Residual Antigenicity of Lyophilized Porcine Skin Shown in vitro by Immunological Methods

Objective: In vitro diffusion experiments were performed to assess the permeation of magnesium sulfate across pig skin. Method: The mean thickness of the dermatomed porcine skin was 648 ± 12 µm. Magnesium concentration was measured using inductively coupled plasma-optical emission spectroscopy. Transdermal flux of magnesium sulfate across MN-treated and untreated porcine skin was obtained from the slope of the steady-state linear portion of cumulative amount versus time curve. Results: Statistical analysis of the results was done with Student’s t-test. The transdermal flux of magnesium sulfate across microneedle-treated porcine skin was 134.19 ± 2.4 µg/cm2/h and transdermal flux across untreated porcine skin was 4.64 ± 0.05 µg/cm2/h. Confocal microscopy was used to visualize the microchannels created by a solid microneedle roller (500 µm). Conclusion: From our confocal microscopy studies, it was evident that the 500 μm long microneedles disrupted the stratum corneum and created microchannels measuring 191 ± 37 µm. The increase in transdermal flux across the microneedle-treated skin was statistically significant compared to that of controls, i.e., without the application of microneedles. With the application of microneedles, the transdermal flux of magnesium permeated over 12 h was approximately 33-fold higher in comparison to passive diffusion across an intact stratum corneum.

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Leishmania infantum and Dirofilaria immitis coinfection in dogs in Greece

Parasitology Open ◽

10.1017/pao.2016.15 ◽

2016 ◽

Vol 2 ◽

Cited By ~ 1

Author(s):

PANTELIS NTAIS ◽

VASILIKI CHRISTODOULOU ◽

EMMANOUIL DOKIANAKIS ◽

MARIA ANTONIOU

Keyword(s):

Leishmania Infantum ◽

Dirofilaria Immitis ◽

Low Cost ◽

Blood Cultures ◽

Molecular Techniques ◽

Immunological Methods ◽

Parasitic Diseases ◽

Survival Potential ◽

Knott’S Test

SUMMARYLeishmaniasis and dirofilariasis are parasitic diseases of humans and dogs, worldwide, and they are often found as coinfections in endemic areas. Cases of human and canine dirofilariasis have being reported in Greece and leishmaniasis is endemic in most prefectures in humans and dogs. In most cases, dirofilariasis is established by parasitological (the modified Knott's test) and/or immunological methods, whilst for leishmaniasis molecular techniques and culture are also used. During an epidemiological study in Greece, 22·1% of the 5772 dogs studied were found positive by serology forLeishmania.Blood cultures of 165 (12·94%) of these animals producedLeishmaniapromastigotes and 26 (2·03%)Dirofilariamicrofilariae (L1), whilst only in two (0·16%) bothLeishmaniaandDirofilariaL1 appeared. The aim was to assess coinfections by the two parasites in dogs in Greece, the isolation and survival ofDirofilariamicrofilariae andLeishmaniapromastigotes using clotted blood (a fast, simple and low-cost method) and the survival potential of the two parasites in coexistence,in vitro.

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A Laboratory Method to Measure Skin Surface Staining by Cigarette Smoke, Tobacco Heating Products and E-Cigarettes

Contributions to Tobacco & Nicotine Research ◽

10.2478/cttr-2021-0013 ◽

2021 ◽

Vol 30 (4) ◽

pp. 158-166

Author(s):

Annette Dalrymple ◽

Emma-Jayne Bean ◽

Jesse Thissen ◽

Holger Behrsing ◽

Steven Coburn ◽

...

Keyword(s):

