Biomineralization of soil with crude soybean urease using different calcium salts

Calcium salt is an important contributing factor for calcium-based biomineralization.To study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this paper.Two series of biomineralization tests in solution and sand column,respectively,were conducted.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) crystals.The experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this study.The difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

Biomimetic biomineralization nanoplatform-mediated differentiation therapy and phototherapy for cancer stem cell inhibition and antitumor immunity activation

Growing evidence suggests that the presence of cancer stem cells(CSCs)is a major challenge in current tumor treatments,especially the transition from non-CSCs to differentiation of CSCs for evading conventional therapies and driving metastasis.Here we propose a therapeutic strategy of synergistic differentiation therapy and phototherapy to induce differentiation of CSCs into mature tumor cells by differentiation inducers and synergistic elimination of them and normal cancer cells through phototherapy.In this work,we synthesized a biomimetic nanoplatform loaded with IR-780 and all-trans retinoic acid(ATRA)via biomineralization.This method can integrate aluminum ions into small-sized protein carriers to form nanoclusters,which undergo responsive degradation under acidic conditions and facilitate deep tumor penetration.With the help of CSC differentiation induced by ATRA,IR-780 inhibited the self-renewal of CSCs and cancer progression by generating hyperthermia and reactive oxygen species in a synergistic manner.Furthermore,ATRA can boost immunogenic cell death induced by phototherapy,thereby strongly causing a systemic anti-tumor immune response and efficiently eliminating CSCs and tumor cells.Taken together,this dual strategy represents a new paradigm of targeted eradication of CSCs and tumors by inducing CSC differentiation,improving photothermal therapy/photodynamic therapy and enhancing antitumor immunity.

Biomineralization of Uranium: A Simulated Experiment and Its Significance

A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were: 35°C, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments, might have participated in the biomineralization of this uranium deposit. There is an important difference in the order- disorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.

Does acid pickling of Mg-Ca alloy enhance biomineralization?

The mechanical and physical properties of biodegradable magnesium(Mg)alloys make them suitable for temporary orthopaedic implants.The success of these alloys depends on their performance in the physiological environment.In the present work,surface modification of Mg-Ca binary alloy by acid pickling for better biomineralization and controlled biodegradation is explored.The corrosion rates of nitric and phosphoric acid treated samples were analysed by conducting electrochemical corrosion tests.In vitro degradation behaviour was studied using immersion test in simulated body fluid(SBF).The sample surfaces were characterized using scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).It is seen that acid pickling leads to significant improvement in biomineralization and develop in situ calcium phosphate(Ca P)coating on the sample surfaces.In addition,the treated samples recorded a reduced degradation rate in the SBF compared to untreated samples.Thus,acid pickling is suggested as an effective surface treatment method to tailor the biomineralization and degradation behaviour of the Mg-Ca alloy in the physiological environment.

Redox control of magnetosome biomineralization

Magnetotactic bacteria can orientate in the Earth’s magnetic field to search for their preferred microoxic environments,which is achieved by their unique organelles,the magnetosomes.Magnetosomes contain nanometer-sized crystal particles of magnetic iron minerals,which are only synthesized in lowoxygen environments.Although the mechanism of aerobic repression for magnetosome biomineralization has not yet fully understood,a series of studies have verified that redox modulation is pivotal for magnetosome formation.In this review,these advances in redox modulation for magnetosome biosynthesis are highlighted,mainly including respiration pathway enzymes,specific magnetosome-associated redox proteins,and oxygen-or nitrate-sensing regulators.Furthermore,their relationship during magnetosome biomineralization is discussed to give insight into redox control and biomineralization and inspire potential solutions for the application of respiration pathways to improve the yields of magnetosome.

