Research

11 pages, 2986 KiB

Open AccessFeature PaperArticle

Magnetic Properties of Collagen–Chitosan Hybrid Materials with Immobilized Superparamagnetic Iron Oxide Nanoparticles (SPIONs)

by Sylwia Fiejdasz, Adriana Gilarska, Tomasz Strączek, Maria Nowakowska and Czesław Kapusta

Materials 2021, 14(24), 7652; https://doi.org/10.3390/ma14247652 - 12 Dec 2021

Cited by 3 | Viewed by 2160

Abstract

The paper presents results of our studies on hybrid materials based on polymers of natural origin containing superparamagnetic iron oxide nanoparticles (SPIONs). Such nanoparticles, coated with the chitosan derivative, were immobilized in a chitosan-collagen hydrogel matrix by crosslinking with genipin. Three types of [...] Read more.

The paper presents results of our studies on hybrid materials based on polymers of natural origin containing superparamagnetic iron oxide nanoparticles (SPIONs). Such nanoparticles, coated with the chitosan derivative, were immobilized in a chitosan-collagen hydrogel matrix by crosslinking with genipin. Three types of biopolymer matrices of different collagen-to-chitosan ratios were studied. A thorough magnetic characterization was performed, including magnetic susceptibility, magnetization, and hysteresis loop measurements in a temperature range of 4 K to 300 K and a magnetic field induction up to 8 Tesla. The effect of SPION immobilization and material composition on the magnetic properties of the hybrids was investigated. The results showed that hybrid materials with covalently bounded SPIONs preserved the superparamagnetic character of SPIONs and exhibited promising magnetic properties, which are important for their potential applications. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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16 pages, 5115 KiB

Open AccessArticle

Raman Spectroscopy as a Novel Method for the Characterization of Polydioxanone Medical Stents Biodegradation

by Jan Loskot, Daniel Jezbera, Aleš Bezrouk, Rafael Doležal, Rudolf Andrýs, Vendula Francová, Dominik Miškář and Alena Myslivcová Fučíková

Materials 2021, 14(18), 5462; https://doi.org/10.3390/ma14185462 - 21 Sep 2021

Cited by 6 | Viewed by 2053

Abstract

Polydioxanone (PPDX), as an FDA approved polymer in tissue engineering, is an important component of some promising medical devices, e.g., biodegradable stents. The hydrolytic degradation of polydioxanone stents plays a key role in the safety and efficacy of treatment. A new fast and [...] Read more.

Polydioxanone (PPDX), as an FDA approved polymer in tissue engineering, is an important component of some promising medical devices, e.g., biodegradable stents. The hydrolytic degradation of polydioxanone stents plays a key role in the safety and efficacy of treatment. A new fast and convenient method to quantitatively evaluate the hydrolytic degradation of PPDX stent material was developed. PPDX esophageal stents were degraded in phosphate-buffered saline for 24 weeks. For the first time, the changes in Raman spectra during PPDX biodegradation have been investigated here. The level of PPDX hydrolytic degradation was determined from the Raman spectra by calculating the area under the 1732 cm⁻¹ peak shoulder. Raman spectroscopy, unlike Fourier transform infrared (FT-IR) spectroscopy, is also sensitive enough to monitor the decrease in the dye content in the stents during the degradation. Observation by a scanning electron microscope showed gradually growing cracks, eventually leading to the stent disintegration. The material crystallinity was increasing during the first 16 weeks, suggesting preferential degradation of the amorphous phase. Our results show a new easy and reliable way to evaluate the progression of PPDX hydrolytic degradation. The proposed approach can be useful for further studies on the behavior of PPDX materials, and for clinical practice. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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16 pages, 27091 KiB

Open AccessArticle

Hydrophobic UV-Curable Powder Clear Coatings: Study on the Synthesis of New Crosslinking Agents Based on Raw Materials Derived from Renewable Sources

by Dominika Czachor-Jadacka, Barbara Pilch-Pitera, Maciej Kisiel and Justyna Gumieniak

Materials 2021, 14(16), 4710; https://doi.org/10.3390/ma14164710 - 20 Aug 2021

Cited by 2 | Viewed by 2511

Abstract

Methods for the synthesis of urethane acrylates used as new crosslinking agents for hydrophobic UV-curable powder clear coatings were developed. In the synthesis of urethane acrylates, isophorone diisocyanate, glycerin, xylitol, polyethylene glycol and polysiloxane KF-6000, as well as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, [...] Read more.

