Spatial and spatiotemporal variation in metapopulation structure affects population dynamics in a passively dispersing arthropod

The spatial and temporal variation in the availability of suitable habitat within metapopulations determines colonization-extinction events, regulates local population sizes and eventually affects local population and metapopulation stability. Insights into the impact of such a spatiotemporal variation on the local population and metapopulation dynamics are principally derived from classical metapopulation theory and have not been experimentally validated. By manipulating spatial structure in artificial metapopulations of the spider mite Tetranychus urticae, we test to which degree spatial (mainland-island metapopulations) and spatiotemporal variation (classical metapopulations) in habitat availability affects the dynamics of the metapopulations relative to systems where habitat is constantly available in time and space (patchy metapopulations). Our experiment demonstrates that (i) spatial variation in habitat availability decreases variance in metapopulation size and decreases density-dependent dispersal at the metapopulation level, while (ii) spatiotemporal variation in habitat availability increases patch extinction rates, decreases local population and metapopulation sizes and decreases density dependence in population growth rates. We found dispersal to be negatively density dependent and overall low in the spatial variable mainland-island metapopulation. This demographic variation subsequently impacts local and regional population dynamics and determines patterns of metapopulation stability. Both local and metapopulation-level variabilities are minimized in mainland-island metapopulations relative to classical and patchy ones

Biomimetic nanomaterials for pulmonary infections: A prospective view in drug delivery systems

Respiratory infections are quite challenging due to their complexity in ailments and composition of viral genetic material and their rate of proliferation. In particular, the eradication of viral illness is still a concern, irrespective of advancements in prevention and remedial procedures. The nature of the viral particle with the possibility of rapid transmission is prone to attach on the deposited surface for days together. This antigen expulses due to sneezing or coughing resulted in multiphase turbulent flow, contaminates the surroundings and is carried away by simple touch or inhalation and find newer hosts for instance, SARSCoV-2 aerosols remain viable for about an hour leading to infection. The present review focuses on the remedial aspects of respiratory infections through a knowledge-based approach towards nanosystems. The complete under- standing of standard antiviral drugs and the remodelling of these drugs through nanosystems still is the need of the hour. The genetic material and epidemiology of viral antigen, help in redefining standard drugs along with nanocarriers to achieve more feasible and hour-based approach. The main goal of this review is to elaborate on the repurposing of existing standard antiviral drugs and ways to accelerate their mode of action to promote a feasible and hour-based approach. The consolidated three-dimensional approaches aimed at sustained, targeted and optimized levels of drug concentration in the circulating system along with bioactive nanocarriers which could effectively pass the cell membrane were reported. The platforms for nanomaterial evolution depend on nature of source, size, structure, and their unique functionalities (Stable, speedy, and long-lasting recovery procedure). However, the research activities and literature on coronavirus have been overwhelming but the information on the sustainability of nanotherapy in SARS-CoV-2 is still in the developmental stage. Hereby, the clinicalaspects of SARS-CoV-2 and the eradication strategy developed for antiviral infections through nanotechnology will pave the way ahead for treating upcoming new variants or other pandemics

Nanocharacterization in Dentistry

About 80% of US adults have some form of dental disease. There are a variety of new dental products available, ranging from implants to oral hygiene products that rely on nanoscale properties. Here, the application of AFM (Atomic Force Microscopy) and optical interferometry to a range of dentistry issues, including characterization of dental enamel, oral bacteria, biofilms and the role of surface proteins in biochemical and nanomechanical properties of bacterial adhesins, is reviewed. We also include studies of new products blocking dentine tubules to alleviate hypersensitivity; antimicrobial effects of mouthwash and characterizing nanoparticle coated dental implants. An outlook on future “nanodentistry” developments such as saliva exosomes based diagnostics, designing biocompatible, antimicrobial dental implants and personalized dental healthcare is presented

シアノ架橋配位高分子の熱処理によるナノ構造有する酸化物及び炭化物の合成

早大学位記番号:新7333早稲田大

The future of layer-by-layer assembly: A tribute to ACS Nano associate editor Helmuth Möhwald

