In this study, biosilica of high purity was successfully prepared from marine diatom （Nitzschia closterium and Thalassiosira） biomass using an optimized novel method with acid washing treatment followed by thermal t...In this study, biosilica of high purity was successfully prepared from marine diatom （Nitzschia closterium and Thalassiosira） biomass using an optimized novel method with acid washing treatment followed by thermal treatment of the biomass. The optimal condition of the method was 2% diluted HCl washing and baking at 600℃. The SiO2 contents of N. closterium biosilica and Thalassiosira biosilica were 92.23% and 91.52%, respectively, which were both higher than that of diatomite biosilica. The SiO2 morphologies of both biosilica are typical amorphous silica. Besides, IV. closterium biosilica possessed micropores and fibers with a surface area of 59.81 m^2/g. And Thalassiosira biosilica possessed a mesoporous hierarchical skeleton with a surface area of 9.91 m^2/g. The results suggest that the biosilica samples obtained in this study present highly porous structures. The prepared porous biosilica material possesses great potential to be used as drug delivery carrier, biosensor, biocatalyst as well as adsorbent in the future.展开更多
Biogenic silica with amazing diversity of nanostructure shells, fibers andgranules in diatoms and sponges is mediated by proteins and polysaccharides and forms at ambientpressure and temperatures. Chemical synthetic m...Biogenic silica with amazing diversity of nanostructure shells, fibers andgranules in diatoms and sponges is mediated by proteins and polysaccharides and forms at ambientpressure and temperatures. Chemical synthetic methods, in contrast, have to rely on extreme pHand/or surfactants to induce the condensation of silica precursors into specific patterns. One kindof benign synthesis method through plant cell wall template-directed ordered biosilica materialsunder ambient conditions is intriguing in this context. Organized silica materials in intercellularspaces of epidermal cells of tall fescue leaves were synthesized through molecular recognitionbetween Si-OH and polysaccharide-OH or glycoprotein-OH of main components of plant cell walls andcellular processing as well when Si(OEt)_4 was supplied rather than monosilicic acid. Thebiosynthesis of structural silica in tall fescue plant was correlated with the Si species applied,reflecting the slower condensation from tetraethoxysilane (TEOS) and thus providing greateropportunities for structural control by the underlying matrix of cell walls. The composition wasestimated by energy dispersive X-ray (EDX) spectra on a scanning electron microscope. All organizedstructures showed carbon, oxygen and silicon peaks, indicating that their formations differ fromnatural siliceous process.展开更多
In the last 15 years biomineralization, in particular biosilicification （i.e., the formation of biogenic silica, SiO2）, has become an exciting source of inspiration for the development of novel bionic approaches, fo...In the last 15 years biomineralization, in particular biosilicification （i.e., the formation of biogenic silica, SiO2）, has become an exciting source of inspiration for the development of novel bionic approaches, following ＂Nature as model＂. Among the silica forming organisms there are the sponges that have the unique property to catalyze their silica skeletons by a specific enzyme termed silicatein. In the present review we summarize the present state of knowledge on silicatein-mediated ＂biosilica＂ formation in marine sponges, the involvement of further molecules in silica metabolism and their potential application in biomedicine. Recent advancements in the production of bone replacement material and in the potential use as a component in the treatment of osteoporosis are highlighted.展开更多
Hemorrhage control requires hemostatic materials that are both efective and biocompatible.Among these,diatom biosilica(DBs)could signifcantly improve hemorrhage control,but it induces hemolysis(the hemolysis rate>5...Hemorrhage control requires hemostatic materials that are both efective and biocompatible.Among these,diatom biosilica(DBs)could signifcantly improve hemorrhage control,but it induces hemolysis(the hemolysis rate>5%).Thus,the purpose of this study was to explore the infuence of Ca^(2+)biomineralization on DBs for developing fast hemostatic materials with a low hemolysis rate.Here,CaCl_(2)was added to the diatom medium under high light(cool white,fuorescent lamps,67.5µmol m^(−2) s^(−1)),producing Ca-DBs-3 with a particle size of 40-50μm and a Ca^(2+)content of Ca-DBs-3 obtained from the higher concentration CaCl_(2)group(6.7 mmol L^(−1))of 0.16%.The liquid absorption capacity of Ca-DBs-3 was 30.43±0.57 times its dry weight;the in vitro clotting time was comparable to QuikClot®zeolite;the hemostatic time and blood loss using the rat tail amputation model were 36.40±2.52 s and 0.39±0.12 g,which were 40.72%and 19.50%of QuikClot®zeolite,respectively.Ca-DBs-3 showed no apparent toxicity to L929 cells(cell viability>80%)and was non-hemolysis(the hemolysis rate<2%).This study prepared Ca-DBs-3 with a rapid hemostatic efect and good biocompatibility,providing a path to develop diatom biosilica hemostatic materials.展开更多
