys, interviews and analysis of the physical artefacts produced by the Makers during the collaboration. The data was analysed using a mixed methods approach. Our findings suggest that the BIT framework, in its current format, primarily enhances design for resource efficiency and recovery by promoting practical, mono-material strategies that could help address the obstacles for reclaiming the substances captured within a product by either mechanical or chemical means. The framework also appears to facilitate the consolidation of two or more processing steps along the value chain, which presents potential in reducing the effort (energy) required to produce a particular product. Longevity is supported via multifunctional design strategies introduced by more complex biological systems such as muscular hydrostats.

Effects of Hyperlipidemia on Osseointegration of Dental Implants and Its Strategies

Hyperlipidemia refers to the abnormal increase in plasma lipid level exceeding the normal range. At present, a large number of patients require dental implantation. However, hyperlipidemia affects bone metabolism, promotes bone loss, and inhibits the osseointegration of dental implants through the mutual regulation of adipocytes, osteoblasts, and osteoclasts. This review summarized the effects of hyperlipidemia on dental implants and addressed the potential strategies of dental implants to promote osseointegration in a hyperlipidemic environment and to improve the success rate of dental implants in patients with hyperlipidemia. We summarized topical drug delivery methods to solve the interference of hyperlipidemia in osseointegration, which were local drug injection, implant surface modification and bone-grafting material modification. Statins are the most effective drugs in the treatment of hyperlipidemia, and they also encourage bone formation. Statins have been used in these three methods and have been found to be positive in promoting osseointegration. Directly coating simvastatin on the rough surface of the implant can effectively promote osseointegration of the implant in a hyperlipidemic environment. However, the delivery method of this drug is not efficient. Recently, a variety of efficient methods of simvastatin delivery, such as hydrogels and nanoparticles, have been developed to boost bone formation, but few of them were applied to dental implants. Applicating these drug delivery systems using the three aforementioned ways, according to the mechanical and biological properties of materials, could be promising ways to promote osseointegration under hyperlipidemic conditions. However, more research is needed to confirm.

Comparison of methods to explore the morphology and granulometry of biological particles with complex shapes: Interpretation and limitations

The particle size and morphology of the particles represent key factors that significantly influence the physicochemical properties of biological materials and suspensions, the transport phenomena inside the bioreactors and consequently the bioperformances. Many in-situ and ex-situ techniques are used to characterize the distribution functions of these properties. However, each method has its own advantages and disadvantages in defined conditions, and some differences may exist between methods resulting in variations and deviations of morphological measurements. This article aims to compare five different techniques (morphogranulometry MG, laser light diffraction LLD, flow cytometry CYT, settling velocity TSL, and focused beam reflectance measurement FBRM) used to characterize the morphology and granulometry of biological matrices with increasing complexity (model spherical particles, elongated yeast cells, and complex lignocellulosic substrates). The results and their interpretations highlighted several critical and limiting points: principles of measurement, technological and metrological specifications, identification of relevant parameters (diameter, shape), choice of distribution functions (number, volume), and statistical comparisons of populations. The results and their interpretations pointed out several critical points and limitations: principles of measurement, technological and metrological specifications, identification of pertinent parameters (diameter, shape), choice of distribution functions (number, volume), and statistical comparisons of populations. Granulometric methods may hide the complexity of diameter definitions. Examining shape parameters is richer than granulometry, and more complex descriptors (length, width, aspect ratio …) could be addressed. However, all these techniques enable to describe and interpret the observed phenomena (dimorphism, enzymatic hydrolysis) considering either absolute or relative data. • Set of techniques were applied to compare biological materials with complex shapes. • All techniques enable to describe and interpret the observed phenomena. • Limitations of each technique complicate the choice of the most suitable method. • A combinatorial characterization approach is often preferred. • A single parameter remains insufficient to depict the morphological complexity.