Methods for the synthesis of urethane acrylates used as new crosslinking agents for hydrophobic UV-curable powder clear coatings were developed. In the synthesis of urethane acrylates, isophorone diisocyanate, glycerin, xylitol, polyethylene glycol and polysiloxane KF-6000, as well as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, were used. In order to increase the functionality of urethane acrylates, glycerin and xylitol derived from renewable sources were introduced. The chemical structure of the urethane acrylates was verified by IR spectroscopy. UV-curable powder clear coatings were obtained through a combination of urethane acrylates with unsaturated polyester resins. The thermal behavior and crosslinking density were examined using DMA. The obtained coatings were evaluated by performing the following tests: roughness, gloss, scratch resistance, hardness, adhesion to steel and water contact angle. As part of this research, high hydrophobicity and scratch resistance of UV-curable powder clear coatings were developed, which are a VOC-free and economically attractive alternative method for low thermal resistance surface protection, such as for composites, wood and wood-based materials. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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15 pages, 1426 KiB

Open AccessArticle

Polymer Brushes via Surface-Initiated Electrochemically Mediated ATRP: Role of a Sacrificial Initiator in Polymerization of Acrylates on Silicon Substrates

by Monika Flejszar, Paweł Chmielarz, Karol Wolski, Gabriela Grześ and Szczepan Zapotoczny

Materials 2020, 13(16), 3559; https://doi.org/10.3390/ma13163559 - 12 Aug 2020

Cited by 18 | Viewed by 3886

Abstract

Silicon wafers as semiconductors are essential components of integrated circuits in electronic devices. For this reason, modification of the silicon surface is an important factor in the manufacturing of new hybrid materials applied in micro- and nanoelectronics. Herein, copolymer brushes of hydrophilic poly(2-hydroxyethyl [...] Read more.

Silicon wafers as semiconductors are essential components of integrated circuits in electronic devices. For this reason, modification of the silicon surface is an important factor in the manufacturing of new hybrid materials applied in micro- and nanoelectronics. Herein, copolymer brushes of hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) and hydrophobic poly(tert-butyl acrylate) (PtBA) were grafted from silicon wafers via simplified electrochemically mediated atom transfer radical polymerization (seATRP) according to a surface-initiated approach. The syntheses of PHEA-b-PtBA copolymers were carried out with diminished catalytic complex concentration (successively 25 and 6 ppm of Cu). In order to optimize the reaction condition, the effect of the addition of a supporting electrolyte was investigated. A controlled increase in PHEA brush thickness was confirmed by atomic force microscopy (AFM). Various other parameters including contact angles and free surface energy (FSE) for the modified silicon wafer were presented. Furthermore, the effect of the presence of a sacrificial initiator in solution on the thickness of the grafted brushes was reported. Successfully fabricated inorganic–organic hybrid nanomaterials show potential application in biomedicine and microelectronics devices, e.g., biosensors. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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15 pages, 3989 KiB

Open AccessArticle

PEG Grafted Polymethacrylates Bearing Antioxidants as a New Class of Polymer Conjugates for Application in Cosmetology

by Justyna Odrobińska and Dorota Neugebauer

Materials 2020, 13(16), 3455; https://doi.org/10.3390/ma13163455 - 05 Aug 2020

Cited by 5 | Viewed by 2606

Abstract

The amphiphilic copolymers of poly(ethylene glycol) methyl ether methacrylate (MPEGMA) and alkyne functionalized 2-hydroxyethyl methacrylate (AlHEMA) were synthesized by controlled atom transfer radical polymerization (ATRP). The reactions were carried out using the standard ATRP initiator ethyl α-bromoisobutyrate, (EiBBr) and the “bio”initiator bromoester derivative [...] Read more.

The amphiphilic copolymers of poly(ethylene glycol) methyl ether methacrylate (MPEGMA) and alkyne functionalized 2-hydroxyethyl methacrylate (AlHEMA) were synthesized by controlled atom transfer radical polymerization (ATRP). The reactions were carried out using the standard ATRP initiator ethyl α-bromoisobutyrate, (EiBBr) and the “bio”initiator bromoester derivative of 4-n-butylresorcinol (4nBREBr₂). Two substances with antioxidant activity used in cosmetology, (±)-α-lipoic acid (LA) and ferulic acid (FA), were subjected to esterification reactions to introduce azide groups. The “click” reactions between the alkyne contained copolymers and functionalized acids (LA-N₃, FA-N₃) were performed to obtain polymer-antioxidant conjugates (P((HEMA-click-FA)-co-MPEGMA) and P((HEMA-click-LA)-co-MPEGMA)). The conjugation was performed with an efficiency of 20–75%. In vitro experiments in a phosphate buffer saline (PBS) solution at neutral conditions demonstrated that the sufficient release was reached after 2.5 h for FA and 1 h for LA. The rapid release kinetics as well as the polymer carriers, which were applied to regulate the delivery of antioxidant substances, are beneficial in cosmetology. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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15 pages, 2258 KiB

