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1.
Nat Commun ; 12(1): 696, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514734

RESUMO

Azoles are five-membered heterocycles often found in the backbones of peptidic natural products and synthetic peptidomimetics. Here, we report a method of ribosomal synthesis of azole-containing peptides involving specific ribosomal incorporation of a bromovinylglycine derivative into the nascent peptide chain and its chemoselective conversion to a unique azole structure. The chemoselective conversion was achieved by posttranslational dehydrobromination of the bromovinyl group and isomerization in aqueous media under fairly mild conditions. This method enables us to install exotic azole groups, oxazole and thiazole, at designated positions in the peptide chain with both linear and macrocyclic scaffolds and thereby expand the repertoire of building blocks in the mRNA-templated synthesis of designer peptides.


Assuntos
Azóis/metabolismo , Biomimética/métodos , Biossíntese Peptídica , Peptídeos/metabolismo , Processamento de Proteína Pós-Traducional , Azóis/química , Desenho de Fármacos , Peptídeos/química , Peptidomiméticos/química , Peptidomiméticos/metabolismo
2.
Nat Commun ; 11(1): 5747, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184285

RESUMO

Human skin is a self-healing mechanosensory system that detects various mechanical contact forces efficiently through three-dimensional innervations. Here, we propose a biomimetic artificially innervated foam by embedding three-dimensional electrodes within a new low-modulus self-healing foam material. The foam material is synthesized from a one-step self-foaming process. By tuning the concentration of conductive metal particles in the foam at near-percolation, we demonstrate that it can operate as a piezo-impedance sensor in both piezoresistive and piezocapacitive sensing modes without the need for an encapsulation layer. The sensor is sensitive to an object's contact force directions as well as to human proximity. Moreover, the foam material self-heals autonomously with immediate function restoration despite mechanical damage. It further recovers from mechanical bifurcations with gentle heating (70 °C). We anticipate that this material will be useful as damage robust human-machine interfaces.


Assuntos
Biomimética/instrumentação , Técnicas Biossensoriais/instrumentação , Impedância Elétrica , Técnicas Eletroquímicas/instrumentação , Pele , Materiais Biomiméticos , Biomimética/métodos , Técnicas Biossensoriais/métodos , Condutividade Elétrica , Técnicas Eletroquímicas/métodos , Eletrodos , Desenho de Equipamento , Humanos , Fenômenos Mecânicos , Nanoestruturas , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Pele/lesões , Propriedades de Superfície , Cicatrização
3.
Nat Commun ; 11(1): 5166, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33056999

RESUMO

Many creatures have the ability to traverse challenging environments by using their active muscles with anisotropic structures as the motors in a highly coordinated fashion. However, most artificial robots require multiple independently activated actuators to achieve similar purposes. Here we report a hydrogel-based, biomimetic soft robot capable of multimodal locomotion fueled and steered by light irradiation. A muscle-like poly(N-isopropylacrylamide) nanocomposite hydrogel is prepared by electrical orientation of nanosheets and subsequent gelation. Patterned anisotropic hydrogels are fabricated by multi-step electrical orientation and photolithographic polymerization, affording programmed deformations. Under light irradiation, the gold-nanoparticle-incorporated hydrogels undergo concurrent fast isochoric deformation and rapid increase in friction against a hydrophobic substrate. Versatile motion gaits including crawling, walking, and turning with controllable directions are realized in the soft robots by dynamic synergy of localized shape-changing and friction manipulation under spatiotemporal light stimuli. The principle and strategy should merit designing of continuum soft robots with biomimetic mechanisms.


