Project description:We developed a microbial catalytic concept and strategy to prepare calcium carbonate with micro/nanostructures on the surface of bioceramics to improve bone-forming bioactivity. It involves three processes: bacterial adhesion on biomaterials, production of carbonate assisted with bacteria, nucleation and growth of calcium carbonate nano-crystals on the surface of bioceramics. The microbially catalyzed biominerals exhibited relatively uniform micro/nanostructures on both 2D and 3D CaSiO3 bioceramics. The descriptive analysis of RNA-sequencing revealed that the topographic and chemical cues presented by microbially catalyzed micro/nanostructures could stimulate the biological processes including adhesion, proliferation and differentiation. The study offers a microbially catalytic concept and strategy of fabricating micro/nanostructured biomaterials for tissue regeneration.
Project description:In nature, bacteria reside in biofilms - multicellular differentiated communities held together by extracellular matrix. In this work, we identified a novel subpopulation essential for biofilm formation – mineral-forming cells in Bacillus subtilis biofilms. This subpopulation contains an intracellular calcium-accumulating niche, in which the formation of a calcium carbonate mineral is initiated. As the biofilm colony develops, this mineral grows in a controlled manner, forming a functional macrostructure that serves the entire community. Consistently, biofilm development is prevented by inhibition of calcium uptake. Taken together, our results provide a clear demonstration of the orchestrated production of calcite exoskeleton, critical to morphogenesis in simple prokaryotes. We expect future research exploring this newly discovered process to shed further light on mechanisms of bacterial development.
Project description:Amorphous calcium carbonate (ACC) is a non-crystalline form of calcium carbonate, which is composed of aggregated nano-size primary particles. Here, we wanted to evaluate how ACC affects gene expression in a human lung cancer cell line (A549).
