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1.
Sci Technol Adv Mater ; 25(1): 2338786, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38680949

RESUMO

Electrochemical grafting of organic molecules to metal surfaces has been well-known as an efficient tool enabling tailored modification of surface at the nanoscale. Among many compounds with the ability to undergo the process of electrografting, iodonium salts belong to less frequently used, especially when compared with the most popular diazonium salts. Meanwhile, due to their increased stability, iodonium salts may be used in situations where the use of diazonium salts is constrained. The aim of this study was to examine the effect of the electrochemical reduction of iodonium salts on the physicochemical properties of Pt electrodes, and the possibility to form pro-adhesive layers facilitating further functionalization purposes. Consequently, we have selected four commercially available iodonium salts (diphenyliodonium chloride, bis(4-tertbutylphenyl)iodonium hexafluorophosphate, (4-nitrophenyl)(2,4,6-trimethylphenyl)iodonium triflate, bis(4-methylphenyl)iodonium hexafluorophosphate), and attached them to the surface of Pt electrodes by means of an electrochemical reduction process. As-formed layers were then extensively characterized in terms of wettability, roughness and charge transfer properties, and used as pro-adhesive coatings prior to the deposition of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS. Due to the increase in hydrophilicity and roughness, modified electrodes increased the stability of PEDOT:PSS coating while maintaining its high capacitance.


Adhesion and charge transfer between PEDOT:PSS and the surface of the electrode are significantly improved by a simple electrode modification strategy using the electrochemical grafting of commercially available iodonium salts.

2.
Sci Rep ; 13(1): 18365, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884622

RESUMO

The design of biomaterials able to facilitate cell adhesion is critical in the field of tissue engineering. Precise control of surface chemistry at the material/tissue interface plays a major role in enhancing the interactions between a biomaterial and living cells. Bio-integration is particularly important in case of various electrotherapies, since a close contact between tissue and electrode's surface facilitates treatment. A promising approach towards surface biofunctionalization involves the electrografting of diazonium salts followed by the modification of organic layer with pro-adhesive polypeptides. This study focuses on the modification of platinum electrodes with a 4-nitrobenzenediazonium layer, which is then converted to the aminobenzene moiety. The electrodes are further biofunctionalized with polypeptides (polylysine and polylysine/laminin) to enhance cell adhesion. This study also explores the differences between physical and chemical coupling of selected polypeptides to modulate pro-adhesive nature of Pt electrodes with respect to human neuroblastoma SH-SY5Y cells and U87 astrocytes. Our results demonstrate the significant enhancement in cell adhesion for biofunctionalized electrodes, with more amplified adhesion noted for covalently coupled polypeptides. The implications of this research are crucial for the development of more effective and functional biomaterials, particularly biomedical electrodes, which have the potential to advance the field of bioelectronics and improve patients' outcomes.


Assuntos
Neuroblastoma , Polilisina , Humanos , Adesivos , Materiais Biocompatíveis , Peptídeos , Adesão Celular , Propriedades de Superfície
3.
Int J Mol Sci ; 24(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37686012

RESUMO

The deterioration of the performance of polysaccharide-based films over time, particularly their hydrophilicity and mechanical properties, is one of the main problems limiting their applications in the packaging industry. In the present study, we proposed to improve the performance of chitosan-based films through the use of: (1) nanocellulose as an additive to reduce their hydrophilic nature; (2) bio-based plasticizer to improve their mechanical properties; and (3) chestnut extract as an antimicrobial agent. To evaluate their stability over time, the properties of as-formed films (mechanical, hydrophilic, barrier and antibacterial) were studied immediately after preparation and after 7, 14 and 30 days. In addition, the morphological properties of the films were characterized by scanning electron microscopy, their structure by FTIR, their transparency by UV-Vis and their thermal properties by TGA. The films showed a hydrophobic character (contact angle above 100°), barrier properties to oxygen and carbon dioxide and strong antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Moreover, the use of nanofillers did not deteriorate the elongation at breaks or the thermal properties of the films, but their addition reduced the transparency. In addition, the results showed that the greatest change in film properties occurred within the first 7 days after sample preparation, after which the properties were found to stabilize.


