Research

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13 pages, 4055 KiB

Open AccessArticle

Concerning Synthesis of New Biobased Polycarbonates with Curcumin in Replacement of Bisphenol A and Recycled Diphenyl Carbonate as Example of Circular Economy

by Vincenzo De Leo, Michele Casiello, Giuseppe Deluca, Pietro Cotugno, Lucia Catucci, Angelo Nacci, Caterina Fusco and Lucia D’Accolti

Polymers 2021, 13(3), 361; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13030361 - 23 Jan 2021

Cited by 8 | Viewed by 4537

Abstract

Curcumin (CM) is a natural polyphenol well-known for its antioxidant and pharmaceutical properties, that can represent a renewable alternative to bisphenol A (BPA) for the synthesis of bio-based polycarbonates (PC). In the presented strategy, preparation of the CM-based PC was coupled with chemical [...] Read more.

Curcumin (CM) is a natural polyphenol well-known for its antioxidant and pharmaceutical properties, that can represent a renewable alternative to bisphenol A (BPA) for the synthesis of bio-based polycarbonates (PC). In the presented strategy, preparation of the CM-based PC was coupled with chemical recycling of the fossil-based BPA polycarbonate (BPA-PC) conducting a two-steps trans-polymerization that replaces BPA monomer with CM or its tetrahydrogenated colorless product (THCM). In the first step of synthetic strategy, depolymerization of commercial BPA-PC was carried out with phenol as nucleophile, according to our previous procedure based on zinc derivatives and ionic liquids as catalysts, thus producing quantitatively diphenyl carbonate (DPC) e BPA. In the second step, DPC underwent a melt transesterification with CM or THCM monomers affording the corresponding bio-based polycarbonates, CM-PC and THCM-PC, respectively. THCM was prepared by reducing natural bis-phenol with cyclohexene as a hydrogen donor and characterized by ¹H-NMR and MS techniques. Polymerization reactions were monitored by infrared spectroscopy and average molecular weights and dispersity of the two biobased polymers THCM-PC and CM-PC were determined by means of gel permeation chromatography (GPC). Optical properties of the prepared polymers were also measured. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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16 pages, 6866 KiB

Open AccessFeature PaperArticle

Nanocellulose/Fullerene Hybrid Films Assembled at the Air/Water Interface as Promising Functional Materials for Photo-electrocatalysis

by Francesco Milano, Maria Rachele Guascito, Paola Semeraro, Shadi Sawalha, Tatiana Da Ros, Alessandra Operamolla, Livia Giotta, Maurizio Prato and Ludovico Valli

Polymers 2021, 13(2), 243; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13020243 - 12 Jan 2021

Cited by 6 | Viewed by 2538

Abstract

Cellulose nanomaterials have been widely investigated in the last decade, unveiling attractive properties for emerging applications. The ability of sulfated cellulose nanocrystals (CNCs) to guide the supramolecular organization of amphiphilic fullerene derivatives at the air/water interface has been recently highlighted. Here, we further [...] Read more.

Cellulose nanomaterials have been widely investigated in the last decade, unveiling attractive properties for emerging applications. The ability of sulfated cellulose nanocrystals (CNCs) to guide the supramolecular organization of amphiphilic fullerene derivatives at the air/water interface has been recently highlighted. Here, we further investigated the assembly of Langmuir hybrid films that are based on the electrostatic interaction between cationic fulleropyrrolidines deposited at the air/water interface and anionic CNCs dispersed in the subphase, assessing the influence of additional negatively charged species that are dissolved in the water phase. By means of isotherm acquisition and spectroscopic measurements, we demonstrated that a tetra-sulfonated porphyrin, which was introduced in the subphase as anionic competitor, strongly inhibited the binding of CNCs to the floating fullerene layer. Nevertheless, despite the strong inhibition by anionic molecules, the mutual interaction between fulleropyrrolidines at the interface and the CNCs led to the assembly of robust hybrid films, which could be efficiently transferred onto solid substrates. Interestingly, ITO-electrodes that were modified with five-layer hybrid films exhibited enhanced electrical capacitance and produced anodic photocurrents at 0.4 V vs Ag/AgCl, whose intensity (230 nA/cm²) proved to be four times higher than the one that was observed with the sole fullerene derivative (60 nA/cm²). Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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17 pages, 3355 KiB

Open AccessArticle

A 3D Printed Composite Scaffold Loaded with Clodronate to Regenerate Osteoporotic Bone: In Vitro Characterization

by Stefania Cometa, Maria Addolorata Bonifacio, Elisabetta Tranquillo, Antonio Gloria, Marco Domingos and Elvira De Giglio

Polymers 2021, 13(1), 150; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13010150 - 01 Jan 2021

Cited by 9 | Viewed by 3105

Abstract

Additive manufacturing (AM) is changing our current approach to the clinical treatment of bone diseases, providing new opportunities to fabricate customized, complex 3D structures with bioactive materials. Among several AM techniques, the BioCell Printing is an advanced, integrated system for material manufacture, sterilization, [...] Read more.

