Characteristics of polyurethane-based sustained release membranes for drug delivery

AbstractThis paper is focused on the preparation and physicochemical characterization of two poly(ester ether urethane)s with rifampicin in their matrix and different molar concentrations of urethane groups. The polyurethanes with rifampicin were processed as asymmetrical microporous membranes by a phase inversion method and characterized by attenuated total reflection — Fourier transform infrared (ATR-FTIR) spectroscopy and differential scanning calorimetry (DSC). The influence of the surface morphology in the release of drug compounds was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle, and water uptake. The release of rifampicin depends on the molar concentration of urethane groups and also on the surface morphology of the polyurethane membranes. The antibacterial activity was evaluated with S. Epidermidis RP 62 A and P. Aeruginosa ATCC 1544. Finally, the biocompatibility of the polyurethane membranes was studied with human dermal fibroblasts (HDF) to evaluate the potential biomedical applications.

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Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽

10.3390/polym13060878 ◽

2021 ◽

Vol 13 (6) ◽

pp. 878

Author(s):

Krystyna Wnuczek ◽

Andrzej Puszka ◽

Łukasz Klapiszewski ◽

Beata Podkościelna

Keyword(s):

Mechanical Analysis ◽

Attenuated Total Reflection ◽

Scanning Calorimetry ◽

Force Microscopy ◽

Chemical Structures ◽

Atomic Force ◽

Polymeric Blends ◽

Ft Ir ◽

Acrylate Monomers ◽

Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

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Surface Morphology of Single and Multi-Layer Silicon Nitride Dielectric Nano-Coatings on Silicon Dioxide and Polycrystalline Silicon

Materials Science ◽

10.5755/j01.ms.26.1.21479 ◽

2019 ◽

Vol 26 (1) ◽

pp. 25-29

Author(s):

Liga AVOTINA ◽

Elina PAJUSTE ◽

Marina ROMANOVA ◽

Gennady ENICHEK ◽

Aleksandrs ZASLAVSKIS ◽

...

Keyword(s):

Silicon Nitride ◽

Surface Morphology ◽

Polycrystalline Silicon ◽

Chemical Vapour ◽

Attenuated Total Reflection ◽

Infrared Spectrometry ◽

Chemical Bonds ◽

Force Microscopy ◽

Atomic Force ◽

Pressure Chemical

Silicon nitride (Si3N4) in a form of single and multi-layer nanofilms is proposed to be used as a dielectric layer in nanocapacitors for operation in harsh environmental conditions. Characterization of surface morphology, roughness and chemical bonds of the Si3N4 coatings has an important role in production process as the surface morphology affects the contact surface with other components of the produced device. Si3N4 was synthesized by using low pressure chemical vapour deposition method and depositing single and multi-layer (3 – 5 layers) nanofilms on SiO2 and polycrystalline silicon (PolySi). The total thickness of the synthesized nanofilms was 20 – 60 nm. Surface morphology was investigated by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical bonds in the layers were identified by means of Fourier transform infrared spectrometry, attenuated total reflection (FTIR-ATR) method. (From the SEM and AFM images it was estimated that both single and multi-layer coatings are deposited homogenously. Si-N breathing and stretching modes are observed in FTIR spectra and the surface morphology is highly dependent on PolySi, therefore suggesting the decrease of the roughness of the bottom electrode for use in the nanocapacitors.

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Poly(furfuryl alcohol)-Polycaprolactone Blends

Polymers ◽

10.3390/polym11061069 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1069 ◽

Cited By ~ 3

Author(s):

Gabriele Nanni ◽

José A. Heredia-Guerrero ◽

Uttam C. Paul ◽

Silvia Dante ◽

Gianvito Caputo ◽

...

Keyword(s):

Mechanical Properties ◽

Furfuryl Alcohol ◽

Barrier Properties ◽

Tensile Tests ◽

Attenuated Total Reflection ◽

Toxicity Tests ◽

Scanning Calorimetry ◽

Blend Films ◽

Force Microscopy ◽

Atomic Force

Poly(furfuryl alcohol) (PFA) is a bioresin synthesized from furfuryl alcohol (FA) that is derived from renewable saccharide-rich biomass. In this study, we compounded this bioresin with polycaprolactone (PCL) for the first time, introducing new functional polymer blends. Although PCL is biodegradable, its production relies on petroleum precursors such as cyclohexanone oils. With the method proposed herein, this dependence on petroleum-derived precursors/monomers is reduced by using PFA without significantly modifying some important properties of the PCL. Polymer blend films were produced by simple solvent casting. The blends were characterized in terms of surface topography by atomic force microscopy (AFM), chemical interactions between PCL and PFA by attenuated total reflection-Fourier transform infrared (ATR-FTIR), crystallinity by XRD, thermal properties by differential scanning calorimetry (DSC), and mechanical properties by tensile tests and biocompatibility by direct and indirect toxicity tests. PFA was found to improve the gas barrier properties of PCL without compromising its mechanical properties, and it demonstrated sustained antioxidant effect with excellent biocompatibility. Our results indicate that these new blends can be potentially used in diverse applications ranging from food packing to biomedical devices.

