scholarly journals Antibacterial and Antifungal Properties of Composite Polyethylene Materials Reinforced with Neem and Turmeric

2020 ◽  
Author(s):  
Thefye Sunthar ◽  
Elia Marin ◽  
Francesco Boschetto ◽  
Matteo Zanocco ◽  
Hirofumi Sunahara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Food Packaging ◽  
Spectroscopic Characterization ◽  
Fungal Colonization ◽  
Green Technologies ◽  
Reinforcing Particles ◽  
Wide Range ◽  
High Concentrations ◽  
Antibacterial And Antifungal

With the increased scientific interest in green technologies, many researches have been focused on the production of polymeric composites containing naturally occurring reinforcing particles. Apart from increasing mechanical properties, these additions can have a wide range of interesting effects, such as increasing the resistance to bacterial and fungal colonization. In this work, different amounts of two different natural products, namely neem and turmeric, have been added to polyethylene to act as a natural antibacterial and antifungal product for food packaging applications. Microscopic and spectroscopic characterization showed that fractions up to 5% of these products can be dispersed into low-molecular weight polyethylene, while higher amounts could not be properly dispersed and resulted in an inhomogeneous, fragile composite. In vitro testing conducted with Escherichia coli, Staphylococcus aureus and Candida albicans showed a reduced proliferation of pathogens when compared to the polyethylene references. In particular, turmeric, resulted to be more effective against E. coli when compared to neem, while they had similar performances against S. aureus. Against C. albicans, only neem was able to show a good antifungal behavior, at high concentrations. Tensile testing showed that the addition of reinforcing particles reduces the mechanical properties of polyethylene, and, in the case of turmeric, it is further reduced by UV irradiation.

scholarly journals Antibacterial and Antifungal Properties of Composite Polyethylene Materials Reinforced with Neem and Turmeric

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 857
Author(s):  
Thefye P. M. Sunthar ◽  
Elia Marin ◽  
Francesco Boschetto ◽  
Matteo Zanocco ◽  
Hirofumi Sunahara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Food Packaging ◽  
Spectroscopic Characterization ◽  
Fungal Colonization ◽  
Green Technologies ◽  
Reinforcing Particles ◽  
Wide Range ◽  
High Concentrations ◽  
Antibacterial And Antifungal

With the increased scientific interest in green technologies, many researches have been focused on the production of polymeric composites containing naturally occurring reinforcing particles. Apart from increasing mechanical properties, these additions can have a wide range of interesting effects, such as increasing the resistance to bacterial and fungal colonization. In this work, different amounts of two different natural products, namely neem and turmeric, were added to polyethylene to act as a natural antibacterial and antifungal product for food packaging applications. Microscopic and spectroscopic characterization showed that fractions of up to 5% of these products could be dispersed into low-molecular weight polyethylene, while higher amounts could not be properly dispersed and resulted in an inhomogeneous, fragile composite. In vitro testing conducted with Escherichia coli, Staphylococcus aureus, and Candida albicans showed a reduced proliferation of pathogens when compared to the polyethylene references. In particular, turmeric resulted in being more effective against E. coli when compared to neem, while they had similar performances against S. aureus. Against C. albicans, only neem was able to show a good antifungal behavior, at high concentrations. Tensile testing showed that the addition of reinforcing particles reduced the mechanical properties of polyethylene, and in the case of turmeric, it was further reduced by UV irradiation.

Application of the EYTEX™ System to the Evaluation of Cosmetic Products and their Ingredients

1992 ◽  
Vol 20 (1) ◽  
pp. 146-163
Author(s):  
Francis H. Kruszewski ◽  
Laura H. Hearn ◽  
Kyle T. Smith ◽  
Janice J. Teal ◽  
Virginia C. Gordon ◽  
...  
Keyword(s):  
Double Blind ◽  
Eye Irritation ◽  
Ocular Irritation ◽  
Rabbit Eye ◽  
Wide Range ◽  
High Concentrations ◽  
Alkaline Membrane ◽  
Positive Agreement

