scholarly journals Impact of Different Mucoadhesive Polymeric Nanoparticles Loaded in Thermosensitive Hydrogels on Transcorneal Administration of 5-Fluorouracil

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 623 ◽  
Author(s):  
Angela Fabiano ◽  
Anna Maria Piras ◽  
Lorenzo Guazzelli ◽  
Barbara Storti ◽  
Ranieri Bizzarri ◽  
...  
Keyword(s):  
Area Under Curve ◽  
Polymeric Nanoparticles ◽  
Chitosan Nanoparticles ◽  
Surface Characteristics ◽  
Chitosan Derivative ◽  
Thermosensitive Hydrogel ◽  
Thermosensitive Hydrogels ◽  
Ocular Bioavailability ◽  
The Impact ◽  
Time Plot

In a previous paper a thermosensitive hydrogel formulation based on chitosan or its derivatives (TSOH), containing medicated chitosan nanoparticles (Ch NP) for transcorneal administration of 5-fluorouracil (5-FU) was described. The Ch NP-containing TSOH allowed a time-constant 5-FU concentration in the aqueous for 7 h from instillation. The aim of the present work was to study the impact of the surface characteristics of new NP contained in TSOH on ocular 5-FU bioavailability. The Ch derivatives used to prepare NP were quaternary ammonium-Ch conjugate (QA-Ch), S-protected derivative thereof (QA-Ch-S-pro), and a sulphobutyl chitosan derivative (SB-Ch). All NP types had 300–400 nm size, 16–18% encapsulation efficiency, and retained the entrapped drug for at least 15 h. Drug release from TSOH containing NP based on QA-Ch or QA-Ch-S-pro was virtually equal, whereas with TSOH containing NP based on SB-Ch was significantly slower. Instillation, in rabbit eyes, of NP-containing TSOH based on QA-Ch or SB-Ch led to a plateau in the aqueous concentration vs. time plot in the 1–10 h range with significantly enhanced area under curve (AUC). Negative charges on the NP surface slowed down 5-FU release from TSOH while positive charges increased NP contact with the negatively charged ocular surface. Either results in enhanced ocular bioavailability.

Novel Applications of Nanotechnology in Controlling HIV and HSV Infections

2020 ◽  
Vol 12 ◽  
Author(s):  
Sai Akilesh M ◽  
Ashish Wadhwani
Keyword(s):  
Drug Delivery ◽  
Viral Infections ◽  
Polymeric Nanoparticles ◽  
Volume Ratio ◽  
Fold Increase ◽  
Multi Drug Resistance ◽  
Health Crisis ◽  
Pharmaceutical Properties ◽  
Simplex Virus ◽  
The Impact

: Infectious diseases have been prevalent since many decades and viral pathogens have caused global health crisis and economic meltdown on a devastating scale. High occurrence of newer viral infections in the recent years, in spite of the progress achieved in the field of pharmaceutical sciences defines the critical need for newer and more effective antiviral therapies and diagnostics. The incidence of multi-drug resistance and adverse effects due to the prolonged use of anti-viral therapy is also a major concern. Nanotechnology offers a cutting edge platform for the development of novel compounds and formulations for biomedical applications. The unique properties of nano-based materials can be attributed to the multi-fold increase in the surface to volume ratio at the nano-scale, tunable surface properties of charge and chemical moieties. Idealistic pharmaceutical properties such as increased bioavailability and retention times, lower toxicity profiles, sustained release formulations, lower dosage forms and most importantly, targeted drug delivery can be achieved through the approach of nanotechnology. The extensively researched nano-based materials are metal and polymeric nanoparticles, dendrimers and micelles, nano-drug delivery vesicles, liposomes and lipid based nanoparticles. In this review article, the impact of nanotechnology on the treatment of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV) viral infections during the last decade are outlined.

scholarly journals The Impact of Post-Manufacture Treatments on the Surface Characteristics Important for Finishing of OSB and Particleboard

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić
Keyword(s):  
Water Vapour ◽  
Oriented Strand Board ◽  
Construction Material ◽  
Surface Characteristics ◽  
Surface Treatments ◽  
Factors Affecting ◽  
Treatment Conditions ◽  
Water Vapour Absorption ◽  
The Impact

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.

