scholarly journals Inulin-g-poly-D,L-lactide, a Sustainable Amphiphilic Copolymer for Nano-Therapeutics

2021 ◽  
Author(s):  
Carla Sardo ◽  
Teresa Mencherini ◽  
Carmela Tommasino ◽  
Tiziana Esposito ◽  
Paola Russo ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Colloidal Stability ◽  
Preliminary Investigation ◽  
2D Nmr ◽  
Point Of View ◽  
Cancer Therapies ◽  
Amphiphilic Copolymers ◽  
Natural Polysaccharide ◽  
Order Of Magnitude ◽  
Coating Design

Abstract Cancer therapies started to take a big advantage from new nanomedicines on the market. Since then, research tried to better understand how to maximize efficacy whilst maintaining a high safety profile. Polyethylene glycol (PEG), the gold standard for nanomedicines coating design, although in many cases is a winning choice to ensure a long circulation and colloidal stability, in other cases cause, after the first administration, the development in patients of PEG directed immunoglobulins. The phenomenon, called ABC effect, has been studied and correlated with clinical failure because of the premature removal from the circulation by immune mechanism. Therefore, alternatives to PEG need to be found. Here, looking at the backbone structural analogy, the hydrophilicity, flexibility and its GRAS status, the natural polysaccharide Inulin (INU) was investigated as PEG alternative. In particular, the first family of Inulin-g-poly-D,L-lactide amphiphilic copolymers (INU-PLAs) was synthesized. The new materials were fully characterized from the physic-chemical point of view (solubility, 1D and 2D NMR, FT-IR, UV-Vis, GPC, DSC) and showed interesting hybrid properties compared to precursors. Moreover, their ability in forming stable colloids and to serve as a carrier for doxorubicin were investigated and compared with the already well known and well characterized PEGylated counterpart, polyethylene glycol-g-poly-D,L-lactide (PEG-PLA). This preliminary investigation showed INU-PLA to be able to assemble in nanostructures less than 200 nm in size and capable of loading doxorubicin with an encapsulation efficiency in the same order of magnitude of PEG-PLA analogues.

Seed-mediated synthesis and PEG coating of gold nanoparticles for controlling morphology and sizes

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3353-3360
Author(s):  
Susana Helena Arellano Ramírez ◽  
Perla García Casillas ◽  
Christian Chapa González
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Infrared Spectrometry ◽  
Ammonium Bromide ◽  
Chloroauric Acid ◽  
Vis Spectroscopy ◽  
Seed Mediated ◽  
Peg Coating

AbstractA significant area of research is biomedical applications of nanoparticles which involves efforts to control the physicochemical properties through simple and scalable processes. Gold nanoparticles have received considerable attention due to their unique properties that they exhibit based on their morphology. Gold nanospheres (AuNSs) and nanorods (AuNRs) were prepared with a seed-mediated method followed of polyethylene glycol (PEG)-coating. The seeds were prepared with 0.1 M cetyltrimethyl-ammonium bromide (CTAB), 0.005 M chloroauric acid (HAuCl4), and 0.01 M sodium borohydride (NaBH4) solution. Gold nanoparticles with spherical morphology was achieved by growth by aggregation at room temperature, while to achieve the rod morphology 0.1 M silver nitrate (AgNO3) and 0.1 M ascorbic acid solution were added. The gold nanoparticles obtained by the seed-mediated synthesis have spherical or rod shapes, depending on the experimental conditions, and a uniform particle size. Surface functionalization was developed using polyethylene glycol. Morphology, and size distribution of AuNPs were evaluated by Field Emission Scanning Electron Microscopy. The average size of AuNSs, and AuNRs was 7.85nm and 7.96 x 31.47nm respectively. Fourier transform infrared spectrometry was performed to corroborate the presence of PEG in the AuNPs surface. Additionally, suspensions of AuNSs and AuNRs were evaluated by UV-Vis spectroscopy. Gold nanoparticles were stored for several days at room temperature and it was observed that the colloidal stability increased once gold nanoparticles were coated with PEG due to the shield formed in the surface of the NPs and the increase in size which were 9.65±1.90 nm of diameter for AuNSs and for AuNRs were 29.03±5.88 and 8.39±1.02 nm for length and transverse axis, respectively.

