scholarly journals Influence of Drug Incorporation on the Physico-Chemical Properties of Poly(l-Lactide) Implant Coating Matrices—A Systematic Study

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 292
Author(s):  
Daniela Arbeiter ◽  
Thomas Reske ◽  
Michael Teske ◽  
Dalibor Bajer ◽  
Volkmar Senz ◽  
...  
Keyword(s):  
Cyclosporine A ◽  
Chemical Properties ◽  
Tensile Tests ◽  
Local Drug Delivery ◽  
Physico Chemical ◽  
Thermal Measurements ◽  
Implant Coating ◽  
Life Threatening ◽  
And Performance ◽  
Drug Incorporation

Local drug delivery has become indispensable in biomedical engineering with stents being ideal carrier platforms. While local drug release is superior to systemic administration in many fields, the incorporation of drugs into polymers may influence the physico-chemical properties of said matrix. This is of particular relevance as minimally invasive implantation is frequently accompanied by mechanical stresses on the implant and coating. Thus, drug incorporation into polymers may result in a susceptibility to potentially life-threatening implant failure. We investigated spray-coated poly-l-lactide (PLLA)/drug blends using thermal measurements (DSC) and tensile tests to determine the influence of selected drugs, namely sirolimus, paclitaxel, dexamethasone, and cyclosporine A, on the physico-chemical properties of the polymer. For all drugs and PLLA/drug ratios, an increase in tensile strength was observed. As for sirolimus and dexamethasone, PLLA/drug mixed phase systems were identified by shifted drug melting peaks at 200 °C and 240 °C, respectively, whereas paclitaxel and dexamethasone led to cold crystallization. Cyclosporine A did not affect matrix thermal properties. Altogether, our data provide a contribution towards an understanding of the complex interaction between PLLA and different drugs. Our results hold implications regarding the necessity of target-oriented thermal treatment to ensure the shelf life and performance of stent coatings.

Encountering the Survival Strategies Using Various Nano Assemblages

2021 ◽  
pp. 159-187
Author(s):  
Lakshmipathy Muthukrishnan
Keyword(s):  
Antimicrobial Resistance ◽  
Chemical Properties ◽  
Fine Tuning ◽  
Survival Strategies ◽  
Natural Phenomenon ◽  
Physico Chemical ◽  
Life Threatening ◽  
Medicinal Properties ◽  
Micro Organisms ◽  
Microbial Systems

The technological advancements have not only made humans more civilized but have also caused the micro-organisms to develop several survival strategies via antimicrobial resistance to keep pace. Such highly developed microbial systems have been classified as superbugs, exhibiting Trojan-horse mechanism. This uncertain behaviour in microbes has challenged humans to scour around novel moiety to shield themselves from the detrimental effects. One such natural phenomenon that has drawn the attention of researchers is the metal-microbe interaction where microbes were found to be controlled during their interaction with metals. Fine tuning could bestow them with enhanced physico-chemical properties capable of controlling life-threatening micro-organisms. Nano forms of metals (nanoparticles, quantum dots, polymeric nanostructures) exhibiting medicinal properties have been implied toward biomedical theranostics. This chapter highlights the mechanistic antimicrobial resistance and the containment strategy using various nano assemblage highlighting its fabrication and bio-molecular interaction.

scholarly journals Physico-chemical Properties and Performance of High Oleic and Palm-Based Shortenings

2008 ◽  
Vol 57 (11) ◽  
pp. 605-612 ◽  
Author(s):  
Muhamad Roddy Ramli ◽  
Siew Wai Lin ◽  
Cheah Kien Yoo ◽  
Nor Aini Idris ◽  
Miskandar Mat Sahri
Keyword(s):  
Chemical Properties ◽  
High Oleic ◽  
Physico Chemical ◽  
And Performance

scholarly journals Bis(trifluoromethylsulfonyl)imide Ionic Liquids Applied for Fine-Tuning the Cure Characteristics and Performance of Natural Rubber Composites

