RESUMO
Implant-associated infections and delayed osseointegration are major challenges for the clinical success of titanium implants. To enhance antibacterial effects and promote early osseointegration, we developed a synergistic photothermal (PTT)/photodynamic (PDT) therapy strategy based on near-infrared (NIR) responsive biomimetic micro/nano titanate/TiO2-X heterostructure coatings (KMNW and NaMNS) in situ constructed on the surface of titanium implants. Specifically, KMNW and NaMNS significantly enhanced photothermal conversion capabilities, achieving localized high temperatures of 48-51 °C and promoting substantial amounts of reactive oxygen species production under 808 nm irradiation. In vitro antibacterial experiments demonstrated that KMNW achieved the highest antibacterial rates against Staphylococcus aureus and Escherichia coli, at 98.78 and 98.33% respectively. Moreover, by mimicking the three-dimensional fibrous network of the extracellular matrix during bone healing, both KMNW and NaMNS markedly promoted the proliferation and osteogenic differentiation of osteoblasts. In vivo implantation studies further confirmed these findings, with KMNW and NaMNS exhibiting superior antibacterial performance under NIR irradiationâ94.45% for KMNW and 92.66% for NaMNS. Moreover, KMNW and NaMNS also significantly promoted new bone formation and improved osseointegration in vivo. This study presents a promising PTT/PDT therapeutic strategy for dentistry and orthopedics by employing NIR-responsive biomimetic coatings to combat implant-associated infection and accelerate osseointegration.
Assuntos
Antibacterianos , Escherichia coli , Raios Infravermelhos , Osseointegração , Staphylococcus aureus , Titânio , Titânio/química , Titânio/farmacologia , Osseointegração/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , Animais , Staphylococcus aureus/efeitos dos fármacos , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Materiais Biomiméticos/efeitos da radiação , Próteses e Implantes , Fotoquimioterapia , Camundongos , Terapia Fototérmica , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Testes de Sensibilidade Microbiana , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Osteogênese/efeitos dos fármacosRESUMO
BACKGROUND: Currently, there are no curative drugs for hepatitis B virus (HBV). Complete elimination of HBV covalently closed circular DNA (cccDNA) is key to the complete cure of hepatitis B virus infection. The CRISPR/Cas9 system can directly destroy HBV cccDNA. However, a CRISPR/Cas9 delivery system with low immunogenicity and high efficiency has not yet been established. Moreover, effective implementation of precise remote spatiotemporal operations in CRISPR/Cas9 is a major limitation. RESULTS: In this work, we designed NIR-responsive biomimetic nanoparticles (UCNPs-Cas9@CM), which could effectively deliver Cas9 RNP to achieve effective genome editing for HBV therapy. HBsAg, HBeAg, HBV pgRNA and HBV DNA along with cccDNA in HBV-infected cells were found to be inhibited. These findings were confirmed in HBV-Tg mice, which did not exhibit significant cytotoxicity and minimal off-target DNA damage. CONCLUSIONS: The UCNPs-based biomimetic nanoplatforms achieved the inhibition of HBV replication via CRISPR therapy and it is a potential system for efficient treatment of human HBV diseases.
Assuntos
Materiais Biomiméticos , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Hepatite B/terapia , Nanopartículas , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/efeitos da radiação , Técnicas de Transferência de Genes , Vírus da Hepatite B , Raios Infravermelhos , Camundongos , Camundongos Transgênicos , Nanopartículas/química , Nanopartículas/efeitos da radiaçãoRESUMO
Near-infrared (NIR) radiation plays an important role in guided external stimulus therapies; its application in bone-related treatments is becoming more and more frequent. Therefore, metallic biomaterials that exhibit properties activated by NIR are promising for further orthopedic procedures. In this work, we present an adapted electroforming approach to attain a biomorphic nano-holed TiO2 coating on Ti6Al4V alloy. Through a precise control of the anodization conditions, structures revealed the formation of localized nano-pores arranged in a periodic assembly. This specific organization provoked higher stability against thermal oxidation and precise hydrophobic wettability behavior according to Cassie-Baxter's model; both characteristics are a prerequisite to ensure a favorable biological response in an implantable structure for guided bone regeneration. In addition, the periodically arranged sub-wavelength-sized unit cell on the metallic-dielectric structure exhibits a peculiar optical response, which results in higher NIR reflectivity. Accordingly, we have proved that this effect enhances the efficiency of the scattering processes and provokes a significant improvement of light confinement producing a spontaneous NIR fluorescence emission. The combination of the already favorable mechanical and biocompatibility properties of Ti6Al4V, along with suitable thermal stability, wetting, and electro-optical behavior, opens a promising path toward strategic bone therapeutic procedures.