Assuntos
Quitosana , Nanocompostos , Nanofibras , Plastificantes , Celulose , Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacologia
4.
ACS Appl Mater Interfaces ; 15(39): 45701-45712, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37737728

RESUMO

Electrical stimulation has been used successfully for several decades for the treatment of neurodegenerative disorders, including motor disorders, pain, and psychiatric disorders. These technologies typically rely on the modulation of neural activity through the focused delivery of electrical pulses. Recent research, however, has shown that electrically triggered neuromodulation can be further enhanced when coupled with optical stimulation, an approach that can benefit from the development of novel electrode materials that combine transparency with excellent electrochemical and biological performance. In this study, we describe an electrochemically modified, nanostructured indium tin oxide/poly(ethylene terephthalate) (ITO/PET) surface as a flexible, transparent, and cytocompatible electrode material. Electrochemical oxidation and reduction of ITO/PET electrodes in the presence of an ionic liquid based on d-glucopyranoside and bistriflamide units were performed, and the electrochemical behavior, conductivity, capacitance, charge transport processes, surface morphology, optical properties, and cytocompatibility were assessed in vitro. It has been shown that under selected conditions, electrochemically modified ITO/PET films remained transparent and highly conductive and were able to enhance neural cell survival and neurite outgrowth. Consequently, electrochemical modification of ITO/PET electrodes in the presence of an ionic liquid is introduced as an effective approach for tailoring the properties of ITO for advanced bio-optoelectronic applications.


Assuntos
Líquidos Iônicos , Nanoestruturas , Humanos , Oxirredução , Compostos de Estanho/química
5.
Sci Rep ; 13(1): 13049, 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37567895

RESUMO

The excess presence of phosphate(V) ions in the biosphere is one of the most serious problems that negatively affect aqueous biocenosis. Thus, phosphates(V) separation is considered to be important for sustainable development. In the presented study, an original cerium(IV)-modified chitosan-based hydrogel (Ce-CTS) was developed using the chemical co-precipitation method and then used as an adsorbent for efficient removal of phosphate(V) ions from their aqueous solutions. From the scientific point of view, it represents a completely new physicochemical system. It was found that the adsorptive removal of phosphate(V) anions by the Ce-CTS adsorbent exceeded 98% efficiency which is ca. 4-times higher compared with the chitosan-based hydrogel without any modification (non-cross-linked CTS). The best result of the adsorption capacity of phosphates(V) on the Ce-CTS adsorbent, equal to 71.6 mg/g, was a result of adsorption from a solution with an initial phosphate(V) concentration 9.76 mg/dm3 and pH 7, an adsorbent dose of 1 g/dm3, temperature 20 °C. The equilibrium interphase distribution data for the Ce-CTS adsorbent and aqueous solution of phosphates(V) agreed with the theoretical Redlich-Peterson and Hill adsorption isotherm models. From the kinetic point of view, the pseudo-second-order model explained the phosphates(V) adsorption rate for Ce-CTS adsorbent the best. The specific effect of porous structure of adsorbent influencing the diffusional mass transfer resistances was identified using Weber-Morris kinetic model. The thermodynamic study showed that the process was exothermic and the adsorption ran spontaneously. Modification of CTS with cerium(IV) resulted in the significant enhancement of the chitosan properties towards both physical adsorption (an increase of the point of zero charge of adsorbent), and chemical adsorption (through the presence of Ce(IV) that demonstrates a chemical affinity for phosphate(V) anions). The elaborated and experimentally verified highly effective adsorbent can be successfully applied to uptake phosphates(V) from aqueous systems. The Ce-CTS adsorbent is stable in the conditions of the adsorption process, no changes in the adsorbent structure or leaching of the inorganic filling were observed.

6.
Sci Rep ; 13(1): 11530, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460643

RESUMO

Due to the growing demand for robust and environmentally friendly antimicrobial packaging materials, biopolymers have recently become extensively investigated. Although biodegradable biopolymers usually lack mechanical properties, which makes it inevitable to blend them with plasticizers. The purpose of this study was to investigate plasticization efficiency of bio-based plasticizers introduced into sodium alginate compositions containing chestnut extract and their effect on selected film properties, including primarily mechanical and antibacterial properties. The films were prepared by the casting method and sodium alginate was cross-linked with calcium chloride. Six different plasticizers, including three commercially available ones (glycerol, epoxidized soybean oil and palm oil) and three synthesized plasticizers that are mixtures of bio-based plasticizers, were used to compare their influence on the film properties. Interactions between the polymer matrix and the plasticizers were investigated using Fourier transform infrared spectroscopy. The morphological characteristics of the films were characterized by scanning electron microscopy. Thermal properties, tensile strength, elongation at break, hydrophilic, and barrier properties of the obtained films were also determined. To confirm the obtaining of active films through the use of chestnut extract and to study the effect of the proposed plasticizers on the antibacterial activity of the extract, the obtained films were tested against bacteria cultures. The final results showed that all of the obtained films exhibit a hydrophilic character and high barrier effect to oxygen, carbon dioxide and water vapor. In addition, sodium alginate films prepared with chestnut extract and the plasticizer proposed by us, showed better mechanical and antimicrobial properties than the films obtained with chestnut extract and the commercially available plasticizers.