Layer-by-layer (LbL) assembly is a widely used tool for engineering materials and coatings. In this Perspective, dedicated to the memory of ACS Nano associate editor Prof. Dr. Helmuth Möhwald, we discuss the developments and applications that are to come in LbL assembly, focusing on coatings, bulk materials, membranes, nanocomposites, and delivery vehicles

Bioinspired soft nanovesicles for site-selective cancer imaging and targeted therapies

Funding Information: European Research Council, ERC Starting Grant, Grant/Award Number: ERC‐StG‐2019‐848325 Funding information Funding Information: This work is supported by the European Research Council, ERC Starting Grant ‐ ERC‐StG‐2019‐848325. The authors would like to thank Dr. N. K. Jain, Dr. S. Meena, and Dr. Gorain for glancing at this article. We would like to dedicate this article to the memory of late Prof. Sanjiv Sam Gambhir, a molecular imaging and early cancer detection scientist. We have cited all reproduced images and figures in this review. Publisher Copyright: © 2022 Wiley Periodicals LLC.Cell-to-cell communication within the heterogeneous solid tumor environment plays a significant role in the uncontrolled metastasis of cancer. To inhibit the metastasis and growth of cancer cells, various chemically designed and biologically derived nanosized biomaterials have been applied for targeted cancer therapeutics applications. Over the years, bioinspired soft nanovesicles have gained tremendous attention for targeted cancer therapeutics due to their easy binding with tumor microenvironment, natural targeting ability, bio-responsive nature, better biocompatibility, high cargo capacity for multiple therapeutics agents, and long circulation time. These cell-derived nanovesicles guard their loaded cargo molecules from immune clearance and make them site-selective to cancer cells due to their natural binding and delivery abilities. Furthermore, bioinspired soft nanovesicles prevent cell-to-cell communication and secretion of cancer cell markers by delivering the therapeutics agents predominantly. Cell-derived vesicles, namely, exosomes, extracellular vesicles, and so forth have been recognized as versatile carriers for therapeutic biomolecules. However, low product yield, poor reproducibility, and uncontrolled particle size distribution have remained as major challenges of these soft nanovesicles. Furthermore, the surface biomarkers and molecular contents of these vesicles change with respect to the stage of disease and types. Here in this review, we have discussed numerous examples of bioinspired soft vesicles for targeted imaging and cancer therapeutic applications with their advantages and limitations. Importance of bioengineered soft nanovesicles for localized therapies with their clinical relevance has also been addressed in this article. Overall, cell-derived nanovesicles could be considered as clinically relevant platforms for cancer therapeutics. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.publishersversionpublishe