Assuntos
Biomimética/métodos , Locomoção , Nanogéis/química , Robótica/métodos , Fricção , Músculo Esquelético/fisiologia
4.
Nat Commun ; 11(1): 4434, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895393

RESUMO

Neisseria meningitidis serogroup A capsular polysaccharide (MenA CPS) consists of (1 → 6)-2-acetamido-2-deoxy-α-D-mannopyranosyl phosphate repeating units, O-acetylated at position C3 or C4. Glycomimetics appear attractive to overcome the CPS intrinsic lability in physiological media, due to cleavage of the phosphodiester bridge, and to develop a stable vaccine with longer shelf life in liquid formulation. Here, we generate a series of non-acetylated carbaMenA oligomers which are proven more stable than the CPS. An octamer (DP8) inhibits the binding of a MenA specific bactericidal mAb and polyclonal serum to the CPS, and is selected for further in vivo testing. However, its CRM197 conjugate raises murine antibodies towards the non-acetylated CPS backbone, but not the natural acetylated form. Accordingly, random O-acetylation of the DP8 is performed, resulting in a structure (Ac-carbaMenA) showing improved inhibition of anti-MenA CPS antibody binding and, after conjugation to CRM197, eliciting anti-MenA protective murine antibodies, comparably to the vaccine benchmark.


Assuntos
Glicoconjugados/síntese química , Neisseria meningitidis Sorogrupo A/imunologia , Polissacarídeos Bacterianos/síntese química , Vacinas Conjugadas , Animais , Anticorpos Antibacterianos/análise , Anticorpos Neutralizantes/química , Cápsulas Bacterianas/imunologia , Biomimética/métodos , Glicoconjugados/imunologia , Camundongos , Neisseria meningitidis Sorogrupo A/química , Neisseria meningitidis Sorogrupo A/efeitos dos fármacos , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Vacinas Conjugadas/química , Vacinas Conjugadas/microbiologia
5.
Nature ; 585(7826): 518-523, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32968256

RESUMO

Current hardware approaches to biomimetic or neuromorphic artificial intelligence rely on elaborate transistor circuits to simulate biological functions. However, these can instead be more faithfully emulated by higher-order circuit elements that naturally express neuromorphic nonlinear dynamics1-4. Generating neuromorphic action potentials in a circuit element theoretically requires a minimum of third-order complexity (for example, three dynamical electrophysical processes)5, but there have been few examples of second-order neuromorphic elements, and no previous demonstration of any isolated third-order element6-8. Using both experiments and modelling, here we show how multiple electrophysical processes-including Mott transition dynamics-form a nanoscale third-order circuit element. We demonstrate simple transistorless networks of third-order elements that perform Boolean operations and find analogue solutions to a computationally hard graph-partitioning problem. This work paves a way towards very compact and densely functional neuromorphic computing primitives, and energy-efficient validation of neuroscientific models.


Assuntos
Inteligência Artificial , Biomimética/métodos , Simulação por Computador , Engenharia/métodos , Modelos Neurológicos , Potenciais de Ação , Eletrodos , Eletrofisiologia , Lógica
6.
Nat Commun ; 11(1): 4283, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883967

RESUMO

Our understanding of the spatiotemporal regulation of cardiogenesis is hindered by the difficulties in modeling this complex organ currently by in vitro models. Here we develop a method to generate heart organoids from mouse embryonic stem cell-derived embryoid bodies. Consecutive morphological changes proceed in a self-organizing manner in the presence of the laminin-entactin (LN/ET) complex and fibroblast growth factor 4 (FGF4), and the resulting in vitro heart organoid possesses atrium- and ventricle-like parts containing cardiac muscle, conducting tissues, smooth muscle and endothelial cells that exhibited myocardial contraction and action potentials. The heart organoids exhibit ultrastructural, histochemical and gene expression characteristics of considerable similarity to those of developmental hearts in vivo. Our results demonstrate that this method not only provides a biomimetic model of the developing heart-like structure with simplified differentiation protocol, but also represents a promising research tool with a broad range of applications, including drug testing.