Hot-Water Deposition of Pyritic Stromatolite and Its Relation to Biomineralization

Pyritic stromatolite, a rich pyrite ore, is scattered as reef masses in sedex deposits of the Proterozoic Yanshan rift trough. The pyritic stromatolite consists of a core and alternating concentric rims of light colloidal pyrite and dark organic materials. The concentric rims are cemented together by trichomes highly similar to the trichomic microorganisms inhabiting substantively around the black chimneys on the current sea beds while the core is composed chiefly of groups of thermophilous sulphur bacteria. Biomarkers for the molecules of pyritic stromatolite include pristane, phytane, regular isoprenoids paraffin, methyl-heptadecyl, and so on. This study reveals the existence of methane-yielding bacteria in the pyritic stromatolite and reflects the evolution of thermophilous thallophyta.

Biomineralization Precursor Carrier System Based on Carboxyl- Functionalized Large Pore Mesoporous Silica Nanoparticles

Bone and teeth are derived from intrafibrillarly mineralized collagen fibrils as the second level of hierarchy.According to polymer-induced liquid-precursor process,using amorphous calcium phosphate precursor(ACP)is able to achieve intrafibrillar mineralization in the case of bone biomineral in vitro.Therefore,ACP precursors might be blended with any osteoconductive scaffold as a promising bone formation supplement for in-situ remineralization of collagens in bone.In this study,mesoporous silica nanoparticles with carboxyl-functionalized groups and ultra large-pores have been synthesized and used for the delivery of liquid like biomimetic precursors(ACP).The precursor delivery capacity of the nanoparticles was verified by the precursor release profile and successful mineralization of 2D and 3D collagen models.The nanoparticles could be completely degraded in 60 days and exhibited good biocompatibility as well.The successful translational strategy for biomineralization precursors showed that biomineralization precursor laden ultra large pore mesoporous silica possessed the potential as a versatile supplement in demineralized bone formation through the induction of intrafibrillar collagen mineralization.

Biomineralization of the Surface of PLGA-(ASP-PEG) Modified with the K_(16) and RGD-containing Peptide

K16 and RGD-containing peptide was used to modify the surface of three-dimensional PLGA-（ASP-PEG） matrix, then the modified PLGA-（ASP-PEG） was incubated in modified simulated body fluid （SBF）. The biomineralization of the modified PLGA- （ASP-PEG） was explored, and the peptide was synthesized with solid phase synthesis technology and linked cova-lently to PLGA-（ASP-PEG） through cross-linker （Sulfo-LC-SPDP）, which was characterized with XPS. The modified PLGA-（ASP-PEG） （Experiment group, EG） and PLGA-（ASP-PEG） （Control group, CG） were all incubated into SBF for 10 d, and the growth of hydroxyapatite （HA） nanocrys-tals was confirmed with XRD, EDS and SEM. HPLC shows that peptide purity is 94.13%, while MS analysis shows that molecular value of peptide is 2741.26. Binding energy of the sulphur in EG was 164 eV is detected by XPS, and the ratio of carbon and sulphur is 99.746：0.1014. SEM analysis demonstrates the better growth of bonelike HA nanocrystals in EG than that in CG. The component of mineral in EG consisted mainly of hydroxyapatite containing low crystalline nanocrystals, and the Ca/P ratio is about 1.60, which is similar to that of natural bone, while the Ca/P ratio in CG is 1.52. PLGA-（ASP-PEG） modified with peptide provided enough functional groups for biomineralization, and possessed the bonelike structure.

Biomineralization in the La' erma Gold Deposit of the Western Qinling Mountains

Geological and geochemical studies and experiments on mineralization indicate that the source bed of the La' erma gold deposit in the south subbelt of the western Qinling Mountains is hydrothermal cherts in the Cambrian Taiyangding Group. Organic geochemical study of the cherts shows that the organic precursors intimately associated with gold are marine bacteria and algae. The gold content in chert,is positively correlated with the amount of bacterial and algal microfossils, and simulation experiments on biomineralization of modern bacteria and algae indicate that bacteria and algae played an important role in the formation of the La' erma gold deposit.

