Frog nest foams exhibit pharmaceutical foam-like properties

Foams have frequently been used as systems for the delivery of cosmetic and therapeutic molecules; however, there is high variability in the foamability and long-term stability of synthetic foams. The development of pharmaceutical foams that exhibit desirable foaming properties, delivering appropriate amounts of the active pharmaceutical ingredient (API) and that have excellent biocompatibility is of great interest. The production of stable foams is rare in the natural world; however, certain species of frogs have adopted foam production as a means of providing a protective environment for their eggs and larvae from predators and parasites, to prevent desiccation, to control gaseous exchange, to buffer temperature extremes, and to reduce UV damage. These foams show great stability (up to 10 days in tropical environments) and are highly biocompatible due to the sensitive nature of amphibian skin. This work demonstrates for the first time that nests of the túngara frog ( Engystomops pustulosus ) are stable ex situ with useful physiochemical and biocompatible properties and are capable of encapsulating a range of compounds, including antibiotics. These protein foam mixtures share some properties with pharmaceutical foams and may find utility in a range of pharmaceutical applications such as topical drug delivery systems.

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Frog nest foam as a drug delivery system

10.1101/2021.01.06.425559 ◽

2021 ◽

Author(s):

Sarah Brozio ◽

Erin M O Shaughnessy ◽

Stuart Woods ◽

Ivan Hall-Barrientos ◽

Patrica E Martin ◽

...

Keyword(s):

Drug Delivery ◽

Drug Delivery System ◽

Delivery System ◽

Active Pharmaceutical Ingredient ◽

Natural World ◽

Ex Situ ◽

Foaming Properties ◽

Amphibian Skin ◽

Tropical Environments ◽

Therapeutic Molecules

Foams have frequently been used as systems for the delivery of cosmetic and therapeutic molecules; however, there is high variability in the foamability and long-term stability of synthetic foams. The development of pharmaceutical foams that exhibit desirable foaming properties, delivering appropriate amounts of the active pharmaceutical ingredient (API) and that have excellent biocompatibility is of great interest. The production of stable foams is rare in the natural world; however, certain species of frogs have adopted foam production as a means of providing a protective environment for their eggs and larvae from a predators and parasites, to prevent desiccation, to control gaseous exchange, temperature extremes, and to reduce UV damage. These foams show great stability (up to 10 days in tropical environments) and are highly biocompatible due to the sensitive nature of amphibian skin. This work demonstrates for the first time, that nests of the Tungara frog (Engystomops pustulosus) is stable ex situ with useful physiochemical and biocompatible properties and is capable of encapsulating a range of compounds, including antibiotics. These protein foam mixtures may find utility as a topical drug delivery system (DDS).

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Structure-Properties Correlation of Cross-Linked Penicillin G Acylase Crystals

Crystals ◽

10.3390/cryst11040451 ◽

2021 ◽

Vol 11 (4) ◽

pp. 451

Author(s):

Marta Kubiak ◽

Janine Mayer ◽

Ingo Kampen ◽

Carsten Schilde ◽

Rebekka Biedendieck

Keyword(s):

Mechanical Stability ◽

Structural Characteristics ◽

Penicillin G ◽

Bacillus Species ◽

Diffusion Limitations ◽

Small Water ◽

Long Term Stability ◽

Atomic Force ◽

First Time

In biocatalytic processes, the use of free enzymes is often limited due to the lack of long-term stability and reusability. To counteract this, enzymes can be crystallized and then immobilized, generating cross-linked enzyme crystals (CLECs). As mechanical stability and activity of CLECs are crucial, different penicillin G acylases (PGAs) from Gram-positive organisms have proven to be promising candidates for industrial production of new semisynthetic antibiotics, which can be crystallized and cross-linked to characterize the resulting CLECs regarding their mechanical and catalytic properties. The greatest hardness and Young’s modulus determined by indentation with an atomic force microscope were observed for CLECs of Bacillus species FJAT-PGA CLECs (26 MPa/1450 MPa), followed by BmPGA (Priestia megaterium PGA, 23 MPa/1170 MPa) and BtPGA CLECs (Bacillus thermotolerans PGA, 11 MPa/614 MPa). In addition, FJAT- and BtPGA CLECs showed up to 20-fold higher volumetric activities compared to BmPGA CLECs. Correlation to structural characteristics indicated that a high solvent content and low number of cross-linking residues might lead to reduced stability. Furthermore, activity seems to be restricted by small water channels due to severe diffusion limitations. To the best of our knowledge, we show for the first time in this study that the entire process chain for the characterization of diverse industrially relevant enzymes can be performed at the microliter scale to discover the most important relationships and limitations.

