Biomimetics, Volume 7, Issue 2 (June 2022) – 50 articles

In this paper, the main features of systems that are required to flexibly modulate energy states of plant cells in response to environmental fluctuations are surveyed and summarized. Plant cells possess multiple sources (chloroplasts and mitochondria) to produce energy that is consumed to drive many processes, as well as mechanisms that adequately provide energy to the processes with high priority depending on the conditions. Such energy-providing systems are tightly linked to sensors that monitor the status of the environment and inside the cell. In addition, plants possess the ability to efficiently store and transport energy both at the cell level and at a higher level. Furthermore, these systems can finely tune the various mechanisms of energy homeostasis in plant cells in response to the changes in environment, also assuring the plant survival under adverse environmental conditions. Electrical power systems are prone to the effects of environmental changes as well; furthermore, they are required to be increasingly resilient to the threats of extreme natural events caused, for example, by climate changes, outages, and/or external deliberate attacks. Starting from this consideration, similarities between energy-related processes in plant cells and electrical power grids are identified, and the potential of mechanisms regulating energy homeostasis in plant cells to inspire the definition of new models of flexible and resilient electrical power grids, particularly microgrids, is delineated. The main contribution of this review is surveying energy regulatory mechanisms in detail as a reference and helping readers to find useful information for their work in this research field. Full article

Many animals have protective anatomical structures that allow for growth and flexibility; these structures contain thin seams called sutures that help the structure to absorb impacts. In this study, we parameterized the stiffness and toughness of a curved archway structure based on three geometric properties of a suture through finite element, quasi-static, three-point bending simulations. Each archway consisted of two symmetric pieces linked by a dovetail suture tab design. The three parameters included suture tab radii (1–5 mm), tangent lengths (0–20 mm), and contact angles (0–40°). In the simulations, a steel indenter was displaced 6.5 mm to induce progressive tab disengagement. Sutures with large contact angles and large tangent lengths generally led to stiffer and tougher structures. Sutures with a small tab radius exhibited the most sensitivity to the input parameters, and the smallest tab radius led to the stiffest and toughest archways. Results suggested that it was a combination of the largest number of tab repeats with the largest possible contact surface area that improved the mechanical response of the archway. The study revealed several suture geometries that hold significant promise, which can aid in the development of hemispherical 3D structures for dynamic impact applications. Full article

Research indicates that deaths due to fall incidents are the second leading cause of unintentional injury deaths in the world. Death by fall due to a person texting or talking on mobile phones while walking, impaired vision, unexpected terrain changes, low balance, weakness, and chronic conditions has increased drastically over the past few decades. Particularly, unexpected terrain changes would many times lead to severe injuries and sometimes death even in healthy individuals. To tackle this problem, a warning system to alert the person of the imminent danger of a fall can be developed. This paper describes a solution for such a warning system used in our bio-inspired wearable pet robot, KiliRo. It is a terrain perception system used to classify the terrain based on visual features obtained from processing the images captured by a camera and notify the wearer of terrain changes while walking. The parrot-inspired KiliRo robot can twist its head and the camera up to 180 degrees to obtain visual feedback for classification. Feature extraction is followed by K-nearest neighbor for terrain classification. Experiments were conducted to establish the efficacy and validity of the proposed approach in classifying terrain changes. The results indicate an accuracy of over 95% across five terrain types, namely pedestrian pathway, road, grass, interior, and staircase. Full article

In this paper, reverse engineering technique was employed to extract the ridges of the hoof ball contour, and hoof ball tissue structure was analyzed based on the bionic prototype of goat hooves. The quantified geometric features were used to design the bionic track shoe pattern, which can enhance its adhesive performance and solve the problem that agricultural tracked vehicles in hilly and mountainous areas are prone to slip due to poor adhesive performance. The monolithic structure of the biomimetic goat hoof track shoe pattern and the ordinary one-line track pattern were arranged and combined; they included six kinds of track shoe models and the adhesive performance was compared. A discrete element system was established based on soil parameter determination to compare the maximum adhesion of different track shoe models. The bionic track shoe samples were prepared for soil bin tests to verify the reliability of the discrete element analysis results. Compared with the ordinary track shoe, the adhesion of the optimal bionic track shoe was improved by 9.1%. Full article

