The concept of developing a biosealant in concrete remediation is based on unique microbial metabolic processes.A common soil microorganism,Sporosarcina pasteurii,can induce CaCO_(3) precipitation in the surroundings ...The concept of developing a biosealant in concrete remediation is based on unique microbial metabolic processes.A common soil microorganism,Sporosarcina pasteurii,can induce CaCO_(3) precipitation in the surroundings in response to environmental cues such as high pH and available nutrients and minerals.A new biomolecule,microbial calcite is introduced as a smart nanomaterial for self-healing concrete-its effects on concrete performance were evaluated with regard to surface crack remediation and durability enhancement.For crack remediation,S.pasteurii cells immobilized on porous glass beads,Siran^(TM),were applied to cracks and tested for stiffness and compressive strengths.For durability tests,cement mortar beams prepared with bacteria were subjected to freeze-thaw cycles and examined for mean expansions and weight changes.Overall performance of the concrete was significantly enhanced by treatment with microbial calcite in simulated concrete cracks and cement mortar beams.展开更多
An ideal intraosseous transcutaneous implant should form a tight seal with soft tissue,besides a requirement of osseointegration at the bone-fixed position.Si substituted hydroxyapatite(Si-HA)nanorods releasing Si ion...An ideal intraosseous transcutaneous implant should form a tight seal with soft tissue,besides a requirement of osseointegration at the bone-fixed position.Si substituted hydroxyapatite(Si-HA)nanorods releasing Si ion and simulating nanotopography of natural tissue were designed on Ti to enhance fibroblast response in vitro and biosealing with soft tissue in vivo.Si-HA nanorods were fabricated by alkali-heat treatment followed with hydrothermal treatment.The hydrothermal formation mechanism of Si-HA nanorods was explored.The surface characteristic of Si-HA nanorods was compared with pure HA nanorods.Fibroblast behaviors in vitro and skin response in vivo on different surfaces were also evaluated.The obtained results show that the substitution of Si did not significantly alter the phase component,morphology,roughness and wettability of HA,but additional Si and more Ca were released from Si-HA into medium.Comparing to pure HA nanrods and Ti substrate,Si-HA nanrods enhanced cell behaviors including proliferation,fibrotic phenotype and collagen secretion in vitro,and reduced epithelial down growth in vivo.The enhanced cell response and biosealing should be due to the releasing of Ca,Si and nanotopography of Si-HA nanorods.Si-HA nanorods can be a potential coating to accelerate skin integration for percutaneous implants in clinic.展开更多
基金funded by the National Science Foundation(Grant numbers:CMS-9802125,INT-0002608,and CMS-0301312).
文摘The concept of developing a biosealant in concrete remediation is based on unique microbial metabolic processes.A common soil microorganism,Sporosarcina pasteurii,can induce CaCO_(3) precipitation in the surroundings in response to environmental cues such as high pH and available nutrients and minerals.A new biomolecule,microbial calcite is introduced as a smart nanomaterial for self-healing concrete-its effects on concrete performance were evaluated with regard to surface crack remediation and durability enhancement.For crack remediation,S.pasteurii cells immobilized on porous glass beads,Siran^(TM),were applied to cracks and tested for stiffness and compressive strengths.For durability tests,cement mortar beams prepared with bacteria were subjected to freeze-thaw cycles and examined for mean expansions and weight changes.Overall performance of the concrete was significantly enhanced by treatment with microbial calcite in simulated concrete cracks and cement mortar beams.
基金We greatly appreciate the Research Fund for the National Natural Science Foundation of China(Grant number 51771142,51571158 and 51631007)National Key Research and Development Program of China No.2016YFC1100600(sub-project 2016YFC1100604)+2 种基金Natural Science Foundation of Shaanxi Province(No.2019TD-020)Key Research and Development Plan of Shaanxi Province(grant number 2018ZDXMGY119)Key Scientific Research Plan of Shaanxi Provincial Department of Education(grant number 18JC001)for financially supporting this work.
文摘An ideal intraosseous transcutaneous implant should form a tight seal with soft tissue,besides a requirement of osseointegration at the bone-fixed position.Si substituted hydroxyapatite(Si-HA)nanorods releasing Si ion and simulating nanotopography of natural tissue were designed on Ti to enhance fibroblast response in vitro and biosealing with soft tissue in vivo.Si-HA nanorods were fabricated by alkali-heat treatment followed with hydrothermal treatment.The hydrothermal formation mechanism of Si-HA nanorods was explored.The surface characteristic of Si-HA nanorods was compared with pure HA nanorods.Fibroblast behaviors in vitro and skin response in vivo on different surfaces were also evaluated.The obtained results show that the substitution of Si did not significantly alter the phase component,morphology,roughness and wettability of HA,but additional Si and more Ca were released from Si-HA into medium.Comparing to pure HA nanrods and Ti substrate,Si-HA nanrods enhanced cell behaviors including proliferation,fibrotic phenotype and collagen secretion in vitro,and reduced epithelial down growth in vivo.The enhanced cell response and biosealing should be due to the releasing of Ca,Si and nanotopography of Si-HA nanorods.Si-HA nanorods can be a potential coating to accelerate skin integration for percutaneous implants in clinic.