Assuntos
Matriz Extracelular/metabolismo , Fator 4 de Crescimento de Fibroblastos/metabolismo , Coração , Células-Tronco Embrionárias Murinas/metabolismo , Organoides , Potenciais de Ação , Diamino Aminoácidos/metabolismo , Animais , Biomimética/métodos , Diferenciação Celular , Linhagem Celular , Células Endoteliais , Coração/crescimento & desenvolvimento , Coração/fisiologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Contração Miocárdica , Miocárdio , Organoides/citologia , Organoides/crescimento & desenvolvimento , Organoides/ultraestrutura
7.
Nat Commun ; 11(1): 4536, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913189

RESUMO

Natural musculoskeletal systems have been widely recognized as an advanced robotic model for designing robust yet flexible microbots. However, the development of artificial musculoskeletal systems at micro-nanoscale currently remains a big challenge, since it requires precise assembly of two or more materials of distinct properties into complex 3D micro/nanostructures. In this study, we report femtosecond laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive protein (bovine serum albumin, BSA) as the smart muscle. To realize the programmable integration of the two materials into a 3D configuration, a successive on-chip two-photon polymerization (TPP) strategy that enables structuring two photosensitive materials sequentially within a predesigned configuration was proposed. As a proof-of-concept, we demonstrate a pH-responsive spider microbot and a 3D smart micro-gripper that enables controllable grabbing and releasing. Our strategy provides a universal protocol for directly printing 3D microbots composed of multiple materials.


Assuntos
Biomimética/métodos , Compostos de Epóxi/efeitos da radiação , Fenômenos Fisiológicos Musculoesqueléticos , Polímeros/efeitos da radiação , Robótica/métodos , Soroalbumina Bovina/efeitos da radiação , Biomimética/instrumentação , Compostos de Epóxi/química , Hidrogéis/química , Hidrogéis/efeitos da radiação , Concentração de Íons de Hidrogênio , Lasers , Polimerização/efeitos da radiação , Polímeros/química , Impressão Tridimensional , Robótica/instrumentação , Soroalbumina Bovina/química
8.
J Vis Exp ; (162)2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32831308

RESUMO

Biomimetics is the use of chemistry and material sciences to mimic biological systems, specifically biological structures, to better humankind. Recently, biomimetic surfaces mimicking the microstructure of leaf surface, were used to study the effects of leaf microstructure on leaf-environment interactions. However, no such tool exists for roots. We developed a tool allowing the synthetic mimicry of the root surface microstructure into an artificial surface. We relied on the soft lithography method, known for leaf surface microstructure replication, using a two-step process. The first step is the more challenging one as it involves the biological tissue. Here, we used a different polymer and curing strategy, relying on the strong, rigid, polyurethane, cured by UV for the root molding. This allowed us to achieve a reliable negative image of the root surface microstructure including the delicate, challenging features such as root hairs. We then used this negative image as a template to achieve the root surface microstructure replication using both the well-established polydimethyl siloxane (PDMS) as well as a cellulose derivative, ethyl cellulose, which represents a closer mimic of the root and which can also be degraded by cellulase enzymes secreted by microorganisms. This newly formed platform can be used to study the microstructural effects of the surface in root-microorganism interactions in a similar manner to what has previously been shown in leaves. Additionally, the system enables us to track the microorganism's locations, relative to surface features, and in the future its activity, in the form of cellulase secretion.


Assuntos
Biomimética/métodos , Raízes de Plantas/química
9.
Nat Commun ; 11(1): 4108, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796840

RESUMO

Replicating biological patterns is promising for designing materials with multifaceted properties. Twisted cholesteric liquid crystal patterns are found in the iridescent tessellated cuticles of many insects and a few fruits. Their accurate replication is extremely difficult since discontinuous patterns and colors must coexist in a single layer without discontinuity of the structures. Here, a solution is demonstrated by addressing striped insect cuticles with a complex twisted organization. Geometric constraints are met by controlling the thermal diffusion in a cholesteric oligomer bilayer subjected to local changes in the molecular anchoring conditions. A multicriterion comparison reveals a very high level of biomimicry. Proof-of-concept prototypes of anti-counterfeiting tags are presented. The present design involves an economy of resources and a high versatility of chiral patterns unreached by the current manufacturing techniques such as metallic layer vacuum deposition, template embossing and various forms of lithography which are limited and often prohibitively expensive.


