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Herein, we demonstrate that modification of TiO2 nanotubes with graphene–strontium and cobalt molybdate perovskite can turn them into active electrocatalysts for hydrogen evolution reaction (HER). For this purpose, a simple method of hydrothermal synthesis of perovskites was developed directly on the TiO2 nanotubes substrate. Moreover, the obtained hybrids were also decorated with graphene oxide (GO) during one-step hydrothermal synthesis. The obtained materials were characterized by scanning electron microscopy with energy dispersive X-ray analysis, Raman spectroscopy, and X-ray diffraction analysis. Catalytic properties were verified by electrochemical methods (linear voltammetry, chronopotentiometry). The obtained hybrids were characterized by much better catalytic properties towards hydrogen evolution reaction compared to TiO2 and slightly worse than platinum. The optimized hybrid catalyst (decorated by GO) can drive a cathodic current density of 10 mA cm−2 at an overpotential of 121 mV for HER with a small Tafel slope of 90 mV dec−1 in 0.2 M H2SO4.

Herein, we demonstrate that modification of TiO

A novel chitin–ethylene glycol hybrid gel was prepared as a hydrogel electrolyte for electrical double-layer capacitors (EDLCs) using 1-butyl-3-methylimidazolium acetate [Bmim][Ac] as a chitin solvent. Examination of the morphology and topography of the chitin–EG membrane showed a homogeneous and smooth surface, while the thickness of the membrane obtained was 27 µm. The electrochemical performance of the chitin–EG hydrogel electrolyte was investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. The specific capacitance value of the EDLC with chitin–EG hydrogel electrolyte was found to be 109 F g−1 in a potential range from 0 to 0.8 V. The tested hydrogel material was electrochemically stable and did not decompose even after 10,000 GCD cycles. Additionally, the EDLC test cell with chitin–EG hydrogel as electrolyte exhibited superior capacitance retention after 10,000 charge/discharge cycles compared with a commercial glass fiber membrane.

The aim of this study was to evaluate the performance of zinc oxide nanoparticles as a photocatalyst for photodegradation of two model non-ionic surfactants (Triton X-100 and C12E10). The first part of the investigation was focused on the synthesis and characterization of ZnO nanoparticles, since its crystalline structure strongly impacts its photocatalytic properties. Based on the results of the XRD analysis, it was concluded that the obtained material occurred in the form of hexagonal wurtzite with a polycrystalline structure. FT-IR and XPS analyses were used to elucidate and confirm the nanomaterial structure, whereas investigation of N2 adsorption/desorption and SEM/TEM imaging allowed to establish that the synthesized ZnO was characterized as a mesoporous material with uniform, spherical shape and particle size fluctuating between 90 and 130 nm. The second part of the study included spectrophotometric assessment of the photodegradation process. The use of the obtained ZnO nanoparticles allowed to achieve efficient photodegradation of both C12E10 (92%) and Triton X-100 (82%) after 1 h of UV irradiation. The Langmuir–Hinshelwood mechanism was used to describe the reaction kinetics. Subsequent LC-MS/MS analysis of the residues indicated that the degradation mechanism is most likely based on both central fission of the surfactant molecules with further terminal oxidation of poly(ethylene glycol) and terminal oxidation leading to carboxylic derivatives of surfactants.

Studies on the identification, properties and function of chitin in sponges (Porifera), which are recognized as the first multicellular organisms on Earth, continue to be of fundamental scientific interest. The occurrence of chitin has so far been reported in 21 marine sponge species and only in two inhabiting fresh water. In this study, we present the discovery of α-chitin in the endemic demosponge Ochridaspongia rotunda, found in Lake Ohrid, which dates from the Tertiary. The presence of chitin in this species was confirmed using special staining, a chitinase test, FTIR, Raman and NEXAFS spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). In contrast to the case of marine sponges, chitin in O. rotunda has been found only within its holdfast, suggesting a role of chitin in the attachment of the sponge to the hard substratum. Isolated fibrous matter strongly resemble the shape and size of the sponge holdfast with membrane-like structure.

The main purpose of this study was to investigate the extraction of essential oils from plants by the supercritical fluid extraction technique. However, other interesting information, regarding the process optimization, is also discussed. Therefore, logical steps were identified to completely describe the process. These steps were divided into three parts: (1) characterization of essential oils; (2) properties attributed to the supercritical fluid, including supercritical fluid extraction, parameters affecting the procedure such as temperature, pressure, particle size, modifier, flow rate, and water, the importance of fractionation, types of collection methods, the antimicrobial and antioxidant activities of essential oils extracted by supercritical fluid, advantages and drawbacks of this method in comparison with other extraction techniques; and (3) the use of experimental designs, including screening, optimizing and modeling, in the process of supercritical fluid extraction of essential oils.

