Production and Characterization of Glutathione-Chitosan Conjugate Films as Systems for Localized Release of Methotrexate

Cancer is one of the most serious public health problems that affect humanity. Diverse delivery systems of anticancer drugs have been developed to enhance the treatment effectiveness and patient compliance. Thus, drug delivery systems from polymeric films could be an interesting and promising alternative, especially for skin chemotherapeutics. In this work, polymeric films based on glutathione-chitosan conjugates with degrees of thiolation of 4.4%, 5.1% and 7.0% were synthetized by casting-evaporation method and subsequent loading with methotrexate. The surface properties of these films were evaluated by contact angle and spreading rate measurements. The sessile drop methods along with the thermodynamic parameter of work of adhesion were determined using the Young–Dupré semi-empirical model. The in vitro methotrexate release was assessed at a pH of 4.5 and 7.4 simulating physiological conditions. Data from the resulting profiles were fitted to the order one, Higuchi, Peppas–Sahlin and Korsmeyer–Peppas kinetic models. The results suggest a strong relationship between the thiolation degree and hydrophilic surface properties such as contact angle and water spreading rate, whereas the work of adhesion was not significantly affected. Further, these polymer films could control the methotrexate release through diverse mechanisms such as diffusion and relaxation depending on the thiolation degree and the aqueous medium employed. In fact, as thiolation degree increased, the release mechanism shifted from a primary diffusional type towards a predominant relaxation-driven mechanism. These polymer films could be used as modified systems for anticancer local delivery.

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SURFACE PROPERTIES OF FUSED SALTS AND GLASSES: II, CONTACT ANGLE AND WORK OF ADHESION ON GOLD AND PLATINUM IN VARIOUS ATMOSPHERES

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1938.tb15765.x ◽

1938 ◽

Vol 21 (6) ◽

pp. 205-213 ◽

Cited By ~ 7

Author(s):

Bennett S. Ellefson ◽

Nelson W. Taylor

Keyword(s):

Contact Angle ◽

Surface Properties ◽

Work Of Adhesion ◽

Fused Salts

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On the microhydrodynamics of superspreading

Journal of Fluid Mechanics ◽

10.1017/s0022112010006531 ◽

2011 ◽

Vol 670 ◽

pp. 1-4 ◽

Cited By ~ 19

Author(s):

C. MALDARELLI

Keyword(s):

Contact Angle ◽

Aqueous Phase ◽

Contact Line ◽

Sessile Drop ◽

Numerical Study ◽

Dynamic Contact Angle ◽

Hydrophobic Surface ◽

Dynamic Contact ◽

Spreading Rate ◽

Spreading Rates

Droplets of an aqueous phase placed on a very hydrophobic, waxy surface bead-up rather than spread, forming a sessile drop with a relatively large contact angle at the edge of the drop. Surfactant molecules, when dissolved in the aqueous phase, can facilitate the wetting of an aqueous drop on a hydrophobic surface. One class of surfactants, superwetters, can cause aqueous droplets to move very rapidly over a hydrophobic surface, thereby completely wetting the surface (superspreading). A recent numerical study of the hydrodynamics of superspreading by Karapetsas, Craster & Matar (J. Fluid Mech., this issue, vol. 670, 2011, pp. 5–37) provides a clear explanation of how these surfactants cause such a dramatic change in wetting behaviour. The study shows that large spreading rates occur when the surfactant can transfer directly from the air/aqueous to the aqueous/hydrophobic solid interface at the contact line. This transfer reduces the concentration of surfactant on the fluid interface, which would otherwise be elevated due to the advection accompanying the drop spreading. The reduced concentration creates a Marangoni force along the fluid surface in the direction of spreading, and a concave rim in the vicinity of the contact line with a large dynamic contact angle. Both of these effects act to increase the spreading rate. The molecular structure of the superwetters allows them to assemble on a hydrophobic surface, enabling the direct transfer from the fluid to the solid surface at the contact line.