Cigarette Smoke ◽

Skin Surface ◽

Laboratory Method ◽

Porcine Skin ◽

Skin Sample ◽

Side Stream ◽

Air Control ◽

And Control ◽

Skin Samples

Summary Exhaled or side-stream cigarette smoke (CS) may visually stain a consumer's skin over time. Tobacco heating products (THPs) and e-cigarettes (ECs) have reduced staining potential because they do not produce side-stream aerosols and their exhaled aerosols have significantly reduced levels of toxicants, particles and odour. Here we assess discolouration of porcine skin in vitro after exposure to particulate matter (PM) or aerosols from CS (3R4F), two THPs (glo and glo sens) and an EC (iSwitch Maxx). PM was prepared by capturing aerosols on Cambridge filter pads and eluting with dimethyl sulfoxide (DMSO). Abattoir-obtained porcine skin samples were incubated with PM or DMSO control at 37 °C between 0 and 6.0 h. For aerosol assessment, porcine skin samples were exposed to between 50 and 400 puffs of the products, or air control, using a smoking machine. Colour profiles and staining levels of each skin sample were measured at different timepoints and puff thresholds using a spectrophotometer. Staining increased with time and dose, the greatest changes being observed following exposure to aerosols and PM from CS. THP, EC and control values were significantly different from CS after 0.5 h exposure to PM or 50 puffs of aerosols. The minimal staining induced by THPs and EC was comparable to controls. These data suggest that THPs and ECs could offer hygiene benefits to consumers who switch from smoking cigarettes. Further studies are required to assess the longer-term effects of THPs and ECs on skin discoloration. [Contrib. Tob. Nicotine Res. 30 (2021) 158–166]

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Intake of Flavonoids from Astragalus Membranaceus Ameliorated Brain Impairment in Diabetic Mice Via Modulating Brain-Gut Axis

10.21203/rs.3.rs-1127751/v1 ◽

2021 ◽

Author(s):

Li Xuling ◽

Junling Gu ◽

Zhe Wang ◽

Jing Lin ◽

Tingting Zhao ◽

...

Keyword(s):

Gut Microbiota ◽

Brain Damage ◽

High Fat Diet ◽

Fasting Blood Glucose ◽

Synaptic Function ◽

Astragalus Membranaceus ◽

Immunological Methods ◽

Diabetic Mice ◽

High Fat

Abstract Background: Brain impairment is one of a major complication of diabetes. Dietary flavonoids have been recommended to prevent brain damage. Astragalus membranaceus is a herbal medicine commonly used to relieve the complications of diabetes. Flavonoids is one of the major ingredients of Astragalus membranaceus, but its function and mechanism on diabetic encepholopathy is still unknown.Methods: Type 2 diabetes mellitus (T2DM) model was induced by high fat diet and STZ in C57BL/6J mice, and BEnd.3 and HT22 cell lines were applied in the in vitro study. Quality of flavonoids was evaluated by LC-MS/MS. Differential expressed proteins in the hippocampus were evaluated by proteomics; influence of the flavonoids on composition of gut microbiota was analyzed by metagenomics. Mechanism of the flavonoids on diabetic encepholopathy was analyzed by Q-PCR, Western Blot, and multi-immunological methods et al. Results: We found that flavonoids from Astragalus membranaceus (TFA) significantly ameliorated brain damage by modulating gut-microbiota-brain axis: TFA oral administration decreased fasting blood glucose and food intake, repaired blood brain barrier, protected hippocampus synaptic function; improved hippocampus mitochondrial biosynthesis and energy metabolism; and enriched the intestinal microbiome in high fat diet/STZ-induced diabetic mice. In the in vitro study, we found TFA increased viability of HT22 cells and preserved gut barrier integrity in CaCO2 monocellular layer, and PGC1α/AMPK pathway participated in this process. Conclusion: Our findings demonstrated that flavonoids from Astragalus Membranaceus ameliorated brain impairment via gut-brain axis. Our present study provided an alternative solution on preventing and treating diabetic cognition impairment.

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Preparation, Characterisation, and Topical Delivery of Terbinafine

Pharmaceutics ◽

10.3390/pharmaceutics11100548 ◽

2019 ◽

Vol 11 (10) ◽

pp. 548 ◽

Cited By ~ 6

Author(s):

A. S. M. Monjur Al Hossain ◽

Bruno C. Sil ◽

Fotis Iliopoulos ◽

Rebecca Lever ◽

Jonathan Hadgraft ◽

...