Assuntos
Ligas/química , Materiais Biomiméticos/química , Materiais Revestidos Biocompatíveis/química , Ligas/efeitos da radiação , Materiais Biomiméticos/efeitos da radiação , Materiais Revestidos Biocompatíveis/efeitos da radiação , Interações Hidrofóbicas e Hidrofílicas , Raios Infravermelhos , Porosidade , Titânio/química , Titânio/efeitos da radiação , MolhabilidadeRESUMO
A key aspect of living cells is their ability to harvest energy from the environment and use it to pump specific atomic and molecular species in and out of their system-typically against an unfavourable concentration gradient1. Active transport allows cells to store metabolic energy, extract waste and supply organelles with basic building blocks at the submicrometre scale. Unlike living cells, abiotic systems do not have the delicate biochemical machinery that can be specifically activated to precisely control biological matter2-5. Here we report the creation of microcapsules that can be brought out of equilibrium by simple global variables (illumination and pH), to capture, concentrate, store and deliver generic microscopic payloads. Borrowing no materials from biology, our design uses hollow colloids serving as spherical cell-membrane mimics, with a well-defined single micropore. Precisely tunable monodisperse capsules are the result of a synthetic self-inflation mechanism and can be produced in bulk quantities. Inside the hollow unit, a photoswitchable catalyst6 produces a chemical gradient that propagates to the exterior through the membrane's micropore and pumps target objects into the cell, acting as a phoretic tractor beam7. An entropic energy barrier8,9 brought about by the micropore's geometry retains the cargo even when the catalyst is switched off. Delivery is accomplished on demand by reversing the sign of the phoretic interaction. Our findings provide a blueprint for developing the next generation of smart materials, autonomous micromachinery and artificial cell-mimics.
Assuntos
Materiais Biomiméticos/metabolismo , Materiais Biomiméticos/efeitos da radiação , Biomimética , Membrana Celular/metabolismo , Coloides/metabolismo , Coloides/efeitos da radiação , Transporte Biológico Ativo/efeitos da radiação , Materiais Biomiméticos/química , Membrana Celular/efeitos da radiação , Coloides/química , Emulsões/química , Entropia , Concentração de Íons de Hidrogênio , LuzRESUMO
Reduction of an iminium CâN double bond is the most important phase I metabolism process associated with the cytotoxic property of quaternary benzophenanthridine alkaloids (QBAs). Inspired by the light-mediated reduction of QBAs with nicotinamide adenine dinucleotide, a visible-light-promoted reductive functionalization reaction of QBAs is reported in this study. C4-Alkyl-1,4-dihydropyridines (DHPs) enable the direct reductive alkylation of QBA independently, serving as both single-electron-transfer reductant reagents under irradiation with 455 nm blue light in the absence of photocatalysts and additional additives. Our protocol can be further applied to the semisynthesis of natural 6-substituted dihydrobenzophenanthridine derivatives such as O-acetyl maclekarpine E.