Pure copper chromite nanoparticles were prepared through an efficient route using copper nitrate and chromium nitrate. For the first time, various amino acids were employed as capping agents in the presence of propylene glycol and ethylene glycol in order to prepare these nanostructures. A number of experiments were performed to examine the effect of stabilization agents, alkaline agents and connecting agents on the shape, grain size and photodegradation behavior of CuCr2O4. The results showed that the type of stabilization agent and reducing agent creates numerous changes in terms of the size and photocatalytic performance of copper chromite. The effects of several factors, including the type of pollutant, grain size of CuCr2O4 nanostructures, pH and dosage of dye, on the photocatalytic behavior of copper chromite nanostructure were evaluated. Solutions of methylene blue, methyl orange and rhodamine B were employed as model contaminants. The maximum photocatalytic activity of the CuCr2O4 nanostructure was achieved for the rhodamine B contaminant under UV irradiation. When the CuCr2O4/Ag nanostructure was used instead of CuCr2O4 nanoparticles, the photocatalytic activity during the degradation of rhodamine B increased from 76 to 91%.

In this study, novel MnWO4/TmVO4 ternary nano-hybrids were synthesized effectively via a simple sonochemical method. The products were characterized in detail with the use of modern analytical techniques including XRD, EDX, TEM, DRS, BET, PL, and VSM. To the authors’ best knowledge, this is the first report on the synthesis and photocatalytic performance of MnWO4/TmVO4 ternary nano-hybrids in the degradation of rhodamine B (Rh B), 2-naphthol (Na), phenol red (Ph R), and eosin Y (EY) under visible light. Based on the degradation results, MnWO4/TmVO4 is shown to have higher photodegradation ability than pure TmVO4 or MnWO4 nanoparticles. It was also found that maximum degradation (99.2%) is achieved in the case of Rh B dye.

Praca zostala zrealizowana w ramach projektow badawczych Politechniki Poznanskiej 03/32/DSPB/0806 i 03/32/DSMK/0810.

Analysis was carried out to determine the physicochemical characteristics – morphological and structural, electrokinetic properties, elemental composition and functional groups – of peat, with a view to its use as a potential adsorbent of heavy metal ions from aqueous solutions. A significant part of the study comprised tests of adsorption of nickel(II) and lead(II) ions from model solutions. It was determined how the parameters of the adsorption process (time, pH, quantity of sorbent) influence the effectiveness of removal of nickel(II) and lead(II) ions. The adsorption kinetics are also described, using a pseudo-first-order model and pseudo-second-order models of types 1–4. The results show strong correspondence to a pseudo-second-order kinetics model of type 1 ( r 2 = 0.999 for all initial concentrations). Another key part of the analysis was the use of the Langmuir and Freundlich models to determine the adsorption isotherms. The experimental data were in strong correspondence with Langmuir’s isotherm model. The sorption capacities of peat with respect to nickel(II) and lead(II) ions were 61.27 mg(Ni 2+ )/g and 82.31 mg(Pb 2+ )/g. Desorption tests confirmed the possibility of reusing peat as an effective sorbent of environmentally harmful metals. A mechanism is also proposed for the adsorption of Ni 2+ and Pb 2+ ions on adsorbent.

This work presents an Extreme Biomimetic approach for the development of a novel non-enzymatic electrochemical glucose sensor based on modification of a glassy carbon electrode (GCE) with CuO-chitosan nanocomposite. The impact of the synthesis conditions on the structure of the formed CuO-chitosan nanocomposites was analyzed in detail using a variety of analytical techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). To investigate electrocatalytic activity towards glucose oxidation and to optimize the synthesis process, the modified electrodes (CuO-CS/GCE) were tested by amperometric and potentiometric methods The CuO-CS sensor based on CuO-CS_100 Exhibits 20% better electrocatalytic activity than a CuO sensor with CuO obtained under the same process conditions. The CuO-CS/GCE sensor for glucose oxidation displays high sensitivity (503 μA mM cm−2) with a high detection limit (LOD of 11 μM), short response time (within 6 s), and very good long-term stability and reproducibility. Electrochemical measurements confirmed that the CuO-chitosan nanocomposite obtained after 18 h of hydrothermal reaction at 100 °C was the most efficient modifier of GCE. These results clearly indicate that the novel CuO-CS/GCE sensor is very promising for future application in devices used to detect glucose in biological fluids.

Biologically induced and controlled mineralization of metals promotes the development of protective structures to shield cells from thermal, chemical, and ultraviolet stresses. Metal biomineralization is widely considered to have been relevant for the survival of life in the environmental conditions of ancient terrestrial oceans. Similar behavior is seen among extremophilic biomineralizers today, which have evolved to inhabit a variety of industrial aqueous environments with elevated metal concentrations. As an example of extreme biomineralization, we introduce the category of “forced biomineralization”, which we use to refer to the biologically mediated sequestration of dissolved metals and metalloids into minerals. We discuss forced mineralization as it is known to be carried out by a variety of organisms, including polyextremophiles in a range of psychrophilic, thermophilic, anaerobic, alkaliphilic, acidophilic, and halophilic conditions, as well as in environments with very high or toxic metal ion concentrations. While much additional work lies ahead to characterize the various pathways by which these biominerals form, forced biomineralization has been shown to provide insights for the progression of extreme biomimetics, allowing for promising new forays into creating the next generation of composites using organic-templating approaches under biologically extreme laboratory conditions relevant to a wide range of industrial conditions.