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Preparation and Growth of Pb2Sr2Y0.5Ca0.5Cu3O8+δ Thin Film Superconductors

MRS Proceedings ◽

10.1557/proc-285-287 ◽

1992 ◽

Vol 285 ◽

Author(s):

S.H.H. Naqvi ◽

M. Vickers ◽

S. Tarling ◽

P. Barnes ◽

I.W. Boyd

Keyword(s):

Thin Film ◽

Pulsed Laser ◽

Growth Conditions ◽

Laser Deposition ◽

Ex Situ ◽

Dc Resistivity ◽

Basic Set ◽

Zero Resistance ◽

Van Der Pauw ◽

First Time

ABSTRACTThe lead based superconductor Pb2Sr2Y0.5Ca0.5Cu3O8+δ is a most complex material. If any oxygen is present in the PbO-CuOδ-PbO sandwich layer (i.e. if δ>0) the superconductivity deteriorates. This is also a most difficult material to grow not only because of the large number of cation stoichiometries which have to be precisely balanced but also because of the tendency for multiple phases to form. Pulsed laser deposition (PLD) has been applied to prepare thin films of the 2213-phase on MgO (100) single crystal substrates at low temperature (300°C) in low oxidizing atmospheres. A basic set of ex-situ growth conditions has been determined which produce for the first time good quality films of this material as characterized by DC resistivity using the Van der Pauw method, as well as EDX and XRD. The layers are reasonably c-axis oriented and display a superconducting onset transition temperature of 79K and zero resistance at 65K after subsequent annealing in a nitrogen ambient.

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Landscapes of the ‘Coast of Death’: dolmen topographies of NW Iberia

10.31235/osf.io/y9xfg ◽

2021 ◽

Author(s):

Gail Higginbottom ◽

Antonio César González-García ◽

Miguel Carrero-Pazos ◽

Benito Vilas-Estévez ◽

Víctor López-López

Keyword(s):

Natural World ◽

The South ◽

South Eastern ◽

Eastern Side ◽

Nw Iberia ◽

Natural Landscapes ◽

First Time

This paper investigates the dolmen landscapes of Neolithic communities found within Costa da Morte (Coast of Death), Galicia. Its goal is to uncover whether or not the megalithic monuments of a particular and coherent area of the south-eastern side of the Atlantic Façade are situated in relation to complex locational variables. In particular, in this paper, we explore the entirety of their surrounding topography. For the very first time, we were able to demonstrate that very specific natural landscapes surrounding the dolmens of this region in Iberia were likely selectively drawn upon, expanding our understanding of the Neolithic of this area and the people's relationship with their natural world.

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Importance of the pyrolysis for microstructure and superconducting properties of CSD-grown GdBa2Cu3O7−x-HfO2 nanocomposite films by the ex-situ approach

Scientific Reports ◽

10.1038/s41598-020-75587-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Pablo Cayado ◽

Hannes Rijckaert ◽

Els Bruneel ◽

Manuela Erbe ◽

Jens Hänisch ◽

...