Remnants of an Powerful Ancient “Dynasty”:Material Cycle and Biomineralization in Modern Seafloor Hydrothermal System

The origin of ancient banded iron formation （BIF） has remained unclear for a long time. How the precipitation process occurred and what the environmental condition was have been widely discussed among scientists, because the period when the major BIFs deposited （-2.8 to 1.8Ga） is the same time when biosphere and atmosphere significantly changed. Based on the discovery of modern seafloor hydrothermal vents, it is possible that reductive environment controlled by vent system is related to the environment where BIF was deposited. According to matter source.

Biomineralization of Zinc-Phosphate-Based Nano Needles by Living Microalgae

Up to now, chemical synthesis routes only provide restricted opportunities for the formation of structured nano particles. In contrast, living microorganisms generate nano materials of well defined shapes by the precise control of biomineralization. Here we reveal new principles for the generation of functional nano materials through the process of biomineralization. We used the detoxification mechanism of the unicellular alga Scenedesmus obliquus to generate a techno logically interesting zinc-phosphate-based nano material. The algae were incubated in media with a sublethal zinc concentration (6.53 mg Zn dm-3) for 4 weeks. Using BF-and ADF-STEM imaging combined with analytical XEDS we could show that nano needles containing phosphorus and zinc were formed inside the living cells. Further more, the cells incubated with zinc show a strong fluorescence. Our findings indicate that the algae used polyphosphate bodies for detoxification of the zinc ions, leading to the generation of intracellular zinc-phosphate-based nano needles. Beside the technological application of this material, the fluorescent cells can be used for labeling of e.g. biological probes. This new experimental protocol for the production of an inorganic functional material can be applied also for other substances.

A Chicken's Egg as a Reaction Vessel to Explore Biomineralization

Natural composites, formed through biomineralization, have highly ordered structures which have been aptly explored for functional applications. Though the role of organic phases has been well understood in biomineralization, not enough attention has been paid to the role of bio-membranes which are often found encapsulating the chamber in which mineralization occurs. We have used the natural protein and semi-permeable membrane of chicken eggs to grow different materials such as ceramics, semi-metals and metals to understand the role of bio-membranes in biomineralization. We here report the successful biomimetic synthesis of calcite, cadmium sulphide, and silver having homogeneous morphologies. We have found that the membrane operates like a tuned gateway, playing a significant role in controlling the morphology of the inorganic crystals formed during biomineralization.

In vivo and in vitro biomineralization in the presence of the inner-shell film of pearl oyster

The inner shell surface is the biomineralization site in shell formation and an inner-shell film covers it. This surface is composed of two regions： an outer calcitic region and an inner aragonitic region. In this study, some amalgamated calcite crystals were found in the calcitic region and some aragonitic ＂imprints＂ were found in the central part of the aragonitic region. The ＂imprints＂ are probably the trace of mantle cells that adhered to the inner shell surface when the shell was produced. Furthermore, to build a novel in vitro biomineralization system, the inner-shell film was detached from the shell and introduced to the calcitic crystallization solution. Crystallization experiments showed that nacre proteins could induce aragonite crystals in the novel system but inhibited calcite growth in the absence of the inner-shell film. These data suggested that the inner-shell film may induce aragonite growth in vivo by combining nacre proteins.

In Vitro Biomineralization of Glutaraldehyde Crosslinked Chitosan/Glutamic Acid Films

In vitro biomineralization of glutaraldehyde crosslinked chitosan/glutamic acid films were studied. IR and ESCA （electron spectroscopy for chemical analysis） determinations confirm that chitosan and glutamic acid are successfully crosslinked by glutaraldehyde to form chitosan-glutamic acid surfaces. Composite films were soaked in saturated Ca（OH）2 solution for 8 d and then immersed in simulated body fluid （SBF） for more than 20 d. Morphological characterizations and structure of cal-cium phosphate coatings deposited on the films were studied by SEM, XRD, and EDAX （energy dispersive X-ray analysis）. Initially, the treatment in SBF results in the formation of single-layer cal-cium phosphate particles over the film surface. As immersion time increases, further nucleation and growth produce the simulated calcium-carbonate hydroxyapatite coating. ICP results show Ca/P ratio of calcium phosphate coating is a function of SBF immersion time. The inducing of glutamic acid improves the biomineralization property of chitosan films.