The giant bones of whales (Cetacea) are the largest extant biomineral-based constructs known. The fact that such mammalian bones can grow up to 7 m long raises questions about differences and similarities to other smaller bones. Size and exposure to environmental stress are good reasons to suppose that an unexplored level of hierarchical organization may be present that is not needed in smaller bones. The existence of such a macroscopic naturally grown structure with poorly described mechanisms for biomineralization is an example of the many yet unexplored phenomena in living organisms. In this article, we describe key observations in macrobiomineralization and suggest that the large scale of biomineralization taking place in selected whale bones implies they may teach us fundamental principles of the chemistry, biology, and biomaterials science governing bone formation, from atomistic to the macrolevel. They are also associated with a very lipid rich environment on those bones. This has implications for bone development and damage sensing that has not yet been fully addressed. We propose that whale bone construction poses extreme requirements for inorganic material storage, mediated by biomacromolecules. Unlike extinct large mammals, cetaceans still live deep in large terrestrial water bodies following eons of adaptation. The nanocomposites from which the bones are made, comprising biomacromolecules and apatite nanocrystals, must therefore be well adapted to create the macroporous hierarchically structured architectures of the bones, with mechanical properties that match the loads imposed in vivo. This massive skeleton directly contributes to the survival of these largest mammals in the aquatic environments of Earth, with structural refinements being the result of 60 million years of evolution. We also believe that the concepts presented in this article highlight the beneficial uses of multidisciplinary and multiscale approaches to study the structural peculiarities of both organic and inorganic phases as well as mechanisms of biomineralization in highly specialized and evolutionarily conserved hard tissues.

The marine sponges of the order Verongiida (Demospongiae: Porifera) have survived on our planet for more than 500 million years due to the presence of a unique strategy of chemical protection by biosynthesis of more than 300 derivatives of biologically active bromotyrosines as secondary metabolites. These compounds are synthesized within spherulocytes, highly specialized cells located within chitinous skeletal fibers of these sponges from where they can be extruded in the sea water and form protective space against pathogenic viruses, bacteria and other predators. This chitin is an example of unique biomaterial as source of substances with antibiotic properties. Traditionally, the attention of researchers was exclusively drawn to lipophilic bromotyrosines, the extraction methods of which were based on the use of organic solvents only. Alternatively, we have used in this work a biomimetic water-based approach, because in natural conditions, sponges actively extrude bromotyrosines that are miscible with the watery environment. This allowed us to isolate 3,5-dibromoquinolacetic acid from an aqueous extract of the dried demosponge Aplysina aerophoba and compare its antimicrobial activity with the same compound obtained by the chemical synthesis. Both synthetic and natural compounds have shown antimicrobial properties against clinical strains of Staphylococcus aureus, Enterococcus faecalis and Propionibacterium acnes. Supplementary Information The online version contains supplementary material available at 10.1007/s00339-020-04167-0.

Selected hypermineralized bones (rostrum and tympanic bullae) have yet to be characterized for diverse species of whales (Cetacea). Hypermineralization in these structures is an example of extreme biomineralization that, however, occurs at temperatures around 36 °C. In this study we present the results of analytical investigations of the specimen of tympanic bulla isolated from gray whale (Eschrichtius robustus) for the first time. Examination of the internal surface of the bone mechanically crushed under a press revealed the presence of a lipid-containing phase, which did not disappear even after complete demineralization of the bone material. Additionally, analytical investigations including CARS, ATR-FTIR, Raman and XRD confirmed the presence of carbonated bioapatite and a collagen- lipid complex as the main components of this up to 2.34 kg/cm3 dense bone. Our experimental results open the way for further research on understanding of the principles of hypermineralization in highly specialized whale bones.

Molluscan shells are an example of a mineral-based biocomposite material, and most studies to date have focused on understanding their biomineralization mechanisms. Meanwhile, large amounts of these shells are produced as waste globally by seafood which is used by other industries as a source of biogenic calcium carbonates. In this study, we propose a simple methodological approach for isolation ofConchixes, the organic scaffolds that resemble the size and shapes of mollusks shells, using gentle EDTA-based demineralization of the shells. Such mineral-free biological materials have been extracted from selected representatives of marine and fresh water bivalves, as well as from marine and terrestrial gastropods under study. Key pathways to practical applications of molluscanconchixeswith regards to pharmacy, cosmetics, feed and feed additives, biomedicine and bioinspired materials science are also discussed.

Chitin is the second most abundant biopolymer and functions as the main structural component in a variety of living organisms. In nature, chitin rarely occurs in a pure form, but rather as nanoorganized chitin-proteins, chitin-pigments, or chitin-mineral composite biomaterials. Although chitin has a long history of scientific studies, it is still extensively investigated for practical applications in medicine, biotechnology, and biomimetics. The complexity of chitin has required the development of highly sensitive analytical methods for its identification. These methods are crucial for furthering disease diagnostics as well as advancing modern chitin-related technologies. Here we provide a summary of chitin identification by spectroscopic (NEXAFS, FTIR, Raman, NMR, colorimetry), chromatographic (TLC, GC, HPLC), electrophoretic (HPCE), and diffraction methods (XRD, WAXS, SAXS, HRTEM-SAED). Biochemical and immunochemical (ELISA, immunostaining) methods are described with respect to their medical application. This review outlines the history as well as the current progress in the analytical methods for chitin identification.