The rate of incidentally detected pancreatic cystic lesions (PCLs) has increased over the past decade and was recently reported at 8%. These lesions pose a unique challenge, as each subtype of PCL carries a different risk of malignant transformation, ranging from 0% (pancreatic pseudocyst) to 34–68% (main duct intraductal papillary mucinous neoplasm). It is imperative to correctly risk-stratify the malignant potential of these lesions in order to provide the correct care course for the patient, ranging from monitoring to surgical intervention. Even with the multiplicity of guidelines (i.e., the American Gastroenterology Association guidelines and Fukuoka/International Consensus guidelines) and multitude of diagnostic information, risk stratification of PCLs falls short. Studies have reported that 25–64% of patients undergoing PCL resection have pancreatic cysts with no malignant potential, and up to 78% of mucin-producing cysts resected harbor no malignant potential on pathological evaluation. Clinicians are now incorporating artificial intelligence technology to aid in the management of these difficult lesions. This review article focuses on advancements in artificial intelligence within digital pathomics, radiomics, and genomics as they apply to the diagnosis and risk stratification of PCLs. Full article

Existing research on mycelium-based materials recognizes the binding capacity of fungal hyphae. Fungal hyphae digest and bond to the surface of the substrate, form entangled networks, and enhance the mechanical strength of mycelium-based composites. This investigation was driven by the results of an ongoing project, where we attempt to provide basic concepts for a broad application of a mycelium and chipped wood composite for building components. Simultaneously, we further explore the binding capacity of mycelium and chipped wood composites with a series of experiments involving different mechanical interlocking patterns. Although the matrix material was analyzed on a micro-scale, the samples were developed on a meso-scale to enhance the bonding surface. The meso-scale allows exploring the potential of the bio-based material for use in novel construction systems. The outcome of this study provides a better understanding of the material and geometrical features of mycelium-based building elements. Full article

Minimally invasive endovascular embolization is a widely used clinical technique used for the occlusion of blood vessels to treat various diseases. Different occlusive agents ranging from gelatin foam to synthetic polymers such as poly(vinyl alcohol) (PVA) have been commercially used for embolization. However, these agents have some drawbacks, such as undesired toxicity and unintended and uncontrolled occlusion. To overcome these issues, several polymer-based embolic systems are under investigation including biocompatible and biodegradable microspheres, gelling liquid embolic with controlled occlusive features, and trackable microspheres with enhanced safety profiles. This review aims to summarize recent advances in current and emerging polymeric materials as embolization agents with varying material architectures. Furthermore, this review also explores the potential of combining injectable embolic agents and cell therapy to achieve more effective embolization with the promise of outstanding results in treating various devastating diseases. Finally, limitations and challenges in developing next-generation multifunctional embolic agents are discussed to promote advancement in this emerging field. Full article

The perceptions and definitions of healthy indoor environments have changed significantly throughout architectural history. Today, molecular biology teaches us that microbes play important roles in human health, and that isolation from them puts not only us but also other inhabitants of urban landscapes, at risk. In order to provide an environment that makes honeybees more resilient to environmental changes, we aim for combining the thermal insulation functionality of mycelium materials with bioactive therapeutic properties within beehive constructions. By identifying mycelial fungi’s interactions with nest-related materials, using digital methods to design a hive structure, and engaging in additive manufacturing, we were able to develop a set of methods for designing and fabricating a fully grown hive. We propose two digital methods for modelling 3D scaffolds for micro-super organism co-occupation scenarios: “variable-offset” and “iterative-subtraction”, followed by two inoculation methods for the biofabrication of scaffolded fungal composites. The HIVEOPOLIS project aims to diversify and complexify urban ecological niches to make them more resilient to future game changers such as climate change. The combined functions of mycelium materials have the potential to provide a therapeutic environment for honeybees and, potentially, humans in the future. Full article

