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Fluorapatite/CaCO3 thin films were synthesized by mimicking their biogenic counterparts found in teeth using a biomimetic mineralization method. The synthetic heterostructure composites combine well and exhibit excellent mechanical properties.

Calcite mesocrystals were proposed, and have been widely reported, to form in the presence of polymer additives via oriented assembly of nanoparticles. However, the formation mechanism and the role of polymer additives remain elusive. Here, inspired by the biomineralization process of sea urchin spine comprising magnesium calcite mesocrystals, we show that calcite mesocrystals could also be obtained via attachment of amorphous calcium carbonate (ACC) nanoparticles in the presence of inorganic zinc ions. Moreover, we demonstrate that zinc ions can induce the formation of temporarily stabilized amorphous nanoparticles of less than 20 nm at a significantly lower calcium carbonate concentration as compared to pure solution, which is energetically beneficial for the attachment and occlusion during calcite growth. The cation-mediated particle attachment crystallization significantly improves our understanding of mesocrystal formation mechanisms in biomineralization and offers new opportunities to bioprocess inspired inorganic ions regulated materials fabrication.

The coronavirus disease 2019 (COVID-19) pandemic caused extensive loss of life worldwide. Further, the COVID-19 and influenza mix-infection had caused great distress to the diagnosis of the disease. To control illness progression and limit viral spread within the population, a real-time reverse-transcription PCR (RT-PCR) assay for early diagnosis of COVID-19 was developed, but detection was time-consuming (4-6 h). To improve the diagnosis of COVID-19 and influenza, we herein developed a recombinase polymerase amplification (RPA) method for simple and rapid amplification of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 and Influenza A (H1N1, H3N2) and B (influenza B). Genes encoding the matrix protein (M) for H1N1, and the hemagglutinin (HA) for H3N2, and the polymerase A (PA) for Influenza B, and the nucleocapsid protein (N), the RNA-dependent-RNA polymerase (RdRP) in the open reading frame 1ab (ORF1ab) region, and the envelope protein (E) for SARS-CoV-2 were selected, and specific primers were designed. We validated our method using SARS-CoV-2, H1N1, H3N2 and influenza B plasmid standards and RNA samples extracted from COVID-19 and Influenza A/B (RT-PCR-verified) positive patients. The method could detect SARS-CoV-2 plasmid standard DNA quantitatively between 10

As one of the most delicate bioprocesses in nature, biosilicification is closely related to biosilica with various morphologies, and has provided abundant inspiration to materials synthesis. In the present study, to explore the biosilica formation process and fabricate silica with an exquisite microstructure for lithium-ion battery (LIB) electrodes, a bacterial phage (M13) is used as a biotemplate to synthesize silica with diverse morphologies: cylinders, hexagonal prisms, assemblies of smaller cylinders and nanowires. A facile ethanol bath method is conducted to coat the nanowires with nitrogen-containing carbon and carbon-coated SiO2 nanowires with mesochannels (C@msSiO2NWs) are first used as anode materials for LIBs. Attributed to the uniform carbon coating and parallel mesochannel structure, the electronic conductivity and capacity to accommodate volume variations were significantly improved. In the electrochemical performance test, the composites calcined at 750 °C (C@msSiO2NWs-750) show an impressive capacity of 653 mA h g−1 at a current density of 500 mA g−1 and stability (1000 cycles). In view of the electrochemical test outcomes, the preparation of a sophisticated structure with an outstanding potential is easily achieved via a biomimetic strategy.

Bioinspired hydrogels have promising prospects in applications such as wearable devices, human health monitoring equipment, and soft robots due to their multifunctional sensing properties resembling natural skin. However, the preparation of intelligent hydrogels that provide feedback on multiple electronic signals simultaneously, such as human skin receptors, when stimulated by external contact pressure remains a substantial challenge. In this study, we designed a bioinspired hydrogel with multiple conductive capabilities by incorporating carbon nanotubes into a chelate of calcium ions with polyacrylic acid and sodium alginate. The bioinspired hydrogel consolidates self-healing ability, stretchability, 3D printability, and multiple conductivities. It can be fabricated as an integrated strain sensor with simultaneous piezoresistive and piezocapacitive performances, exhibiting sensitive (gauge factor of 6.29 in resistance mode and 1.25 kPa-1 in capacitance mode) responses to subtle pressure changes in the human body, such as finger flexion, knee flexion, and respiration. Furthermore, the bioinspired strain sensor sensitively and discriminatively recognizes the signatures written on it. Hence, we expect our ideas to provide inspiration for studies exploring the use of advanced hydrogels in multifunctional skin-like smart wearable devices.