2021 ◽  
Vol 22 (7) ◽  
pp. 3678
Author(s):  
Anna Sowińska ◽  
Magdalena Maciejewska ◽  
Anna Grajewska
Keyword(s):  
Ionic Liquids ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Chemical Properties ◽  
Fine Tuning ◽  
Crosslinking Degree ◽  
Cure Characteristics ◽  
Physico Chemical ◽  
Elastomer Composites ◽  
And Performance

The goal of this work was to apply ionic liquids (ILs) with bis(trifluoromethylsulfonyl)imide anion (TFSI) for fine-tuning the cure characteristics and physico-chemical properties of elastomer composites based on a biodegradable natural rubber (NR) matrix. ILs with TFSI anion and different cations, such as alkylpyrrolidinium, alkylammonium, and alkylsulfonium cations, were applied to increase the efficiency of sulfur vulcanization and to improve the performance of NR composites. Thus, the influence of ILs on the vulcanization of NR compounds, as well as crosslink density and physical properties of NR vulcanizates, including tensile properties, thermal stability, and resistance to thermo-oxidative aging was explored. The activity of ILs seems to be strongly dependent on their cation. Pyrrolidinium and ammonium ILs effectively supported the vulcanization, reducing the optimal vulcanization time and temperature of NR compounds and increasing the crosslink density of the vulcanizates. Consequently, vulcanizates with these ILs exhibited higher tensile strength than the benchmark without IL. On the other hand, sulfonium ILs reduced the torque increment owing to the lower crosslinking degree of elastomer but significantly improved the resistance of NR composites to thermo-oxidation. Thus, TFSI ILs can be used to align the curing behavior and performance of NR composites for particular applications.

Synthesis of nanosized mixed metal oxides heat and corrosion resistant pigments: CaMnO3, Ca2Cr2O5 and CaSb2O6

2015 ◽  
Vol 44 (6) ◽  
pp. 379-385 ◽  
Author(s):  
Osama A. G. Wahba ◽  
Ali M. Hassan ◽  
H. Abd El-wahab ◽  
A. Mohy-Eldin ◽  
A.M. Naser ◽  
...  
Keyword(s):  
Low Cost ◽  
Chemical Properties ◽  
Mixed Metal Oxide ◽  
Corrosion Resistant ◽  
Content Type ◽  
Mixed Metal ◽  
Nanosized Materials ◽  
Physico Chemical ◽  
And Performance ◽  
Co Precipitation

Purpose – The purpose of this paper is to investigate the synthesis of calcium-based group of mixed metal oxide (MMO) pigments. The evaluation of these pigments as heat and corrosion resistant was also explored. Design/methodology/approach – Two simple synthesis techniques, namely, co-precipitation and solid-state calcination method, were used to synthesise nanosized MMO pigments. And then the physico-chemical requirements according to standards for the synthesised pigments are investigated. Findings – The prepared MMO pigments were mainly in the single phase double oxide forms. The prepared oxides exhibited good heat (up to 600°C) and corrosion resistance properties (in 5 per cent NaCl for 500 h). Research limitations/implications – This paper investigates the physico-chemical properties of synthesised calcium-based group of MMO pigments. And then evaluate it as heat and corrosion resistant paints. The simple techniques used for synthesis of nanosized MMO pigments will significantly improve the research and development of pigments’ structure and performance. Practical implications – Calcium-based MMO pigments can be used as heat and corrosion resistant pigments. The easy synthesis of the mixed oxide pigments will open the door for further vital special industrial uses and applications. Originality/value – Low cost, simple techniques and using naturally abundant material can be used for mass production of some other low-cost nanosized materials.

scholarly journals Applying additivity rule to determine physico-chemical properties of edible oil blends based on known parameters of component oils