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Preparation and Characterization of Polysulfone / Recam® Composite Membranes for Potable Water Production

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1012.79 ◽

2020 ◽

Vol 1012 ◽

pp. 79-83

Author(s):

Priscila Anadão ◽

Hélio Wiebeck

Keyword(s):

Infrared Spectroscopy ◽

Composite Membranes ◽

Polymer Chains ◽

Inversion Method ◽

Mechanical Resistance ◽

Force Microscopy ◽

Fourier Transformed Infrared Spectroscopy ◽

Atomic Force ◽

Wet Phase Inversion ◽

Phase Inversion Method

Polysulfone/ Recam® composite membranes were prepared via the wet-phase inversion method. The interactions between polysulfone and additive were revealed by Fourier-transformed infrared spectroscopy and atomic force microscopy. Material properties, such as thermal and mechanical ones, were also analyzed. The increase of rugosity by augmenting the Recam® content was depicted by AFM images. Infrared spectroscopy provided very useful information about the interactions between polymer chains and additive. Thermal stability and mechanical resistance showed dependence on the additive content, which were higher for higher contents.

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Research on the Porous Structures and Properties of Composite Membranes of Polysulfone and Nanocrystalline Cellulose

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.391 ◽

2011 ◽

Vol 675-677 ◽

pp. 391-394

Author(s):

Shuai Li ◽

Yuan Gao ◽

Lu Bai ◽

Wei Qian Tian ◽

Li Ping Zhang

Keyword(s):

Pure Water ◽

Water Flux ◽

Composite Membranes ◽

Nanocrystalline Cellulose ◽

Inversion Method ◽

Porous Structures ◽

Force Microscopy ◽

Cellulose Pulp ◽

Atomic Force ◽

Phase Inversion Method

Nanocrystalline cellulose (NCC) was used to improve hydrophilic property and permeability of polysulfone (PS) membrane. It was prepared from cellulose pulp by acid-catalyzed hydrolysis and high-pressure homogenization. The casting solution of a PS/NCC blend was obtained by adding NCC to a PS membrane solution and the composite membrane was prepared by phase-inversion method. In addition, the concentration of NCC was increased gradually from 0 wt% to 1.1 wt% during the preparation in order to examine the pure water flux and the retention of a bovine serum albumin (BSA). Simultaneously, the porosity and mean pore size of the membrane was detected and calculated. The result showed that the capacity for ultrafiltration was enhanced with appropriate NCC content. The membranes were also observed with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to explore their porous structures.

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Investigations on the Properties and Performance of Mixed-Matrix Polyethersulfone Membranes Modified with Halloysite Nanotubes

Polymers ◽

10.3390/polym11040671 ◽

2019 ◽

Vol 11 (4) ◽

pp. 671 ◽

Cited By ~ 4

Author(s):

Mozia ◽

Grylewicz ◽

Zgrzebnicki ◽

Darowna ◽

Czyżewski

Keyword(s):

Membrane Fouling ◽

Halloysite Nanotubes ◽

Positive Influence ◽

Inversion Method ◽

Fouling Resistance ◽

Force Microscopy ◽

Atomic Force ◽

Wet Phase Inversion ◽

And Performance ◽

Phase Inversion Method

Ultrafiltration (UF) polyethersulfone (PES) membranes were prepared by wet phase inversion method. Commercial halloysite nanotubes (HNTs) in the amount of 0.5–4 wt % vs PES (15 wt %) were introduced into the casting solution containing the polymer and N,N-dimethylformamide as a solvent. The morphology, physicochemical properties and performance of the membranes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), zeta potential, porosity and contact angle analyses, as well as permeability measurements. Moreover, the antifouling properties of the membranes were evaluated during UF of a model solution of bovine serum albumin (BSA). The research revealed a positive influence of modification with HNTs on hydrophilicity, water permeability and antifouling properties of the PES membranes. The most significant improvement of permeability was obtained in case of the membrane containing 2 wt % of HNTs, whereas the highest fouling resistance was observed for 0.5 wt % HNTs content. It was found that a good dispersion of HNTs can be obtained only at loadings below 2 wt %. Based on the results a relation between severity of membrane fouling and surface roughness was proved. Moreover, an increase of the roughness of the modified membranes was found to be accompanied by an increase of isoelectric point values.

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Etching Treatment Effect on Surface Morphology of Dental Structures

Revista de Chimie ◽

10.37358/rc.17.11.5958 ◽

2017 ◽

Vol 68 (11) ◽

pp. 2700-2703 ◽

Cited By ~ 2

Author(s):

Kamel Earar ◽

Vasile Iulian Antoniac ◽

Sorana Baciu ◽

Simion Bran ◽

Florin Onisor ◽

...

Keyword(s):

Electron Microscopy ◽

Surface Morphology ◽

Phosphoric Acid ◽

Human Teeth ◽

Strong Bond ◽

Force Microscopy ◽

Atomic Force ◽

Human Dentine ◽

Dental Surface ◽

Scanning Electron

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.

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