A living organism is a complex “biosynthesis factory” for the fabrication of materials under environmentally benign conditions, which is worth studying to extend synthesis techniques. Inspired by the formation process of pearls, living mussels have been used to direct the formation of nitrogen-doped anatase TiO2. Here, instead of only synthesizing single-phase materials, we extend the technique for the fabrication of a SnO2/graphene oxide composite. The tin chloride hydroxide hydrate precursor transforms into SnO2 nanocrystals in situ on the surface of graphene oxide with good dispersion and high load to form a homogeneous microstructure under the direction of mussels at ambient temperature. The SnO2/graphene oxide composite exhibits improved lithium storage performance as the anode of a lithium-ion battery. A stable reversible capacity can be achieved, which is up to 1099 mA h g−1 after 100 cycles at a current density of 100 mA g−1. This study demonstrates the possibility and practicability of synthesizing anthropogenically useful composite materials in living organisms, which is advantageous to extend synthesis methods and reduce energy consumption.

Bone is a highly calcified tissue with 60 wt% inorganic components. It is made up of mineralized collagen fibrils, where the platelet-like hydroxyapatite nanocrystals deposit within the collagen fibrils in an oriented manner. Inspired by the special structure and biological activity of bone, we realize the intrafibrillar mineralization of collagen films with oriented calcium fluoride nanocrystals in vitro. Amorphous calcium fluoride (ACF) precursors are generated by polyacrylic acid through polymer-induced liquid precursor processes. The precursors are ready to infiltrate and fill the gap zones laterally and then diffuse to occupy the whole space inside the collagen longitudinally. Finally, the fully mineralized collagen fibrils exhibit a single-crystal-like structure after transforming precursors to co-oriented nanocrystals under the influence of arranged collagen molecules. Expanding the collagen mineralization from 1D fibrils to 2D films, the growth of mineralized areas on the films with a reaction-limited behavior is found. The kinetic rate of growth is around 0.2-0.3 μm min-1, which depends on the pH of the solution. Furthermore, the mineralized collagen films exhibit an enhanced ability of cell proliferation over the pure collagen matrices. Understanding the mineralization of artificial collagen-based scaffolds may have broad promising potentials for bone tissue regeneration and repair in the future.

Silk fibroin is a promising biomaterial that has been used for tissue engineering applications. However, the influence of silk fibroin on the mineralization of calcium phosphate in different biological environments has not been discussed before. In this work, we fabricated organized silk fibroin film as the organic framework and amorphous calcium phosphate (ACP) deposited on the films as precursors. The transformation pathways and morphology of ACP was then studied in both enzyme and PBS (phosphate buffer saline) solutions. While only hydroxyapatite (HA) crystals formed in enzyme solution, a mixture of tricalcium phosphate (TCP) and HA crystals were obtained in PBS solution, which can be related to the variations of the content of silk fibroin and pH of the solution. Therefore, silk fibroin films can have an important effect on the mineralization process of calcium phosphate in different biological environments. In addition, cell cultivation experiments show that the silk films after mineralization promoted osteogenesis and exhibited good biocompatibility.