Assuntos
Biomimética/métodos , Biofísica/métodos , Cristais Líquidos/química , Óptica e Fotônica/métodos , Animais , Insetos
10.
Nat Commun ; 11(1): 3377, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32632100

RESUMO

The mammary gland is a highly vascularized tissue capable of expansion and regression during development and disease. To enable mechanistic insight into the coordinated morphogenic crosstalk between the epithelium and vasculature, we introduce a 3D microfluidic platform that juxtaposes a human mammary duct in proximity to a perfused endothelial vessel. Both compartments recapitulate stable architectural features of native tissue and the ability to undergo distinct forms of branching morphogenesis. Modeling HER2/ERBB2 amplification or activating PIK3CA(H1047R) mutation each produces ductal changes observed in invasive progression, yet with striking morphogenic and behavioral differences. Interestingly, PI3KαH1047R ducts also elicit increased permeability and structural disorganization of the endothelium, and we identify the distinct secretion of IL-6 as the paracrine cause of PI3KαH1047R-associated vascular dysfunction. These results demonstrate the functionality of a model system that facilitates the dissection of 3D morphogenic behaviors and bidirectional signaling between mammary epithelium and endothelium during homeostasis and pathogenesis.


Assuntos
Glândulas Mamárias Humanas/metabolismo , Morfogênese/genética , Mutação , Comunicação Parácrina/genética , Biomimética/métodos , Linhagem Celular , Células Cultivadas , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Endotélio Vascular/crescimento & desenvolvimento , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Humanos , Glândulas Mamárias Humanas/irrigação sanguínea , Glândulas Mamárias Humanas/crescimento & desenvolvimento , Fenótipo , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo
11.
Nat Commun ; 11(1): 3668, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699271

RESUMO

Restoration is becoming a vital tool to counteract coastal ecosystem degradation. Modifying transplant designs of habitat-forming organisms from dispersed to clumped can amplify coastal restoration yields as it generates self-facilitation from emergent traits, i.e. traits not expressed by individuals or small clones, but that emerge in clumped individuals or large clones. Here, we advance restoration science by mimicking key emergent traits that locally suppress physical stress using biodegradable establishment structures. Experiments across (sub)tropical and temperate seagrass and salt marsh systems demonstrate greatly enhanced yields when individuals are transplanted within structures mimicking emergent traits that suppress waves or sediment mobility. Specifically, belowground mimics of dense root mats most facilitate seagrasses via sediment stabilization, while mimics of aboveground plant structures most facilitate marsh grasses by reducing stem movement. Mimicking key emergent traits may allow upscaling of restoration in many ecosystems that depend on self-facilitation for persistence, by constraining biological material requirements and implementation costs.


Assuntos
Adaptação Fisiológica , Recuperação e Remediação Ambiental/métodos , Hydrocharitaceae/fisiologia , Áreas Alagadas , Zosteraceae/fisiologia , Plásticos Biodegradáveis , Biomimética/métodos , Ecologia/métodos , Recuperação e Remediação Ambiental/instrumentação , Florida , Países Baixos , Água do Mar , Suécia , Clima Tropical , Índias Ocidentais
12.
PLoS One ; 15(7): e0235808, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722674

RESUMO

One of the central aims of synthetic biology (SB) is to better understand the mechanisms of life by trying to develop and synthesize new forms and perhaps modes of life. While the question of what is life has occupied mankind for centuries, there is a lack of empirical research examining the basic concepts of life scientists within SB themselves refer to and build on. In order to gain insights into these fundamental concepts, we conducted a qualitative interview study with scientists working in the field of SB. The aim was to gain a better understanding of the underlying understandings, principles, and characteristics of (synthetic) life on the one hand, and the entangled consequences for the conducted experiments and studies as well as the pursued scientific approaches. We identified four primarily underlying basic concepts of life which serve as a fundamental framework for current and further scientific research within SB and have implications for research questions, approaches and aims as well as for the evaluation of scientific results.