In vivo biomimetic biomineralization using living organisms known as biomineralizers is currently a major research trend. Industrially cultivated terrestrial snails, such as the common garden snail Cornu aspersum, represent a simple model organism that is ideal for use in experiments on the regeneration of the calcified shell after the excavation of a corresponding shell fragment. The mollusk’s artificially damaged shell is regenerated via the formation of an organic regenerative membrane, which serves as a native template for in vivo biocalcification. In this study, for the first time, a special plexiglass device for non-lethal fixation of living snails, enabling real-time monitoring of their ability to regenerate their shells using digital microscopy, has been proposed and tested. As an alternative to natural biomineralization using the mollusk’s own sources, we propose chitin- and collagen-based templates, which have been shown to be effectively calcified by living snails. The results indicate that the type of organic template used for in vivo biomineralization has a substantial effect on the nature of the mineral phases.

β-Chitinous scaffolds isolated from the skeleton of marine cephalopod Sepia officinalis were used as a template for the in vitro formation of ZnO under conditions (70 °C) which are extreme for biological materials. Novel β-chitin/ZnO film-like composites were prepared for the first time by hydrothermal synthesis, and were thoroughly characterized using numerous analytical methods including Raman spectroscopy, HR-TEM and XRD. We demonstrate the growth of hexagonal ZnO nanocrystals on the β-chitin substrate. Our chitin/ZnO composites presented in this work show antibacterial properties against Gram positive bacteria and can be employed for development of inorganic–organic wound dressing materials.

This work determines the effect of the addition of various amounts of vanadium oxide on the work of a cell built from a hybrid VxOy-TiO2-rGO system in a lithium-ion cell. Moreover, a new method based on solvothermal chemistry is proposed for the creation of a new type of composite material combining reduced graphene, vanadium oxide and crystalline anatase. The satisfactory electrochemical properties of VxOy-TiO2-rGO hybrids can be attributed to the perfect matching of the morphology and structure of VxOy-TiO2 and rGO. In addition, it is also responsible for the partial transfer of electrons from rGO to VxOy-TiO2, which increases the synergistic interaction of the VxOy-TiO2-rGO hybrid to the reversible storage of lithium. In addition a full cell was created LiFePO4/VxOy-TiO2-rGO. The cell showed good cyclability while providing a capacity of 120 mAh g−1.

One of the major challenges of implantology is to design nanoscale modifications of titanium implant surfaces inducing osseointegration. The aim of this study was to investigate the behavior of rat osteoblasts cultured on anodized TiO2 nanotubes of different crystallinity (amorphous and anatase phase) up to 24 days. TiO2 nanotubes were fabricated on VT1–0 titanium foil via a two-step anodization at 20 V using NH4F as an electrolyte. Anatase-phase samples were prepared by heat treatment at 500 °C for 1 h. VT1–0 samples with flat surfaces were used as controls. Primary rat osteoblasts were seeded over experimental surfaces for several incubation times. Scanning electron microscopy (SEM) was used to analyze tested surfaces and cell morphology. Cell adhesion and proliferation were investigated by cell counting. Osteogenic differentiation of cells was evaluated by qPCR of runt-related transcription factor 2 (RUNX2), osteopontin (OPN), integrin binding sialoprotein (IBSP), alkaline phosphatase (ALP) and osteocalcin (OCN). Cell adhesion and proliferation, cell morphology and the expression of osteogenic markers were affected by TiO2 nanotube layered substrates of amorphous and anatase crystallinity. In comparison with flat titanium, along with increased cell adhesion and cell growth a large portion of osteoblasts grown on the both nanostructured surfaces exhibited an osteocyte-like morphology as early as 48 h of culture. Moreover, the expression of all tested osteogenic markers in cells cultured on amorphous and anatase TiO2 nanotubes was upregulated at least at one of the analyzed time points. To summarize, we demonstrated that amorphous and anodized TiO2 layered substrates are highly biocompatible with rat osteoblasts and that the surface modification with about 1500 nm length nanotubes of 35 ± 4 (amorphous phase) and 41 ± 8 nm (anatase phase) in diameter is sufficient to induce their osteogenic differentiation. Such results are significant to the engineering of coating strategies for orthopedic implants aimed to establish a more efficient bone to implant contact and enhance bone repair.

Among marine demosponges (Porifera: Demospongiae), only representatives of the order Verongiida have been recognized to synthetize both biologically active substances as well as scaffolds-like fibrous skeletons made of structural aminopolysaccharide chitin. The unique 3D architecture of such scaffolds open perspectives for their applications in waste treatment, biomimetics and tissue engineering. Here, we focus special attention to the demosponge Pseudoceratina purpurea collected in the coastal waters of Singapore. For the first time the detailed description of the isolation of chitin from the skeleton of this sponge and its identification using diverse bioanalytical tools were carried out. Calcofluor white staining, FTIR analysis, electrospray ionization mass spectrometry (ESI-MS), SEM, and fluorescence microscopy as well as a chitinase digestion assay were applied in order to confirm with strong evidence the finding of alpha-chitin in the skeleton of P. purpurea. We suggest that the discovery of chitin within representatives of Pseudoceratinidae family is a perspective step in evaluation of these verongiid sponges as novel renewable sources for both chitin and biologically active metabolites, which are of prospective use for marine oriented biomedicine and pharmacology, respectively.