Additive manufacturing (AM) is changing our current approach to the clinical treatment of bone diseases, providing new opportunities to fabricate customized, complex 3D structures with bioactive materials. Among several AM techniques, the BioCell Printing is an advanced, integrated system for material manufacture, sterilization, direct cell seeding and growth, which allows for the production of high-resolution micro-architectures. This work proposes the use of the BioCell Printing to fabricate polymer-based scaffolds reinforced with ceramics and loaded with bisphosphonates for the treatment of osteoporotic bone fractures. In particular, biodegradable poly(ε-caprolactone) was blended with hydroxyapatite particles and clodronate, a bisphosphonate with known efficacy against several bone diseases. The scaffolds’ morphology was investigated by means of Scanning Electron Microscopy (SEM) and micro-Computed Tomography (micro-CT) while Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Photoelectron Spectroscopy (XPS) revealed the scaffolds’ elemental composition. A thermal characterization of the composites was accomplished by Thermogravimetric analyses (TGA). The mechanical performance of printed scaffolds was investigated under static compression and compared against that of native human bone. The designed 3D scaffolds promoted the attachment and proliferation of human MSCs. In addition, the presence of clodronate supported cell differentiation, as demonstrated by the normalized alkaline phosphatase activity. The obtained results show that the BioCell Printing can easily be employed to generate 3D constructs with pre-defined internal/external shapes capable of acting as a temporary physical template for regeneration of cancellous bone tissues. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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18 pages, 3177 KiB

Open AccessArticle

An In-Silico Pipeline for Rapid Screening of DNA Aptamers against Mycotoxins: The Case-Study of Fumonisin B1, Aflatoxin B1 and Ochratoxin A

by Fulvio Ciriaco, Vincenzo De Leo, Lucia Catucci, Michelangelo Pascale, Antonio F. Logrieco, Maria C. DeRosa and Annalisa De Girolamo

Polymers 2020, 12(12), 2983; https://0-doi-org.brum.beds.ac.uk/10.3390/polym12122983 - 14 Dec 2020

Cited by 10 | Viewed by 2675

Abstract

Aptamers are single-stranded oligonucleotides selected by SELEX (Systematic Evolution of Ligands by EXponential Enrichment) able to discriminate target molecules with high affinity and specificity, even in the case of very closely related structures. Aptamers have been produced for several targets including small molecules [...] Read more.

Aptamers are single-stranded oligonucleotides selected by SELEX (Systematic Evolution of Ligands by EXponential Enrichment) able to discriminate target molecules with high affinity and specificity, even in the case of very closely related structures. Aptamers have been produced for several targets including small molecules like mycotoxins; however, the high affinity for their respective target molecules is a critical requirement. In the last decade, the screening through computational methods of aptamers for their affinity against specific targets has greatly increased and is becoming a commonly used procedure due to its convenience and low costs. This paper describes an in-silico approach for rapid screening of ten ssDNA aptamer sequences against fumonisin B1 (FB1, n = 3), aflatoxin B1 (AFB1, n = 2) and ochratoxin A (OTA, n = 5). Theoretical results were compared with those obtained by testing the same aptamers by fluorescent microscale thermophoresis and by magnetic beads assay for their binding affinity (K_D) revealing a good agreement. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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12 pages, 5428 KiB

Open AccessArticle

Mechanistic Study of Synergistic Antimicrobial Effects between Poly (3-hydroxybutyrate) Oligomer and Polyethylene Glycol

by Ziheng Zhang, Jun Li, Linlin Ma, Xingxing Yang, Bin Fei, Polly H. M. Leung and Xiaoming Tao

Polymers 2020, 12(11), 2735; https://0-doi-org.brum.beds.ac.uk/10.3390/polym12112735 - 18 Nov 2020

Cited by 8 | Viewed by 2783

Abstract

Extended from our previous finding that poly (3-hydroxybutyrate) (PHB) oligomer is an effective antimicrobial agent against gram-positive bacteria, gram-negative bacteria, fungi and multi-drug resistant bacteria, this work investigates the effect of polyethylene glycol (PEG) on the antimicrobial effect of PHB oligomer. To investigate [...] Read more.

