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"CLSM"
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Mechanism of transdermal permeation promotion of lipophilic drugs by ethosomes
by
Shi, Deshun
,
Yang, Li
,
Wu, Dongze
in
4-Chloro-7-nitrobenzofurazan - analogs & derivatives
,
4-Chloro-7-nitrobenzofurazan - pharmacokinetics
,
Acne
2017
Ethosomes can promote the penetration of lipophilic drugs into the skin, but the underlying mechanism is still unknown. The purpose of this study was to investigate the mechanism of transdermal permeation promotion of lipophilic drugs by ethosomes. The formulation of ethosomes was optimized using the Box-Behnken experimental design, in which Rhodamine B and 1-palmitoyl-2-{12-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]dodecanoyl}-
-glycero-3-phosphocholine were used to simulate a model lipophilic drug and act as a fluorescent tracer of ethosomal phospholipids, respectively. Liposomes with the same phospholipid concentration and a hydroethanolic solution with the same ethanol concentration were also prepared as controls. The percutaneous progression of the above fluorescent preparations was observed by confocal laser scanning microscopy, and the fluorescence intensity of the images was analyzed. The optimized ethosome formulation consisted of 2.45% yolk phospholipids, 30% ethanol, and 67.55% distilled water. The percutaneous permeation of Rhodamine B in the optimized ethosomes was superior to that in hydroethanolic solution (
<0.05) and liposomes (
<0.05). The ethosomes could penetrate the skin via the percutaneous pathway of the hair follicle and stratum corneum, while during the process of penetration, the vesicles were broken and the phospholipids were retained in the upper epidermis, with the test compounds penetrating gradually. The superior percutaneous penetration of ethosomes was linked to the synergistic effects of their ingredients. The percutaneous pathways of ethosomes included open hair follicles and stratum corneum pathways. In addition, the vesicles might break up during percutaneous penetration in the superficial layer of the skin, allowing the test compounds to keep permeating into the deeper layer alone, while the phospholipid was retained in the upper epidermis.
Journal Article
Gluten Polymer Networks—A Microstructural Classification in Complex Systems
2018
A classification of gluten polymer networks would support a better understanding of structure-function relationships of any gluten polymer material and thus, the control of processing properties. However, quantification and interpretation of the gluten network structures is challenging due to their complexity. Thus, the network formation was altered by specific gluten-modifying agents (glutathione, ascorbic acid, potassium bromate, glucose oxidase, transglutaminase, bromelain) in this study in order to clarify if structural alterations can be detected on a microstructural level and to specify different polymer arrangements in general. Microstructure analysis was performed by confocal laser scanning microscopy followed by quantification with protein network analysis. It was shown that alterations in gluten microstructure could be elucidated according to the kind of modification in cross-linking (disulphide, (iso) peptide, dityrosyl). Linear correlations of structural network attributes among each other were found, leading to an assertion in general: the higher the branching rate, the thinner the protein threads and the larger the interconnected protein aggregate. Considering the morphological attribute lacunarity, a quantitative classification of different gluten arrangements was established. These assertions were extended by using unspecific gluten-modifying agents in addition to the specific ones. Ultimately, five network types were proposed based on diverse polymer arrangements.
Journal Article
Antimicrobial, Antibiofilm, and Anticancer Activities of Syzygium aromaticum Essential Oil Nanoemulsion
by
Hassanin, Mahmoud M. H.
,
Al-Askar, Abdulaziz A.
,
Hashem, Amr H.
in
Anti-Bacterial Agents - chemistry
,
Anti-Bacterial Agents - pharmacology
,
antibiofilm activity
2023
In the current study, clove oil nanoemulsion (CL-nanoemulsion) and emulsion (CL-emulsion) were prepared through an ecofriendly method. The prepared CL-nanoemulsion and CL-emulsion were characterized using dynamic light scattering (DLS) and a transmission electron microscope (TEM), where results illustrated that CL-nanoemulsion droplets were approximately 32.67 nm in size and spherical in shape, while CL-nanoemulsion droplets were approximately 225.8 nm with a spherical shape. The antibacterial activity of CL-nanoemulsion and CL-emulsion was carried out using a microbroth dilution method. Results revealed that the preferred CL-nanoemulsion had minimal MIC values between 0.31 and 5 mg/mL. The antibiofilm efficacy of CL-nanoemulsion against S. aureus significantly decreased the development of biofilm compared with CL-emulsion. Furthermore, results illustrated that CL-nanoemulsion showed antifungal activity significantly higher than CL-emulsion. Moreover, the prepared CL-nanoemulsion exhibited outstanding antifungal efficiency toward Candida albicans, Cryptococcus neoformans, Aspergillus brasiliensis, A. flavus, and A. fumigatus where MICs were 12.5, 3.12, 0.78, 1.56, and 1.56 mg/mL, respectively. Additionally, the prepared CL-nanoemulsion was analyzed for its antineoplastic effects through a modified MTT assay for evaluating apoptotic and cytotoxic effects using HepG2 and MCF-7 cell lines. MCF-7 breast cancer cells showed the lowest IC50 values (3.4-fold) in CL-nanoemulsion relative to that of CL-emulsion. Thus, CL-nanoemulsion induces apoptosis in breast cancer cells by inducing caspase-8 and -9 activity and suppressing VEGFR-2. In conclusion, the prepared CL-nanoemulsion had antibacterial, antifungal, and antibiofilm as well as anticancer properties, which can be used in different biomedical applications after extensive studies in vivo.