Keyword(s):

Processing Parameters ◽

Nanocomposite Films ◽

Ex Situ ◽

Superconducting Properties ◽

Critical Temperatures ◽

Solution Deposition ◽

Nanoparticle Distribution ◽

Current Densities ◽

First Time ◽

Lower Heating

Abstract For the first time, GdBa2Cu3O7−x nanocomposites were prepared by chemical solution deposition following the ex-situ approach. In particular, ~ 220 nm GdBa2Cu3O7−x-HfO2 (GdBCO-HfO2) nanocomposite films were fabricated starting from a colloidal solution of 5 mol% HfO2 nanoparticles. Hereby, one of the main challenges is to avoid the accumulation of the nanoparticles at the substrate interface during the pyrolysis, which would later prevent the epitaxial nucleation of the GdBCO grains. Therefore, the effect of pyrolysis processing parameters such as heating ramp and temperature on the homogeneity of the nanoparticle distribution has been investigated. By increasing the heating ramp to 300 °C/h and decreasing the final temperature to 300 °C, a more homogenous nanoparticle distribution was achieved. This translates into improved superconducting properties of the grown films reaching critical temperatures (Tc) of 94.5 K and self-field critical current densities ($${J}_{\mathrm{c}}^{\mathrm{sf}}$$ J c sf ) at 77 K of 2.1 MA/cm2 with respect to films pyrolyzed at higher temperatures or lower heating ramps.

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Scribing Method for Carbon Perovskite Solar Modules

Energies ◽

10.3390/en13071589 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1589 ◽

Cited By ~ 2

Author(s):

Simone M. P. Meroni ◽

Katherine E. A. Hooper ◽

Tom Dunlop ◽

Jenny A. Baker ◽

David Worsley ◽

...

Keyword(s):

Screen Printing ◽

Fill Factor ◽

Transparent Electrode ◽

Perovskite Solar Cell ◽

Metal Contacts ◽

Good Efficiency ◽

Long Term Stability ◽

First Time

The fully printable carbon triple-mesoscopic perovskite solar cell (C-PSC) has already demonstrated good efficiency and long-term stability, opening the possibility of lab-to-fab transition. Modules based on C-PSC architecture have been reported and, at present, are achieved through the accurate registration of each of the patterned layers using screen-printing. Modules based on this approach were reported with geometric fill factor (g-FF) as high as 70%. Another approach to create the interconnects, the so-called scribing method, was reported to achieve more than 90% g-FF for architectures based on evaporated metal contacts, i.e., without a carbon counter electrode. Here, for the first time, we adopt the scribing method to selectively remove materials within a C-PSC. This approach allowed a deep and selective scribe to open an aperture from the transparent electrode through all the layers, including the blocking layer, enabling a direct contact between the electrodes in the interconnects. In this work, a systematic study of the interconnection area between cells is discussed, showing the key role of the FTO/carbon contact. Furthermore, a module on 10 × 10 cm2 substrate with the optimised design showing efficiency over 10% is also demonstrated.

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Targeted Release of Probiotics from Enteric Microparticulated Formulations

Polymers ◽

10.3390/polym11101668 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1668 ◽

Cited By ~ 7

Author(s):

Cristina Yus ◽

Ruben Gracia ◽

Ane Larrea ◽

Vanesa Andreu ◽

Silvia Irusta ◽

...

Keyword(s):