Composites containing biological materials with nanostructured architecture have become of great interest in modern materials science, yielding both interesting chemical properties and inspiration for biomimetic research. Herein, we describe the preparation of a novel 3D nanostructured MnO2-based composite developed using a carbonized proteinaceous spongin template by an extreme biomimetics approach. The thermal stability of the spongin-based scaffold facilitated the formation of both carbonized material (at 650 °C with exclusion of oxygen) and manganese oxide with a defined nanoscale structure under 150 °C. Remarkably, the unique network of spongin fibers was maintained after pyrolysis and hydrothermal processing, yielding a novel porous support. The MnO2-spongin composite shows a bimodal pore distribution, with macropores originating from the spongin network and mesopores from the nanostructured oxidic coating. Interestingly, the composites also showed improved electrochemical properties compared to those of MnO2. Voltammetry cycling demonstrated the good stability of the material over more than 3,000 charging/discharging cycles. Additionally, electrochemical impedance spectroscopy revealed lower charge transfer resistance in the prepared materials. We demonstrate the potential of extreme biomimetics for developing a new generation of nanostructured materials with 3D centimeter-scale architecture for the storage and conversion of energy generated from renewable natural sources.

This work presents an extreme biomimetics route for the modification of the surface of fibre-based scaffolds of poriferan origin by the creation of novel nanostructured multiphase biocomposites. The exceptional thermal stability of the nanostructured sponge chitin allowed for the formation of a novel nanocrystalline chitin-(Ti,Zr)O2 composite with a well-defined nanoscale structure under hydrothermal conditions (160 °C). Using a combination of experimental techniques, including X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, EDX mapping and near-edge electron loss spectroscopy (ELNES) in TEM and thermogravimetry/differential scanning calorimetry coupled with mass spectrometry; we showed that this bioorganic scaffold facilitates selective crystallization of TiO2, predominantly in form of anatase, over the monoclinic zirconium dioxide (baddeleyite). The control of the crystal morphology through the chitin templates is also demonstrated. Obtained samples were characterized in terms of their photoluminescent properties and photocatalytic performance. These data confirm the high potential of the extreme biomimetics approach for developing a new generation of multiphase biopolymer-based nanostructured materials.

Chitin, as a fundamental polysaccharide in invertebrate skeletons, continues to be actively investigated, especially with respect to new sources and the development of effective methods for its extraction. Recent attention has been focused on marine crustaceans and sponges; however, the potential of spiders (order Araneae) as an alternative source of tubular chitin has been overlooked. In this work, we focused our attention on chitin from up to 12 cm-large Theraphosidae spiders, popularly known as tarantulas or bird-eating spiders. These organisms “lose” large quantities of cuticles during their molting cycle. Here, we present for the first time a highly effective method for the isolation of chitin from Caribena versicolor spider molt cuticle, as well as its identification and characterization using modern analytical methods. We suggest that the tube-like molt cuticle of this spider can serve as a naturally prefabricated and renewable source of tubular chitin with high potential for application in technology and biomedicine.

A glassy carbon electrode (GCE) was modified with a nanocomposite prepared from polymerized β-cyclodextrin (β-CD) and reduced graphene oxide (rGO). The modified GCE is shown to enable the voltammetric determination of traces of levofloxacin (LEV) by various electrochemical techniques. Experimental factors affecting the results including the amount of the substrates in preparation of the nanocomposite, accumulation time, the scan rate and pH value of the electrolyte were optimized. The modified GCE, best operated at a working potential of 1.00 V (vs. Ag/AgCl), has two linear response ranges, one for low LEV concentrations (100 pmol L−1 to 100 nmol L−1), and one for higher LEV concentrations (100 nmol L−1 to 100 μmol L−1). The limit of detection and sensitivity are calculated to be 30 pmol L−1 and 467.33 nA μmol L−1 cm−2, respectively. The modified GCE demonstrates a number of advantages such as high sensitivity and selectivity, low LOD, excellent reproducibility, high surface-to-volume ratio, and good electrocatalytic activity towards LEV. The sensor was successfully applied to the determination of LEV in spiked human serum samples.

The bioactive bromotyrosine-derived alkaloids and unique morphologically-defined fibrous skeleton of chitin origin have been found recently in marine demosponges of the order Verongiida. The sophisticated three-dimensional (3D) structure of skeletal chitinous scaffolds supported their use in biomedicine, tissue engineering as well as in diverse modern technologies. The goal of this study was the screening of new species of the order Verongiida to find another renewable source of naturally prefabricated 3D chitinous scaffolds. Special attention was paid to demosponge species, which could be farmed on large scale using marine aquaculture methods. In this study, the demosponge Pseudoceratina arabica collected in the coastal waters of the Egyptian Red Sea was examined as a potential source of chitin for the first time. Various bioanalytical tools including scanning electron microscopy (SEM), fluorescence microscopy, FTIR analysis, Calcofluor white staining, electrospray ionization mass spectrometry (ESI-MS), as well as a chitinase digestion assay were successfully used to confirm the discovery of α-chitin within the skeleton of P. arabica. The current finding should make an important contribution to the field of application of this verongiid sponge as a novel renewable source of biologically-active metabolites and chitin, which are important for development of the blue biotechnology especially in marine oriented biomedicine.