Nanoengineered Core-Shell Structures Using Tubile Halloysite Clay

Halloysite nanotubes are a versatile nanomaterial that can be used in a wide variety of applications. They have a unique structure which could be described as a flat material that consists of silica on one side and alumina on the other; this structure is rolled up in a way naturally forming an internal 10-15 nm lumen and interlayer spacing. This could lead to many potential applications for example incorporating halloysite as a template material or as a support structure. They are an inexpensive clay material that is available in large quantities (thousands of tons), so they may be practically used in industrial applications. In this work, they were used as a support structure for catalysts, gas sensors, as well as lithium sulfur batteries. In catalysis it is essential to minimize aggregation of catalytic nanoparticles as aggregation leads to a reduction of surface area used for conducting chemical reactions. Support structures are used to minimize this aggregation. Halloysite nanotubes were used as a support structure to chemically attach two different catalytic metal nanoparticles: cobalt and ruthenium. There are a variety of techniques to synthesize catalytic nanoparticles onto/inside halloysite. To enhance inner-wall and lumen metal cluster formation for ruthenium, we intercalated the tube with furfuraldehyde and then converted it to tetradentate ligands which have shown specific binding to Ru3+ ions from ethanol solution at elevated temperatures. One of the purposes of the ligands is to increase the amount of ruthenium loaded inside the halloysite. The other purpose is to firmly hold the ruthenium inside the halloysite to prevent leakage of Ru. Metal particles of 2-5 nm diameters were formed both in the central lumen and in the interlayer spaces of the tube walls. This core-shell engineered catalyst was tested in hydrogenation of aromatics. Maximum turnover frequency (TOF) achieved was 17282 h-1 in terms of hydrogen uptake per surface area of Ru-atoms. For halloysite-based ruthenium catalysts some metal leaching was observed after the 1st reaction cycle, which may be attributed to poorly retained nanoparticles located outside of the nanotubes, but these Ru-core-shell nanocatalysts were recycled up to ten times without loss of catalytic activity. Halloysite was also used to load cobalt for catalytic purposes. Active cobalt mesocatalysts were prepared using four main methods: Wet impregnation of cobalt chloride into halloysite, adsorption of cobalt (II, III) oxide onto halloysite, and cobalt chloride linkage onto/into halloysite using azines as well as APTES. It turned out that the most efficient catalyst was the halloysite loaded with cobalt chloride using the azine acetone as a ligand with an R value (L/min x g(cat)) of three, which is higher than other previously made cobalt mesocatalysts which typically range from 0.9-2.9. In addition to supporting metal catalytic nanoparticles, halloysite was used to load zirconia nanoparticles for gas sensor applications. We synthesized Y2O3-ZrO2 on halloysite clay nanotubes, an example of an external metal oxide – internal ceramic coreshell system. This produced 5-10 nm diameter particles on the nanotubes. This system should limit the particle agglomeration at working temperatures of 500 ºC. Halloysite nanotubes were also used as a nanoconfinement structure to load sulfur particles for increasing lithium-sulfur battery efficiency. The available nanoscale space in the lumen of halloysites nanotubes and between assembled halloysites clusters help suppress the dissolution and migration of polysulfides in liquid electrolyte solution. The halloysite-sulfur cathode composite was incorporated into coin batteries, and the halloysite/sulfur composites successfully improve the cycling stability, retaining ~84% of the starting capacity for over 250 cycles

Development of enzyme-functionalized hybrid mesoporous nanodevices for advanced chemical communication