Targeted Delivery ◽

Target Tissue ◽

Release Formulation ◽

Long Term Stability ◽

Pharmaceutical Ingredients ◽

Efficient Delivery ◽

Synthesized Materials ◽

First Time ◽

Targeted Release

The development of advanced probiotic delivery systems, which preserve bacteria from degradation of the gastrointestinal tract and achieve a targeted release mediated by pH-independent swelling, is of great interest to improve the efficient delivery of probiotic bacteria to the target tissue. Gram-positive and Gram-negative bacteria models (Lactobacillus acidophilus (Moro) Hansen and Mocquot (ATCC® 4356™) and Escherichia coli S17, respectively) have been successfully encapsulated for the first time in pH-independent microparticulate polymethacrylates (i.e., Eudraguard biotic) used for the targeted delivery of nutraceuticals to the colon. These bacteria have also been encapsulated within the mucoadhesive polymethacrylate Eudragit RS 100 widely used as targeted release formulation for active pharmaceutical ingredients. The enteric microparticles remained unaltered under simulated gastric conditions and released the contained viable microbial cargo under simulated intestinal conditions. Buoyancies of 90.2% and 57.3% for Eudragit and Eudraguard microparticles, respectively, and long-term stability (5 months) for the encapsulated microorganisms were found. Cytotoxicity of the microparticles formulated with both polymers was evaluated (0.5–20 mg/mL) on Caco-2 cells, showing high cytocompatibility. These results underline the suitability of the synthesized materials for the successful delivery of probiotic formulations to the target organ, highlighting for the first time the potential use of Eudraguard biotic as an effective enteric coating for the targeted delivery of probiotics.

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Enhancement of efficiency and long-term stability in graphene/Si-quantum-dot heterojunction photodetectors by employing bis(trifluoromethanesulfonyl)-amide as a dopant for graphene

Journal of Materials Chemistry C ◽

10.1039/c7tc04647b ◽

2017 ◽

Vol 5 (48) ◽

pp. 12737-12743 ◽

Cited By ~ 14

Author(s):

Dong Hee Shin ◽

Chan Wook Jang ◽

Ju Hwan Kim ◽

Jong Min Kim ◽

Ha Seung Lee ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Dot ◽

Term Stability ◽

Long Term Stability ◽

Si Quantum Dot ◽

First Time ◽

Si Quantum Dots

Bis(trifluoromethanesulfonyl)-amide (TFSA) is for the first time employed as a dopant for graphene for graphene/Si-quantum-dots-based photodetectors.

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Novel synthesis and electrochemical investigations of ZnO/C composites for lithium-ion batteries

Journal of Materials Science ◽

10.1007/s10853-021-06125-4 ◽

2021 ◽

Author(s):

E. Thauer ◽

G. S. Zakharova ◽

E. I. Andreikov ◽

V. Adam ◽

S. A. Wegener ◽

...

Keyword(s):

Lithium Ion Batteries ◽

Electronic Conductivity ◽

Lithium Ion ◽

Nitrogen Atmosphere ◽

Ex Situ ◽

Ion Diffusion ◽

Storage Mechanism ◽

Treatment Conditions ◽

One Step ◽

First Time

AbstractFor the first time, ZnO/C composites were synthesized using zinc glycerolate as a precursor through one-step calcination under a nitrogen atmosphere. The effect of the heat treatment conditions on the structure, composition, morphology as well as on the electrochemical properties regarding application in lithium-ion batteries are investigated. The products obtained by calcination of the precursor in nitrogen at 400—800 °C consist of zinc oxide nanoparticles and amorphous carbon that is in-situ generated from organic components of the glycerolate precursor. When used as anode material for lithium-ion batteries, the as-prepared ZnO/C composite synthesized at a calcination temperature of 700 °C delivers initial discharge and charge capacities of 1061 and 671 mAh g−1 at a current rate of 100 mA g−1 and hence 1.5 times more than bare ZnO, which reaches only 749/439 mAh g−1. The native carbon improves the conductivity, allowing efficient electronic conductivity and Li-ion diffusion. By means of ex-situ XRD studies a two-step storage mechanism is proven.

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Nature, Labor, and the Rise of Capitalism

Monthly Review ◽

10.14452/mr-069-01-2017-05_3 ◽

2017 ◽

Vol 69 (1) ◽

pp. 42

Author(s):

Martin Empson

Keyword(s):

Economic System ◽

Natural World ◽

Time Production ◽

Monthly Review ◽

Human Needs ◽

The Past ◽

Basic Goods ◽

First Time

Capitalism was a radical break with the past: for the first time, production of basic goods was driven by the accumulation of wealth for its own sake, and not primarily to satisfy human needs. Likewise, we are alienated from the natural world, as the products of our own labor are no longer under our control. Our very perception of nature is shaped by an economic system that treats "the environment" as a collection of commodities to be exploited.Click here to purchase a PDF version of this article at the Monthly Review website.

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