The Impact of Bioconjugation on the Interfacial Activity of a Protein Biosurfactant

2018 ◽  
Author(s):  
Hossam H Tayeb ◽  
Marina Stienecker ◽  
Anton Middelberg ◽  
Frank Sainsbury
Keyword(s):  
Polyethylene Glycol ◽  
Colloidal Stability ◽  
Point Mutations ◽  
Pharmaceutical Formulations ◽  
Industrial Processes ◽  
Parent Molecule ◽  
Site Specific ◽  
Interfacial Activity ◽  
Surface Active ◽  
The Impact

Biosurfactants, are surface active molecules that can be produced by renewable, industrially scalable biologic processes. DAMP4, a designer biosurfactant, enables the modification of interfaces via genetic or chemical fusion to functional moieties. However, bioconjugation of addressable amines introduces heterogeneity that limits the precision of functionalization as well as the resolution of interfacial characterization. Here we designed DAMP4 variants with cysteine point mutations to allow for site-specific bioconjugation. The DAMP4 variants were shown to retain the structural stability and interfacial activity characteristic of the parent molecule, while permitting efficient and specific conjugation of polyethylene glycol (PEG). PEGylation results in a considerable reduction on the interfacial activity of both single and double mutants. Comparison of conjugates with one or two conjugation sites shows that both the number of conjugates as well as the mass of conjugated material impacts the interfacial activity of DAMP4. As a result, the ability of DAMP4 variants with multiple PEG conjugates to impart colloidal stability on peptide-stabilized emulsions is reduced. We suggest that this is due to constraints on the structure of amphiphilic helices at the interface. Specific and efficient bioconjugation permits the exploration and investigation of the interfacial properties of designer protein biosurfactants with molecular precision. Our findings should therefore inform the design and modification of biosurfactants for their increasing use in industrial processes, and nutritional and pharmaceutical formulations.

Judicial geography as a legal science and academic discipline

2019 ◽  
Vol 5 (4) ◽  
pp. 122-137
Author(s):  
Almaz F. Abdulvaliev
Keyword(s):  
Criminal Law ◽  
Climatic Factors ◽  
Academic Discipline ◽  
Preliminary Investigation ◽  
Criminal Procedure ◽  
Mapping Method ◽  
Research Field ◽  
Point Of View ◽  
Theoretical Development ◽  
New Research

This article presents the conceptual foundations for the formation of a new research field “Judicial Geography”, including the prerequisites for its creation, academic, and theoretical development, both in Russia and abroad. The purpose of the study is to study the possibility of applying geographical methods and means in criminal law, criminal procedure, and in judicial activity in general via the academic direction “Judicial Geography”. The author describes in detail the main elements of judicial geography and its role and significance for such legal sciences, as criminal law, criminal procedure, criminalistics, and criminology among others. The employed research methods allow showing the main vectors of the development of judicial geography, taking into account the previous achievements of Russian and worldwide academics. The author indicates the role and place of judicial geography in the system of legal sciences. This study suggests a concept of using scientific geographical methods in the study of various legal phenomena of a criminal and criminal-procedural nature when considering the idea of building judicial bodies and judicial instances, taking into account geographical and climatic factors. In this regard, the author advises to introduce the special course “Judicial Geography”, which would allow law students to study the specifics of the activities of the judiciary and preliminary investigation authorities from a geographical point of view, as well as to use various geographical methods, including the mapping method, in educational and practical activities. The author concludes that forensic geography may become a new milestone for subsequent scientific research in geography and jurisprudence.

scholarly journals A Cytotoxic Porphyrin from North Pacific Brittle Star Ophiura sarsii

Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 11
Author(s):  
Antonina Klimenko ◽  
Robin Huber ◽  
Laurence Marcourt ◽  
Estelle Chardonnens ◽  
Alexey Koval ◽  
...  
Keyword(s):  
North Pacific ◽  
Ethanol Extract ◽  
2D Nmr ◽  
Brittle Star ◽  
Inert Material ◽  
Cancer Therapies ◽  
The North ◽  
Anti Cancer ◽  
One Step ◽  
The North Pacific