Toward a Robust Canopy Hydrology Scheme with Precipitation Subgrid Variability

2007 ◽  
Vol 8 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Dagang Wang ◽  
Guiling Wang
Keyword(s):  
Land Surface ◽  
Surface Characteristics ◽  
Hydrological Processes ◽  
Canopy Interception ◽  
Time Step ◽  
Covered Area ◽  
Surface Models ◽  
Physically Based ◽  
Interception Loss ◽  
The Impact

Abstract Representation of the canopy hydrological processes has been challenging in land surface modeling due to the subgrid heterogeneity in both precipitation and surface characteristics. The Shuttleworth dynamic–statistical method is widely used to represent the impact of the precipitation subgrid variability on canopy hydrological processes but shows unwanted sensitivity to temporal resolution when implemented into land surface models. This paper presents a canopy hydrology scheme that is robust at different temporal resolutions. This scheme is devised by applying two physically based treatments to the Shuttleworth scheme: 1) the canopy hydrological processes within the rain-covered area are treated separately from those within the nonrain area, and the scheme tracks the relative rain location between adjacent time steps; and 2) within the rain-covered area, the canopy interception is so determined as to sustain the potential evaporation from the wetted canopy or is equal to precipitation, whichever is less, to maintain somewhat wet canopy during any rainy time step. When applied to the Amazon region, the new scheme establishes interception loss ratios of 0.3 at a 10-min time step and 0.23 at a 2-h time step. Compared to interception loss ratios of 0.45 and 0.09 at the corresponding time steps established by the original Shuttleworth scheme, the new scheme is much more stable under different temporal resolutions.

scholarly journals Translating the fabrication of protein-loaded poly(lactic-co-glycolic acid) nanoparticles from bench to scale-independent production using microfluidics

2020 ◽  
Vol 10 (3) ◽  
pp. 582-593 ◽  
Author(s):  
Carla B. Roces ◽  
Dennis Christensen ◽  
Yvonne Perrie
Keyword(s):  
Particle Size ◽  
Glycolic Acid ◽  
Polymeric Nanoparticles ◽  
Physicochemical Characteristics ◽  
European Medicines Agency ◽  
Protein Encapsulation ◽  
Human Use ◽  
Rate Ratios ◽  
The Impact ◽  
Process Controls

AbstractIn the formulation of nanoparticles, poly(lactic-co-glycolic acid) (PLGA) is commonly employed due to its Food and Drug Administration and European Medicines Agency approval for human use, its ability to encapsulate a variety of moieties, its biocompatibility and biodegradability and its ability to offer a range of controlled release profiles. Common methods for the production of PLGA particles often adopt harsh solvents, surfactants/stabilisers and in general are multi-step and time-consuming processes. This limits the translation of these drug delivery systems from bench to bedside. To address this, we have applied microfluidic processes to develop a scale-independent platform for the manufacture, purification and monitoring of nanoparticles. Thereby, the influence of various microfluidic parameters on the physicochemical characteristics of the empty and the protein-loaded PLGA particles was evaluated in combination with the copolymer employed (PLGA 85:15, 75:25 or 50:50) and the type of protein loaded. Using this rapid production process, emulsifying/stabilising agents (such as polyvinyl alcohol) are not required. We also incorporate in-line purification systems and at-line particle size monitoring. Our results demonstrate the microfluidic control parameters that can be adopted to control particle size and the impact of PLGA copolymer type on the characteristics of the produced particles. With these nanoparticles, protein encapsulation efficiency varies from 8 to 50% and is controlled by the copolymer of choice and the production parameters employed; higher flow rates, combined with medium flow rate ratios (3:1), should be adopted to promote higher protein loading (% wt/wt). In conclusion, herein, we outline the process controls for the fabrication of PLGA polymeric nanoparticles incorporating proteins in a rapid and scalable manufacturing process.

scholarly journals Evaluating the Antibacterial Activity and Mode of Action of Thymol-Loaded Chitosan Nanoparticles Against Plant Bacterial Pathogen Xanthomonas campestris pv. campestris