465 cosmetic product formulations and raw ingredients were evaluated with the EYTEX™ system to determine the potential of this in vitro alternative for identifying eye irritation potential. The EYTEX™ system is a non-animal, biochemical procedure developed by Ropak Laboratories, Irvine, CA, that was designed to approximate the Draize rabbit eye irritation assay for the evaluation of ocular irritation. Avon Products Inc. provided all the test samples, which included over 30 different product types and represented a wide range of eye irritancy. All the EYTEX™ protocols available at the time of this study were used. Samples were evaluated double-blind with both the membrane partition assay (MPA) and the rapid membrane assay (RMA). When appropriate, the standard assay (STD) and the alkaline membrane assay (AMA) were used, as well as specific, documented protocol modifications. EYTEX™ results were correlated with rabbit eye irritation data which was obtained from the historical records of Avon Products Inc. A positive agreement of EYTEX™ results with the in vivo assay was demonstrated by an overall concordance of 80%. The assay error was 20%, of which 18% was due to an overestimation of sample irritancy (false positives) and 2% was attributed to underestimation (false negatives). Overestimation error in this study was due in part to the inability of the protocols to accurately classify test samples with very low irritation potential. Underestimation of sample irritancy was generally associated with ethoxylated materials and high concentrations of specific types of surfactants. 100% sensitivity and 85% predictability were described by the data, indicating the efficiency of EYTEX™ in identifying known irritants. A specificity rate of 39% showed the EYTEX™ assay to be weak in discerning non-irritants. However, the EYTEX™ protocols used in this study were not designed to identify non-irritants. A compatibility rate of 99% proved the effectiveness of the EYTEX™ assay in accommodating a diversity of product types. The EYTEX™ system protocols, when used appropriately, can provide a conservative means of assessing the irritant potential of most cosmetic formulations and their ingredients.

Prostacyclin and cerebral vessel relaxation

1982 ◽  
Vol 57 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Kamal S. Paul ◽  
Eric T. Whalley ◽  
Christine Forster ◽  
Richard Lye ◽  
John Dutton
Keyword(s):  
Angiotensin Ii ◽  
Arterial Spasm ◽  
Cerebral Vessel ◽  
Content Type ◽  
Wide Range ◽  
Potent Vasodilator ◽  
Dose Dependent Fashion ◽  
Basilar Arteries ◽  
High Concentrations

✓ The authors have studied the ability of prostacyclin to reverse contractions of human basilar arteries in vitro that were induced by a wide range of substances implicated in the etiology of cerebral arterial spasm. Prostacyclin (10−10 to 10−6M) caused a dose-related reversal of contractions induced by 5-hydroxytryptamine, noradrenaline, angiotensin II, prostaglandin (PG)F2α, and U-46619 (a thromboxane-A2 mimetic). These agents were tested at concentrations or volumes that produced almost maximum or maximum responses and those that produced approximately 50% of the maximum response. Contractions induced by maximum concentrations of angiotensin II and U-46619 were least affected by prostacyclin. In addition, contractions induced by thromboxane-A2 generated from guinea-pig lung were reversed in a dose-dependent fashion by prostacyclin. This ability of prostacyclin to physiologically antagonize contractions of the human basilar artery in vitro induced by high concentrations of various spasmogenic agents suggests that such a potent vasodilator agent or more stable analogue may be of value in the treatment of such disorders as cerebral arterial spasm following subarachnoid hemorrhage.

Effects of polymethoxylated flavone metabolites on apoB100 secretion and MTP activity in Huh7.5 cells

2021 ◽  
Vol 18 ◽  
Author(s):  
Danielle R. Gonçalves ◽  
Thais B. Cesar ◽  
John A. Manthey ◽  
Paulo I. Costa
Keyword(s):  
Lipid Synthesis ◽  
Dependent Manner ◽  
Transfer Protein ◽  
Low Concentrations ◽  
Wide Range ◽  
Cell Assays ◽  
Polymethoxylated Flavones ◽  
High Concentrations