Open AccessArticle

Antimicrobial Activity of Hybrid Nanomaterials Based on Star and Linear Polymers of N,N′-Dimethylaminoethyl Methacrylate with In Situ Produced Silver Nanoparticles

by Paulina Teper, Anna Sotirova, Violeta Mitova, Natalia Oleszko-Torbus, Alicja Utrata-Wesołek, Neli Koseva, Agnieszka Kowalczuk and Barbara Mendrek

Materials 2020, 13(13), 3037; https://doi.org/10.3390/ma13133037 - 07 Jul 2020

Cited by 17 | Viewed by 2473

Abstract

Well-defined linear and multi-arm star polymer structures were used as the templates for in situ synthesis and stabilization of silver nanoparticles (AgNPs). This approach led to hybrid nanomaterials with high stability and antibacterial activity to both Gram-positive and Gram-negative bacterial strains. The ecologically [...] Read more.

Well-defined linear and multi-arm star polymer structures were used as the templates for in situ synthesis and stabilization of silver nanoparticles (AgNPs). This approach led to hybrid nanomaterials with high stability and antibacterial activity to both Gram-positive and Gram-negative bacterial strains. The ecologically friendly so called “green” synthesis of nanomaterials was performed through AgNPs preparation in the aqueous solutions of star and linear poly(N,N′-dimethylaminoethyl methacrylate)s (PDMAEMAs); the process was followed with time. The size, shape, and zeta potential of the obtained hybrids were determined. To our knowledge, this is the first time that the antibacterial activity of PDMAEMA hybrid nanomaterial against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa was investigated and assessed by minimum inhibitory concentration (MIC) and minimum biocidal concentration (MBC). Completely quaternized with ethyl bromide, star and linear PDMAEMAs were used in comparative biological tests. The modification of the polymers with in situ-formed AgNPs increased the antibacterial properties against all studied strains of bacteria by several times in comparison to non-modified polymers and quaternized polymers. These results yield novel nanohybrid materials that can be useful for applications in medicine and biology. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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16 pages, 3115 KiB

Open AccessArticle

Poly(2-oxazoline) Matrices with Temperature-Dependent Solubility—Interactions with Water and Use for Cell Culture

by Natalia Oleszko-Torbus, Marcelina Bochenek, Alicja Utrata-Wesołek, Agnieszka Kowalczuk, Andrzej Marcinkowski, Andrzej Dworak, Agnieszka Fus-Kujawa, Aleksander L. Sieroń and Wojciech Wałach

Materials 2020, 13(12), 2702; https://doi.org/10.3390/ma13122702 - 13 Jun 2020

Cited by 6 | Viewed by 1892

Abstract

In this work, we studied the stability of matrices with temperature-dependent solubility and their interactions with water at physiological temperature for their application in cell culture in vitro. Gradient copolymers of 2-isopropyl- with 2-n-propyl-2-oxazoline (P(iPrOx-nPrOx)) were used to prepare the matrices. The comonomer [...] Read more.

In this work, we studied the stability of matrices with temperature-dependent solubility and their interactions with water at physiological temperature for their application in cell culture in vitro. Gradient copolymers of 2-isopropyl- with 2-n-propyl-2-oxazoline (P(iPrOx-nPrOx)) were used to prepare the matrices. The comonomer ratio during polymerization was chosen such that the cloud point temperature (T_CP) of the copolymer was below 37 °C while the glass transition (T_g) was above 37 °C. The role of the support for matrices in the context of their stability in aqueous solution was examined. Therefore, matrices in the form of both self-supported bulk polymer materials (fibrillar mats and molds) and polymer films supported on the silica slides were examined. All of the matrices remained undissolved when incubated in water at a temperature above T_CP. For the self-supported mats and molds, we observed the loss of shape stability, but, in the case of films supported on silica slides, only slight changes in morphology were observed. For a more in-depth investigation of the origin of the shape deformation of self-supported matrices, we analyzed the wettability, thickness, and water uptake of films on silica support because the matrices remained undeformed under these conditions. It was found that, above the T_CP of P(iPrOx-nPrOx), the wettability of the films decreased, but at the same time the films absorbed water and swelled. We examined how this specific behavior of the supported films influenced the culture of fibroblasts. The temperature-dependent solubility of the matrices and the possibility of noninvasive cell separation were also examined. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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17 pages, 3170 KiB