Extended from our previous finding that poly (3-hydroxybutyrate) (PHB) oligomer is an effective antimicrobial agent against gram-positive bacteria, gram-negative bacteria, fungi and multi-drug resistant bacteria, this work investigates the effect of polyethylene glycol (PEG) on the antimicrobial effect of PHB oligomer. To investigate and explain this promoting phenomenon, three hypothetic mechanisms were proposed, that is, generation of new antimicrobial components, degradation of PHB macromolecules and dissolution/dispersion of PHB oligomer by PEG. With a series of systematic experiments and characterizations of high-performance liquid chromatography–mass spectrometry (HPLC-MS), it was deducted that PEG promotes the antimicrobial effect of PHB oligomer synergistically through dissolution/dispersion, owing to its amphipathy, which improves the hydrophilicity of PHB oligomer. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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16 pages, 742 KiB

Open AccessArticle

Manufacture of Reduced Fat White-Brined Cheese with the Addition of β-Glucans Biobased Polysaccharides as Textural Properties Improvements

by Efthymia Kondyli, Eleni C. Pappa, Alexandra Kremmyda, Dimitris Arapoglou, Maria Metafa, Christos Eliopoulos and Cleanthes Israilides

Polymers 2020, 12(11), 2647; https://0-doi-org.brum.beds.ac.uk/10.3390/polym12112647 - 10 Nov 2020

Cited by 15 | Viewed by 2400

Abstract

β-Glucan, isolated from the mushroom Pleurotus ostreatus, at a concentration of 0.4%, was used in the manufacture of reduced-fat white-brined cheese from sheep milk. Control reduced-fat cheese was also produced from the same milk without the addition of β-glucan. The resultant cheeses [...] Read more.

β-Glucan, isolated from the mushroom Pleurotus ostreatus, at a concentration of 0.4%, was used in the manufacture of reduced-fat white-brined cheese from sheep milk. Control reduced-fat cheese was also produced from the same milk without the addition of β-glucan. The resultant cheeses were examined for their physicochemical characteristics, color and textural properties, and level of proteolysis and lipolysis. Furthermore, cheeses were evaluated organoleptically. In general, there were no statistical differences in the physicochemical characteristics and proteolysis levels found between both cheeses. The addition of β-glucan improved textural properties, and the cheeses received favorable grades for all the organoleptic characteristics. There were no flavor defects (such as a bitter taste) described by the panellists in this study. Generally, the addition of β-glucan did not significantly affect total free fatty acid content; however, at 180 days of ripening and storage, cheeses with the addition of β-glucan had a higher (p < 0.05) content than cheeses without β-glucan. The major fatty acids were acetic acid and capric acid. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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14 pages, 2767 KiB

Open AccessArticle

Biomimetic Polyurethane 3D Scaffolds Based on Polytetrahydrofuran Glycol and Polyethylene Glycol for Soft Tissue Engineering

by Kun Luo, Li Wang, Xiaohu Chen, Xiyang Zeng, Shiyi Zhou, Peicong Zhang and Junfeng Li

Polymers 2020, 12(11), 2631; https://0-doi-org.brum.beds.ac.uk/10.3390/polym12112631 - 09 Nov 2020

Cited by 17 | Viewed by 3074

Abstract

In this study, a novel polyurethane porous 3D scaffold based on polyethylene glycol (PEG) and polytetrahydrofuran glycol (PTMG) was developed by in situ polymerization and freeze drying. Aliphatic hexamethylene diisocyanate (HDI) as a nontoxic and safe agent was adopted to produce the rigid [...] Read more.