Background: The increased use of dental implants in oral rehabilitation has been followed by the development of new biomaterials as well as improvements in the performance of biomaterials already in use. This triggers the need for appropriate analytical approaches to assess the biological and, ultimately, clinical benefits of these approaches. Aims: To address the role of physical, chemical, mechanical, and biological characteristics in order to determine the critical parameters to improve biological responses and the long-term effectiveness of dental implant surfaces. Data sources and methods: Web of Science, MEDLINE and Lilacs databases were searched for the last 30 years in English, Spanish and Portuguese idioms. Results: Chemical composition, wettability, roughness, and topography of dental implant surfaces have all been linked to biological regulation in cell interactions, osseointegration, bone tissue and peri-implant mucosa preservation. Conclusion: Techniques involving subtractive and additive methods, especially those involving laser treatment or embedding of bioactive nanoparticles, have demonstrated promising results. However, the literature is heterogeneous regarding study design and methodology, which limits comparisons between studies and the definition of the critical determinants of optimal cell response. Full article

Background: The presence of posterior crossbite can trigger aesthetic and functional changes as mandibular asymmetry in individuals, contributing to asymmetrical muscle function. Mandibular asymmetry and respective condyle adaptation may be an etiological factor in temporomandibular disorder. This study aims to evaluate the effects of maxillary expansion on the position and angulation of the condyles as well as the intercondylar distance in children with cleft lip and palate. Methods: Twenty-five individuals with cleft lip and palate who underwent maxillary expansion were selected. Condylar changes were evaluated by cone beam computed tomography using the Pullinger and Hollender formula. To determine the statistically significant differences between the variables, the Student t-test and the Benjamini–Hochberg correction method for multiple comparisons were used. Results: No statistically significant differences between angulation and condylar position before and after maxillary expansion were found. The intercondylar distance tended to increase in growing individuals with cleft lip and palate after maxillary expansion. Conclusions: Intercondylar distance shows a tendency to increase after expansion regardless of the cleft phenotype. No differences were found in angulation and condylar position with the changes in occlusion resulting from maxillary expansion. Full article

Hot-water repellency is of great challenge on traditional superhydrophobic surfaces due to the condensation of tiny droplets within the cavities of surface textures, which builds liquid bridges to connect the substrate and hot water and thus destroys the surface water-repellence performance. For the unique structural features and scales, current approaches to fabricate surfaces with hot-water repellency are always complicated and modified by fluorocarbon. Here, we propose a facile and fluorine-free one-step vapor-deposition method for fabricating excellent hot-water-repellent surfaces, which at room temperature even repel water droplets of temperature up to 90 °C as well as other normal-temperature droplets with surface tension higher than 48.4 mN/m. We show that whether the unique hot-water repellency is achieved depends on a trade-off between the solid–liquid contact time and hot-vapor condensation time, which determines the probability of formation of liquid bridges between the substrate and hot-water. Moreover, the designed surfaces exhibit excellent self-cleaning performance in some specific situations, such as oil medium, hot water and condensation environments. We envision that this facile and fluorine-free strategy for fabricating excellent hot-water-repellent surfaces could be valuable in popularizing their practical applications. Full article