It is shown that lignosulfonate (LS) can be used as an effective reducing agent for gold ions and simultaneously as a stabilizing agent for gold nanoparticles (AuNPs). When organically modified silica is introduced to the reaction mixture, most of the AuNPs grow on the surface of the silica due to hydrophobic interactions between LS and organic layers covering the solid particles. It was also found that the structure of the organic layer is crucial for the effective deposition of gold nanoparticles onto silica spheres in terms of particle size and gold content in the final SiO2-LS-AuNPs composites. Due to the hydrophobicity of the modified silica it was necessary to carry out the modification in mixed organic/aqueous solvent. The polarity of the organic co-solvent was found to have an effect on the size of the deposited Au-NPs and their quantity. The physical appearance of the obtained hybrids was analyzed by colorimetry, and their structure and composition were evaluated using transmission electron microscopy (TEM). Additionally dispersive and thermal properties were examined by dynamic light scattering (DLS) and thermogravimetry (TG), respectively. The obtained multifunctional hybrid materials exhibits remarkable catalytic activity for the reduction of C.I. Basic Blue 9 (Methylene Blue) by borohydride.

A new chitosan/sponge chitin – based membrane (CS/CH membrane) was prepared via the casting method for the first time. We used the demineralized skeleton of the marine demosponge Ianthella basta as a source for a chitinous network. The obtained membrane was immersed in 1 M LiOAc (lithium acetate) solution and tested in an Electric Double Layer Capacitor (EDLC) cell. For comparison, chitosan (CS) with LiOAc solution was also tested. The studies performed indicated good properties of the CS/CH membrane. Very good mechanical stability (for use in electrochemical capacitors) and electrochemical properties of the CS membrane were achieved by the addition of chitin isolated from the sponge to the polymer matrix. Their electrochemical performances were tested in EDLC cells by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The specific capacitances of the tested capacitor cells were found to be approximately 97 F g−1 and 88 F g−1 with CS/CH and CS membranes (in the voltage range 0–0.8 V), respectively.

Diverse fields of modern environmental technology are nowadays focused on the discovery and development of new sources for oil spill removal. An especially interesting type of sorbents is those of natural origin—biosorbents—as ready-to-use constructs with biodegradable, nontoxic, renewable and cost-efficient properties. Moreover, the growing problem of microplastic-related contamination in the oceans further encourages the use of biosorbents. Here, for the first time, naturally pre-designed molting cuticles of the Theraphosidae spider Avicularia sp. “Peru purple”, as part of constituting a large-scale spider origin waste material, were used for efficient sorption of crude oil. Compared with currently used materials, the proposed biosorbent of spider cuticular origin demonstrates excellent ability to remain on the water surface for a long time. In this study the morphology and hydrophobic features of Theraphosidae cuticle are investigated for the first time. The unique surface morphology and very low surface free energy (4.47 ± 0.08 mN/m) give the cuticle-based, tube-like, porous biosorbent excellent oleophilic–hydrophobic properties. The crude oil sorption capacities of A. sp. “Peru purple” molt structures in sea water, distilled water and fresh water were measured at 12.6 g/g, 15.8 g/g and 16.6 g/g respectively. These results indicate that this biomaterial is more efficient than such currently used fibrous sorbents as human hairs or chicken feathers. Four cycles of desorption were performed and confirmed the reusability of the proposed biosorbent. We suggest that the oil adsorption mechanism is related to the brush-like and microporous structure of the tubular spider molting cuticles and may also involve interaction between the cuticular wax layers and crude oil.

Marine demosponges (Porifera: Demospongiae) are recognized as first metazoans which have developed over millions of years of evolution effective survival strategies based on unique metabolic pathways to produce both biologically active secondary metabolites and biopolymer-based stiff skeletons with 3D architecture. Up to date, among marine demosponges, only representatives of the Verongiida order have been known to synthetize biologically active substances as well as skeletons made of structural polysaccharide chitin. This work, to our knowledge, demonstrates for the first time that chitin is an important structural component within skeletons of non-verongiid demosponges Acarnus wolffgangi and Echinoclathria gibbosa collected in the Red Sea. Calcofluor white staining, FTIR and Raman analysis, ESI-MS, SEM, and fluorescence microscopy as well as a chitinase digestion assay were applied in order to confirm, with strong evidence, the finding of α-chitin in the skeleton of both species. We suggest that, the finding of chitin within these representatives of Poecilosclerida order is a promising step in the evaluation of these sponges as novel renewable sources for both biologically active metabolites and chitin, which are of prospective application for pharmacology and biomedicine.

Chitin and lignin are important, widespread, natural biopolymers and they have gained much attention in various branches of science. Recently, due to the unique properties of these biopolymers, special attention has been paid to the synthesis of various chitin-based and lignin-based inorganic-organic hybrids with defined porous structure parameters. This chapter reviews the use of spray drying as a useful technique for controlled synthesis of inorganic-organic functional materials, with chitin-silica and lignin-silica as examples.

Chitinous scaffolds isolated from the skeleton of marine sponge Aplysina cauliformis were used as a template for the deposition of polyhedral oligomeric silsesquioxanes (POSS). These chitin–POSS based composites with hydrophobic properties were prepared for the first time using solvothermal synthesis (pH 3, temp 80 °C), and were thoroughly characterized. The resulting material was studied using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and thermogravimetry. A mechanism for the chitin-POSS interaction after exposure to these solvothermal conditions is proposed and discussed.