Diatom frustules,considered as novel bio-functional materials,display a diversity of patterns and unique micro-and nanostructures which may be useful in many areas of application.Existing devices directly use the orig...Diatom frustules,considered as novel bio-functional materials,display a diversity of patterns and unique micro-and nanostructures which may be useful in many areas of application.Existing devices directly use the original structure of the biosilica frustules,limiting their function and structural scale.Current research into the shapes,materials and structural properties of frustules are considered;a series of frustule processing methods including structure processing,material modification,bonding and assembly techniques are reviewed and discussed.The aim is to improve the function of diatom frustules allowing them to meet the design requirements of different types of micro devices.In addition,the importance of the comprehensive use of diatom processing methods in device research is discussed using biosensors and solar cells as examples,and the potential of bio-manufacturing technology based on diatom frustules is examined.展开更多
Sponges are the oldest and the simplest but not primitive multicellular animals. They represent the earliest evolutionary metazoan phylum still extant. It was a long and painful scientific process to posi-tion the mos...Sponges are the oldest and the simplest but not primitive multicellular animals. They represent the earliest evolutionary metazoan phylum still extant. It was a long and painful scientific process to posi-tion the most enigmatic and mysterious metazoan,the Porifera,into their correct phylogenetic place among the eukaryotes in general and multicellular animals in particular. As living fossils,sponges provide the best evidence for the early evolution of Metazoa. More recently,interest has been focused on the bionic applications of sponges' siliceous spicules,after the discovery of their unique structure and high fiber performance. In this review,the emergence of sponges,evolutionary novelties found in sponges,and the phylogenetic position of sponges in early metazoan evolution are highlighted. In ad-dition,the present state of knowledge on silicatein-mediated "biosilica" formation in marine sponges,including the involvement of other molecules in silica metabolism and their potential application in nanobiotechnology and medicine,is given.展开更多
基金Supported by the Public Science and Technology Research Funds Projects of Ocean,China(No.201305022)the PhD Start-up Fund of Natural Science Foundation of Guangdong Province,China(No.2014A030310326)
文摘In this study, biosilica of high purity was successfully prepared from marine diatom （Nitzschia closterium and Thalassiosira） biomass using an optimized novel method with acid washing treatment followed by thermal treatment of the biomass. The optimal condition of the method was 2% diluted HCl washing and baking at 600℃. The SiO2 contents of N. closterium biosilica and Thalassiosira biosilica were 92.23% and 91.52%, respectively, which were both higher than that of diatomite biosilica. The SiO2 morphologies of both biosilica are typical amorphous silica. Besides, IV. closterium biosilica possessed micropores and fibers with a surface area of 59.81 m^2/g. And Thalassiosira biosilica possessed a mesoporous hierarchical skeleton with a surface area of 9.91 m^2/g. The results suggest that the biosilica samples obtained in this study present highly porous structures. The prepared porous biosilica material possesses great potential to be used as drug delivery carrier, biosensor, biocatalyst as well as adsorbent in the future.
基金theNationalNaturalScienceFoundationofChina (No 39870 480 )andNationalKeyBasicResearchFoundation(No.G19990 1170 0 )
文摘Biogenic silica with amazing diversity of nanostructure shells, fibers andgranules in diatoms and sponges is mediated by proteins and polysaccharides and forms at ambientpressure and temperatures. Chemical synthetic methods, in contrast, have to rely on extreme pHand/or surfactants to induce the condensation of silica precursors into specific patterns. One kindof benign synthesis method through plant cell wall template-directed ordered biosilica materialsunder ambient conditions is intriguing in this context. Organized silica materials in intercellularspaces of epidermal cells of tall fescue leaves were synthesized through molecular recognitionbetween Si-OH and polysaccharide-OH or glycoprotein-OH of main components of plant cell walls andcellular processing as well when Si(OEt)_4 was supplied rather than monosilicic acid. Thebiosynthesis of structural silica in tall fescue plant was correlated with the Si species applied,reflecting the slower condensation from tetraethoxysilane (TEOS) and thus providing greateropportunities for structural control by the underlying matrix of cell walls. The composition wasestimated by energy dispersive X-ray (EDX) spectra on a scanning electron microscope. All organizedstructures showed carbon, oxygen and silicon peaks, indicating that their formations differ fromnatural siliceous process.
