RESUMO
Living organisms have evolved sophisticated cell-mediated biomineralization mechanisms to build structurally ordered, environmentally adaptive composite materials. Despite advances in biomimetic mineralization research, it remains difficult to produce mineralized composites that integrate the structural features and 'living' attributes of their natural counterparts. Here, inspired by natural graded materials, we developed living patterned and gradient composites by coupling light-inducible bacterial biofilm formation with biomimetic hydroxyapatite (HA) mineralization. We showed that both the location and the degree of mineralization could be regulated by tailoring functional biofilm growth with spatial and biomass density control. The cells in the composites remained viable and could sense and respond to environmental signals. Additionally, the composites exhibited a maximum 15-fold increase in Young's modulus after mineralization and could be applied to repair damage in a spatially controlled manner. Beyond insights into the mechanism of formation of natural graded composites, our study provides a viable means of fabricating living composites with dynamic responsiveness and environmental adaptability.
Assuntos
Adesinas Bacterianas/genética , Biofilmes/efeitos da radiação , Durapatita/química , Proteínas de Escherichia coli/genética , Escherichia coli/efeitos da radiação , Proteínas/genética , Adesinas Bacterianas/metabolismo , Adesinas Bacterianas/efeitos da radiação , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/efeitos da radiação , Biofilmes/crescimento & desenvolvimento , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Materiais Biomiméticos/efeitos da radiação , Biomineralização/efeitos da radiação , Engenharia Celular/métodos , Relação Dose-Resposta à Radiação , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/efeitos da radiação , Expressão Gênica , Luz , Mytilus , Proteínas/metabolismo , Proteínas/efeitos da radiação , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/efeitos da radiaçãoRESUMO
The current work explores the surface morphology of the laser-ablated bone using Yb-fiber coupled Nd:YAG laser (λ = 1064 nm) in continuous wave mode. As the laser-ablated region contains physiochemically modified carbonized and nonstructural region, it becomes unknown material for the body. Thus, biomineralization on such a laser-ablated region was assessed by in vitro immersion test in noncellular simulated body fluid. The presence of hydroxyapatite was detected in the precipitated mineral product using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction analysis. The effect of varying laser parameters on distribution of surface morphology features was identified and its corresponding effect on biomineralization was studied.
Assuntos
Biomineralização/efeitos da radiação , Osso e Ossos/efeitos da radiação , Lasers de Estado Sólido , Osso e Ossos/ultraestrutura , Durapatita/química , Espectrometria por Raios X , Propriedades de Superfície , Temperatura , Difração de Raios XRESUMO
Various cancer cells have been demonstrated to have the capacity to form plasmonic gold nanoparticles when chloroauric acid is introduced to their cellular microenvironment. But their biomedical applications are limited, particularly considering the millimolar concentrations and longer incubation period of ionic gold. Here, we describe a simplistic method of intracellular biomineralization to produce plasmonic gold nanoparticles at micromolar concentrations within 30 min of application utilizing polyethylene glycol as delivery vector for ionic gold. We have characterized this process for intracellular gold nanoparticle formation, which progressively accumulates proteins as the ionic gold clusters migrate to the nucleus. This nano-vectorized application of ionic gold emphasizes its potential biomedical opportunities while reducing the quantity of ionic gold and required incubation time. To demonstrate its biomedical potential, we further induce in-situ biosynthesis of gold nanoparticles within MCF7 tumor mouse xenografts which is followed by its photothermal remediation.