Assuntos
Benzofenantridinas/química , Materiais Biomiméticos/química , Alquilação , Benzofenantridinas/efeitos da radiação , Materiais Biomiméticos/efeitos da radiação , Transporte de Elétrons , Luz , Estrutura MolecularRESUMO
Phycobiliproteins are a class of light-harvesting fluorescent proteins existing in cyanobacteria and microalgae, which harvest light and convert it into electricity. Owing to recent demands on environmental-friendly and renewable apparatuses, phycobiliproteins have attracted substantial interest in bioenergy and sustainable devices. However, converting energy from biological materials remains challenging to date. Herein, we report a novel scheme to enhance biological light-harvesting through light-matter interactions at the biointerface of whispering-gallery modes (WGMs), where phycobiliproteins were employed as the active gain material. By exploiting microdroplets as a carrier for light-harvesting biomaterials, strong local electric field enhancement and photon confinement at the cavity interface resulted in significantly enhanced bio-photoelectricity. A threshold-like behavior was discovered in photocurrent enhancement and the WGM modulated fluorescence. Systematic studies of biologically produced photoelectricity and optical mode resonance were carried out to illustrate the impact of the cavity quality factor, structural geometry, and refractive indices. Finally, a biomimetic system was investigated by exploiting cascade energy transfer in phycobiliprotein assembly composed of three light-harvesting proteins. The key findings not only highlight the critical role of optical cavity in light-harvesting but also offer deep insights into light energy coupling in biomaterials.
Assuntos
Materiais Biomiméticos/química , Ficocianina/química , Ficoeritrina/química , Materiais Biomiméticos/efeitos da radiação , Eletricidade , Luz , Cristais Líquidos/química , Cristais Líquidos/efeitos da radiação , Óptica e Fotônica , Ficocianina/efeitos da radiação , Ficoeritrina/efeitos da radiação , Estudo de Prova de Conceito , RefratometriaRESUMO
Fabricating antibacterial hydrogels with antimicrobial drugs and synthetic biocompatible biomimetic hydrogels is a promising strategy for practical medical applications. Here, we report a bicomponent hydrogel composed of a biomimetic polyisocyanopetide (PIC) hydrogel and a photodynamic antibacterial membrane-intercalating conjugated oligoelectrolyte (COE). The aggregation behavior and aggregate size of the COEs in water can be regulated using the PIC hydrogel, which could induce COEs with higher reactive oxygen species (ROS) production efficiency and increased association of COEs toward bacteria, therefore enhancing the antibacterial efficiency. This strategy provides a facile method for developing biomimetic hydrogels with high antibacterial capability.
Assuntos
Antibacterianos/farmacologia , Hidrogéis/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Polímeros/farmacologia , Tiadiazóis/farmacologia , Tiofenos/farmacologia , Antibacterianos/química , Antibacterianos/efeitos da radiação , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Materiais Biomiméticos/efeitos da radiação , Escherichia coli/efeitos dos fármacos , Fluoresceínas/química , Fluoresceínas/metabolismo , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Hidrogéis/química , Hidrogéis/efeitos da radiação , Luz , Testes de Sensibilidade Microbiana , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Tiadiazóis/química , Tiadiazóis/efeitos da radiação , Tiofenos/química , Tiofenos/efeitos da radiaçãoRESUMO
2D metal-organic framework (MOF) film as the active layer show promising application prospects in various fields including sensors, catalysis, and electronic devices. However, exploring the application of 2D MOF film in the field of artificial synapses has not been implemented yet. In this work, we fabricated a novel 2D MOF film (Cu-THPP, THPP=5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine), and further used it as an active layer to explore the application in the simulation of human brain synapses. It shows excellent light-stimulated synaptic plasticity properties, and exhibits the foundation function of synapses such as long-term plasticity (LTP), short-term plasticity (STP), and the conversion of STP to LTP. Most critically, the MOF based artificial synaptic device exhibits an excellent stability in atmosphere. This work opens the door for the application of 2D MOF film in the simulation of human brain synapses.