Triple-negative breast cancer (TNBC) represents the deadliest form of gynecological tumors currently lacking targeted therapies. The ethanol extract of the North Pacific brittle star Ophiura sarsii presented promising anti-TNBC activities. After elimination of the inert material, the active extract was submitted to a bioguided isolation approach using high-resolution semipreparative HPLC-UV, resulting in one-step isolation of an unusual porphyrin derivative possessing strong cytotoxic activity. HRMS and 2D NMR resulted in the structure elucidation of the compound as (3S,4S)-14-Ethyl-9-(hydroxymethyl)-4,8,13,18-tetramethyl-20-oxo-3-phorbinepropanoic acid. Never identified before in Ophiuroidea, porphyrins have found broad applications as photosensitizers in the anticancer photodynamic therapy. The simple isolation of a cytotoxic porphyrin from an abundant brittle star species we describe here may pave the way for novel natural-based developments of targeted anti-cancer therapies.

Microwave Activation of Homogeneous and Heterogeneous Catalytic Reactions

1997 ◽  
Vol 62 (2) ◽  
pp. 347-354 ◽  
Author(s):  
Milan Hájek
Keyword(s):  
Active Sites ◽  
Specific Effect ◽  
Point Of View ◽  
Heterogeneous Reactions ◽  
Microwave Activation ◽  
Rate Enhancement ◽  
Heterogeneous Catalytic ◽  
Order Of Magnitude ◽  
And Performance ◽  
Alkylation Reactions

Microwave heating was applied in homogeneous and in heterogeneous reactions and the results were compared from the point of view of activation of chemical reactions. Reactions including the addition of halo compounds to alkenes catalyzed by copper and ruthenium complexes in different solvents and NaY zeolite catalyzed alkylation of secondary amine in the absence of solvent were studied as model reactions to compare possibilities of microwave activation of reactants and catalysts. Rate enhancement of over one order of magnitude in homogeneous reactions was caused mainly by thermal dielectric heating effect which resulted from the effective coupling of microwaves to polar solvents. Activation of reactants and catalysts was very low if any. In heterogeneously catalyzed alkylation reactions highly efficient activation of zeolite catalyst was recorded. The results indicated that the best reaction conditions were in experiments when both activation of catalyst and performance of reaction were carried out under microwave conditions. Rate enhancement was most probably caused by "hot spots" or by "selective heating" of active sites. In both homogeneous and heterogeneous reactions non-thermal activation (specific effect) was excluded.

scholarly journals Preliminary investigation of a polyethylene glycol hydrogel “nerve glue”

2014 ◽  
Vol 04 (01) ◽  
pp. e98-e102 ◽  
Author(s):  
Jonathan Isaacs ◽  
Ivette Klumb ◽  
Candice McDaniel
Keyword(s):  
Polyethylene Glycol ◽  
Preliminary Investigation

scholarly journals Effect of Addition of Pomegranate Peel in the Ration with or Without Polyethylene Glycol on Productive Performance of Lactating Goats

2021 ◽  
Author(s):  
Abd El-Kader Mahmoud Kholif ◽  
Gamal Eldeen Aboulfotouh ◽  
Ola Gamal Ahmed Hassan ◽  
Abdelalim Mohamed Abd El-Mola
Keyword(s):  
Polyethylene Glycol ◽  
Milk Yield ◽  
Animal Feed ◽  
Economic Assessment ◽  
Point Of View ◽  
Pomegranate Juice ◽  
Feed Conversion ◽  
Pomegranate Peel ◽  
Lactating Goats ◽  
The Impact