Open AccessArticle

Pioglitazone-Loaded Nanostructured Hybrid Material for Skin Ulcer Treatment

by Agnieszka Rojewska, Anna Karewicz, Karolina Karnas, Karol Wolski, Mateusz Zając, Kamil Kamiński, Krzysztof Szczubiałka, Szczepan Zapotoczny and Maria Nowakowska

Materials 2020, 13(9), 2050; https://doi.org/10.3390/ma13092050 - 28 Apr 2020

Cited by 11 | Viewed by 3375

Abstract

Pioglitazone, a popular antidiabetic drug, which was recently shown to be effective in the treatment of skin ulcers, was successfully encapsulated in polysaccharide nanoparticles and used as a bioactive component of the wound-dressing material based on modified bacterial nanocellulose. Alginate and hydroxypropyl cellulose [...] Read more.

Pioglitazone, a popular antidiabetic drug, which was recently shown to be effective in the treatment of skin ulcers, was successfully encapsulated in polysaccharide nanoparticles and used as a bioactive component of the wound-dressing material based on modified bacterial nanocellulose. Alginate and hydroxypropyl cellulose were used as a matrix for the nanoparticulate drug-delivery system. The matrix composition and particles’ size, as well as drug encapsulation efficiency and loading, were optimized. Pioglitazone hydrochloride (PIO) loaded particles were coated with chitosan introduced into the crosslinking medium, and covalently attached to the surface of bacterial nanocellulose functionalized with carboxyl groups. PIO was released from the surface of the hybrid material in a controlled manner for 5 days. Preliminary cytotoxicity studies confirmed safety of the system at PIO concentrations as high as 20 mg/mL. The obtained hybrid system may have potential application in the treatment of skin ulcers e.g., in diabetic foot. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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15 pages, 2159 KiB

Open AccessFeature PaperArticle

Hydrophobically Coated Superparamagnetic Iron Oxides Nanoparticles Incorporated into Polymer-Based Nanocapsules Dispersed in Water

by Elżbieta Gumieniczek-Chłopek, Joanna Odrobińska, Tomasz Strączek, Agnieszka Radziszewska, Szczepan Zapotoczny and Czesław Kapusta

Materials 2020, 13(5), 1219; https://doi.org/10.3390/ma13051219 - 09 Mar 2020

Cited by 5 | Viewed by 2582

Abstract

This paper reports the characterization of iron oxide magnetic nanoparticles obtained via the thermal decomposition of an organometallic precursor, which were then loaded into nanocapsules prepared via the emulsification process in the presence of an amphiphilic derivative of chitosan. The applied synthetic method [...] Read more.

This paper reports the characterization of iron oxide magnetic nanoparticles obtained via the thermal decomposition of an organometallic precursor, which were then loaded into nanocapsules prepared via the emulsification process in the presence of an amphiphilic derivative of chitosan. The applied synthetic method led to the formation of a hydrophobic layer on the surface of nanoparticles that enabled their loading in the hydrophobic liquid inside of the polymer-based capsules. The average diameter of nanoparticles was determined to be equal to 15 nm, and they were thoroughly characterized using X-ray diffraction (XRD), magnetometry, and Mössbauer spectroscopy. A core–shell structure consisting of a wüstite core and maghemite-like shell was revealed, resulting in an exchange bias effect and a considerable magnetocrystalline anisotropy at low temperatures and a superparamagnetic behavior at room temperature. Importantly, superparamagnetic behavior was observed for the aqueous dispersion of the nanocapsules loaded with the superparamagnetic nanoparticles, and the dispersion was shown to be very stable (at least 48 weeks). The results were analyzed and discussed with respect to the potential future applications of these nanoparticles and nanocapsules based on biopolymers as platforms designed for the magnetically navigated transport of encapsulated hydrophobic substances. Full article

(This article belongs to the Special Issue Functional Polymeric Materials for Biomedical and Environmental Applications)

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