Collagen fibrils present periodic structures, which provide space for intrafibrillar growth of oriented hydroxyapatite nanocrystals in bone and contribute to the good mechanical properties of bone. However, there are not many reports focused on bioprocess-inspired synthesis of non-native inorganic materials inside collagen fibrils and detailed forming processes of crystals inside collagen fibrils remain poorly understood. Herein, the rapid intrafibrillar mineralization of calcium fluoride nanocrystals with a periodically patterned nanostructure is demonstrated. The negatively charged calcium fluoride precursor phase infiltrates collagen fibrils through the gap zones creating an intricate periodic mineralization pattern. Later, the nanocrystals initially filling the gap zones only expand gradually into the remaining space within the collagen fibrils. Mineralized tendons with organized calcium fluoride nanocrystals acquire mechanical properties (indentation elastic modulus ∼25.1 GPa and hardness ∼1.5 GPa) comparable or even superior to those of native human dentin and lamellar bone. Understanding the mineral growth processes in collagen may facilitate the development of tissue engineering and repairing.

The formation of natural structures found in biological systems is wonderful and can be completed at ambient temperatures in contrast to artificial technologies wherein harsh conditions are common prerequisites. A new research direction, "bioprocess inspired manufacturing", is proposed for fabricating advanced materials with novel structures and functions. Nacre consists of an ordered multilayer structure of crystalline calcium carbonate lamellae separated by organic layers exhibiting mechanical toughness, which transcends that of its constituent components. Inspired by the nacre formation process, a microscale additive manufacturing mineralization method is proposed for achieving a multilayered organic-inorganic layered structure. In this work, layered calcite was synthesized on the surface of chitosan (CS) films at room temperature under the coordinated control of magnesium ions (Mg2+) and polyacrylic acid (PAA). The CS films and layered calcite are sequentially assembled in a layer-by-layer deposition approach to form an organic-inorganic hybrid structure. The nacre-like chitosan/CaCO3 (CS/CaCO3) composites exhibit high transparency and underwater superoleophobicity. Impressively, the hardness (2.35 ± 0.03 GPa) and Young's modulus (58.1 ± 0.5 GPa) of the as-prepared (CS/CaCO3) composites are comparable to those of their biological counterparts. This study provides a rational bioprocess-inspired room-temperature mineralization method to develop advanced composite materials with good performance.

This study presents an innovative surface-diffusion mechanism for the growth of substrate-free and catalyst-free boron nitride nanosheets (BNNSs) by annealing an ammonium borate hydroxide hydrate precursor in a NH3 chemical vapor deposition system. At elevated temperatures, part of NH4B5O8 slowly decomposes and forms B2O3, and flowing NH3 gradually diffuses to the B2O3 surface to form vertically aligned BNNSs. The lateral dimension and crystallinity of the BNNSs increase, while their thickness decreases with the continuous surface-diffusion reaction. The residual NH4B5O8 and B2O3 absorbs moisture in the air to constitute NH4B5O8·4H2O and H3BO3 substrates. With increasing annealing temperature and soaking time (at 1400 °C for 7 h), all NH4B5O8 decomposes and the surface-diffusion reaction between B2O3 and NH3 completely occurs, forming substrate-free BNNSs with a lateral dimension of 1 μm and a thickness of 10 nm. This reliable approach for synthesizing BNNSs paves the way for future applications in advanced ceramic composites.

Biocomposite hydrogels are promising for applications in wearable flexible strain sensors. Nevertheless, the existing biocomposite hydrogels are still hard to meet all requirements, which limits the practical application. Here, inspired by the structure and composition of natural ferritin, we design a PAAm-Ferritin hybrid hydrogel through a facile method. Ferritin is uniformly distributed in the cross-linking networks and acts as a nanocage spring model, leading to the enhanced tensile strength of the hydrogel. The fracture stress is 99 kPa at 1400% maximum elongation. As fabricated PAAm-Ferritin hybrid hydrogels exhibit high toughness and low elastic modulus (21 kPa). The PAAm-Ferritin hybrid hydrogels present excellent biocompatibility and increased conductivity compared with PAAm hydrogel. Impressively, as a wearable flexible strain sensor, the PAAm-Ferritin hybrid hydrogels have high sensitivity (gauge factor = 2.06), excellent reliability, and cycling stability. This study indicates the feasibility of utilizing ferritin to synthesize functional materials, which is conducive to expanding the use of protein synthesis of materials technology and application fields.