Keyword(s):

Propylene Glycol ◽

Fungal Infections ◽

Isopropyl Myristate ◽

Limited Information ◽

Free Base ◽

Porcine Skin ◽

Salt Form ◽

Scanning Calorimetry ◽

Polyethylene Glycol 200

Terbinafine (TBF) is commonly used in the management of fungal infections of the skin because of its broad spectrum of activity. Currently, formulations containing the free base and salt form are available. However, there is only limited information in the literature about the physicochemical properties of this drug and its uptake by the skin. In this work, we conducted a comprehensive characterisation of TBF, and we also examined its percutaneous absorption in vitro in porcine skin. TBF-free base was synthesised from the hydrochloride salt by a simple proton displacement reaction. Both the free base and salt form were further analysed using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Delivery of TBF-free base in excised porcine skin was investigated from the following solvents: Isopropyl myristate (IPM), propylene glycol monolaurate (PGML), Transcutol® (TC), propylene glycol (PG), polyethylene glycol 200 (PEG 200), oleic acid (OL), ethanol (EtOH), and isopropyl alcohol (IPA). Permeation and mass balance studies confirmed that PG and TC were the most efficacious vehicles, delivering higher amounts of TBF-free base to the skin compared with a commercial gel (p < 0.05). These preliminary results are promising and will inform the development of more complex formulations in future work.

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Design and Evaluation of a Poly(Lactide-co-Glycolide)-Based In Situ Film-Forming System for Topical Delivery of Trolamine Salicylate

Pharmaceutics ◽

10.3390/pharmaceutics11080409 ◽

2019 ◽

Vol 11 (8) ◽

pp. 409 ◽

Cited By ~ 2

Author(s):

Yujin Kim ◽

Moritz Beck-Broichsitter ◽

Ajay Banga

Keyword(s):

Porcine Skin ◽

Adhesive Film ◽

Film Forming ◽

Small Joint ◽

Gastrointestinal Side Effects ◽

Permeation Studies ◽

Polymeric Solutions ◽

Poly Ethylene

Trolamine salicylate (TS) is a topical anti-inflammatory analgesic used to treat small joint pain. The topical route is preferred over the oral one owing to gastrointestinal side effects. In this study, a poly(lactide-co-glycolide) (PLGA)-based in situ bio-adhesive film-forming system for the transdermal delivery of TS was designed and evaluated. Therefore, varying amounts (0%, 5%, 10%, 20%, and 25% (w/w)) of PLGA (EXPANSORB® DLG 50-2A, 50-5A, 50-8A, and 75-5A), ethyl 2-cyanoacrylate, poly (ethylene glycol) 400, and 1% of TS were dissolved together in acetone to form the bio-adhesive polymeric solution. In vitro drug permeation studies were performed on a vertical Franz diffusion cell and dermatomed porcine ear skin to evaluate the distinct formulations. The bio-adhesive polymeric solutions were prepared successfully and formed a thin film upon application in situ. A significantly higher amount of TS was delivered from a formulation containing 20% PLGA (45 ± 4 µg/cm2) and compared to PLGA-free counterpart (0.6 ± 0.2 µg/cm2). Furthermore, the addition of PLGA to the polymer film facilitated an early onset of TS delivery across dermatomed porcine skin. The optimized formulation also enhanced the delivery of TS into and across the skin.

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An Investigation of the Influence of PEG 400 and PEG-6-Caprylic/Capric Glycerides on Dermal Delivery of Niacinamide

Polymers ◽

10.3390/polym12122907 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2907

Author(s):

Yanling Zhang ◽

Majella E. Lane ◽

David J. Moore

Keyword(s):

Skin Permeation ◽

Ternary Systems ◽

Pharmaceutical Products ◽

Porcine Skin ◽

Peg 400 ◽

Skin Delivery ◽

Dermal Delivery ◽

Binary And Ternary Systems ◽

Skin Retention

Polyethylene glycols (PEGs) and PEG derivatives are used in a range of cosmetic and pharmaceutical products. However, few studies have investigated the influence of PEGs and their related derivatives on skin permeation, especially when combined with other solvents. Previously, we reported niacinamide (NIA) skin permeation from a range of neat solvents including propylene glycol (PG), Transcutol® P (TC), dimethyl isosorbide (DMI), PEG 400 and PEG 600. In the present work, binary and ternary systems composed of PEGs or PEG derivatives combined with other solvents were investigated for skin delivery of NIA. In vitro finite dose studies were conducted (5 μL/cm2) in porcine skin over 24 h. Higher skin permeation of NIA was observed for all vehicles compared to PEG 400. However, overall permeation for the binary and ternary systems was comparatively low compared with results for PG, TC and DMI. Interestingly, values for percentage skin retention of NIA for PEG 400:DMI and PEG 400:TC were significantly higher than values for DMI, TC and PG (p < 0.05). The findings suggest that PEG 400 may be a useful component of formulations for the delivery of actives to the skin rather than through the skin. Future studies will expand the range of vehicles investigated and also look at skin absorption and residence time of PEG 400 compared to other solvents.