Assuntos
Materiais Biomiméticos/química , Membranas Artificiais , Estruturas Metalorgânicas/química , Materiais Biomiméticos/efeitos da radiação , Biomimética/métodos , Cobre/química , Cobre/efeitos da radiação , Luz , Estruturas Metalorgânicas/efeitos da radiação , Plasticidade Neuronal , Porfirinas/química , Porfirinas/efeitos da radiação , Sinapses/químicaRESUMO
Chlorophyll special pairs in photosynthetic reaction centers function as both exciton acceptors and primary electron donors. Although the macrocyclic natural pigments contain Mg(II), the central metal in most synthetic analogs is Zn(II). Here we report that insertion of either Al(III) or Ga(III) into an imidazole-substituted corrole affords an exceptionally robust photoactive dimer. Notably, attractive electronic interactions between dimer subunits are relatively strong, as documented by signature changes in NMR and electronic absorption spectra, as well as by cyclic voltammetry, where two well-separated reversible redox couples were observed. EPR spectra of one-electron oxidized dimers closely mimic those of native special pairs, and strong through-space interactions between corrole subunits inferred from spectroscopic and electrochemical data are further supported by crystal structure analyses (3 Å interplanar distances, 5 Å lateral shifts, and 6 Å metal to metal distances).
Assuntos
Materiais Biomiméticos/química , Imidazóis/química , Metaloporfirinas/química , Alumínio/química , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/efeitos da radiação , Clorofila/química , Elétrons , Gálio/química , Imidazóis/síntese química , Imidazóis/efeitos da radiação , Luz , Metaloporfirinas/síntese química , Metaloporfirinas/efeitos da radiação , Estrutura Molecular , OxirreduçãoRESUMO
The experimental investigation of the unidirectional motion characterizing the photoisomerization of single-molecule rotary motors requires accessible lab prototypes featuring an electronic circular dichroism (ECD) signal that is sensitive to the geometrical and electronic changes occurring during an ultrafast reactive process. Here we report a combined experimental/computational study of a candidate obtained via the asymmetrization of a light-driven biomimetic molecular switch. We show that the achieved motor has an ECD band that is remarkably sensitive to the isomerization motion, and it is therefore suitable for time-resolved ECD studies. However, we also find that, unexpectedly, the synthesized motor isomerizes on a time scale longer than the subpicosecond time measured for the achiral parent, a result that points to alternative candidates conserving a high reaction speed.
Assuntos
Materiais Biomiméticos/química , Indanos/química , Pirrolidinonas/química , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/efeitos da radiação , Dicroísmo Circular , Teoria da Densidade Funcional , Indanos/síntese química , Indanos/efeitos da radiação , Modelos Químicos , Pirrolidinonas/síntese química , Pirrolidinonas/efeitos da radiação , Rotação , Estereoisomerismo , Raios UltravioletaRESUMO
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
Global alterations in the metabolic network provide substances and energy to support tumor progression. To fuel these metabolic processes, extracellular matrix (ECM) plays a dominant role in supporting the mass transport and providing essential nutrients. Here, we report a fibrinogen and thrombin based coagulation system to construct an artificial ECM (aECM) for selectively cutting-off the tumor metabolic flux. Once a micro-wound is induced, a cascaded gelation of aECM can be triggered to besiege the tumor. Studies on cell behaviors and metabolomics reveal that aECM cuts off the mass transport and leads to a tumor specific starvation to inhibit tumor growth. In orthotopic and spontaneous murine tumor models, this physical barrier also hinders cancer cells from distant metastasis. The in vivo gelation provides an efficient approach to selectively alter the tumor mass transport. This strategy results in a 77% suppression of tumor growth. Most importantly, the gelation of aECM can be induced by clinical operations such as ultrasonic treatment, surgery or radiotherapy, implying this strategy is potential to be translated into a clinical combination regimen.