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Ageing of modified wood. Part 1: Wetting properties of acetylated, furfurylated, and thermally modified wood

Holzforschung ◽

10.1515/hf.2010.040 ◽

2010 ◽

Vol 64 (3) ◽

Cited By ~ 20

Author(s):

Lars Elof Bryne ◽

Magnus E.P. Wålinder

Keyword(s):

Contact Angle ◽

Sessile Drop ◽

Contact Angles ◽

Work Of Adhesion ◽

Base Interaction ◽

Hydrophobic Character ◽

Wetting Properties ◽

Heat Treated ◽

Contact Angle Analysis ◽

Modified Wood

Abstract The main objective of this work was to apply contact angle analysis to predict work of adhesion (W a ) between some modified wood materials and certain thermoplastics and adhesives. Wetting properties, i.e., contact angles, were measured by the Wilhelmy method on both freshly prepared and aged veneer samples of unmodified and acetylated Scots pine, furfurylated radiata pine, and heat treated Norway spruce. The sessile drop method was used to measure contact angles on a phenol resorcinol formaldehyde, an emulsion polymer isocyanate, and a one-component polyurethane adhesive. Contact angle data were also collected from the literature on polyethylene, polyvinyl chloride, polymethyl methacrylate, polystyrene, and Nylon 6. Contact angle analysis based on the Chang-Qin-Chen model was then applied to determine so-called acid-base interaction parameters and W a between the wood samples and the selected thermoplastics and adhesives. Results show that the ageing process led to an increased hydrophobic character of unmodified, heat treated, and furfurylated wood samples. The freshly prepared acetylated wood samples had a pronounced hydrophobic character which remained approximately constant after ageing. The predicted W a between the wood and the adhesives was considerably higher than that between the wood and the thermoplastics. Furthermore, the predicted W a between the acetylated wood and both the thermoplastics and water was approximately unchanged when comparing the fresh and aged samples. In contrast, the ageing of all other wood samples resulted in a dramatic decrease of the wood-water W a and a moderate decrease of the wood-thermoplastics W a . The wood-adhesives W a , however, was unchanged for the unmodified and furfurylated wood when comparing the fresh and aged samples and even increased for heat treated and acetylated wood samples.

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Endgroup and Sidechain Functionalization of Surface-Initiated ROMP Thin Films: Progress Towards ROMP-Based Molecular Wires

10.26434/chemrxiv.5954518 ◽

2018 ◽

Author(s):

Nicholas Marshall

Keyword(s):

Thin Films ◽

Contact Angle ◽

Cyclic Voltammetry ◽

Polymer Films ◽

Conjugated Polymer ◽

Ring Opening ◽

Molecular Wires ◽

Metathesis Polymerization ◽

Cross Metathesis ◽

Active Ester

A set of experiments in surface-initiated ring-opening metathesis polymerization, including end-functionalization of growing brushes and contact angle/cyclic voltammetry measurements. We report preparation and CV of two different conjugated polymer films, and several endgroup and sidechain functionalization experiments using cross-metathesis and active ester substitution.<br>

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Chitosan-based Polymer Matrix for Pharmaceutical Excipients and Drug Delivery

Current Medicinal Chemistry ◽

10.2174/0929867325666180927100817 ◽

2019 ◽

Vol 26 (14) ◽

pp. 2502-2513 ◽

Cited By ~ 9

Author(s):

Md. Iqbal Hassan Khan ◽

Xingye An ◽

Lei Dai ◽

Hailong Li ◽

Avik Khan ◽

...