During bone formation, collagen fibrils mineralize with carbonated hydroxyapatite, leading to a hybrid material with excellent properties. Other minerals are also known to nucleate within collagen in vitro. For a series of strontium- and calcium-based minerals, we observed that their precipitation leads to a contraction of collagen fibrils, reaching stresses as large as several megapascals. The magnitude of the stress depends on the type and amount of mineral. Using in-operando synchrotron x-ray scattering, we analyzed the kinetics of mineral deposition. Whereas no contraction occurs when the mineral deposits outside fibrils only, intrafibrillar mineralization generates fibril contraction. This chemomechanical effect occurs with collagen fully immersed in water and generates a mineral-collagen composite with tensile fibers, reminiscent of the principle of reinforced concrete.

The inflammatory response has been implicated in various cardiac and systemic diseases. Epigallocatechin-3-gallate (EGCG), the major polyphenol extracted from green tea, has various biological and pharmacological properties, such as anti-inflammation, anti-oxidative and anti-tumorigenesis. To some extent, the mechanism of EGCG in the inflammatory response that characterizes myocardial dysfunction is not fully understood. The present study aimed to investigate the inhibiting effect of EGCG on lipopolysaccharide (LPS)-induced inflammation in vitro. Treatment with LPS affected rat H9c2 cardiomyocytes and induced an inflammatory response. However, the LPS-induced effects were attenuated after treatment with EGCG. The present results demonstrated that EGCG treatment repressed several inflammatory mediators, such as vascular endothelial growth factor, chemokine ligand 5, chemokine ligand 2, intercellular adhesion molecule-1, matrix metalloproteinase-2, tumor necrosis factor-α and nitric oxide (induced by LPS), and the repressing effect of EGCG on inflammatory response was dose-dependent in the range of 6.25-100 µM. EGCG inhibited these marked inflammatory key signaling molecules by reducing the expression of phospho-nuclear factor-κB p65, -Akt, -ERK and -MAPK p38 while the total protein level of these signal proteins were not affected. In conclusion, the present findings suggested that EGCG possesses cardiomyocyte-protective action in reducing the LPS-induced inflammatory response due to the inhibition of the phosphorylation of Akt and ERK signaling molecules.

To explore the clinical effect and adverse reactions of Strychnos nux-vomica in bortezomib-induced peripheral neuropathy (BIPN) of patients with multiple myeloma (MM).A total of 19 MM patients with BIPN were enrolled and Nux Vomica Capsule (NVC, 0.4 g, thrice daily) were orally administrated for 30 days. Comparative analysis on parameters between pre- and post-therapy, including peripheral neuropathy (PN) grade, neurotoxicity score, Chinese medicine (CM) syndrome score, total neuropathy score (TNS), coagulation function, and serum nerve growth factor (NGF) levels were conducted. The adverse events were monitored.In BIPN of MM patients who received NVC, PN grade was lowered, neurotoxicity score was obviously decreased (P⩽0.01), and both CM syndrome score and TNS were remarkably decreased (P0.01). After the therapy, activated partial thromboplastin time was prolonged (P0.01) and fibrinogen was declined (P0.05), showing improvement in the hypercoagulable state of patients. No significant difference of NGF recovery degrees was detected between pre- and post-therapy (P0.05). No evident adverse reactions were observed during the course of treatment.Strychnos nux-vomica L. has significantly effect with a good safety in treatment of BIPN in MM patients.

Inspired from the occlusion of macromolecules in mineral crystals during the biomineralization process, the occlusion mechanism of functional guest species into a host matrix is gradually revealed in artificial systems. However, the guest species within calcite crystals are limited to the nanometer scale. Herein, using amorphous calcium carbonate (ACC) as a precursor and taking advantage of the crystallization of vaterite by the attachment of ACC nanoparticles, micrometer-sized modified Escherichia coli (E. coli) was incorporated into vaterite crystals. The occlusion content of bacteria within the vaterite crystal could reach up to 16 wt%. On the contrary, the occlusion of E. coli into calcite crystals, which proceeded via ion-by-ion addition growth, was only confined to the surface layer. Through modifying the surface structure or chemical composition of bacteria, the strong interaction between the surface of the bacteria and calcium carbonate has proved to be the key factor for successful occlusion. Interestingly, the genetically modified green fluorescent protein (GFP)-E. coli/vaterite composites exhibited stable fluorescence for more than six months with little attenuation and the lifetime could be more than 1.2 μs. It was demonstrated that a combination of the amorphous precursor crystallization pathway and a suitable surface structure of the foreign species can significantly enhance the occlusion efficiency of micrometer-sized species in crystals.