Tesis por compendio[ES] La presente tesis doctoral se centra en el diseño, síntesis y caracterización de varios nanodispositivos híbridos orgánico-inorgánicos, utilizando como soporte nanopartículas de sílice mesoporosa equipadas con enzimas y puertas moleculares, los cuales muestran capacidades comunicativas además de la evaluación de diferentes estrategias de comunicación. El primer capítulo incluye un resumen de diferentes conceptos sobre los que se fundamentan los estudios realizados tales como nanotecnología, materiales de sílice mesoporosa, materiales con puertas moleculares que reaccionan a estímulos específicos, partículas Janus y biocomputación. Finalmente, se incluyen conceptos básicos acerca de la comunicación química, materiales y estrategias empleados hasta ahora y ejemplos representativos. A continuación, en el segundo capítulo, se presentan los objetivos generales de esta tesis doctoral que son abordados en los siguientes capítulos experimentales. El tercer capítulo muestra un sistema de biocomputación para liberación basado en nanopartículas Janus de oro-sílice mesoporosa capaces de comunicarse con el entorno procesando la información e imitando la función lógica booleana propia de un demultiplexer y que resulta en la liberación controlada de la carga. Se muestra que dicho nanodispositivo puede llevar a cabo sus funciones en medios complejos como en células cancerígenas. En el cuarto capítulo, se presenta un modelo circular de comunicación dentro de una red de tres nanopartículas diferentes basado en el intercambio jerárquicamente programado de mensajes químicos. La parte mesoporosa del nanodispositivo 1 (S1βgal) es cargada con la especie fluorescente [Ru(bpy)3]Cl2 y tapada con cadenas de oligo(etilenglicol) que contienen puentes disulfuro y que funcionan como puertas moleculares, mientras que la enzima β-galactosidasa es unida a la parte del oro. En la nanopartícula 2 (S2galox), la enzima galactosa oxidasa es inmovilizada en la cara del oro mientras que la sílice mesoporosa es cargada con 4-(bromometil)benzoato de metilo y los poros tapados con un derivado de arilboronato autoinmolante sensible a H2O2 que forma un complejo huéspedanfitrión con β-ciclodextrina. Finalmente, el nanodispositivo 3 (S3est) es funcionalizado con la enzima esterasa en la parte del oro, cargada con la especie reductora hidroclururo de tris(2-carboxietil)fosfina (TCEP) en la parte mesoporosa y tapada con una nanoválvula supramolecular que responde a pH (βciclodextrina:benzimidazol). En el quinto capítulo, se muestra un modelo interactivo de comunicación química entre una nanopartícula Janus abiótica y un organismo vivo (Saccharomyces cerevisiae). En particular, el nanodispositivo está basado en nanopartículas funcionalizadas con glucosa oxidasa en la parte del oro, cargadas con el genotóxico fleomicina y tapadas con la puerta molecular sensible a pH (βciclodextrina:benzimidazol). El microorganismo usado en el estudio es una levadura modificada que expresa GFP bajo el control del promotor del gen RNR3; la transcripción de dicho gen es inducida con la exposición a agentes que dañan el ADN. La ruta de comunicación interactiva empieza con la adición de sacarosa (estímulo de entrada) la cual es hidrolizada en glucosa por la invertasa localizada en el espacio periplásmico de las levaduras y que difunde al nanodispositivo donde es trasformada en el correspondiente ácido por la glucosa oxidasa de la parte del oro. La bajada local de pH da lugar a la apertura de la nanoválvula sensible a pH del nanovehículo y con ello a la liberación de fleomicina (mensaje de vuelta) que induce la expresión de GFP (señal de salida) en las levaduras. En el sexto capítulo, proponemos una estrategia para establecer una comunicación lineal entre dos microorganismos diferentes que no interactúan entre ellos mediada por un nanodispositivo que actúa como traductor químico. Finalmente, las conclusiones generales de la presente tesis doctoral son expuestas en el capítulo siete. El estudio de las capacidades comunicativas de los nanodispositivos mesoporosos funcionalizados con enzimas permite la construcción de estrategias de cooperación entre diferentes entidades que permiten funcionalidades que van más allá que aquellas llevadas a cabo por agentes individuales.[CA] La present tesi doctoral es centra en el disseny, síntesi i caracterització de diversos nanodispositius híbrids orgànic-inorgànics, utilitzant com a suport nanopartícules de sílice mesoporosa equipades amb enzims i portes moleculars, i que mostren capacitats comunicatives a més de l’avaluació de diferents estratègies de comunicació. El primer capítol inclou un resum de diferents conceptes sobre els quals es fonamenten els estudis realitzats com ara nanotecnologia, materials de sílice mesoporosa, materials amb portes moleculars que reaccionen a estímuls específics, partícules Janus i biocomputació. Finalment, s’inclouen conceptes bàsics sobre la comunicació química, materials i estratègies utilitzades fins ara i exemples representatius. A continuació, en el segon capítol, es presenten els objectius generals d’aquesta tesi doctoral que són abordats en els següents capítols experimentals. El tercer capítol mostra un sistema de biocomputació per alliberament basat en nanopartícules Janus d’or-sílice mesoporosa capaços de comunicar-se amb l’entorn processant la informació i imitant la funció lògica booleana pròpia d’un demultiplexer i que resulta en l’alliberament controlat de la càrrega. Es mostra que aquest nanodispositiu pot dur a terme les seves funcions en mitjans complexos com en cèl·lules canceroses. En el quart capítol, es presenta un model circular de comunicació dins d’una xarxa de tres nanopartícules diferents basat en l’intercanvi jeràrquicament programat de missatges químics. La part mesoporosa del nanodispositiu 1 (S1βgal) es carrega amb l’espècie fluorescent [Ru(bpy)3]Cl2 i es tapa amb cadenes d’oligo(etilenglicol) que contenen ponts disulfur i que funcionen com portes moleculars, mentre que l’enzim β-galactosidasa s’immobilitza a la part de l’or. A la nanopartícula 2 (S2galox), l’enzim galactosa oxidasa s’immobilitza a la cara de l’or mentre que la sílice mesoporosa es carrega amb 4-(bromometil)benzoat de metil i els porus són tapats amb un derivat d’arilboronat autoimmolant sensible a H2O2 que forma un complex hoste-amfitrió amb β-ciclodextrina. Finalment, el nanodispositu 3 (S3est) es funcionalitza amb l’enzim esterasa en la part de l’or, es carrega amb l’espècie reductora hidroclurur de tris (2-carboxietil) fosfina (TCEP) a