Design of hierarchical lattice structures attainable by additive manufacturing techniques

Readiness of new materials that are simultaneously lightweight, damage-resistant, multifunctional, and sustainable is a primary need for many technology sectors. Thanks to additive manufacturing, lattice materials appear to be ideal candidates to meet this challenge. By designing their unit cells and structural organization, multiscale materials with unique combinations of properties can be obtained. Nevertheless, many gaps remain to be filled for their effective and efficient design. Nature, exploiting hierarchical architectures on a material scale, actually amplifies the properties of biological materials and combines them in ways we cannot achieve yet in synthetic materials. In materials design, we are still far from such a level of perfection. To narrow this gap and expand the current knowledge on the effects of hierarchy on the mechanical behaviour of materials, we numerically studied the mechanical response of 3D hierarchical lattice specimens under a four-point bending loading scenario. For this, we selected two types of unit cells with different structural behaviour and combined them together into different specimen topologies. The results show that, through hierarchy, it is possible to tailor lattice material performances, achieving benefits in terms of both specific mechanical properties and multifunctionality. The evidence found opens new horizons for applications such as heat exchangers, mechanical filters, scaffolds, energy storage, and packaging.

An Overview of Electron Accelerator Applications in Environmental Protection with an Emerging Pollutants Decomposing approach

Bachground: In recent years, problems related to environmental damage and natural resource degradation are receiving increased attention from researchers throughout the world. This occurs mostly, through un-eco-friendly technology used to produce industrial products. Therefore, eco-friendly science and technology (green technology) which can empower and control the existing coal power plant for the virtue of society and the earth is required. Today, the design and application of electron accelerator has been well developed due to reliability, larger capacity, greater energy range, and cost reduction. Technologies that use particle accelerators are considered critical to advance high-tech processes in various economic fields, including material processing, sterilization of medical products, environmental protection, medicine, cargo inspection, chemical analysis, nuclear energy, etc. High-energy and high-power beams pose the ability to alter the physical, chemical, and biological properties of materials on an industrial scale. This technology has received more attention than other conventional treatment methods due to the need for smaller areas, high electrical efficiency, and production of by-products such as fertilizers. The electronic beam process in the treatment of off-gas, wastewater, and sludge, as well as the decomposition of emerging contaminants, is mentioned as a non-chemical, additive-free process that uses radiolysis to effectively decompose contaminants. The literature addresses various applications of electron accelerators in order to modify the physical, chemical, or biological properties of industrial pollutants in the liquid, solid, and gas phases through treatment by ionizing radiation to control environmental pollution. Many advantages can be achieved through this method, which is known as radiation processing.

Correlation of the DNA Concentration of Human Samples to Electrical Bioimpedance Measurements: A Pilot Study.

It is necessary to evaluate the total deoxyribonucleic acid (DNA) concentration in gene expression assays. The existing techniques require equipment that is expensive for many labs in developing countries. Portable and inexpensive equipment is needed for easy and economical DNA quantification. Electrical bioimpedance spectroscopy (EBiS) is a non-invasive and inexpensive technique for examining the electrical properties of biological materials. The aim of this study was to explore a potential correlation between the measurement of total DNA extracted from human samples by UV-Vis spectrophotometry and EBiS. Hence, after quantifying the total DNA extracted from each sample by UV-Vis spectroscopy, EBiS was recorded and a possible correlation between the two measurements was analyzed. Considering the bioimpedance phase parameter at 5.24 MHz, a significant correlation was found with total DNA, especially when the concentration was below 100 ng/μL (Spearman coefficient = 0.82, p<0.005). Additional experiments are warranted to confirm these findings.

Determining Spatial Variability of Elastic Properties for Biological Samples Using AFM.

Measuring the mechanical properties (i.e., elasticity in terms of Young's modulus) of biological samples using Atomic Force Microscopy (AFM) indentation at the nanoscale has opened new horizons in studying and detecting various pathological conditions at early stages, including cancer and osteoarthritis. It is expected that AFM techniques will play a key role in the future in disease diagnosis and modeling using rigorous mathematical criteria (i.e., automated user-independent diagnosis). In this review, AFM techniques and mathematical models for determining the spatial variability of elastic properties of biological materials at the nanoscale are presented and discussed. Significant issues concerning the rationality of the elastic half-space assumption, the possibility of monitoring the depth-dependent mechanical properties, and the construction of 3D Young's modulus maps are also presented.