Keyword(s):

Drug Delivery ◽

Drug Delivery Systems ◽

Drug Carrier ◽

Drug Loading ◽

Delivery Systems ◽

Cancer Drug ◽

Release Mechanism ◽

Innovative Drug ◽

Pharmaceutical Excipients ◽

Weight Variation

The development of innovative drug delivery systems, versatile to different drug characteristics with better effectiveness and safety, has always been in high demand. Chitosan, an aminopolysaccharide, derived from natural chitin biomass, has received much attention as one of the emerging pharmaceutical excipients and drug delivery entities. Chitosan and its derivatives can be used for direct compression tablets, as disintegrant for controlled release or for improving dissolution. Chitosan has been reported for use in drug delivery system to produce drugs with enhanced muco-adhesiveness, permeation, absorption and bioavailability. Due to filmogenic and ionic properties of chitosan and its derivative(s), drug release mechanism using microsphere technology in hydrogel formulation is particularly relevant to pharmaceutical product development. This review highlights the suitability and future of chitosan in drug delivery with special attention to drug loading and release from chitosan based hydrogels. Extensive studies on the favorable non-toxicity, biocompatibility, biodegradability, solubility and molecular weight variation have made this polymer an attractive candidate for developing novel drug delivery systems including various advanced therapeutic applications such as gene delivery, DNA based drugs, organ specific drug carrier, cancer drug carrier, etc.

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Comparative studies of nitrogen plasma and argon plasma treatment on the strength of PBO fibre reinforced high-temperature resistant thermoplastic composite

High Performance Polymers ◽

10.1177/0954008320987296 ◽

2021 ◽

pp. 095400832098729

Author(s):

K Sudheendra ◽

Jennifer Vinodhini ◽

M Govindaraju ◽

Shantanu Bhowmik

Keyword(s):

Contact Angle ◽

High Temperature ◽

Plasma Treatment ◽

Sessile Drop ◽

Dynamic Contact Angle ◽

Argon Plasma ◽

Film Surface ◽

Fibre Surface ◽

Nitrogen Plasma ◽

Thermoplastic Composite

The study involves the processing of a novel poly [1, 4-phenylene-cis-benzobisoxazole] (PBO) fibre reinforced high-temperature thermoplastic composite with polyaryletherketone (PAEK) as the matrix. The PBO fibre and the PAEK film surface was modified using the method of argon and nitrogen plasma treatment. The investigation primarily focuses on evaluating the tensile properties of the fabricated laminates and correlating it with the effect of plasma treatment, surface characteristics, and its fracture surface. A 5% decrease in tensile strength was observed post argon plasma treatment while a 27% increase in strength was observed post nitrogen plasma treatment. The morphology of the failure surface was investigated by scanning electron microscopy and an interfacial failure was observed. Furthermore, the effect of plasma on the wettability of PBO fibres and PAEK film surface was confirmed by the Dynamic Contact Angle analysis and sessile drop method respectively. FTIR spectral analysis was done to investigate the effect of plasma treatment on the chemical structure on the surface. The results of the wettability study showed that the argon plasma treatment of the fibre surface increased its hydrophobicity while nitrogen plasma treatment resulted in the reduction of contact angle.

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Increasing Storage Modulus, Contact Angle and Surface Tension of Airway Mucus Increases Clearance by Simulated Cough Through a Model Trachea

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19703 ◽

2010 ◽

Author(s):

Anpalaki J. Ragavan ◽

Cahit A. Evrensel ◽

Peter Krumpe

Keyword(s):

Surface Tension ◽

Contact Angle ◽

Storage Modulus ◽

Surface Properties ◽

Respiratory Diseases ◽

Interactive Effects ◽

Altered Surface ◽

Human Trachea ◽

Tension Increase ◽

And Storage

Altered surface and viscoelastic material properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effects of the surface properties (contact angle and surface tension) and storage modulus with relatively unchanged viscosity on displacement of the simulated mucus aliquot during simulated cough through a model adult human trachea is investigated. For the mucus simulants used in this study contact angle and surface tension increase significantly as storage modulus increase while viscosity remains practically unchanged. Displacement of mucus simulant aliquots increased significantly with increasing storage modulus (and contact angle) at a given cough velocity in the range between 5 meters/second (m/s) and 30 m/s with duration 0.3 s. Results suggest that the interactive effects of elasticity and surface properties may help facilitate mucus displacement at low cough velocities.

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