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Novel Design Approaches in the Fabrication of Polymeric Microarray Patches via Micromoulding

Micromachines ◽

10.3390/mi11060554 ◽

2020 ◽

Vol 11 (6) ◽

pp. 554 ◽

Cited By ~ 2

Author(s):

Inken Ramöller ◽

Emma McAlister ◽

Abigail Bogan ◽

Ana Cordeiro ◽

Ryan Donnelly

Keyword(s):

Skin Barrier ◽

Systemic Delivery ◽

Porcine Skin ◽

Density Maps ◽

In Vitro Permeation ◽

Wide Range ◽

Significant Difference ◽

Permeation Studies ◽

Novel Design

The focus on novel systems for transdermal delivery of therapeutic agents has increased considerably over recent years, as this administration route comes with many advantages. Polymeric microarray patches (MAPs) are minimally invasive devices that enable systemic delivery of a wide range of drugs by overcoming the outer skin barrier. Conventionally, MAPs fabricated by micromoulding have a low needle density. In this study, the performance of hydrogel-forming MAPs cast using novel industrially manufactured micromoulds with a high needle density (600 needles/0.75 cm2) was compared to that of MAPs obtained using conventional moulds with a lower density (196 needles/0.89 cm2). Surrounding holders for micromoulds were designed for time-efficient fabrication of MAPs. The influence of needle densities on mechanical strength, insertion efficiency and in vitro permeation of ibuprofen sodium (IBU) was analysed. Insertion of both MAPs into an artificial skin model and neonatal porcine skin was comparable. No significant difference was observed in permeation studies of IBU (p > 0.05), with a delivery of 8.7 ± 1.7 mg for low-density and 9.5 ± 0.1 mg for high-density MAPs within 24 h. This highlights the potential of these novel micromoulds for manufacturing polymeric MAPs with a higher needle density for future applications.

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Usefulness of Artificial Membrane, Strat-M®, in the Assessment of Drug Permeation from Complex Vehicles in Finite Dose Conditions

Pharmaceutics ◽

10.3390/pharmaceutics12020173 ◽

2020 ◽

Vol 12 (2) ◽

pp. 173 ◽

Cited By ~ 2

Author(s):

Florencio Jr Arce ◽

Narumi Asano ◽

Gerard Lee See ◽

Shoko Itakura ◽

Hiroaki Todo ◽

...

Keyword(s):

Human Skin ◽

Cosmetic Products ◽

Artificial Membrane ◽

Porcine Skin ◽

Comparative Performance ◽

Permeability Characteristics ◽

In Vitro Methods ◽

Rank Orders ◽

Franz Diffusion Cells

The ban on the use of animals in testing cosmetic products has led to the development of animal-free in vitro methods. Strat-M® is an artificial membrane engineered to mimic human skin and is recommended as a replacement for skin. However, its usefulness in the assessment of the permeation of cosmetics in in-use conditions remains unverified. No data have been published on its comparative performance with the membrane of choice, porcine skin. The comparative permeability characteristics of Strat-M® and porcine skin were investigated using Franz diffusion cells. Caffeine (CF) and rhododendrol (RD) in complex vehicles with varying concentrations of polyols were applied as finite and infinite doses. Good rank orders of permeation from finite dose experiments were observed for RD. High correlations were observed in RD permeation between Strat-M® and porcine skin under finite and infinite dose conditions, whereas only finite dose conditions for CF were associated with good correlations. Permeation from formulations with high polyol content and residual formulations was enhanced due to the disruption of the integrity of the Strat-M® barrier. The usefulness of Strat-M® in the assessment of dermal permeation may be limited to finite dose conditions and not applicable to infinite dose conditions or formulations applied in layers.

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