Journal Article
Methods to Evaluate Skin Penetration In Vitro
by
Gácsi, Attila
,
Budai-Szűcs, Mária
,
Zsikó, Stella
in
Cholesterol
,
CLSM
,
confocal Raman microscopy
2019
Dermal and transdermal drug therapy is increasing in importance nowadays in drug development. To completely utilize the potential of this administration route, it is necessary to optimize the drug release and skin penetration measurements. This review covers the most well-known and up-to-date methods for evaluating the cutaneous penetration of drugs in vitro as a supporting tool for pharmaceutical research scientists in the early stage of drug development. The aim of this article is to present various experimental models used in dermal/transdermal research and summarize the novel knowledge about the main in vitro methods available to study skin penetration. These techniques are: Diffusion cell, skin-PAMPA, tape stripping, two-photon microscopy, confocal laser scanning microscopy, and confocal Raman microscopic method.
Journal Article
Pseudomonas syringae pv. actinidiae
by
Cellini, Antonio
,
Spinelli, Francesco
,
Scortichini, Marco
in
Actinidia
,
Actinidia - physiology
,
Apoplast
2020
Since 2008, the kiwifruit industry has been devastated by a pandemic outbreak of Pseudomonas syringae pv. actinidiae (Psa), the causal agent of bacterial canker. This disease has become the most significant limiting factor in kiwifruit production. Psa colonizes different organs of the host plant, causing a specific symptomatology on each of them. In addition, the systemic invasion of the plant may quickly lead to plant death. Despite the massive risk that this disease poses to the kiwifruit industry, studies focusing on Psa ecology have been sporadic, and a comprehensive description of the disease epidemiology is still missing. Optimal environmental conditions for infection, dispersal and survival in the environment, or the mechanisms of penetration and colonization of host tissues have not been fully elucidated yet. The present work aims to provide a synthesis of the current knowledge, and a deeper understanding of the epidemiology of kiwifruit bacterial canker based on new experimental data. The pathogen may survive in the environment or overwinter in dormant tissues and be dispersed by wind or rain. Psa was observed in association with several plant structures (stomata, trichomes, lenticels) and wounds, which could represent entry points for apoplast infection. Environmental conditions also affect the bacterial colonization, with lower optimum values of temperature and humidity for epiphytic than for endophytic growth, and disease incidence requiring a combination of mild temperature and leaf wetness. By providing information on Psa ecology, these data sets may contribute to plan efficient control strategies for kiwifruit bacterial canker.
Journal Article
Green Synthesis of Silver Nanoparticles from Camellia sinensis and Its Antimicrobial and Antibiofilm Effect against Clinical Isolates
2022
The green synthesis method of was used for the synthesis of silver nanoparticles using Camellia sinensis (green tea). The Camellia sinensis silver nanoparticles (CS-AgNPs) were characterized using different techniques, including UV-Vis (ultra violet-visible), SEM (scanning electron microscopy), TEM (transmission electron microscopy), and XRD (X-ray diffraction). The average size of the CS-AgNPs was 52 nm, according to TEM. The CS-AgNPs showed excellent antibacterial and antifungal activity. The MIC (minimum inhibitory concentration) against bacterial isolates varied from 31.25 to 62.5 µg/mL, whereas for fungal isolates, the MIC varied from 125 to 250 µg/mL. The presence of a zone in the well diffusion assay showed the antimicrobial nature of CS-AgNPs. Further, CLSM (confocal laser scanning microscopy) showed that CS-AgNPs possess antibiofilm activity. The interaction of CS-AgNPs with the Candidal cells was analyzed using TEM, and it was revealed that CS-AgNPs entered the cell and disrupted the cell machinery.
Journal Article
A promising microbial α-amylase production, and purification from Bacillus cereus and its assessment as antibiofilm agent against Pseudomonas aeruginosa pathogen
by
Mustafa, Abd-El-Rahman A.
,
Abo-Kamer, Amal M.