Assuntos
Anti-Infecciosos , Plastificantes , Plastificantes/química , Alginatos/química , Polímeros , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Resistência à Tração
7.
Bioelectrochemistry ; 153: 108484, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37302335

RESUMO

The continuous progression in the field of electrotherapies implies the development of multifunctional materials exhibiting excellent electrochemical performance and biocompatibility, promoting cell adhesion, and possessing antibacterial properties. Since the conditions favouring the adhesion of mammalian cells are similar to conditions favouring the adhesion of bacterial cells, it is necessary to engineer the surface to exhibit selective toxicity, i.e., to kill or inhibit the growth of bacteria without damaging mammalian tissues. The aim of this paper is to introduce a surface modification approach based on a subsequent deposition of silver and gold particles on the surface of a conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT). The resulting PEDOT-Au/Ag surface is found to possess optimal wettability, roughness, and surface features making it an excellent platform for cell adhesion. By depositing Ag particles on PEDOT surface decorated with Au particles, it is possible to reduce toxic effects of Ag particles, while maintaining their antibacterial activity. Besides, electroactive and capacitive properties of PEDOT-Au/Ag account for its applicability in various electroceutical therapies.


Assuntos
Ouro , Prata , Animais , Prata/farmacologia , Prata/química , Ouro/química , Polímeros/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Antibacterianos/farmacologia , Mamíferos
8.
Bioelectrochemistry ; 152: 108465, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37207477

RESUMO

The ability to study and regulate cell behavior at a biomaterial interface requires a strict control over its surface chemistry. Significance of studying cell adhesion in vitro and in vivo has become increasingly important, particularly in the field of tissue engineering and regenerative medicine. A promising surface modification route assumes using organic layers prepared by the method of electrografting of diazonium salts and their further functionalization with biologically active molecules as cell adhesion promoters. This work reports the modification of platinum electrodes with selected diazonium salts and poly-L-lysine to increase the number of sites available for cell adhesion. As-modified electrodes were characterized in terms of their chemical and morphological properties, as well as wettability. In order to monitor the process of cell attachment, biofunctionalized electrodes were used as substrates for culturing human neuroblastoma SH-SY5Y cells. The experiments revealed that cell adhesion is favored on the surface of diazonium-modified and poly-L-lysine coated electrodes, indicating proposed modification route as a valuable strategy enhancing the integration between bioelectronic devices and neural cells.


Assuntos
Neuroblastoma , Polilisina , Humanos , Adesão Celular , Propriedades de Superfície , Sais , Eletrodos
9.
Membranes (Basel) ; 13(4)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37103811

RESUMO

Recent years have shown a growing interest in the application of membranes exhibiting magnetic properties in various separation processes. The aim of this review is to provide an in-depth overview of magnetic membranes that can be successfully applied for gas separation, pervaporation, ultrafiltration, nanofiltration, adsorption, electrodialysis, and reverse osmosis. Based on the comparison of the efficiency of these separation processes using magnetic and non-magnetic membranes, it has been shown that magnetic particles used as fillers in polymer composite membranes can significantly improve the efficiency of separation of both gaseous and liquid mixtures. This observed separation enhancement is due to the variation of magnetic susceptibility of different molecules and distinct interactions with dispersed magnetic fillers. For gas separation, the most effective magnetic membrane consists of polyimide filled with MQFP-B particles, for which the separation factor (αrat O2/N2) increased by 211% when compared to the non-magnetic membrane. The same MQFP powder used as a filler in alginate membranes significantly improves water/ethanol separation via pervaporation, reaching a separation factor of 12,271.0. For other separation methods, poly(ethersulfone) nanofiltration membranes filled with ZnFe2O4@SiO2 demonstrated a more than four times increase in water flux when compared to the non-magnetic membranes for water desalination. The information gathered in this article can be used to further improve the separation efficiency of individual processes and to expand the application of magnetic membranes to other branches of industry. Furthermore, this review also highlights the need for further development and theoretical explanation of the role of magnetic forces in separation processes, as well as the potential for extending the concept of magnetic channels to other separation methods, such as pervaporation and ultrafiltration. This article provides valuable insights into the application of magnetic membranes and lays the groundwork for future research and development in this area.