Background: Citrus polymethoxylated flavones (PMFs) reduce the synthesis of liver lipoproteins in animal and in vitro cell assays, but few studies have evaluated the direct effects of their metabolites on this highly regulated process. Objective: To investigate the effects of representative metabolites of PMF on the secretion of liver lipoproteins using the mammalian cell Huh7.5. Method: In this study, the influences of three PMFs and five previously isolated PMF metabolites on hepatic apoB-100 secretion and microsomal transfer protein (MTP) activity were evaluated. Tangeretin (TAN), nobiletin (NOB) and 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), and their glucuronides (TAN-Gluc, NOB-Gluc and HMF-Gluc) and oxidatively demethylated metabolites (TAN-OH, NOB-OH, HMF-OH) were incubated with Huh7.5 cells to measure their inhibitory effects on lipid synthesis. Results: The results showed that TAN, HMF and TAN-OH reduced the secretion of apoB-100 in a dose-dependent manner, while NOB and the other tested metabolites showed no inhibition. MTP activity in the Huh7.5 cells was significantly reduced in the presence of low concentrations of TAN, and in high concentrations of NOB-OH. This study also showed that PMFs and PMF metabolites produced a wide range of effects on apoB-100 secretion and MTP activity. Conclusion: The results suggest that while PMFs and their metabolites control dyslipidemia in vivo, the inhibition of MTP activity cannot be the only pathway influenced by these compounds.

scholarly journals Rapid Biodegradation of the Organophosphorus Insecticide Chlorpyrifos by Cupriavidus nantongensis X1T

2019 ◽  
Vol 16 (23) ◽  
pp. 4593 ◽  
Author(s):  
Shi ◽  
Fang ◽  
Qin ◽  
Chen ◽  
Wu ◽  
...  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Aquatic Organisms ◽  
Organophosphorus Hydrolase ◽  
Organophosphorus Insecticides ◽  
Ph Values ◽  
Qpcr Analysis ◽  
Wide Range ◽  
Degradation Activity ◽  
High Concentrations

Chlorpyrifos was one of the most widely used organophosphorus insecticides and the neurotoxicity and genotoxicity of chlorpyrifos to mammals, aquatic organisms and other non-target organisms have caused much public concern. Cupriavidus nantongensis X1T, a type of strain of the genus Cupriavidus, is capable of efficiently degrading 200 mg/L of chlorpyrifos within 48 h. This is ~100 fold faster than Enterobacter B-14, a well-studied chlorpyrifos-degrading bacterial strain. Strain X1T can tolerate high concentrations (500 mg/L) of chlorpyrifos over a wide range of temperatures (30–42 °C) and pH values (5–9). RT-qPCR analysis showed that the organophosphorus hydrolase (OpdB) in strain X1T was an inducible enzyme, and the crude enzyme isolated in vitro could still maintain 75% degradation activity. Strain X1T can simultaneously degrade chlorpyrifos and its main hydrolysate 3,5,6-trichloro-2-pyridinol. TCP could be further metabolized through stepwise oxidative dechlorination and further opening of the benzene ring to be completely degraded by the tricarboxylic acid cycle. The results provide a potential means for the remediation of chlorpyrifos- contaminated soil and water.

scholarly journals Mechanically Improved and Multifunctional CFRP Enabled by Resins with High Concentrations Epoxy-Functionalized Fluorographene Fillers

2021 ◽  
Author(s):  
Junhua Wei
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Elastic Modulus ◽  
Carbon Fiber ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Reinforcing Particles ◽  
Thermoset Resin ◽  
High Concentrations ◽  
Carbon Based

To meet the maximum potential of the mechanical properties of carbon fiber reinforced plastics (CFRP), stress transfer between the carbon fibers through the polymer matrix must be improved. A recent promising approach reportedly used reinforcing particles as fillers dispersed in the resin. Carbon based fillers are an excellent candidate for such reinforcing particles due to their intrinsically high mechanical properties, structure and chemical nature similar to carbon fiber and high aspect ratio. They have shown great potential in increasing the strength, elastic modulus and other mechanical properties of interest of CFRPs. However, a percolation threshold of ~1% of the carbon-based particle concentration in the base resin has generally been reported, beyond which the mechanical properties deteriorate due to particle agglomeration. As a result, the potential for further increase of the mechanical properties of CFRPs with carbon-based fillers is limited. We report a significant increase in the strength and elastic modulus of CFRPs, achieved with a novel reinforced thermoset resin that contains high loadings of epoxy-reacted fluorographene (ERFG) fillers. We found that the improvement in mechanical performance of CFRPs was correlated with increase in ERFG loading in the resin. Using a novel thermoset resin containing 10 wt% ERFG filler, CFRPs fabricated by wet layup technique with twill weaves showed a 19.6% and 17.7% increase in the elastic modulus and tensile strength respectively. In addition, because of graphene’s high thermal conductivity and high aspect ratio, the novel resin enhanced CFRPs possessed 59.3% higher through-plane thermal conductivity and an 81-fold reduction in the hydrogen permeability. The results of this study demonstrate that high loadings of functionalized particles dispersed in the resin is a viable path towards fabrication of improved, high-performance CFRP parts and systems.