Mesoporous silica particles of controlled size and shape are potentially beneficial for many applications, but their usage may be limited by the complex procedure of fabrication. Biotemplating provides a facile approach to synthesize materials with desired shapes. Herein, a bioinspired design principle is adopted through displaying silaffin-derived 5R5 proteins on the surface of Escherichia coli by genetic manipulations. The genetically modified Escherichia coli provides a three-dimensional template to regulate the synthesis of rod-shaped silica. The silicification is initiated on the cell surface under the functionality of 5R5 proteins and subsequentially the inner space is gradually filled. Density functional theory simulation reveals the interfacial interactions between silica precursors and R5 peptides at the atomic scale. There is a large conformation change of this protein during biosilicification. Electrostatic interactions contribute to the high affinity between positively charged residues (Lys4, Arg16, Arg17) and negatively charged tetraethyl orthosilicate. Hydrogen bonds develop between Arg16 (O⋯H), Arg17 (O⋯H and N⋯H), Leu19 (O⋯H) residues and the forming silica agglomerates. In addition, the resulting rod-shaped silica copy of the bacteria can transform into mesoporous SiOx nanorods composed of carbon-coated nanoparticles after carbonization, which is shown to allow superior lithium storage performance.

To investigate the mechanism of honokiol (HNK) on bladder cancer cells and its synergistic anticancer effect with hydroxycamptothecin (HCPT).Control, HNK, HCPT, and HNK plus HCPT groups were established. The morphological characteristics of T24 cells were examined microscopically. The maximal experimental concentration of HNK and HCPT were determined according to IC10 detected by MTT. T24 cell viability and the percentage of apoptotic cells were assessed on the basis of MTT and flow cytometric analysis. The expression of caspase-3, caspase-9, phosphorylated nuclear factor-kappa B (NF-κB)-p65, Akt, and extracellular signal-regulated kinase (ERK) proteins were analyzed by Western blot.Apoptosis in T24 cells was observed microscopically in both the HNK and HCPT groups and even more obvious in the HNK plus HCPT groups. The percentage of T24 cell viability decreased down to 19.41% , and the percentage of apoptotic cells rose to 54.08% when treated with HNK plus HCPT in an HNK dose-dependent manner. The induction of caspase-3 and caspase-9 proteins and the inhibition of phosphorylation of NF-κB-p65, Akt, and ERK proteins in T24 cells were demonstrated in the HNK groups, and more significantly in the HNK plus HCPT groups, but not in the HCPT group.The anticancer effect of HNK may be due to the activation of the caspase pathway and inhibition of phosphorylation of NF-κB, Akt, and ERK. HNK in combination with HCPT produces a synergistic cell-killing effect on bladder cancer cells.

The formation of natural structures found in biological systems is wonderful and can be completed at ambient temperatures in contrast to artificial technologies wherein harsh conditions are common prerequisites. A new research direction, "bioprocess inspired manufacturing", is proposed for fabricating advanced materials with novel structures and functions. Nacre consists of an ordered multilayer structure of crystalline calcium carbonate lamellae separated by organic layers exhibiting mechanical toughness, which transcends that of its constituent components. Inspired by the nacre formation process, a microscale additive manufacturing mineralization method is proposed for achieving a multilayered organic-inorganic layered structure. In this work, layered calcite was synthesized on the surface of chitosan (CS) films at room temperature under the coordinated control of magnesium ions (Mg2+) and polyacrylic acid (PAA). The CS films and layered calcite are sequentially assembled in a layer-by-layer deposition approach to form an organic-inorganic hybrid structure. The nacre-like chitosan/CaCO3 (CS/CaCO3) composites exhibit high transparency and underwater superoleophobicity. Impressively, the hardness (2.35 ± 0.03 GPa) and Young's modulus (58.1 ± 0.5 GPa) of the as-prepared (CS/CaCO3) composites are comparable to those of their biological counterparts. This study provides a rational bioprocess-inspired room-temperature mineralization method to develop advanced composite materials with good performance.