la part mesoporosa i es tapa amb una nanoválvula supramolecular que respon a pH (β-ciclodextrina:benzimidazol). En el cinqué capítol, es mostra un model interactiu de comunicació química entre una nanopartícula Janus abiòtica i un organisme viu (Saccharomyces cerevisiae). En particular, el nanodispositiu està basat en nanopartícules funcionalitzades amb glucosa oxidasa en la part de l’or, carregades amb el genotòxic fleomicina i tapades amb la porta molecular sensible a pH (βciclodextrina:benzimidazol). El microorganisme utilitzat en l’estudi és un rent modificat que expressa GFP sota el control del promotor del gen RNR3; la transcripció d’aquest gen és induïda amb l’exposició a agents que danyen l’ADN. La ruta de comunicació interactiva comença amb l’addició de sacarosa (estímul d’entrada) la qual és hidrolitzada en glucosa per la invertasa localitzada en l’espai periplasmàtic dels rents i que difon al nanodispositiu on és transformada en el corresponent àcid per la glucosa oxidasa de la part de l’or. La baixada local de pH dona lloc a l’obertura de la nanoválvula sensible a pH del nanovehicle i amb això l’alliberament de fleomicina (missatge de tornada) que indueix l’expressió de GFP (senyal de sortida) en el rent. En el sisé capítol, proposem una estratègia per establir una comunicació lineal entre dos microorganismes diferents que no interactuen entre ells facilitada per un nanodispositiu que actua com a traductor químic. Finalment, les conclusions generals de la present tesi doctoral són exposades en el capítol set. L’estudi de les capacitats comunicatives dels nanodispositius mesoporosos funcionalitzats amb enzims permet la construcció d’estratègies de cooperació entre diferents entitats que permeten funcionalitats que van més enllà que aquelles dutes a terme per agents individuals. Esperem que els resultats obtinguts inspiren aplicacions futures en diferents àrees com ara biomedicina, nanorobots, materials que imiten la naturalesa i tecnologies de la informació.[EN] This PhD Thesis is focused on the design, synthesis and characterization of several hybrid organic-inorganic nanodevices using mesoporous silica nanoparticles equipped with enzymes and molecular gates which display communication capabilities as well as the design and evaluation of different communication strategies. The first chapter includes an overview of the different concepts which lay the foundations of the presented studies such as nanotechnology, mesoporous silica materials, stimuli-responsive gated materials, Janus particles and biocomputing. Basic concepts of chemical communication, materials and enabling technologies employed so far and representative examples in this field are also included. Next, in the second chapter, the general objectives of this PhD Thesis that are addressed in the following experimental chapters are presented. The third chapter shows a biocomputing delivery system based on Janus gold-mesoporous silica nanoparticles capable of chemically communicating with the environment and processing the information mimicking a demultiplexer Boolean logic function which results in a programmed cargo release. Finally, it is shown that such nanodevice is operative in complex media such as cancer cells. In the fourth chapter, it is presented a circular model of communication within a network of three different nanoparticles based on the hierarchically programmed exchange of chemical messages. The mesoporous face of nanodevice 1 (S1βgal) is loaded with the fluorescent dye [Ru(bpy)3]Cl2 and capped with disulfidecontaining oligo(ethylene glycol) chains acting as gatekeepers, whereas the enzyme β-galactosidase is attached to the gold face. In nanoparticle 2 (S2galox), the enzyme galactose oxidase is immobilized on the Au face, while the mesoporous silica is loaded with methyl 4-(bromomethyl)benzoate and the mesopores capped with a H2O2-sensitive self-immolative arylboronate derivative which forms a host-guest complex with β-cyclodextrin. Finally, the nanodevice 3 (S3est) is functionalized with the enzyme esterase on the Au face, loaded with the reductive species tris(2- carboxyethyl)phosphine hydrochloride (TCEP) in the mesoporous face and capped with a pH-responsive supramolecular nanovalve (β-cyclodextrin:benzimidazole). In the fifth chapter, it is showed an interactive model of chemical communication between an abiotic Janus nanoparticle and a living organism (Saccharomyces cerevisiae). In particular, the nanodevice is based on Janus goldmesoporous silica nanoparticles functionalized with glucose oxidase on the Au face, loaded with the genotoxin phleomycin and capped with a pH-responsive (βcyclodextrin:benzimidazole) gatekeeper. The microorganism used in the studies is an engineered budding yeast that expresses GFP under the control of the RNR3 promoter; RNR3 gene transcription is induced upon exposure to DNA-damaging agents. The interactive communication pathway starts with the addition of sucrose (input) which is hydrolyzed into glucose by invertase located in periplasmic space of yeasts and diffuses to the nanodevice where it is transformed into the corresponding acid by glucose oxidase on the Au face. The local drop in pH leads to uncapping of the pH-sensitive nanovalve in the nanocarrier and the release of phleomycin (feedback messenger) that induces GFP expression (output) in yeasts. In the sixth chapter, we propose a strategy to establish linear communication between two different non-interacting microorganisms mediated by a nanodevice which acts as a chemical “nanotranslator”. Finally, the general conclusions from this PhD Thesis are presented in chapter seven. The study of communication capabilities of enzyme-functionalized mesoporous nanodevices enables the construction of strategies of cooperation between different entities allowing sophisticated functionalities that go beyond those carried out by individual agents. We hope that the obtained results inspire future applications in different areas such as biomedicine, nanorobots, life-like materials and information technologies.The authors wish to thank the Spanish Government (projects RTI2018-100910-B-C41 and RTI2018-101599-B-C22 (MCUI/AEI/FEDER, UE), CTQ2017-87954-P), the Generalitat Valenciana (PROMETEO 2018/024), the Comunidad de Madrid (IND2017/BMD7642) and CIBER-BBN (NANOCOMMUNITY project) for support.De Luis Fernández, B. (2021). Development of enzyme-functionalized hybrid mesoporous nanodevices for advanced chemical communication [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171506TESISCompendi