Removal of Au(III) from Aqueous Au(III) Solution Using Microbial Cells by Biosorption and Biomineralization

The demand for gold has increased in the medical and industrial fields. Therefore, recycling this element has become essential. Although gold recovery using microbes has been investigated, there is a dearth of these studies on identifying the species that have a high gold recovering ability. Herein, gold (III) removal by microbial cells was investigated to obtain basic information on gold (III) removal from aqueous systems by biosorption and biomineralization. High amounts of gold were removed from the solution containing hydrogen tetrachloroaurate (III) by the tested microbial species, which included bacteria, fungi and yeasts. However, relatively less gold was recovered by biosorption using gram-positive bacteria, fungi, and yeasts than that by gram-negative bacteria. Therefore, we first examined gold (III) removal by biosorption and biomineralization by Pseudomonas saccharophila, which was able to remove the largest amounts of gold (III). Incubation time and other factors affecting gold removal were then examined. P. saccharophila removed about half the amount of gold (III) by biosorption and the remaining half by biomineralization.

Inorganic ionic polymerization:From biomineralization to materials manufacturing

Biomineralization process regulates the growth of inorganic minerals by complex molecules,proteins,and cells,endowing bio-materials with marvels structures and excellent properties.The intricate structures and compositions found in biominerals have inspired scientists to design and synthesize numerous artificial biomimetic materials.The methodology for controlling the formation of inorganics plays a pivotal role in achieving biomimetic structures and compositions.However,the current approach predominantly relies on the classical nucleation theory,which hinders the precise preparation of inorganic materials by replicating the biomineralization strategy.Recently,the development of“inorganic ionic polymerization”strategy has enabled us to regulate the arrangement of inorganic ions from solution to solid phase,which establishes an artificial way to produce inorganic materials analogous to the biomineralization process.Based on inorganic ionic polymerization,a series of achievements have been realized for the biomimetic preparation,including moldable construction of inorganic materials,hard tissue regeneration,and high-performance biomimetic materials.Moreover,the utilization of inorganic ionic polymerization has also facilitated the production of numerous advanced materials,including novel structures that exceed the current knowledge of materials science.The inorganic ionic polymerization system provides new artificial strategies and methodologies for the controllable synthesis of inorganics,which mimics the biomineralization process,paving the way for the future development of more high-performance materials.

An Injectable silk-based hydrogel as a novel biomineralization seedbed for critical-sized bone defect regeneration

The healing process of critical-sized bone defects urges for a suitable biomineralization environment. However, the unsatisfying repair outcome usually results from a disturbed intricate milieu and the lack of in situ mineralization resources. In this work, we have developed a composite hydrogel that mimics the natural bone healing processes and serves as a seedbed for bone regeneration. The oxidized silk fibroin and fibrin are incorporated as rigid geogrids, and amorphous calcium phosphate (ACP) and platelet-rich plasma serve as the fertilizers and loam, respectively. Encouragingly, the seedbed hydrogel demonstrates excellent mechanical and biomineralization properties as a stable scaffold and promotes vascularized bone regeneration in vivo. Additionally, the seedbed serves a succinate-like function via the PI3K-Akt signaling pathway and subsequently orchestrates the mitochondrial calcium uptake, further converting the exogenous ACP into endogenous ACP. Additionally, the seedbed hydrogel realizes the succession of calcium resources and promotes the evolution of the biotemplate from fibrin to collagen. Therefore, our work has established a novel silk-based hydrogel that functions as an in-situ biomineralization seedbed, providing a new insight for critical-sized bone defect regeneration.