In this study, a novel polyurethane porous 3D scaffold based on polyethylene glycol (PEG) and polytetrahydrofuran glycol (PTMG) was developed by in situ polymerization and freeze drying. Aliphatic hexamethylene diisocyanate (HDI) as a nontoxic and safe agent was adopted to produce the rigid segment in polyurethane polymerization. The chemical structure, macrostructure, and morphology—as well as mechanical strength of the scaffolds—were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and tensile tests. The results show that the HDI can react mildly with hydroxyl (–OH) groups of PEG and PTMG, while gas foaming action caused by the release of CO₂ occurred simultaneously in the reactive process, resulting in a uniform porous structure of PU scaffold. Moreover, the scaffolds were soaked in water and freeze dried to obtain higher porosity and more interconnective microstructures. The scaffolds have a porosity of over 70% and pore size from 100 to 800 μm. The mechanical properties increased with increasing PEG content, while the hydrophilicity increased as well. After immersion in simulated body fluid (SBF), the scaffolds presented a stable surface structure. The gas foaming/freezing drying process is an excellent method to prepare skin tissue engineering scaffold from PTMG/PEG materials with high porosity and good inter connectivity. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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18 pages, 4169 KiB

Open AccessArticle

Preparation and Barrier Performance of Layer-Modified Soil-Stripping/Cassava Starch Composite Films

by Lijie Huang, Xiaoxue Han, Haobin Chen, Shuxiang An, Hanyu Zhao, Hao Xu, Chongxing Huang, Shuangfei Wang and Yang Liu

Polymers 2020, 12(7), 1611; https://0-doi-org.brum.beds.ac.uk/10.3390/polym12071611 - 20 Jul 2020

Cited by 10 | Viewed by 2504

Abstract

In this study, we investigated the barrier properties of a montmorillonite-reinforced biomass material, starch. Organically modified montmorillonite materials were prepared from natural montmorillonite by reacting it with dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride or octadecyl trimethyl ammonium chloride under ultrasonic [...] Read more.

In this study, we investigated the barrier properties of a montmorillonite-reinforced biomass material, starch. Organically modified montmorillonite materials were prepared from natural montmorillonite by reacting it with dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride or octadecyl trimethyl ammonium chloride under ultrasonic conditions. The composite starch films incorporated with these organically modified montmorillonite samples were characterized by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy and X-ray diffraction. The results showed that the introduction of montmorillonite decreases the transmittance of the composite film by 10% in the visible region and significantly inhibits UV-light transmittance. The decomposition temperature of the composite film ranges from 200 to 500 °C, with a weight loss rate of 80%. The distance between the montmorillonite layers increases from 0.14 nm in the non-magnetized state to 1.49 nm after magnetization. The oxygen permeability of the starch film modified by organic montmorillonite (0.067 cm³/m²·d) is lower than that of the montmorillonite starch film without magnetization (0.097cm³/m²·d). The oxygen barrier capacity is close to zero. Particularly in the ordered magnetic montmorillonite starch composite film, the oxygen barrier ability is the best. Therefore, modified montmorillonite could serve as an excellent reinforcing agent for cassava starch films and effectively improve the oxygen barrier performance of the films. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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Review

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24 pages, 4476 KiB

Open AccessReview

Recent Advancements in Polymer/Liposome Assembly for Drug Delivery: From Surface Modifications to Hybrid Vesicles

by Vincenzo De Leo, Francesco Milano, Angela Agostiano and Lucia Catucci

Polymers 2021, 13(7), 1027; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13071027 - 26 Mar 2021

Cited by 88 | Viewed by 7691

Abstract

Liposomes are consolidated and attractive biomimetic nanocarriers widely used in the field of drug delivery. The structural versatility of liposomes has been exploited for the development of various carriers for the topical or systemic delivery of drugs and bioactive molecules, with the possibility [...] Read more.

Liposomes are consolidated and attractive biomimetic nanocarriers widely used in the field of drug delivery. The structural versatility of liposomes has been exploited for the development of various carriers for the topical or systemic delivery of drugs and bioactive molecules, with the possibility of increasing their bioavailability and stability, and modulating and directing their release, while limiting the side effects at the same time. Nevertheless, first-generation vesicles suffer from some limitations including physical instability, short in vivo circulation lifetime, reduced payload, uncontrolled release properties, and low targeting abilities. Therefore, liposome preparation technology soon took advantage of the possibility of improving vesicle performance using both natural and synthetic polymers. Polymers can easily be synthesized in a controlled manner over a wide range of molecular weights and in a low dispersity range. Their properties are widely tunable and therefore allow the low chemical versatility typical of lipids to be overcome. Moreover, depending on their structure, polymers can be used to create a simple covering on the liposome surface or to intercalate in the phospholipid bilayer to give rise to real hybrid structures. This review illustrates the main strategies implemented in the field of polymer/liposome assembly for drug delivery, with a look at the most recent publications without neglecting basic concepts for a simple and complete understanding by the reader. Full article

(This article belongs to the Special Issue Progress in Polymer Research: From Sustainable Materials to Biomedical Application)

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