,
Mostafa, Faten A.
in
Ammonium
,
Ammonium sulfate
,
Amylase
2023
Background and aim
The purpose of the current study is to isolate a heavily amylase-producing bacteria of the genus
Bacillus
from soil samples, optimize the production of the enzyme, purify it, and evaluate its activity against biofilm-producing bacteria. A total of 12 soil samples were collected and screened for promising
Bacillus
species with good amylolytic activity. Isolation was done by serial dilution and plating technique and amylolytic activity was determined by starch agar plate method. Among the 12
Bacillus
isolates recovered from soil samples, 7 showed positive α-amylase production. The best isolate that recorded the greatest amylolytic activity was selected for further studies. This isolate was identified by 16S rRNA sequencing as
Bacillus cereus
and registered under gene bank accession number OP811897. Furthermore, the α-amylase enzyme was produced by a submerged fermentation technique using best production media and partially purified by ammonium sulfate and chilled ethanol and molecular weight had been determined by SDS-PAGE gel electrophoresis. The production of α-amylase was optimized experimentally by one-factor at a time protocol and statistically by Plackett–Burman design as well as RSM CCD design. Data obtained from OFAT and CCD revealed that α-amylase activities were 1.5- and twofold respectively higher as compared to un-optimized conditions. The most significant factors had been identified and optimized by CCD design.
Results
Among the eleven independent variables tested by PBD, glucose, peptone, (NH4)
2
SO4, and Mg SO
4
were the most significant parameters for α-amylase production with an actual yield of 250U/ml. The best physical parameters affecting the enzyme production were incubation time at 35 °C, and pH 5.5 for 48 h. The partially purified enzyme with 60% ammonium sulphate saturation with 1.38- fold purification showed good stability characteristics at a storage temperature of 4 °C and pH up to 8.5 for 21 days. Antibiofilm activity of purified α-amylase was determined against
Pseudomonas aeruginosa
(ATCC 35659) by spectrophotometric analysis and CLSM microscopic analysis. Results demonstrated biofilm inhibition by 84% of the formed
Pseudomonas
biofilm using a microtiter plate assay and thickness inhibition activity by 83% with live/Dead cells percentage of 17%/83% using CLSM protocol.
Conclusions
A highly stable purified α-amylase from
B. cereus
showed promising antibiofilm activity against one of the clinically important biofilm-forming MDR organisms that could be used as a cost-effective tool in pharmaceutical industries.
Journal Article
Bacillus‐based probiotic cleansers reduce the formation of dry biofilms on common hospital surfaces
by
Rout, Simon P.
,
Humphreys, Paul N.
,
Wormald, Richard
in
Antimicrobial agents
,
Bacillus
,
biofilm
2023
In the absence of liquid suspension, dry biofilms can form upon hard surfaces within a hospital environment, representing a healthcare‐associated infection risk. Probiotic cleansers using generally recognized as safe organisms, such as those of the Bacillus genus, represent a potential strategy for the reduction of dry biofilm bioburden. The mechanisms of action and efficacy of these cleaners are, however, poorly understood. To address this, a preventative dry biofilm assay was developed using steel, melamine, and ceramic surfaces to assess the ability of a commercially available Bacillus spp. based probiotic cleanser to reduce the surface bioburden of Escherichia coli and Staphylococcus aureus. Via this assay, phosphate‐buffered saline controls were able to generate dry biofilms within 7 days of incubation, with the application of the probiotic cleanser able to prevent >97.7% of dry biofilm formation across both pathogen analogs and surface types. Further to this, surfaces treated with the probiotic mixture alone also showed a reduction in dry biofilm across both pathogen and surface types. Confocal laser scanning microscopy imaging indicated that the probiotic bacteria were able to germinate and colonize surfaces, likely forming a protective layer upon these hard surfaces. We developed a test method for assessing the prevention of the adhesion of organisms to surfaces that could generate dry biofilm material. The study used a probiotic blend of Bacillus and a formulated product to assess their efficacy and visualize the presence of pathogen analogs on the surface of three material types.
Journal Article
Biogenic Gold Nanoparticles as Potent Antibacterial and Antibiofilm Nano-Antibiotics against Pseudomonas aeruginosa
2020
Plant-based synthesis of eco-friendly nanoparticles has widespread applications in many fields, including medicine. Biofilm—a shield for pathogenic microorganisms—once formed, is difficult to destroy with antibiotics, making the pathogen resistant. Here, we synthesized gold nanoparticles (AuNPs) using the stem of an Ayurvedic medicinal plant, Tinospora cordifolia, and studied the action of AuNPs against Pseudomonas aeruginosa PAO1 biofilm. The synthesized AuNPs were characterized by techniques such as ultraviolet-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, energy-dispersive X-ray diffraction, X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy. The AuNPs were spherically shaped with an average size of 16.1 nm. Further, the subminimum inhibitory concentrations (MICs) of AuNPs (50, 100, and 150 µg/mL) greatly affected the biofilm-forming ability of P. aeruginosa, as observed by crystal violet assay and SEM, which showed a decrease in the number of biofilm-forming cells with increasing AuNP concentration. This was further justified by confocal laser scanning microscopy (CLSM), which showed irregularities in the structure of the biofilm at the sub-MIC of AuNPs. Further, the interaction of AuNPs with PAO1 at the highest sub-MIC (150 µg/mL) showed the internalization of the nanoparticles, probably affecting the tendency of PAO1 to colonize on the surface of the nanoparticles. This study suggests that green-synthesized AuNPs can be used as effective nano-antibiotics against biofilm-related infections caused by P. aeruginosa.
Journal Article