Assuntos
Biomimética , Biologia Sintética , Biomimética/métodos , Compreensão , Feminino , Humanos , Masculino , Origem da Vida , Pesquisa , Pesquisadores , Biologia Sintética/métodos
13.
Nat Commun ; 11(1): 3091, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555159

RESUMO

Phytoalexins have attracted much attention due to their health-promoting effects and their vital role in plant health during the last years. Especially the 6a-hydroxypterocarpans glyceollin I and glyceollin II, which may be isolated from stressed soy plants, possess a broad spectrum of bioactivities such as anticancer activity and beneficial contributions against western diseases by anti-oxidative and anti-cholesterolemic effects. Aiming for a catalytic asymmetric access to these natural products, we establish the asymmetric syntheses of the natural isoflavonoids (-)-variabilin, (-)-homopterocarpin, (-)-medicarpin, (-)-3,9-dihydroxypterocarpan, and (-)-vestitol by means of an asymmetric transfer hydrogenation (ATH) reaction. We successfully adapt this pathway to the first catalytic asymmetric total synthesis of (-)-glyceollin I and (-)-glyceollin II. This eight-step synthesis features an efficient one-pot transformation of a 2'-hydroxyl-substituted isoflavone to a virtually enantiopure pterocarpan by means of an ATH and a regioselective benzylic oxidation under aerobic conditions to afford the susceptible 6a-hydroxypterocarpan skeleton.


Assuntos
Isoflavonas/metabolismo , Pterocarpanos/metabolismo , Sesquiterpenos/metabolismo , Produtos Biológicos/metabolismo , Biomimética/métodos , Regulação da Expressão Gênica de Plantas
14.
Proc Natl Acad Sci U S A ; 117(22): 11947-11953, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32424103

RESUMO

Living tissues, heterogeneous at the microscale, usually scatter light. Strong scattering is responsible for the whiteness of bones, teeth, and brain and is known to limit severely the performances of biomedical optical imaging. Transparency is also found within collagen-based extracellular tissues such as decalcified ivory, fish scales, or cornea. However, its physical origin is still poorly understood. Here, we unveil the presence of a gap of transparency in scattering fibrillar collagen matrices within a narrow range of concentration in the phase diagram. This precholesteric phase presents a three-dimensional (3D) orientational order biomimetic of that in natural tissues. By quantitatively studying the relation between the 3D fibrillar network and the optical and mechanical properties of the macroscopic matrices, we show that transparency results from structural partial order inhibiting light scattering, while preserving mechanical stability, stiffness, and nonlinearity. The striking similarities between synthetic and natural materials provide insights for better understanding the occurring transparency.


Assuntos
Materiais Biomiméticos , Colágenos Fibrilares , Animais , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/química , Biomimética/métodos , Córnea/química , Colágenos Fibrilares/síntese química , Colágenos Fibrilares/química
15.
Proc Natl Acad Sci U S A ; 117(22): 11931-11939, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32424105