Assuntos
Materiais Biomiméticos/administração & dosagem , Matriz Extracelular/química , Neoplasias/terapia , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/efeitos da radiação , Materiais Biomiméticos/química , Materiais Biomiméticos/efeitos da radiação , Linhagem Celular Tumoral/transplante , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Quimiorradioterapia/métodos , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Matriz Extracelular/efeitos da radiação , Feminino , Fibrinogênio/administração & dosagem , Fibrinogênio/química , Fibrinogênio/efeitos da radiação , Géis , Humanos , Injeções Intravenosas , Metabolômica , Camundongos , Neoplasias/metabolismo , Trombina/administração & dosagem , Trombina/química , Trombina/efeitos da radiação , Terapia por Ultrassom/métodos , Ondas UltrassônicasRESUMO
Biological ion channels and ion pumps with sub-nanometer sizes modulate ion transport in response to external stimuli. Realizing such functions with sub-nanometer solid-state nanopores has been an important topic with wide practical applications. Herein, we demonstrate a biomimetic photoresponsive ion channel and photodriven ion pump using a porphyrin-based metal-organic framework membrane with pore sizes comparable to hydrated ions. We show that the molecular-size pores enable precise and robust optoelectronic ion transport modulation in a broad range of concentrations, unparalleled with conventional solid-state nanopores. Upon decoration with platinum nanoparticles to form a Schottky barrier photodiode, photovoltage across the membrane is generated with "uphill" ion transport from low concentration to high concentration. These results may spark applications in energy conversion, ion sieving, and artificial photosynthesis.
Assuntos
Materiais Biomiméticos/química , Estruturas Metalorgânicas/química , Nanoporos , Materiais Biomiméticos/efeitos da radiação , Canais Iônicos/química , Luz , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/efeitos da radiação , Platina/química , Porfirinas/química , Porfirinas/efeitos da radiaçãoRESUMO
Photofunctionalization mediated by ultraviolet (UV) rays changes the physico-chemical characteristics of titanium (Ti) and improves the biological activity of dental implants. However, the role of UV-mediated photofunctionalization of biofunctional Ti surfaces on the antimicrobial and photocatalytic activity remains unknown and was investigated in this study. Commercially pure titanium (cpTi) discs were divided into four groups: (1) machined samples without UV light application [cpTi UV-]; (2) plasma electrolytic oxidation (PEO) treated samples without UV light application [PEO UV-]; (3) machined samples with UV light application [cpTi UV+]; and (4) PEO-treated samples with UV light application [PEO UV+]. The surfaces were characterized according to their morphology, roughness, crystalline phase, chemical composition and wettability. The photocatalytic activity and proteins adsorption were measured. For the microbiological assay, Streptococcus sanguinis was grown on the disc surfaces for 1 h and 6 h, and the colony forming units and bacterial organization were evaluated. In addition, to confirm the non-cytotoxic effect of PEO UV +, human gingival fibroblast (HGF) cells were cultured in a monolayer onto each material surface and the cells viability and proliferation evaluated by a fluorescent cell staining method. PEO treatment increased the Ti surface roughness and wettability (p < 0.05). Photofunctionalization reduced the hydrocarbon concentration and enhanced human blood plasma proteins and albumin adsorption mainly for the PEO-treated surface (p < 0.05). PEO UV+ also maintained higher wettability values for a longer period and provided microbial reduction at 1 h of bacterial adhesion (p = 0.012 vs. PEO UV-). Photofunctionalization did not increase the photocatalytic activity of Ti (p > 0.05). Confocal microscopy analyses demonstrated that PEO UV+ had no cell damage effect on HGF cells growth even after 24 h of incubation. The photofunctionalization of a biofunctional PEO coating seems to be a promising alternative for dental implants as it increases blood plasma proteins adsorption, reduces initial bacterial adhesion and presents no cytotoxicity effect.