Employees play a critical role in the success of corporate sustainability initiatives, yet sustained employee engagement is a constant challenge. The psychology literature states that to intrinsically motivate employees to engage in sustainability, there must be opportunity for employees to engage in practices that are directly relevant to their job duties. Traditional ad hoc initiatives such as Earth Week events, recycling challenges and so on, are not sufficient to derive this type of intrinsic motivation. Therefore, the goal of this study was to examine the psychological impact of a biomimicry sustainable innovation training program, to intrinsically motivate R&D employees to reconnect with nature and identify whether this promotes creative thinking and employee engagement. Due to COVID-19 restrictions, the current study conducted virtual workshops with R&D employees and demonstrated that biomimicry training was intrinsically motivating to employees and was valued as a practice that could be incorporated into R&D job duties. In conclusion, this study provides an adaptable procedural template for biomimicry training with a corporate audience. The results demonstrate a strong business case for organizations to experiment with biomimicry by illustrating its potential to create positive change across several business units beyond sustainable innovation to include human resources and sustainable marketing. Full article

New bone formation starts from the initial reaction between a scaffold surface and the extracellular matrix. This research aimed to evaluate the effects of various amounts of calcium, phosphate, sodium, sulfur, and chloride ions on osteoblast-like cell differentiation using tetra-polymers of amorphous calcium phosphate (ACP), calcium sulfate hemihydrate (CSH), alginic acid, and hydroxypropyl methylcellulose. Moreover, 3D-printed scaffolds were fabricated to determine the ion distribution and cell differentiation. Various proportions of ACP/CSH were prepared in ratios of 0%, 13%, 15%, 18%, 20%, and 23%. SEM was used to observe the morphology, cell spreading, and ion complements. The scaffolds were also examined for calcium ion release. The mouse osteoblast-like cell line MC3T3-E1 was cultured to monitor the osteogenic differentiation, alkaline phosphatase (ALP) activity, total protein synthesis, osteocalcin expression (OCN), and calcium deposition. All 3D-printed scaffolds exhibited staggered filaments, except for the 0% group. The amounts of calcium, phosphate, sodium, and sulfur ions increased as the amounts of ACP/CSH increased. The 18%ACP/CSH group significantly exhibited the most ALP on days 7, 14, and 21, and the most OCN on days 14 and 21. Moreover, calcium deposition and mineralization showed the highest peak after 7 days. In conclusion, the 18%ACP/CSH group is capable of promoting osteoblast-like cell differentiation on 3D-printed scaffolds. Full article

Biomimetics is the interdisciplinary cooperation of biology and technology that offers solutions to practical problems by analyzing biological systems and transferring their principles into applications. This review article focused on biomimetic innovations, including bio-inspired soft robots and swarm robots that could serve multiple functions, including the harvesting of fruits, pest control, and crop management. The research demonstrated commercially available biomimetic innovations, including robot bees by Arugga AI Farming and the Robotriks Traction Unit (RTU) precision farming equipment. Additionally, soft robotic systems have made it possible to mitigate the risk of surface bruises, rupture, the crushing destruction of plant tissue, and plastic deformation in the harvesting of fruits with a soft rind such as apples, cherries, pears, stone fruits, kiwifruit, mandarins, cucumbers, peaches, and pome. Even though the smart farming technologies, which were developed to mimic nature, could help prevent climate change and enhance the intensification of agriculture, there are concerns about long-term ecological impact, cost, and their inability to complement natural processes such as pollination. Despite the problems, the market for bio-inspired technologies with potential agricultural applications to modernize farming and solve the abovementioned challenges has increased exponentially. Future research and development should lead to low-cost FEA robotic grippers and FEA-tendon-driven grippers for crop harvesting. In brief, soft robots and swarm robotics have immense potential in agriculture. Full article