scholarly journals Tissue Engineering for the Insertions of Tendons and Ligaments: An Overview of Electrospun Biomaterials and Structures

2021 ◽  
Vol 9 ◽  
Author(s):  
Alberto Sensini ◽  
Gabriele Massafra ◽  
Carlo Gotti ◽  
Andrea Zucchelli ◽  
Luca Cristofolini
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Myotendinous Junction ◽  
Stress Concentrations ◽  
Comprehensive Overview ◽  
Electrospinning Technique ◽  
Junction Site ◽  
Wide Range ◽  
Myotendinous Junctions

The musculoskeletal system is composed by hard and soft tissue. These tissues are characterized by a wide range of mechanical properties that cause a progressive transition from one to the other. These material gradients are mandatory to reduce stress concentrations at the junction site. Nature has answered to this topic developing optimized interfaces, which enable a physiological transmission of load in a wide area over the junction. The interfaces connecting tendons and ligaments to bones are called entheses, while the ones between tendons and muscles are named myotendinous junctions. Several injuries can affect muscles, bones, tendons, or ligaments, and they often occur at the junction sites. For this reason, the main aim of the innovative field of the interfacial tissue engineering is to produce scaffolds with biomaterial gradients and mechanical properties to guide the cell growth and differentiation. Among the several strategies explored to mimic these tissues, the electrospinning technique is one of the most promising, allowing to generate polymeric nanofibers similar to the musculoskeletal extracellular matrix. Thanks to its extreme versatility, electrospinning has allowed the production of sophisticated scaffolds suitable for the regeneration of both the entheses and the myotendinous junctions. The aim of this review is to analyze the most relevant studies that applied electrospinning to produce scaffolds for the regeneration of the enthesis and the myotendinous junction, giving a comprehensive overview on the progress made in the field, in particular focusing on the electrospinning strategies to produce these scaffolds and their mechanical, in vitro, and in vivo outcomes.

scholarly journals Sustainable Boron Nitride Nanosheet-Reinforced Cellulose Nanofiber Composite Film with Improved Mechanical Properties and Oxygen Barrier without the Cost of Color and Brittleness

2018 ◽  
Author(s):  
Hoang-Linh Nguyen ◽  
Zahid Hanif ◽  
Seul-A. Park ◽  
Bong Gill Choi ◽  
Thang Hong Tran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Boron Nitride ◽  
Composite Film ◽  
Food Packaging ◽  
Color Change ◽  
Cellulose Nanofiber ◽  
Oxygen Barrier ◽  
Boron Nitride Nanosheet

Herein, we introduce a boron nitride nanosheet (BNNS)-reinforced cellulose nanofiber (CNF) film as a sustainable oxygen barrier film that can potentially be applied in food packaging. Most of commodity plastics are oxygen-permeable. CNF exhibits an ideal oxygen transmittance rate (OTR) of <1 cc/m2/day in highly controlled conditions. A CNF film typically fabricated by the air drying of a CNF aqueous solution reveals an OTR of 19.08 cc/m2/day. The addition of 0-5 wt% BNNS to the CNF dispersion before drying results in a composite film with highly improved OTR, 4.7 cc/m2/day, which is sufficient for meat and cheese packaging. BNNS as a 2D nanomaterial increases the pathway of oxygen gas and reduces the chances of pin-hole formation during film fabrication involving water drying. In addition, BNNS improves the mechanical properties of the CNF films (Young’s modulus and tensile strength) without significant elongation reductions, probably due to the good miscibility of CNF and BNNS in the aqueous solution. BNNS addition also produces negligible color change, which is important for film aesthetics. An in vitro cell experiment was performed to reveal the low cytotoxicity of the CNF/BNNS composite. This composite film has great potential as a sustainable high-performance food packaging material.