Assuntos
Materiais Biomiméticos/efeitos da radiação , Materiais Revestidos Biocompatíveis/efeitos da radiação , Implantes Dentários , Raios Ultravioleta , Adsorção , Aderência Bacteriana/efeitos dos fármacos , Materiais Biomiméticos/farmacologia , Proteínas Sanguíneas/metabolismo , Catálise , Células Cultivadas , Materiais Revestidos Biocompatíveis/farmacologia , Contagem de Colônia Microbiana , Eletrólise , Humanos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Oxirredução , Espectroscopia Fotoeletrônica , Streptococcus sanguis/efeitos dos fármacos , Streptococcus sanguis/crescimento & desenvolvimento , Propriedades de Superfície , Titânio/farmacologia , Difração de Raios XRESUMO
The harmful cyanobacteria blooms which usually form in spring and summer, cause global eutrophication of freshwater and coastal marine ecosystems. This study tried to utilize cyanobacteria as a raw material to produce biological poly(vinyl)alcohol-based films. Cyanobacteria was firstly modified with poly(ethylene glycol), guanidine hydrochloride, carboxymethyl cellulose and 3-glycidoxypropyltrimethoxysilane as plasticizer, modifier, toughening agent and coupling agent, respectively. And then the modified cyanobacteria was introduced to poly(vinyl)alcohol and cellulose nanofibers/poly(vinyl)alcohol matrix to improve the barrier properties of poly(vinyl)alcohol to light and water. Compared with poly(vinyl)alcohol and cellulose nanofibers/poly(vinyl)alcohol films, the obtained cyanobacteria/poly(vinyl)alcohol and the cyanobacteria/cellulose nanofibers/poly(vinyl)alcohol composites exhibit better resistance to light and water. More interestingly, we found that after adding cyanobacteria, the poly(vinyl)alcohol-based films present better barrier properties to blue-violet light and red light. In adddition, introducing cyanobacteria into poly(vinyl)alcohol or cellulose nanofibers/poly(vinyl)alcohol matrix increases the surface roughness and contact angle to water of the composites.
Assuntos
Materiais Biomiméticos/química , Cianobactérias/química , Luz , Álcool de Polivinil/química , Água/química , Materiais Biomiméticos/efeitos da radiação , Celulose/química , Guanidina/química , Teste de Materiais , Nanofibras/química , Oxigênio/química , Plastificantes/química , Propriedades de Superfície , Raios UltravioletaRESUMO
Ultrasonic techniques could be good candidates to aid the assessment of osteoporosis detection, due to their non-intrusiveness and low cost. While earlier studies made use of the measured ultrasonic phase velocity and attenuation inside the bone, very few have considered an inverse identification of both the intrinsic pore microstructure and the mechanical properties of the bone, based on Biot's model. The main purpose of this work is to present an in vitro methodology for bone identification, adopting a statistical Bayesian inference technique using ultrasonic transmitted signals, which allows the retrieval of the identified parameters and their uncertainty. In addition to the bone density, Young's modulus and Poisson's ratio, the bone pore microstructure parameters (porosity, tortuosity, and viscous length) are identified. These additional microstructural terms could improve the knowledge on the correlations between bone microstructure and bone diseases, since they provide more information on the trabecular structure. In general, the exact properties of the saturating fluid are unknown (bone marrow and blood in the case of bone study) so in this work, the fluid properties (water) are identified during the inference as a proof of concept.
Assuntos
Materiais Biomiméticos/química , Condução Óssea , Osso e Ossos/química , Modelos Teóricos , Ondas Ultrassônicas , Teorema de Bayes , Materiais Biomiméticos/efeitos da radiação , Densidade Óssea , Osso e Ossos/efeitos da radiação , Módulo de Elasticidade , Humanos , Porosidade , ViscosidadeRESUMO
The intrinsic relationship between the properties of green fluorescent protein (GFP) and its encapsulated small molecular light machine has spurred many biomimicking studies, aiming at revealing the detailed mechanism and further promoting its wide applications in different disciplines. However, how to build a similar confined microenvironment to mimic the cavity of a ß-barrel and the fluorescence turn-on process is a fundamental challenge for both chemists and biologists. Herein, two distinct exo- and endo-functionalized tetraphenylethylene (TPE)-based M12L24 nanospheres with precise distribution of anchored TPE moieties and unique photophysical properties were constructed by means of a coordination-driven self-assembly strategy. Under dilute conditions, the nanospheres fluoresce more strongly than the corresponding TPE subcomponents. Meanwhile, the endo-functionalized sphere is able to induce a higher local concentration and more restrained motion of the enclosed 24 TPE units compared with exo-functionalized counterpart and thus induces much stronger emission due to the restriction of the rotation of the pendant TPE units. The biomimetic methodology developed here represents a promising way to understand and construct artificial GFP materials on the platforms of supramolecular coordination complexes.