This work presents an extreme biomimetics route for the creation of nanostructured biocomposites utilizing a chitinous template of poriferan origin. The specific thermal stability of the nanostructured chitinous template allowed for the formation under hydrothermal conditions of a novel germanium oxide-chitin composite with a defined nanoscale structure. Using a variety of analytical techniques (FTIR, Raman, energy dispersive X-ray (EDX), near-edge X-ray absorption fine structure (NEXAFS), and photoluminescence (PL) spectroscopy, EDS-mapping, selected area for the electron diffraction pattern (SAEDP), and transmission electron microscopy (TEM)), we showed that this bioorganic scaffold induces the growth of GeO2 nanocrystals with a narrow (150–300 nm) size distribution and predominantly hexagonal phase, demonstrating the chitin template’s control over the crystal morphology. The formed GeO2–chitin composite showed several specific physical properties, such as a striking enhancement in photoluminescence exceeding values previously reported in GeO2-based biomaterials. These data demonstrate the potential of extreme biomimetics for developing new-generation nanostructured materials.

An advanced functional silica/lignin material was obtained and tested as a novel adsorbent of nickel(II) and cadmium(II) ions. The ‘green’ sorbent was obtained chemically from the commercial silica Syloid®244 and kraft lignin. The resulting hybrid material exhibited specific physicochemical and structural properties, which were determined by a number of methods, including Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy, electrophoretic light scattering, nitrogen sorption and others. The surface area of the hybrid material was 223 m 2 /g. The obtained material was tested as an adsorbent of hazardous metals from aqueous solutions, and an analysis was made of parameters influencing the effectiveness of the adsorption process, such as duration, pH of solution and mass of adsorbent. The kinetics of the process were approximated by pseudo-first-order and pseudo-second-order models; the experimental data were found to correspond well to the pseudo-second-order model, with correlation coefficient r 2 = 0.999. The isotherms of adsorption equilibrium were fitted by the Langmuir and Freundlich models using a nonlinear regression method, and good correspondence of the experimental data to the Langmuir isotherm was obtained.

A chitin/lignin material with defined physicochemical and morphological properties was used as an effective adsorbent of environmentally toxic metals from model systems. Particularly significant is its use in the neutralization of real industrial wastes. The ions Ni 2+ , Cu 2+ , Zn 2+ and Pb 2+ were adsorbed on the functional sorbent, confirming the high sorption capacity of the newly obtained product, primarily due to the presence on its surface of numerous active functional groups from the component biopolymers. The kinetics of the process of ion adsorption from model solution were investigated, and the experimental data were found to fit significantly better to a type 1 pseudo-second-order kinetic model, as confirmed by the high correlation coefficient of 0.999 for adsorption of both nickel(II) copper(II) zinc(II) and lead(II) ions. The experimental data obtained on the basis of adsorption isotherms corresponded to the Langmuir model. The sorption capacity of the chitin/lignin material was measured at 70.41 mg(Ni 2+ )/g, 75.70 mg(Cu 2+ )/g, 82.41 mg(Zn 2+ )/g and 91.74 mg(Pb 2+ )/g. Analysis of thermodynamic parameters confirmed the endothermic nature of the process. It was also shown that nitric acid is a very effective desorbing (regenerating) agent, enabling the chitin/lignin material to be reused as an effective sorbent of metal ions. The sorption abilities of the chitin/lignin system with respect to particular metal ions can be ordered in the sequence Ni 2+ 2+ 2+ 2+ . Tests were also performed with the adsorption of ions of nickel(II), copper(II), zinc(II) and lead(II) from wastewater obtained from galvanization and battery production plants, confirming the ability of the chitin/lignin sorbent to adsorb harmful ions from real industrial wastes.

It is shown that the chemical reduction of silver ions by lignosulfonate (LS) in a mixed aqueous–organic solvent produces silver nanoparticles (AgNPs). If, additionally, spherical silica (SiO2) (surface-functionalized with various organic groups) is introduced to the reaction mixture, the LS-stabilized Ag-NPs are deposited on the surface of the silica spheres, forming a SiO2–LS–AgNPs hybrid material. The efficiency of the process is found to depend significantly on both the polarity of the organic solvent and the hydrophobicity of the SiO2-grafted functionalities. The most effective synthesis was in a mixed dimethylformamide–water solvent with octadecylsilane-functionalized SiO2. It is concluded that hydrophobic forces are essential for the successful coupling of LS–AgNPs with the surface of the modified silica. The formation of LS–AgNPs was monitored by UV-Vis spectroscopy, and the properties of the final hybrid materials were determined by EDS, elemental analysis, NIBS, TGA colorimetric analysis and HRTEM techniques. The resulting SiO2–LS–AgNPs hybrids were also used as SERS substrates with Rhodamine 6G as a test molecule.