Rational Design and Development of Purely Peptidic Amphiphiles for Gene Delivery

Gene therapy depends on viral and non-viral delivery systems to ferry nucleic acids into target cells 1,2. In recent years, gene insertion and interference therapies have made a ground breaking impact in the treatment of rare inherited diseases, neurological disorders, cardiac diseases, and cancer 3. Several disadvantages associated with viral vectors, such as high toxicity and immunogenicity, limitation in size of transgenic DNA, and high manufacturing cost have triggered the rapid expansion of non-viral delivery systems including peptide-based vectors 4. The advantages of peptides are not only their biocompatibility and biodegradability, but sheer limitless possible combinations and modifications of amino acid residues that are able to promote the assembly of modular, multiplexed delivery systems 5. With the advantages of peptides in mind, we looked into the potential of peptide-based nanoassemblies in developing a non-viral gene delivery system. The thesis is structured to successively address (i) the design and development of purely amphiphilic peptides self-assembling into multicompartment micelles (MCMs), (ii) the efficient DNA cargo entrapment up to 100 nucleotides in length into self-assembled peptide MCMs and the delivery thereof, and (iii) targeting of oligonucleotides to the nucleus via a nuclear localization signal (NLS) integrated in the peptide-based carrier. The challenge was to rationally design the peptides and identify the proper conditions in which the DNA entrapment does not interfere with multicompartment micellar self-assembly. In addition, to fulfil the prerequisites of a successful gene delivery system that overcomes cellular barriers, we incorporated biologically active amino acids in our peptide sequences. A systematic characterization of the physicochemical features of the peptidic nanostructures was carried out to gain insight into the mechanism underlying self-assembly and to shed light on ways to tune these features for prospective biomedical applications. Taking into account our findings on how the size/type of genetic payload together with the peptide amphiphile’s charge and length impact the self-assembly process, we successfully established a non-toxic, purely peptidic delivery system that serves as a cornerstone for developing oligonucleotide therapy platforms