Assuntos
Materiais Biomiméticos/química , Corantes Fluorescentes/química , Nanosferas/química , Estilbenos/química , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/efeitos da radiação , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/efeitos da radiação , Proteínas de Fluorescência Verde/química , Ligantes , Nanosferas/efeitos da radiação , Estilbenos/síntese química , Estilbenos/efeitos da radiação , Raios UltravioletaRESUMO
Rhodopsin, composed of opsin and isomeric retinal, acts as the primary photoreceptor by converting light into electric signals. Inspired by rhodopsin, we have fabricated a light-regulated ionic gate on the basis of the design of a graphene oxide (GO)-biomimetic DNA-nanochannel architecture. In this design, photoswitchable azobenzene (Azo)-DNA is introduced to the surface of porous anodic alumina (PAA) membrane. With modulation of the interaction between the GO blocker and Azo-DNA via flexibly regulating trans and cis states of Azo under the irradiation of visible and ultraviolet light, alternatively, the ionic gate is switched between ON and OFF states. This newly constructed ionic gate can possess high efficiency for the control of ion transport because of the high blocking property of GO and the rather tiny path within the barrier layer which are both first employed to fabricate ionic gate. We anticipate that this rhodopsin-like ionic gate may provide a new model and method for the investigation of ion channel, ion function, and ion quantity. In addition, because of the advantages of simple fabrication, good biocompatibility, and universality, this bioinspired system may have potential applications as optical sensors, in photoelectric transformation, and in controllable drug delivery.
Assuntos
Materiais Biomiméticos/química , DNA/química , Grafite/química , Transporte de Íons/efeitos dos fármacos , Óxido de Alumínio/química , Compostos Azo/química , Compostos Azo/efeitos da radiação , Materiais Biomiméticos/efeitos da radiação , DNA/efeitos da radiação , Técnicas Eletroquímicas , Grafite/efeitos da radiação , Transporte de Íons/efeitos da radiação , Membranas Artificiais , Rodopsina/química , Estereoisomerismo , Raios UltravioletaRESUMO
Fluorescent nanoarchitectures, such as hydrophobic micelles and hydrophilic vesicles decorated with fluorescent carbon nanoparticles, were fabricated from one fatty acid by means of photo-triggering. The biomimetic nanostructures, like cell membrane structures, have applications in fluorescence imaging in both the cell cytoplasm and nucleus. Besides, hydrophobic micelles can be used as very stable fluorescent inks.
Assuntos
Materiais Biomiméticos/química , Ácidos Graxos/química , Corantes Fluorescentes/química , Nanopartículas/química , Células A549 , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/efeitos da radiação , Materiais Biomiméticos/toxicidade , Carbono/química , Carbono/efeitos da radiação , Carbono/toxicidade , Ácidos Graxos/efeitos da radiação , Ácidos Graxos/toxicidade , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/efeitos da radiação , Corantes Fluorescentes/toxicidade , Humanos , Interações Hidrofóbicas e Hidrofílicas , Tinta , Membranas Artificiais , Micelas , Microscopia Confocal , Nanopartículas/efeitos da radiação , Nanopartículas/toxicidade , Raios Ultravioleta , Água/químicaRESUMO
A well-characterized ultrasound tissue-mimicking material (TMM) can be important in determining the acoustic output and temperature rise from high intensity therapeutic ultrasound (HITU) devices and also in validating computer simulation models. A HITU TMM previously developed and characterized in our laboratory has been used in our acoustic and temperature measurements as well as modeled in our HITU simulation program. A discrepancy between thermal measurement and simulation, though, led us to further investigate the TMM properties. We found that the 2-parameter analytic fit commonly used to represent the attenuation of the TMM in the computer modeling was not adequate over the entire frequency range of interest, 1 MHz to 8 MHz in this study, indicating that we and others may have not been characterizing TMMs, and possibly tissue, optimally. By comparing measurements and simulations, we found that a 3-parameter analytic fit for attenuation gave a more accurate value for attenuation at 1 MHz and 2 MHz, and using that fit the temperature rise measurements in the TMM that agreed more closely with the simulation results.