Abstract The industries of Pomegranate juice processing generate enormous waste in peel’s form which are suggested and evaluated as a supplement in animal feed but pomegranate peel have high percent of tannins, So the aim of this paper is to assess the impact of mixing pomegranate peel (PP), detanninated pomegranate peel (DPP) and pomegranate peel with polyethylene glycol (PEG) on the digestibility of nutrients, the yield of goats milk and its composition, feed conversion and some parameters of blood. Moreover, simple economic assessment of the examined rations are considered. Sixteen lactating Zaraibi goats of about 3-4 years old (in their 2nd to 4th of lactation seasons with an average body weight of about 25 + 0.5 kg are used in the present study. After 14 days of parturition was randomly assigned into four groups, four animals per each tested ration (R) for 90days, R1: Control : 50% CFM + 25% Egyptian clover and 25% wheat straw, R2: Control ration+1% PP, R3: Control ration+1% PP + 20 g (PEG) and R4:Control ration+1% DPP. The results revealed that the PP contained 90.85% DM, 4.84% CP, 15.53% CF, 87.21%OM, 4.69% EE, 62.15% NFE and 15.28% tannins. No significant differences were found between the tested rations regarding nutrients digestibility except EE digestibility. Nutritive values of R2 and R3 were slightly higher than R4 and R1, respectively. Ration three (R3) was the best ration for daily milk yield and total milk yield, where R4 showed the worst one. Also, there are no significant differences for dry matter, SV and TDN intake. While, values of DCP intake were higher significantly (P<0.05), for R3 and R2 followed by R4 then R1. Regarding feed conversion, R4 was superior to other tested rations followed by R1 then R3 followed by R2. All blood serum parameters were in the normal rang which support that the healthy effect of tested additives in goats rations. It seems that R2 and R3 could be used successfully for lactating goats, but R3 is very expensive from economical point of view, where R3 was negatively economical effect, and not recommended.

The influence of polyethylene glycol passivation on the surface plasmon resonance induced photothermal properties of gold nanorods

Nanoscale ◽  
2018 ◽  
Vol 10 (28) ◽  
pp. 13684-13693 ◽  
Author(s):  
Ramesh Marasini ◽  
Arunkumar Pitchaimani ◽  
Tuyen Duong Thanh Nguyen ◽  
Jeffrey Comer ◽  
Santosh Aryal
Keyword(s):  
Surface Plasmon Resonance ◽  
Heat Conduction ◽  
Polyethylene Glycol ◽  
Surface Plasmon ◽  
Gold Nanorods ◽  
Plasmon Resonance ◽  
Colloidal Stability ◽  
Surface Passivation ◽  
Liquid Interface ◽  
Comprehensive Study

This comprehensive study suggested an optimum PEG polymer length of 5 kDa is advantageous for surface passivation and colloidal stability of AuNRs, which also maximizes the heat conduction from the nanorod–liquid interface to the surroundings, thereby, enhancing photothermal efficiency.

A kinetic model for magnetostriction of a ferrogel with physical networking

2021 ◽  
Vol 379 (2205) ◽  
pp. 20200315 ◽  
Author(s):  
A. P. Safronov ◽  
A. Yu. Zubarev ◽  
E. A. Mikhnevich ◽  
E. V. Rusinova
Keyword(s):  
Magnetic Particles ◽  
Guar Gum ◽  
Loss Modulus ◽  
Liquid Droplet ◽  
Mechanical Analysis ◽  
Strontium Hexaferrite ◽  
Theme Issue ◽  
Natural Polysaccharide ◽  
Order Of Magnitude ◽  
Kinetics Of

Kinetics of magnetostriction of ferrogel with physical networking based on natural polysaccharide guar gum with embedded strontium hexaferrite magnetic particles were studied in the uniform magnetic field 420 mT. An ellipsoidal sample was elongated by 37% along the applied field and contracted by 15% in the transverse direction, while its volume was kept constant. The characteristic time of magnetostriction was 440 s. Dynamic mechanical analysis in an oscillatory mode showed that the deformation of ferrogel is mostly elastic rather than viscous. Its storage modulus was almost constant in a frequency range of 0.1–100 Hz and by at least an order of magnitude larger than the loss modulus. Meanwhile, a developed theoretical model based on the elasto-viscous behaviour of the ferrogel failed to estimate correctly the experimental value of its magnetostriction. Calculated values of the elongation of ferrogel in the field were several orders of magnitude lower than those observed in the experiment for the ferrogel with physical networking. Consistency between the experiment and the theory was achieved using the alternative consideration based on the deformation of a liquid droplet of ferrofluid. The applicability of such an approach was discussed concerning structural relaxation properties of the ferrogel with physical networking. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

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