Surgical scene understanding is a key barrier for situation-aware robotic surgeries and the associated surgical training. With the presence of domain shifts and the inclusion of new instruments and tissues, learning domain generalization (DG) plays a pivotal role in expanding instrument–tissue interaction detection to new domains in robotic surgery. Mimicking the ability of humans to incrementally learn new skills without forgetting their old skills in a similar domain, we employ incremental DG on scene graphs to predict instrument–tissue interaction during robot-assisted surgery. To achieve incremental DG, incorporate incremental learning (IL) to accommodate new instruments and knowledge-distillation-based student–teacher learning to tackle domain shifts in the new domain. Additionally, we designed an enhanced curriculum by smoothing (E-CBS) based on Laplacian of Gaussian (LoG) and Gaussian kernels, and integrated it with the feature extraction network (FEN) and graph network to improve the instrument–tissue interaction performance. Furthermore, the FEN’s and graph network’s logits are normalized by temperature normalization (T-Norm), and its effect in model calibration was studied. Quantitative and qualitative analysis proved that our incrementally-domain generalized interaction detection model was able to adapt to the target domain (transoral robotic surgery) while retaining its performance in the source domain (nephrectomy surgery). Additionally, the graph model enhanced by E-CBS and T-Norm outperformed other state-of-the-art models, and the incremental DG technique performed better than the naive domain adaption and DG technique. Full article

The literature shows that translating the thermal adaptation mechanisms of biological organisms to building design solutions can improve energy performance. In the context of bio-inspired thermoregulation several worthwhile attempts have been made to develop a framework for finding relevant thermal adaptation mechanisms in nature as inspiration for architectural design. However, almost all of these have followed a solution-based approach despite the problem-solving nature of architectural design. Given this, this research set out to take a problem-based approach to biomimetic design. The aim was to investigate the most effective way of accessing biological thermoregulatory solutions to assist architects in finding relevant biological inspirations for the thermal design of buildings. This required the development of an optimal structure for categorizing thermoregulatory mechanisms that could then be used as part of a framework for finding appropriate mechanisms for a particular architectural design problem. This development began with a three-step literature review to find, study, generalize and categorize a comprehensive list of thermal adaptation mechanisms used by animals and plants. This article describes how this literature review was carried out leading to the identification of nine main themes which were analysed for their practicality in informing the structure of the proposed framework. The selected themes were built around the common aspects of biology and architecture, and hence facilitated the categorization of biological thermoregulation mechanisms. This article thus explains the steps taken to develop a structure for generalizing and categorizing thermal adaptation strategies in nature. This article does not report on the list of thermal adaptation mechanisms identified in step 2 of the literature review. Instead, it presents the literature review workflow with a focus on step 3. Given that, discussion of the thermal adaptation mechanisms falls outside the scope of this article. Full article

Most of us get inspired by and interact with the world around us based on visual cues such as the colors and patterns that we see. In nature, coloration takes three primary forms: pigmentary coloration, structural coloration, and bioluminescence. Typically, pigmentary and structural coloration are used by animals and plants for their survival; however, few organisms are able to capture the nearly instantaneous and visually astounding display that cephalopods (e.g., octopi, squid, and cuttlefish) exhibit. Notably, the structural coloration of these cephalopods critically relies on a unique family of proteins known as reflectins. As a result, there is growing interest in characterizing the structure and function of such optically-active proteins (e.g., reflectins) and to leverage these materials across a broad range of disciplines, including bioengineering. In this review, I begin by briefly introducing pigmentary and structural coloration in animals and plants as well as highlighting the extraordinary appearance-changing capabilities of cephalopods. Next, I outline recent advances in the characterization and utilization of reflectins for photonic technologies and and discuss general strategies and limitations for the structural and optical characterization of proteins. Finally, I explore future directions of study for optically-active proteins and their potential applications. Altogether, this review aims to bring together an interdisciplinary group of researchers who can resolve the fundamental questions regarding the structure, function, and self-assembly of optically-active protein-based materials. Full article