RESUMO

Cell surfaces are often decorated with glycoconjugates that contain linear and more complex symmetrically and asymmetrically branched carbohydrates essential for cellular recognition and communication processes. Mannose is one of the fundamental building blocks of glycans in many biological membranes. Moreover, oligomannoses are commonly found on the surface of pathogens such as bacteria and viruses as both glycolipids and glycoproteins. However, their mechanism of action is not well understood, even though this is of great potential interest for translational medicine. Sequence-defined amphiphilic Janus glycodendrimers containing simple mono- and disaccharides that mimic glycolipids are known to self-assemble into glycodendrimersomes, which in turn resemble the surface of a cell by encoding carbohydrate activity via supramolecular multivalency. The synthetic challenge of preparing Janus glycodendrimers containing more complex linear and branched glycans has so far prevented access to more realistic cell mimics. However, the present work reports the use of an isothiocyanate-amine "click"-like reaction between isothiocyanate-containing sequence-defined amphiphilic Janus dendrimers and either linear or branched oligosaccharides containing up to six monosaccharide units attached to a hydrophobic amino-pentyl linker, a construct not expected to assemble into glycodendrimersomes. Unexpectedly, these oligoMan-containing dendrimers, which have their hydrophobic linker connected via a thiourea group to the amphiphilic part of Janus glycodendrimers, self-organize into nanoscale glycodendrimersomes. Specifically, the mannose-binding lectins that best agglutinate glycodendrimersomes are those displaying hexamannose. Lamellar "raft-like" nanomorphologies on the surface of glycodendrimersomes, self-organized from these sequence-defined glycans, endow these membrane mimics with high biological activity.


Assuntos
Biomimética/métodos , Dendrímeros/síntese química , Glicoconjugados/síntese química , Nanopartículas/química , Membrana Celular/química , Glicolipídeos/química , Interações Hidrofóbicas e Hidrofílicas , Isotiocianatos/metabolismo , Lectinas/metabolismo , Manose/metabolismo , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo , Pesquisa Médica Translacional/métodos
16.
Nat Commun ; 11(1): 2151, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358512

RESUMO

One of the key challenges to overcome multidrug resistance (MDR) in cancer is the development of more effective and general strategies to discover bioactive scaffolds. Inspired by natural products, we describe a strategy to achieve this goal by modular biomimetic synthesis of scaffolds of (Z)-allylic-supported macrolides. Herein, an Rh(III)-catalyzed native carboxylic acid-directed and solvent-free C-H activation allylation with high stereoselectivity and chemoselectivity is achieved. The generated poly-substituted allylic alcohol as a multifunctional and biomimetic building block is crucial for the synthesis of (Z)-allylic-supported macrolides. Moreover, the unique allylic-supported macrolides significantly potentiate the sensitivity of tumor cells to cytotoxic agents such as vinorelbine and doxetaxel by reversing p170-glycoprotein-mediated MDR. Our findings will inspire the evolution of synthetic chemistry and open avenues for expedient and diversified synthesis of bioactive macrocyclic molecules.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Biomimética/métodos , Macrolídeos/química , Catálise , Descoberta de Drogas , Resistencia a Medicamentos Antineoplásicos , Vinorelbina/química
17.
J Vis Exp ; (159)2020 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-32449715

RESUMO

A biomimetic NM was developed to serve as a tissue-engineering biological scaffold, which can enhance stem cell anchorage. The biomimetic NM is formed from JBNTs and FN through self-assembly in an aqueous solution. JBNTs measure 200-300 µm in length with inner hydrophobic hollow channels and outer hydrophilic surfaces. JBNTs are positively charged and FNs are negatively charged. Therefore, when injected into a neutral aqueous solution, they are bonded together via noncovalent bonding to form the NM bundles. The self-assembly process is completed within a few seconds without any chemical initiators, heat source, or UV light. When the pH of the NM solution is lower than the isoelectric point of FNs (pI 5.5-6.0), the NM bundles will self-release due to the presence of positively charged FN. NM is known to mimic the extracellular matrix (ECM) morphologically and hence, can be used as an injectable scaffold, which provides an excellent platform to enhance hMSC adhesion. Cell density analysis and fluorescence imaging experiments indicated that the NMs significantly increased the anchorage of hMSCs compared to the negative control.