2022 ◽  
Vol 12 ◽  
Author(s):  
Sarangapani Sreelatha ◽  
Nadimuthu Kumar ◽  
Tan Si Yin ◽  
Sarojam Rajani
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Xanthomonas Campestris ◽  
Membrane Damage ◽  
Chitosan Nanoparticles ◽  
Bacterial Pathogen ◽  
Electron Microscopy Analysis ◽  
Rot Disease ◽  
The Impact

The bacterium Xanthomonas campestris pv. campestris (Xcc) causes black rot disease in cruciferous crops, resulting in severe yield loss worldwide. The excessive use of chemical pesticides in agriculture to control diseases has raised significant concern about the impact on the environment and human health. Nanoparticles have recently gained significant attention in agriculture owing to their promising application in plant disease control, increasing soil fertility and nutrient availability. In the current study, we synthesized thymol-loaded chitosan nanoparticles (TCNPs) and assessed their antibacterial activity against Xcc. The synthesis of TCNPs was confirmed by using ultraviolet–visible spectroscopy. Fourier-transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy analysis revealed the functional groups, size, and shape of TCNPs, with sizes ranging from 54 to 250 nm, respectively. The antibacterial activity of TCNPs against Xcc was investigated in vitro by liquid broth, cell viability, and live dead staining assay, and all of them demonstrated the antibacterial activity of TCNPs. Furthermore, TCNPs were found to directly inhibit the growth of Xcc by suppressing the growth of biofilm formation and the production of exopolysaccharides and xanthomonadin. The ultrastructure studies revealed membrane damage in TCNP-treated Xcc cells, causing a release of intracellular contents. Headspace/gas chromatography (GC)–mass spectrometry (MS) analysis showed changes in the volatile profile of Xcc cells treated with TCNPs. Increased amounts of carbonyl components (mainly ketones) and production of new volatile metabolites were observed in Xcc cells incubated with TCNPs. Overall, this study reveals TCNPs as a promising antibacterial candidate against Xcc.

scholarly journals Tuning the Thermogelation and Rheology of Poly(2-Oxazoline)/poly(2-Oxazine)s Based Thermosensitive Hydrogels for 3D Bioprinting.

2021 ◽  
Author(s):  
Malik Salman Haider ◽  
Taufiq Ahmad ◽  
Mengshi Yang ◽  
Chen Hu ◽  
Lukas Hahn ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Stem Cells ◽  
Gel Strength ◽  
Adipose Derived Stem Cells ◽  
3D Bioprinting ◽  
Thermosensitive Hydrogel ◽  
Clay Nanoparticles ◽  
Hydrogel Matrix ◽  
Thermosensitive Hydrogels ◽  
3D Printed

As one kind of smart material, thermogelling polymers find applications in biofabrication, drug delivery and regenerative medicine. Here, we reported on a novel thermosensitive hydrogel which can be 3D printed using extrusion based printing. Gel strength was found around 3kPa storage modulus with pronounced shear thinning and rapid recovery after stress. Addition of clay nanoparticles (Laponite XLG) improved the rheological profile further. Human adipose derived stem cells were added to the hydrogel matrix, which remained fully viable after printing. Therefore, the presented materials adds to the available material toolbox for 3D bioprinting. <br>

scholarly journals SPATIOLTEMPORAL MODELING THE IMPACT OF SURFACE CHARACTERISTICS VARIATIONS ON LAND SURFACE TEMPERATURE VARIATIONS: A CASE STUDY OF SAMALGHAN VALLY

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 401-405
Author(s):  
M. K. Firozjaei ◽  
M. Makki ◽  
J. Lentschke ◽  
M. Kiavarz ◽  
S. K. Alavipanah
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Single Channel ◽  
Incident Angle ◽  
Surface Characteristics ◽  
Slope Aspect ◽  
Biophysical Parameters ◽  
The Impact