As environmental and energy problems have worsened worldwide, research for developing renewable energy has become urgent. Presently, the primary focus of such research is directed towards the photocatalytic decomposition of water to produce hydrogen as an energy source. Herein, ZnO nanosheet/CdS nanoparticle heterostructures were synthesized by a mild wet chemical reaction and displayed a high photocatalytic efficiency (1040 μmol g−1 h−1) without Pt loading under visible light radiation. The structure was prepared by first constructing two-dimensional nanocrystalline ZnO flowers and then loading CdS nanoparticles onto the nanocrystals. Results show that this structure can facilitate the separation of photogenerated electrons and holes and improve the photocatalytic efficiency and stability of the materials in the photocatalytic decomposition of water. By changing different experimental conditions to prepare a variety of samples and test their properties, we can analyze the optimal parameters for the preparation of this material.

Natural photosynthesis involves a subtle electron transfer mechanism in which freely-moving electron transfer intermediates (plastoquinone and plastocyanin) are capable of effectively separating the photo-generated carriers, and therefore, it has high quantum efficiency. Inspired by this mechanism, in this study, carbonate (CO32-) ions were employed as hole vehicles to promote photo-generated carrier separation, and greatly improved the photocatalytic hydrogen evolution activity of K4Nb6O17 nanosheets. The hydrogen evolution rate at the optimal concentration of CO32- ions reached 2018 μmol h-1 g-1, which was 16.3 times that of the blank sample (124 μmol h-1 g-1). This marked enhancement was based on the transfer of holes from the photocatalyst to the sacrificial reagent (methanol) via CO32- ions; this process is faster than direct hole transfer between the photocatalyst and sacrificial reagent. This bio-inspired strategy provides a facile and cost-effective approach to improve the solar-to-fuel conversion efficiency of photocatalysts.

Tooth enamel is composed of arrayed fluorapatite (FAP) or hydroxyapatite nanorods modified with Mg-rich amorphous layers. Although it is known that Mg2+ plays an important role in the formation of enamel, there is limited research on the regulatory role of Mg2+ in the synthesis of enamel-like materials. Therefore, we focus on the regulatory behavior of Mg2+ in the fabrication of biomimetic mineralized enamel-like structural materials. In the present study, we adopt a bioprocess-inspired room-temperature mineralization technique to synthesize a multilayered array of enamel-like columnar FAP/polymer nanocomposites controlled by Mg2+ (FPN-M). The results reveal that the presence of Mg2+ induced the compaction of the array and the formation of a unique Mg-rich amorphous-reinforced architecture. Therefore, the FPN-M array exhibits excellent mechanical properties. The hardness (2.42 ± 0.01 GPa) and Young's modulus (81.5 ± 0.6 GPa) of the as-prepared FPN-M array are comparable to those of its biological counterparts; furthermore, the enamel-like FPN-M array is translucent. The hardness and Young's modulus of the synthetic array of FAP/polymer nanocomposites without Mg2+ control (FPN) are 0.51 ± 0.04 and 43.5 ± 1.6 GPa, respectively. The present study demonstrates a reliable bioprocess-inspired room-temperature fabrication technique for the development of advanced high-performance composite materials.

After a long period of historical evolution, Chinese courts established a unique, organizational structure known as the ‘Unified System of Jurisdiction and Administration’ in the early 1980s. The system combines adjudication and judicial administration under the full authority of the President of the Court. Although the Unified System once played a positive role in China’s rapid economic growth, it has negatively impacted judicial independence and justice. This negative impact has gradually outweighed the positive effects. Ongoing judicial reform in China is changing the judicial system.