Assuntos
Biomimética/métodos , Matriz Extracelular/metabolismo , Fibronectinas/farmacologia , Células-Tronco Mesenquimais/citologia , Nanotubos/química , Adesão Celular/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/ultraestrutura , Fluorescência , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/ultraestrutura , Nanotubos/ultraestrutura
18.
Nat Commun ; 11(1): 1180, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132524

RESUMO

Many biological tissues offer J-shaped stress-strain responses, since their microstructures exhibit a three-dimensional (3D) network construction of curvy filamentary structures that lead to a bending-to-stretching transition of the deformation mode under an external tension. The development of artificial 3D soft materials and device systems that can reproduce the nonlinear, anisotropic mechanical properties of biological tissues remains challenging. Here we report a class of soft 3D network materials that can offer defect-insensitive, nonlinear mechanical responses closely matched with those of biological tissues. This material system exploits a lattice configuration with different 3D topologies, where 3D helical microstructures that connect the lattice nodes serve as building blocks of the network. By tailoring geometries of helical microstructures or lattice topologies, a wide range of desired anisotropic J-shaped stress-strain curves can be achieved. Demonstrative applications of the developed conducting 3D network materials with bio-mimetic mechanical properties suggest potential uses in flexible bio-integrated devices.


Assuntos
Materiais Biomiméticos/química , Biomimética/métodos , Desenho Assistido por Computador , Anisotropia , Módulo de Elasticidade , Análise de Elementos Finitos , Teste de Materiais , Software , Estresse Mecânico
19.
Talanta ; 212: 120778, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113541

RESUMO

Tailor-made Escherichia coli (E. coli) receptors were created with microcontact imprinted technique and binding events of E. coli were carried out by a surface plasmon resonance (SPR) sensor in aqueous solution and in urine mimic in real time and label-free. N-methacryloyl-(l)-histidine methyl ester (MAH) was selected as a functional monomer to design tailor-made E. coli receptors on the polymeric film and during the formation of the polymeric film on a chip surface, Ag nanoparticles (AgNPs) were entrapped into the polymer mixture in order to lower the detection limit of biomimetic SPR based sensor. The polymeric film was characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), ellipsometer and contact angle measurements. Limit of detection (LOD) was found 0.57 CFU/mL and feasibility of the biomimetic sensor was investigated in urine mimic.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Escherichia coli/isolamento & purificação , Ácidos Polimetacrílicos/química , Ressonância de Plasmônio de Superfície/métodos , Infecções Urinárias/diagnóstico , Biomimética/métodos , Histidina/análogos & derivados , Histidina/química , Limite de Detecção , Nanopartículas Metálicas/química , Metacrilatos/química , Impressão Molecular , Prata/química , Urina/microbiologia
20.
Nat Commun ; 11(1): 1449, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193375

RESUMO

Pollen's practically-indestructible shell structure has long inspired the biomimetic design of organic materials. However, there is limited understanding of how the mechanical, chemical, and adhesion properties of pollen are biologically controlled and whether strategies can be devised to manipulate pollen beyond natural performance limits. Here, we report a facile approach to transform pollen grains into soft microgel by remodeling pollen shells. Marked alterations to the pollen substructures led to environmental stimuli responsiveness, which reveal how the interplay of substructure-specific material properties dictates microgel swelling behavior. Our investigation of pollen grains from across the plant kingdom further showed that microgel formation occurs with tested pollen species from eudicot plants. Collectively, our experimental and computational results offer fundamental insights into how tuning pollen structure can cause dramatic alterations to material properties, and inspire future investigation into understanding how the material science of pollen might influence plant reproductive success.


Assuntos
Ciência dos Materiais , Microgéis/química , Pólen/química , Biomimética/métodos , Química Computacional , Epitopos/química , Epitopos/imunologia , Esterificação , Dureza , Hidrólise , Hidróxidos/química , Microscopia de Fluorescência , Pectinas/química , Pectinas/imunologia , Pólen/imunologia , Polinização/fisiologia , Compostos de Potássio/química , Espectroscopia de Infravermelho com Transformada de Fourier
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