Chitin occurs in a variety of invertebrates, especially in arthropod cuticles, but is rarely reported in the fossil record. Although it has been detected in fossils as old as Middle Cambrian and Silurian, the majority of records come from much younger, Cenozoic deposits. In this paper, we report the preservation of chitin in Early Jurassic neritimorph gastropod egg capsules deposited in bivalve shells from prodelta-deltafront and nearshore paleoenvironments of the Holy Cross Mountains, Poland. We used a number of analytical methods to confirm the presence of chitin preserved in these ancient fossils. This is the first record of chitin preservation in Mesozoic deposits that, interestingly, do not follow the conventional Konservat-Lagerstätten manner of preserving soft-bodied and non-biomineralized organisms. We believe that deltaic settings characterized by episodic, high input of fluvial deposits, oligohaline conditions, and oxygen-poor microenvironment within the sediment—as well as early cementation of sediment infilling the shells—were crucial for chitin preservation. The preservation of chitin in such recalcitrant structures as egg capsules and deposits that formed outside conventional Konservat-Lagerstätten conditions renders it likely similar deposits may yield promise for discoveries of similar biological macromolecules.

WOS: 000412959500037, PubMed: 28185932, Since the discovery of chitin in skeletal structures of sponges (Porifera) in 2007, studies on search of novel species which possess this structural aminopolysaccharide continue up today. The most potential source of chitin is suggested to be localized in the four families of sponges related to the order Verongida (Demospongiae) which nevertheless require further clarification. Here, we report for the first time the isolation and identification of alpha-chitin from the Suberea clavata demosponge (Aplysinidae: Verongida). Raman spectroscopy, Calcofluor White staining, chitinase test and ESI-MS techniques were used to identify chitin. We suggest that the presence of chitin within fibrous skeletons of diverse species of Verongida order, and, especially in all species of the Aplysinidae family, may be useful for the identification of novel, previously unidentified marine demosponges. (C) 2017 Elsevier B.V. All rights reserved., DFG (Germany) [EH 394-3]; PUT research grant (Poland) [03/32/DSPB/0706/2017], This work was supported by DFG Grant EH 394-3 (Germany) and PUT research grant 03/32/DSPB/0706/2017 (Poland). The authors thank Prof. Dr. Yixin Zhang for the use of the ESI-MS instrument and Rob van Soest for his support and comments.

Chitinous scaffolds isolated from marine demosponge Ianthella basta represent novel templates for deposition of metals such as copper and copper oxides. In contrast to traditional Extreme Biomimetics methods which are based on high temperature reactions, here, we propose an alternative way based on a well-known process – electrochemical deposition or plating. This method allows production of 3D composite materials with metallic and metal oxide structures within their surfaces. For the first time chitinous scaffolds of poriferan origin, which possess a 3D network structure, were used for the copper plating. The nanocrystallites of metallic phase obtained on chitinous fibres represents replicas of the original nanofibrous substrate.

Chitin, as a fundamental polysaccharide in invertebrate skeletons, continues to be actively investigated, especially with respect to new sources and the development of effective methods for its extraction. Recent attention has been focused on marine crustaceans and sponges, however, the potential of spiders (order Araneae) as an alternative source of tubular chitin has been overlooked. In this work, we focused our attention on chitin from up to 12 cm-large Theraphosidae spiders, popularly known as tarantulas or bird-eating spiders. These organisms &ldquo, lose&rdquo, large quantities of cuticles during their molting cycle. Here, we present for the first time a highly effective method for the isolation of chitin from Caribena versicolor spider molt cuticle, as well as its identification and characterization using modern analytical methods. We suggest that the tube-like molt cuticle of this spider can serve as a naturally prefabricated and renewable source of tubular chitin with high potential for application in technology and biomedicine.

The bioactive bromotyrosine-derived alkaloids and unique morphologically-defined fibrous skeleton of chitin origin have been found recently in marine demosponges of the order Verongiida. The sophisticated three-dimensional (3D) structure of skeletal chitinous scaffolds supported their use in biomedicine, tissue engineering as well as in diverse modern technologies. The goal of this study was the screening of new species of the order Verongiida to find another renewable source of naturally prefabricated 3D chitinous scaffolds. Special attention was paid to demosponge species, which could be farmed on large scale using marine aquaculture methods. In this study, the demosponge Pseudoceratina arabica collected in the coastal waters of the Egyptian Red Sea was examined as a potential source of chitin for the first time. Various bioanalytical tools including scanning electron microscopy (SEM), fluorescence microscopy, FTIR analysis, Calcofluor white staining, electrospray ionization mass spectrometry (ESI-MS), as well as a chitinase digestion assay were successfully used to confirm the discovery of &alpha, chitin within the skeleton of P. arabica. The current finding should make an important contribution to the field of application of this verongiid sponge as a novel renewable source of biologically-active metabolites and chitin, which are important for development of the blue biotechnology especially in marine oriented biomedicine.

Chitin is a thermostable biopolymer found in various inorganic-organic skeletal structures of numerous invertebrates including sponges (Porifera). The occurrence of chitin within calcium- and silica-based biominerals in organisms living in extreme natural conditions has inspired development of new (extreme biomimetic) synthesis route of chitin-based hybrid materials in vitro. Here, we show for the first time that 3D-α-chitin scaffolds isolated from skeletons of the marine sponge Aplysina aerophoba can be effectively mineralized under hydrothermal conditions (150°C) using ammonium zirconium(IV) carbonate as a precursor of zirconia. Obtained chitin-ZrO2 hybrid materials were characterized by FT-IR, SEM, HRTEM, as well as light and confocal laser microscopy. We suggest that formation of chitin-ZrO2 hybrids occurs due to hydrogen bonds between chitin and ZrO2.