10.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36674709

RESUMO

Vascular regeneration is a complex process, additionally limited by the low regeneration potential of blood vessels. Hence, current research is focused on the design of artificial materials that combine biocompatibility with a certain rate of biodegradability and mechanical robustness. In this paper, we have introduced a scaffold material made of poly(L-lactide-co-glycolide)/poly(isosorbide sebacate) (PLGA/PISEB) fibers fabricated in the course of an electrospinning process, and confirmed its biocompatibility towards human umbilical vein endothelial cells (HUVEC). The resulting material was characterized by a bimodal distribution of fiber diameters, with the median of 1.25 µm and 4.75 µm. Genotyping of HUVEC cells collected after 48 h of incubations on the surface of PLGA/PISEB scaffolds showed a potentially pro-angiogenic expression profile, as well as anti-inflammatory effects of this material. Over the course of a 12-week-long hydrolytic degradation process, PLGA/PISEB fibers were found to swell and disintegrate, resulting in the formation of highly developed structures resembling seaweeds. It is expected that the change in the scaffold structure should have a positive effect on blood vessel regeneration, by allowing cells to penetrate the scaffold and grow within a 3D structure of PLGA/PISEB, as well as stabilizing newly-formed endothelium during hydrolytic expansion.


Assuntos
Células Endoteliais , Alicerces Teciduais , Humanos , Alicerces Teciduais/química , Engenharia Tecidual/métodos
11.
Carbohydr Polym ; 301(Pt A): 120277, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36436848

RESUMO

Chitosan-based films modified with synthesized (propylene glycol monoacetate, propylene glycol esters of fatty acids, and epoxidized propylene glycol esters) and commercial eco-friendly plasticizers (epoxidized soybean oil and epoxidized palm oil) were prepared by a casting technique, with the aim to obtain environmentally friendly materials for packaging applications. To assess the applicability of alternative plasticizers, their properties were compared to the two most common plasticizers, i.e. glycerol and sorbitol. The chemical structure of newly synthesized plasticizers was verified by gas chromatography with mass detector, infrared spectroscopy and 1H NMR; and their acid, epoxy, iodine, and saponification values were determined. Plasticized chitosan-based films were characterized in terms of hydrophilic, barrier, thermal, mechanical properties, zeta potential and morphology, confirming their flexibility and homogeneity. The research confirmed that the alternative plasticizers introduced by us are more effective than commercially available ones, exhibiting lower hydrophilicity and superior mechanical properties compared to samples plasticized with traditional plasticizers. Moreover, these properties were found to be even better after ageing for 10 months.


Assuntos
Quitosana , Plastificantes , Plastificantes/química , Quitosana/química , Glicerol/química , Ésteres , Propilenoglicóis
12.
Materials (Basel) ; 14(24)2021 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-34947261

RESUMO

The process of ethanol dehydration via pervaporation was performed using alginate membranes filled with manganese dioxide and a mixed filler consisting of manganese dioxide on magnetite core MnO2@Fe3O4 particles. The crystallization of manganese dioxide on magnetite nanoparticle surface resulted in a better dispersibility of this mixed filler in polymer matrix, with the preservation of the magnetic properties of magnetite. The prepared membranes were characterized by contact angle, degree of swelling and SEM microscopy measurements and correlated with their effectiveness in the pervaporative dehydration of ethanol. The results show a strong relation between filler properties and separation efficiency. The membranes filled with the mixed filler outperformed the membranes containing only neat oxide, exhibiting both higher flux and separation factor. The performance changed depending on filler content; thus, the presence of optimum filler loading was observed for the studied membranes. The best results were obtained for the alginate membrane filled with 7 wt.% of mixed filler MnO2@Fe3O4 particles. For this membrane, the separation factor and flux equalled to 483 and 1.22 kg·m-2·h-1, respectively.