Biomineralization inspired 3D printed bioactive glass nanocomposite scaffolds orchestrate diabetic bone regeneration by remodeling micromilieu

TypeⅡdiabetes mellitus(TIIDM)remains a challenging clinical issue for both dentists and orthopedists.By virtue of persistent hyperglycemia and altered host metabolism,the pathologic diabetic micromilieu with chronic inflammation,advanced glycation end products accumulation,and attenuated biomineralization severely impairs bone regeneration efficiency.Aiming to“remodel”the pathologic diabetic micromilieu,we 3D-printed bioscaffolds composed of Sr-containing mesoporous bioactive glass nanoparticles(Sr-MBGNs)and gelatin methacrylate(GelMA).Sr-MBGNs act as a biomineralization precursor embedded in the GelMA-simulated extracellular matrix and release Sr,Ca,and Si ions enhancing osteogenic,angiogenic,and immunomodulatory properties.In addition to angiogenic and anti-inflammatory outcomes,this innovative design reveals that the nanocomposites can modulate extracellular matrix reconstruction and simulate biomineralization by activating lysyl oxidase to form healthy enzymatic crosslinked collagen,promoting cell focal adhesion,modulating osteoblast differentiation,and boosting the release of OCN,the noncollagenous proteins(intrafibrillar mineralization dependent),and thus orchestrating osteogenesis through the Kindlin-2/PTH1R/OCN axis.This 3D-printed bioscaffold provides a multifunctional biomineralization-inspired system that remodels the“barren”diabetic microenvironment and sheds light on the new bone regeneration approaches for TIIDM.

Unusual uranium biomineralization induced by green algae: Behavior investigation and mechanism probe

As a biosorbent,algae are frequently used for the biotreatment or bioremediation of water contaminated by heavymetal or radionuclides.However,it is unclear that whether or not the biomineralization of these metal or radionuclides can be induced by algae in the process of bioremediation and what the mechanism is.In this work,Ankistrodsemus sp.has been used to treat the uranium-contaminated water,and more than 98%of uranium in the solution can be removed by the alga,when the initial uranium concentration ranges from 10 to 80 mg/L.Especially,an unusual phenomenon of algae-induced uranium biomineralization has been found in the process of uranium bioremediation and its mineralization mechanism has been explored bymultiple approaches.It is worth noticing that the biomineralization of uranium induced by Ankistrodsemus sp.is significantly affected by contact time and pH.Uranium is captured rapidly on the cell surface via complexation with the carboxylate radical,amino and amide groups of themicroalgae cells,which provides nucleation sites for the precipitation of insolubleminerals.Uranium stimulates Ankistrodsemus sp.to metabolize potassium ions(K+),which may endow algae with the ability to biomineralize uranium into the rose-like compreignacite(K_(2)[(UO_(2))6O_(4)(OH)_(6)]•8H_(2)O).As the time increased,the amorphous gradually converted into compreignacite crystals and a large number of crystals would expand over both inside and outside the cells.To the best of our knowledge,this is the first investigated microalgae with a time-dependent uranium biomineralization ability and superior tolerance to uranium.This work validates that Ankistrodsemus sp.is a promising alga for the treatment of uranium-contaminated wastewater.

MV-mediated biomineralization mechanisms and treatments of biomineralized diseases

As the quality of life improves,people pay more and more attention to health.They are concerned about the causes of diseases,and seek better treatments.The most common diseases are biomineralized diseases,four different kinds of typical examples among which are selected to elaborate their mechanisms and existing treatments.Whether it is tooth and bone in physiological mineralization or cartilage and blood vessel in pathological mineralization,they are all related to matrix vesicle(MV)-mediated biomineralization.MV-mediated biomineralization is the initial stage of biomineralization and the nucleation site mediating collagen mineralization.Definition,composition,biogenesis,and action mechanism of MVs are refined and expounded,especially a novel biomineralization pathway similar to exosome(EX)origin.Four differences are summarized to distinguish MVs and EXs.A series of treatments using MVs to solve biomineralized diseases such as tooth and bone defects,osteoarthritis and atherosclerosis are proposed,and the experimental extraction steps of MVs are summarized.