Currently, the production of sustainable concrete with high strength, durability, and fewer environmental problems has become a priority of concrete industries worldwide. Based on this fact, the effective microorganism (EM) solution was included in the concrete mixtures to modify the engineering properties. Concrete specimens prepared with 50% fly ash (FA) as an ordinary Portland cement (OPC) replacement were considered as the control sample. The influence of EM solution inclusion (at various contents of 0, 5, 10, 15, 20, and 25% weight) in the cement matrix as water replacement was examined to determine the optimum ratio that can enhance the early and late strength of the proposed bio-concrete. The compressive strength, porosity, carbonation depth, resistance to sulphuric acid attack, and the environmental benefits of the prepared bio-concrete were evaluated. The results showed that the mechanical properties and durability performance of the bio-concrete were improved due to the addition of EM and FA. Furthermore, the inclusion of 10% EM could increase the compressive strength of the bio-concrete at 3 (early) and 28 days by 42.5% and 14.6%, respectively. The durability performance revealed a similar trend wherein the addition of 50% FA and 10% EM into the bio-concrete could improve its resistance against acid attack by 35.1% compared to the control specimen. The concrete mix designed with 10% EM was discerned to be optimum, with approximately 49.3% lower carbon dioxide emission compared to traditional cement. Full article

Osteomyelitis is an inflammation of the bone caused by bacterial infection. It usually develops from broken bones, decayed teeth, or heavily punctured wounds. Multi-drug-resistant bacteria are the major hurdle in the treatment of osteomyelitis. The ever-rising antibiotic resistance even leads to amputations or fatalities as a consequence of chronic osteomyelitis. Hence, a single agent with antibacterial activity as well as bone regenerative properties can serve as a potential off-the-shelf product in the treatment of osteomyelitis. Herein, the antibacterial and pro-osteogenic characteristics of copper sericin (Cu-SER) metal–organic frameworks (MOFs) are reported. Sericin, a silk protein with antibacterial activity and an osteoinduction property, acts as an organic template for the deposition of Cu-SER MOFs, similar to collagen during biomineralization in bone. The MOFs exhibit cytocompatibility and osteogenic activity in a dose-dependent manner, as revealed by cell proliferation (alamarBlue) and mineralization (Alizarin Red S and Energy Dispersive X-ray analysis). The bactericidal activity of Cu-SER MOFs was investigated by scanning electron microscopy and a growth kinetic analysis. Together, the report illuminates the unique phenomenon of Cu-SER MOFs that kill bacteria upon contact while being well-tolerated by primary human cells. Hence, Cu-SER MOFs hold the potential to minimize antibiotic dependence. Full article

Bio-inspired design (BID) has the potential to evolve the way engineers and designers solve problems. Several tools have been developed to assist one or multiple phases of the BID process. These tools, typically studied individually and through the performance of college students, have yielded interesting results for increasing the novelty of solutions. However, not much is known about the likelihood of the tools being integrated into the design and development process of established companies. The mixed-methods study presented in this paper seeks to address this gap by providing industry engineers and designers hands-on training with the BID process and four BID tools. Understanding which tools are valued and could be adopted in an industry context is the goal. The results indicate multiple encouraging outcomes including that industry practitioners highly valued the process framework tool (BID canvas) as it allows for flexibility in tool use, as well as valued learning with a suite of BID tools rather than a single one to accommodate different workflows and ways of thinking. Full article

Spiking neural networks are able to control with high precision the rotation and force of single-joint robotic arms when shape memory alloy wires are used for actuation. Bio-inspired robotic arms such as anthropomorphic fingers include more junctions that are actuated simultaneously. Starting from the hypothesis that the motor cortex groups the control of multiple muscles into neural synergies, this work presents for the first time an SNN structure that is able to control a series of finger motions by activation of groups of neurons that drive the corresponding actuators in sequence. The initial motion starts when a command signal is received, while the subsequent ones are initiated based on the sensors’ output. In order to increase the biological plausibility of the control system, the finger is flexed and extended by four SMA wires connected to the phalanges as the main tendons. The results show that the artificial finger that is controlled by the SNN is able to smoothly perform several motions of the human index finger while the command signal is active. To evaluate the advantages of using SNN, we compared the finger behaviours when the SMA actuators are driven by SNN, and by a microcontroller, respectively. In addition, we designed an electronic circuit that models the sensor’s output in concordance with the SNN output. Full article