Abstract. Spatiotemporal mapping and modeling of Land Surface Temperature (LST) variations and characterization of parameters affecting these variations are of great importance in various environmental studies. The aim of this study is a spatiotemporal modeling the impact of surface characteristics variations on LST variations for the studied area in Samalghan Valley. For this purpose, a set of satellite imagery and meteorological data measured at the synoptic station during 1988–2018, were used. First, single-channel algorithm, Tasseled Cap Transformation (TCT) and Biophysical Composition Index (BCI) were employed to estimate LST and surface biophysical parameters including brightness, greenness and wetness and BCI. Also, spatial modeling was used to modeling of terrain parameters including slope, aspect and local incident angle based on DEM. Finally, the principal component analysis (PCA) and the Partial Least Squares Regression (PLSR) were used to modeling and investigate the impact of surface characteristics variations on LST variations. The results indicated that surface characteristics vary significantly for case study in spatial and temporal dimensions. The correlation coefficient between the PC1 of LST and PC1s of brightness, greenness, wetness, BCI, DEM, and solar local incident angle were 0.65, −0.67, −0.56, 0.72, −0.43 and 0.53, respectively. Furthermore, the coefficient coefficient and RMSE between the observed LST variation and modelled LST variation based on PC1s of brightness, greenness, wetness, BCI, DEM, and local incident angle were 0.83 and 0.14, respectively. The results of study indicated the LST variation is a function of s terrain and surface biophysical parameters variations.

Mutual effects of free and nanoencapsulated phenolic compounds on human microbiota

2021 ◽  
Vol 28 ◽  
Author(s):  
Carina Cassini ◽  
Pedro Henrique Zatti ◽  
Valéria Weiss Angeli ◽  
Catia Santos Branco ◽  
Mirian Salvador
Keyword(s):  
Phenolic Compounds ◽  
Gut Microbiota ◽  
Oral Bioavailability ◽  
Polymeric Nanoparticles ◽  
The Body ◽  
Biological Targets ◽  
Chemical Structures ◽  
Metabolic Transformation ◽  
Biological Performance ◽  
The Impact

: Phenolic compounds (PC) have many health benefits such as antioxidant, anticarcinogenic, neuroprotective, and anti-inflammatory activities. All of these activities depend on their chemical structures and their interaction with biological targets in the body. PC occur naturally in polymerized form, linked to glycosides and requires metabolic transformation from their ingestion to their absorption. The gut microbiota can transform PC into more easily absorbed metabolites. The PC, in turn, have prebiotic and antimicrobial actions on the microbiota. Despite this, their low oral bioavailability still compromises biological performance. Therefore, the use of nanocarriers has been demonstrated to be a useful strategy to improve PC absorption and, consequently, their health effects. Nanotechnology is an excellent alternative able to overcome the limits of oral bioavailability of PC, since it offers protection from degradation during their passage through the gastrointestinal tract. Moreover, nanotechnology is also capable of promoting controlled PC release and modulating the interaction between PC and the microbiota. However, little is known about the impact of the nanotechnology on PC effects on the gut microbiota. This review highlights the use of nanotechnology for PC delivery on gut microbiota, focusing on the ability of such formulations to enhance oral bioavailability by applying nanocarriers (polymeric nanoparticles, nanostructured lipid carriers, solid lipid nanoparticles). In addition, the effects of free and nanocarried PC or nanocarriers per se on gut microbiota are also described.

scholarly journals Knocking and Listening: Learning Mechanical Impulse Response for Understanding Surface Characteristics

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 369 ◽  
Author(s):  
Semin Ryu ◽  
Seung-Chan Kim
Keyword(s):  
Intelligent System ◽  
Surface Characteristics ◽  
Machine Learning Techniques ◽  
Test Accuracy ◽  
Learning Approaches ◽  
Well Test ◽  
Mechanical Responses ◽  
Learning Techniques ◽  
The Impact ◽  
Mechanical Impulse

Inspired by spiders that can generate and sense vibrations to obtain information regarding a substrate, we propose an intelligent system that can recognize the type of surface being touched by knocking the surface and listening to the vibrations. Hence, we developed a system that is equipped with an electromagnetic hammer for hitting the ground and an accelerometer for measuring the mechanical responses induced by the impact. We investigate the feasibility of sensing 10 different daily surfaces through various machine-learning techniques including recent deep-learning approaches. Although some test surfaces are similar, experimental results show that our system can recognize 10 different surfaces remarkably well (test accuracy of 98.66%). In addition, our results without directly hitting the surface (internal impact) exhibited considerably high test accuracy (97.51%). Finally, we conclude this paper with the limitations and future directions of the study.

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