2021 ◽  
Vol 126 (1) ◽  
pp. 133-149
Author(s):  
Lucyna Dymińska ◽  
Abduladhim Moamer Albegar ◽  
Adam Zając ◽  
Tadeusz Czuj ◽  
Wojciech Sąsiadek ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Deep Frying ◽  
Chemical Parameters ◽  
Plant Oil ◽  
Oil Blends ◽  
Physico Chemical ◽  
Expected Performance ◽  
Input Dataset ◽  
And Performance ◽  
Oil Blend

In the paper, a procedure was suggested for making plant oil blends of desirable physico-chemical and performance parameters. There was applied a rule of additivity of parameters of component oils in the blend to get oil products with modified nutritional characteristics. The other objective of the research study was to test the usefulness of the procedure when projecting thermal properties of the blends for deep frying. To make oil blends, plant oils were used that were produced by Oleofarm Ltd. The oil blends were analysed using chromatographic and spectroscopic methods. Their chemical parameters constituted an input dataset to make blends of expected performance properties. It was shown experimentally that it was possible to theoretically project physico-chemical and thermal parameters of the final oil blend. When knowing the chemical parameters of individual blend-forming oils, it is possible to employ them to determine the parameters of the final blend. There were suggested oil compositions for the preparation of advantageous blends to be used for deep frying and salad dressings. Thus there was confirmed the purposefulness of blending the oils in order to make a product the qualities of which could be geared to the specific utility purposes.

CONTROL OF PHYSICO-CHEMICAL PROPERTIES OF A LIPID NANOCONTAINER FOR DELIVERY OF DRUGS WITH LOW BIOAVAILABILITY

2020 ◽  
pp. 153-154
Author(s):  
I. Yakimov ◽  
I. Le-Deygen ◽  
A. Skuredina ◽  
E. Kudryashova
Keyword(s):  
Targeted Delivery ◽  
Binding Sites ◽  
Chemical Properties ◽  
Anionic Phospholipid ◽  
Molecular Weights ◽  
Physico Chemical ◽  
Drug Incorporation ◽  
Mannose Derivatives ◽  
Derivatives Of ◽  
Selection Of

We have used two ways to control the physicochemical properties of liposomal nanocontainers for the delivery of fluoroquinolones: variation of the lipid composition of liposomes and selection of a functionalizing polymer based on chitosan mannose derivatives. The presence of anionic phospholipid cardiolipin in the liposome composition increases the loading efficiency by 5-20%. The mechanism of drug incorporation into membranes was studied, and the main binding sites were determined. The functionalization of the liposomal surface was carried out by chitosan mannose derivatives of various molecular weights, potentially providing targeted delivery to alveolar macrophages.

scholarly journals Microstructure and properties of gravity sintered 316l stainless steel powder with nickel boride addition

2016 ◽  
Vol 48 (3) ◽  
pp. 293-302 ◽  
Author(s):  
Dusan Bozic ◽  
Miroljub Vilotijevic ◽  
Jovana Ruzic ◽  
Uros Jovanovic ◽  
Jelena Stasic
Keyword(s):  
Stainless Steel ◽  
Microstructural Analysis ◽  
Chemical Properties ◽  
Steel Powder ◽  
Tensile Tests ◽  
Stainless Steel Powder ◽  
Physico Chemical ◽  
Standard Powder ◽  
Sintered Stainless Steel ◽  
Sintering Method

The present work demonstrates a procedure for synthesis of stainless steel powder by gravity sintering method. As an additive to the basic powder, NiB powder was added in the amount of 0.2 - 1.0 wt.%. Gravity sintering was done in vacuum, at the temperatures of 1100?C-1250?C, in the course of 3 - 60 min, using ceramic mould. Structural characterization was conducted by XRD, and microstructural analysis by optical and scanning electron microscope (SEM). Mechanical properties were investigated by tensile tests with steel rings. Density and permeability were determined by standard techniques for porous samples. Gravity sintered stainless steel with NiB addition had more superior mechanical and physico-chemical properties compared to stainless steel obtained by standard powder metallurgy procedures - pressing and sintering.

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