Hybrid carriers with the mineral CaCO₃/Fe₃O₄ core and the protein–tannin shell are attractive for drug delivery applications due to reliable coupling of anticancer drugs with protein–tannin complex and the possibility of remote control over drug localization and delivery by the external magnetic field. This study aims to elucidate the mechanisms of drug release via enzymatic degradation of a protein–tannin carrier shell triggered by proteolytic hydrolases trypsin and pepsin under physiological conditions. To do this, the carriers were incubated with the enzyme solutions in special buffers to maintain the enzyme activity. The time-lapse spectrophotometric and electron microscopy measurements were carried out to evaluate the degradation of the carriers. It was established that the protein–tannin complex demonstrates the different degradation behavior depending on the enzyme type and buffer medium. The incubation in trypsin solution mostly resulted in the protein shell degradation. The incubation in pepsin solution did not affect the protein component; however, the citric buffer stimulates the degradation of the mineral core. The presented results allow for predicting the degradation pathways of the carriers including the release profile of the loaded cargo under physiological conditions. The viability of 4T1 breast cancer cells with mineral magnetic carriers with protein–tannin shells was investigated, and their movement in the fields of action of the permanent magnet was shown. Full article

Designing with biological materials as a burgeoning approach in the architecture field requires the development of new design strategies and fabrication methods. In this paper, we question if designers can use a parametric design approach while working with living materials. The research uses fungi as a biomaterial probe to experiment with the parametric behavior of living systems. Running design experiments using fungi helps to understand the extent to which biological systems can be considered parametric and, if so, what kind of parametric systems they are. Answering these questions provides a method to work with complex biological systems and may lead to new approaches of fabricating materials by tuning the environmental parameters of biological growth. Full article

A macroscopic continuum model intended to provide predictions for the remodeling process occurring in bone tissue is proposed. Specifically, we consider a formulation in which two characteristic stiffnesses, namely the bulk and shear moduli, evolve independently to adapt the hydrostatic and deviatoric response of the bone tissue to environmental changes. The formulation is deliberately simplified, aiming at constituting a preliminary step toward a more comprehensive modeling approach. The evolutive process for describing the functional adaptation of the two stiffnesses is proposed based on an energetic argument. Numerical experiments reveal that it is possible to model the bone remodeling process with a different evolution for more than one material parameter, as usually done. Moreover, the results motivate further investigations into the subject. Full article

Since the first reported case of COVID-19 in 2019 in China and the official declaration from the World Health Organization in March 2021 as a pandemic, fast and accurate diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has played a major role worldwide. For this reason, various methods have been developed, comprising reverse transcriptase-polymerase chain reaction (RT-PCR), immunoassays, clustered regularly interspaced short palindromic repeats (CRISPR), reverse transcription loop-mediated isothermal amplification (RT-LAMP), and bio(mimetic)sensors. Among the developed methods, RT-PCR is so far the gold standard. Herein, we give an overview of the MIP-based sensors utilized since the beginning of the pandemic. Full article

Biological materials that are created by growing mycelium-forming fungal microorganisms on natural fibers can form a solution to environmental pollution and scarcity of natural resources. Recent studies on the hybridization of mycelium materials with glass improved fire performance; however, the effect of inorganic particles on growth performance and mechanical properties was not previously investigated. Yet, due to the wide variety of reinforcement particles, mycelium nanocomposites can potentially be designed for specific functions and applications, such as fire resistance and mechanical improvement. The objectives of this paper are to first determine whether mycelium materials reinforced with montmorillonite nanoclay can be produced given its inorganic nature, and then to study the influence of these nanoparticles on material properties. Nanoclay–mycelium materials are evaluated in terms of morphological, chemical, and mechanical properties. The first steps are taken in unravelling challenges that exist in combining myco-fabrication with nanomaterials. Results indicate that nanoclay causes a decreased growth rate, although the clay particles are able to penetrate into the fibers’ cell-wall structure. The FTIR study demonstrates that T. versicolor has more difficulty accessing and decaying the hemicellulose and lignin when the amount of nanoclay increases. Moreover, the addition of nanoclay results in low mechanical properties. While nanoclay enhances the properties of polymer composites, the hybridization with mycelium composites was not successful. Full article