13.
Materials (Basel) ; 14(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34640049

RESUMO

An excess concentration of boron in irrigation and drinking water can negatively affect the yield of plants and the human nervous system, respectively. To meet the recommended levels, hybrid biosorbent hydrogel beads based on chitosan and manganese (II-IV) were employed for the removal of boron from aqueous media. The results showed that the biosorbent effectively removed boric acid from the aqueous medium at neutral pH over a sorption time of 2 h and the liquid/hydrogel ratio of 20 mL/g, achieving a maximum sorption capacity near 190 mg/g. The modeling of the sorption equilibrium data indicated that the Freundlich isotherm equation gave the best fit out of the isotherm models examined. A pseudo-second-order model was found to best describe the sorption kinetics. The favorable attachment of manganese to the chitosan structure enabled the sorption of boron and was confirmed by FTIR, RS, XRD, SEM and ICP-OES methods. Boron desorption from the spent biosorbent was successfully achieved in three cycles using a NaOH solution. In general, the results of this research indicate that this method is one of the possibilities for improving water quality and may contribute to reducing pollution of the aquatic environment.

14.
Materials (Basel) ; 14(4)2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578880

RESUMO

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.

15.
Materials (Basel) ; 13(18)2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32961950

RESUMO

Hybrid poly(vinyl alcohol) and alginate membranes were investigated in the process of ethanol dehydration by pervaporation. As a filler, three types of particles containing iron element, i.e., hematite, magnetite, and iron(III) acetyloacetonate were used. The parameters describing transport properties and effectiveness of investigated membranes were evaluated. Additionally, the physico-chemical properties of the resulting membranes were studied. The influence of polymer matrix, choice of iron particles and their content in terms of effectiveness of membranes in the process of ethanol dehydration were considered. The results showed that hybrid alginate membranes were characterized by a better separation factor, while poly(vinyl alcohol) membranes by a better flux. The best parameters were obtained for membranes filled with 7 wt% of iron(III) acetyloacetonate. The separation factor and pervaporative separation index were equal to 19.69 and 15,998 g⋅m-2⋅h-1 for alginate membrane and 11.75 and 14,878 g⋅m-2⋅h-1 for poly(vinyl alcohol) membrane, respectively.

16.
Bioelectrochemistry ; 134: 107528, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32294615

RESUMO

Neuroinflammation is often associated with poor functional recovery and may contribute to or initiate the development of severe neurological disorders, such as epilepsy, Parkinson's disease or Alzheimer's disease. Ibuprofen (IBU), being one of the most commonly used non-steroidal anti-inflammatory drugs, is known to possess neuroprotective activity and serve as a promising therapeutic for the treatment of neuroinflammation. In this study, the potential of an IBU-loaded poly(3,4-ethylenedioxypyrrole) (PEDOP) matrix has been assessed as a neural interface material with an aim to control astrocyte activation and suppress neuroinflammation in vitro. Three types of drug immobilization protocols were investigated, leading to the fabrication of IBU-loaded PEDOP matrices exhibiting a broad spectrum of electrical characteristics, drug release profiles, as well as biological responses. Among all investigated PEDOP formulations, PEDOP matrices formed through a three-step immobilization protocol exhibited the highest charge storage capacity (30 ± 1 mC/cm2) as well as a double layer capacitance of 645.0 ± 51.1 µF, associated with a relatively enlarged surface area. Demonstrating a total drug loading capacity of 150 µg/ml and a release rate constant of 0.15 1/h, this coating formulation may be employed as a safe electrical conducting drug eluting system.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Ibuprofeno/química , Ibuprofeno/farmacologia , Pirróis/química , Composição de Medicamentos , Liberação Controlada de Fármacos
17.
Biomed Mater ; 13(5): 054102, 2018 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-29633721

RESUMO

Electrically conducting polymer formulations have emerged as promising approaches for the development of interfaces and scaffolds in neural engineering, facilitating the development of physicochemically modified constructs capable of cell stimulation through electrical and ionic charge transfer. In particular, topographically functionalized or neuromorphic materials are able to guide the growth of axons and promote enhanced interfacing with neuroelectrodes in vitro. In this study, we present a novel method for the formation of conducting polymer/gold assemblies via a combinational sputter and spin coating technique. The resulting multilayered PEDOT/Au substrates possessed enhanced electrochemical properties as a function of the number of deposited organic/inorganic layers. It was observed that through subsequent electrochemical conditioning it was possible to form neuromorphic fractal-like assemblies of gold particles, which significantly impacted on the electrochemical characteristics of the PEDOT/Au films. PEDOT/Au assemblies were observed to possess unique topographical features, advantageous charge storage capacity (34.9 ± 2.6 mC cm-2) and low electrical impedance (30 ± 2 Ω at 1 kHz). Furthermore, PEDOT/Au assemblies were observed to facilitate the outgrowth of neurites in a mixed ventral mesencephalon cell population and promotean increase in the neurons/astrocytes ratio relative to all experimental groups, indicating PEDOT/Au biomimetic neuromorphic assemblies as promising materials in engineering electrically conductive neural interface systems.