scholarly journals Antibacterial and Antifungal Activities of Ethiopian Medicinal Plants: A Systematic Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Dereje Nigussie ◽  
Gail Davey ◽  
Takele Beyene Tufa ◽  
Malcolm Brewster ◽  
Belete Adefris Legesse ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Plant Species ◽  
Meta Analysis ◽  
Fungal Species ◽  
Antifungal Activities ◽  
Traditional Medicines ◽  
Antibacterial And Antifungal Activities ◽  
Wide Range ◽  
Antibacterial And Antifungal

Background: Podoconiosis and lymphatic filariasis are the most common causes of lower limb lymphoedema in the tropics. Many sufferers experience frequent painful episodes of acute bacterial infection. Plant based traditional medicines are used to treat infections in many countries and are culturally established in Ethiopia. Ethiopian medicinal plants found to have antibacterial and antifungal activities were reviewed with the aim of increasing information about the treatment of wound infections in patients with lymphoedema.Methods: This study collates data from published articles on medicinal plants with antibacterial and antifungal activities in Ethiopia. A systematic search of Scopus, EMBASE, PUBMED/MEDLINE and Google Scholar was undertaken. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed. The protocol was registered on PROSPERO with registration number CRD42019127471. All controlled studies of in vitro antibacterial and antifungal activities were considered. All articles containing the descriptors published until June 28, 2019 were included. The outcome was measured as percent inhibition of microbial growth. For quality assessment of individual in vitro studies, OECD guidelines and the WHO-Good Laboratory Practice (GLP) handbook were used.Results: Seventy-nine studies met the inclusion criteria. A total of 150 plant species and three compounds had been tested against 42 species of bacteria, while 43 plant species had been tested against 22 species of fungus.Conclusion: Materials derived from several Ethiopian medicinal plants have been shown to have promising activity against a variety of bacteria and fungi. Those derived from Azadiractha indica A. Juss. and Lawsonia inerms L. are the most extensively studied against a wide range of gram-negative and positive bacteria, and fungal species.

scholarly journals Candidate Polyurethanes Based on Castor Oil (Ricinus communis), with Polycaprolactone Diol and Chitosan Additions, for Use in Biomedical Applications

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 237 ◽  
Author(s):  
Yomaira Uscátegui ◽  
Luis Díaz ◽  
José Gómez-Tejedor ◽  
Ana Vallés-Lluch ◽  
Guillermo Vilariño-Feltrer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Line ◽  
Castor Oil ◽  
Sessile Drop ◽  
Colorimetric Assay ◽  
Biological Properties ◽  
Wound Dressings ◽  
Cytotoxicity Test ◽  
Wide Range

Polyurethanes are widely used in the development of medical devices due to their biocompatibility, degradability, non-toxicity and chemical versatility. Polyurethanes were obtained from polyols derived from castor oil, and isophorone diisocyanate, with the incorporation of polycaprolactone-diol (15% w/w) and chitosan (3% w/w). The objective of this research was to evaluate the effect of the type of polyol and the incorporation of polycaprolactone-diol and chitosan on the mechanical and biological properties of the polyurethanes to identify the optimal ones for applications such as wound dressings or tissue engineering. Polyurethanes were characterized by stress-strain, contact angle by sessile drop method, thermogravimetric analysis, differential scanning calorimetry, water uptake and in vitro degradation by enzymatic processes. In vitro biological properties were evaluated by a 24 h cytotoxicity test using the colorimetric assay MTT and the LIVE/DEAD kit with cell line L-929 (mouse embryonic fibroblasts). In vitro evaluation of the possible inflammatory effect of polyurethane-based materials was evaluated by means of the expression of anti-inflammatory and proinflammatory cytokines expressed in a cellular model such as THP-1 cells by means of the MILLIPLEX® MAP kit. The modification of polyols derived from castor oil increases the mechanical properties of interest for a wide range of applications. The polyurethanes evaluated did not generate a cytotoxic effect on the evaluated cell line. The assessed polyurethanes are suggested as possible candidate biomaterials for wound dressings due to their improved mechanical properties and biocompatibility.

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