文摘In the last 15 years biomineralization, in particular biosilicification （i.e., the formation of biogenic silica, SiO2）, has become an exciting source of inspiration for the development of novel bionic approaches, following ＂Nature as model＂. Among the silica forming organisms there are the sponges that have the unique property to catalyze their silica skeletons by a specific enzyme termed silicatein. In the present review we summarize the present state of knowledge on silicatein-mediated ＂biosilica＂ formation in marine sponges, the involvement of further molecules in silica metabolism and their potential application in biomedicine. Recent advancements in the production of bone replacement material and in the potential use as a component in the treatment of osteoporosis are highlighted.
基金The work was supported by National Natural Science Foundation of China(U22A20588,82172095)Shandong Provincial Natural Science Foundation(ZR2019QD005)Qingdao Science and Technology Demonstration and Guidance Project(20-3-4-50-nsh).
文摘Hemorrhage control requires hemostatic materials that are both efective and biocompatible.Among these,diatom biosilica(DBs)could signifcantly improve hemorrhage control,but it induces hemolysis(the hemolysis rate>5%).Thus,the purpose of this study was to explore the infuence of Ca^(2+)biomineralization on DBs for developing fast hemostatic materials with a low hemolysis rate.Here,CaCl_(2)was added to the diatom medium under high light(cool white,fuorescent lamps,67.5µmol m^(−2) s^(−1)),producing Ca-DBs-3 with a particle size of 40-50μm and a Ca^(2+)content of Ca-DBs-3 obtained from the higher concentration CaCl_(2)group(6.7 mmol L^(−1))of 0.16%.The liquid absorption capacity of Ca-DBs-3 was 30.43±0.57 times its dry weight;the in vitro clotting time was comparable to QuikClot®zeolite;the hemostatic time and blood loss using the rat tail amputation model were 36.40±2.52 s and 0.39±0.12 g,which were 40.72%and 19.50%of QuikClot®zeolite,respectively.Ca-DBs-3 showed no apparent toxicity to L929 cells(cell viability>80%)and was non-hemolysis(the hemolysis rate<2%).This study prepared Ca-DBs-3 with a rapid hemostatic efect and good biocompatibility,providing a path to develop diatom biosilica hemostatic materials.
基金supported by the National Natural Science Foundation of China (50805005,51075020)the National High Technology Research and Development Program of China (2009AA043804)the Doctoral Candidate Academic Newcomer Award of the Ministry of Education of China
文摘Diatom frustules,considered as novel bio-functional materials,display a diversity of patterns and unique micro-and nanostructures which may be useful in many areas of application.Existing devices directly use the original structure of the biosilica frustules,limiting their function and structural scale.Current research into the shapes,materials and structural properties of frustules are considered;a series of frustule processing methods including structure processing,material modification,bonding and assembly techniques are reviewed and discussed.The aim is to improve the function of diatom frustules allowing them to meet the design requirements of different types of micro devices.In addition,the importance of the comprehensive use of diatom processing methods in device research is discussed using biosensors and solar cells as examples,and the potential of bio-manufacturing technology based on diatom frustules is examined.
基金Supported by the National Natural Science Foundation of China (Grant No. 50402023)
文摘Sponges are the oldest and the simplest but not primitive multicellular animals. They represent the earliest evolutionary metazoan phylum still extant. It was a long and painful scientific process to posi-tion the most enigmatic and mysterious metazoan,the Porifera,into their correct phylogenetic place among the eukaryotes in general and multicellular animals in particular. As living fossils,sponges provide the best evidence for the early evolution of Metazoa. More recently,interest has been focused on the bionic applications of sponges' siliceous spicules,after the discovery of their unique structure and high fiber performance. In this review,the emergence of sponges,evolutionary novelties found in sponges,and the phylogenetic position of sponges in early metazoan evolution are highlighted. In ad-dition,the present state of knowledge on silicatein-mediated "biosilica" formation in marine sponges,including the involvement of other molecules in silica metabolism and their potential application in nanobiotechnology and medicine,is given.