Macroporous scaffolds (cryogels) for the 3D cell culturing of colorectal cancer micro-tumors have been fabricated by cross-linking chitosan and carboxymethyl chitosan (CMC) with 1,4-butandiol diglycidyl ether (BDDGE) under subzero temperature. Due to the different intrinsic properties and reactivity of CMC and chitosan under the same cross-linking conditions, Young′s moduli and swelling of the permeable for HCT 116 cells cryogels varied in the broad range 3–41 kPa and 3500–6000%, respectively. We have demonstrated that the morphology of micro-tumors can be controlled via selection of the polymer for the scaffold fabrication. Although both types of the cryogels had low cytotoxicity and supported fast cell proliferation, round-shaped tightly packed HCT 116 spheroids with an average size of 104 ± 30 µm were formed in CMC cryogels (Young′s moduli 3–6 kPa), while epithelia-like continuous sheets with thickness up to 150 µm grew in chitosan cryogel (Young′s modulus 41 kPa). There was an explicit similarity between HCT 116 micro-tumor morphology in soft (CMC cryogel) or stiff (chitosan cryogel) and in ultra-low attachment or adhesive culture plates, respectively, but cryogels provided the better control of the micro-tumor’s size distribution and the possibility to perform long-term investigations of drug–response, cell–cell and cell–matrix interactions in vitro. Full article

The demand for sustainable materials derived from renewable resources has led to significant research exploring the performance and functionality of biomaterials such as mycelium and bacterial cellulose. Whilst the growing conditions and performance of individual biomaterials are understood, to achieve additional new and enhanced functionality, an understanding of how biomaterials can be used together as composites and hybrids is required. This paper investigates the compatibility of mycelium and bacterial cellulose as two biomaterials with different qualities for the development of a large-scale biohybrid structure, the BioKnit prototype. Their compatibility was tested through preliminary design experiments and a material tinkering approach. The findings demonstrate that under optimal conditions mycelium and bacterial cellulose can grow in each other’s presence and create composites with an extensive array of functions. However, there is a need to develop further fabrication settings that help to maintain optimal growing conditions and nutrition levels, whilst eliminating problems such as contamination and competition during growth. Full article

The aim of this study was to investigate the effects of two process-directing agents (polyaspartic acid and osteopontin) used in a polymer-induced liquid-precursor (PILP) process on the remineralization of bacteria-induced enamel demineralization. Enamel demineralization lesions (depths of about 180–200 µm) were created and exposed to Streptococcus mutans, cultured with a 10% sucrose solution for 21 days, and remineralized using a PILP process (pH = 7.4, 14 days) with a calcium phosphate solution containing either polyaspartic acid or osteopontin in the presence or absence of fluoride (0.5 ppm). The specimens were examined under scanning electron microscopy. The fluoride was successfully incorporated into the PILP remineralization process for both polyaspartic acid and osteopontin. When the fluoride was added to the PILP remineralization solution, there was more uniform remineralization throughout the lesion than with either polyaspartic acid or osteopontin alone. However, in the absence of these process-directing agents, fluoride alone showed less remineralization with the formation of a predominantly surface-only layer. The PILP remineralization process relies on the ability of process-directing agents to stabilize calcium phosphate ions and holds promise for enamel lesion remineralization, and these agents, in the presence of fluoride, seem to play an important role as a booster or supplement in the continuation of remineralization by reducing the mineral gains at the surface layer. Full article