Assuntos
Materiais Biomiméticos/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Materiais Revestidos Biocompatíveis/química , Ouro/química , Neuritos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Polímeros/química , Animais , Eletroquímica , Fractais , Nanopartículas Metálicas/química , Microscopia Eletrônica de Varredura , Neuritos/fisiologia , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície
18.
Chem Zvesti ; 72(5): 1095-1105, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29681683

RESUMO

Chitosan-based membranes filled with different metal oxide particles were prepared and their performance in ethanol dehydration process depending on the type of oxide and loading was discussed. For membrane preparation three oxides: TiO2, Cr2O3 or Fe3O4 were selected. From experimental data suitable ethanol and water transport coefficients were evaluated. As shown in the results, applied fillers in different ways affect the separation properties. Presence of TiO2 significantly affects the normalized total flux, increasing its value. On the other hand, addition of Fe3O4 influences most of all the separation factor, which is the among all investigated membranes. For membranes containing chromium(III) oxide as a filler, improvement in the separation properties is observed only in the case when the Cr2O3 content equals to 5 wt%. Above this concentration significant deterioration of separation properties is observed. The best performance has mixed-matrix membranes (MMMs) with magnetite, where the values of PSI are equal to 16.3 and 296.8 kg/m-2 h µm for pristine and 15 wt% filler content, respectively.

19.
RSC Adv ; 8(69): 39567-39578, 2018 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-35558028

RESUMO

A new type of composite alginate membranes filled with chitosan (CS) and three different modified chitosan submicron particles, i.e. phosphorylated (CS-P), glycidol (CS-G) or glutaraldehyde (CS-GA) crosslinked ones, were prepared, and the pervaporation of water/ethanol mixture was investigated. The influence of various chitosan particles and their content on the transport properties of membranes was discussed. It was found that the addition of chitosan particles into the alginate matrix has a prominent effect on the ethanol/water separation efficiency. All tested membranes are characterized simultaneously by a high flux and selectivity, exhibiting advantageous properties, and outperforming numerous conventional materials. The best results were achieved for alginate membranes filled with phosphorylated chitosan particles at 10 wt%, for which separation factor, flux and PSI were equal to 136.2, 1.90 kg m-2 h-1 and 256.9 kg m-2 h-1, respectively.

20.
Mater Sci Eng C Mater Biol Appl ; 73: 611-615, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28183652

RESUMO

Chemotherapy is one of the most commonly used cancer treatments. Even so, it has significant adverse effects on healthy tissues. These effects can be avoided through the use of regional chemotherapy, an approach based on delivering the anti-cancer agents locally, to the site of cancer tissue accumulation. Among the different classes of biomaterials that are used as drug carriers, conducting polymers allow reversible, electrostatic immobilization and controlled release of a variety of compounds. In this work, we describe a method for producing surfaces possessing anti-cancer activity, which are a potential tool for regional chemotherapy. Our method consists of covering the surface with a conducting polymer matrix, followed by loading that matrix with cytotoxic compounds. We have chosen betulin as the model compound for this study, as it is commonly available triterpene that exhibits cytotoxicity against a variety of tumor cell lines. The presence of betulin in the polymer matrix is confirmed by SEM, EDS and IR spectroscopy. The release of betulin is carried out using two protocols, i.e. passive mode (open circuit conditions) or active (application of constant potential) mode. The biological activity of betulin that was released from the matrix is confirmed by its toxic effect against KB and MCF-7 cancer cell lines (IC50 values of 13.34±0.88µg/mL and 12.57±1.81µg/mL for KB and MCF-7, respectively). The described method of surface modification is shown to be an effective mean of producing surfaces that possess anti-cancer activity, serving as advantageous materials for regional chemotherapy applications.


Assuntos
Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Polímeros/química , Triterpenos/farmacologia , Morte Celular/efeitos dos fármacos , Eletroquímica , Humanos , Células KB , Células MCF-7 , Polimerização , Espectrometria por Raios X , Espectrofotometria Infravermelho
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