bluuebunny/crossref_metadata_2025 huggingface dataset:
A Promising Ultra-Small Unilamellar Carrier System for Enhanced Skin Delivery of α-Mangostin as an Anti-Age-Spot Serum
Authors: Chairunisa Ully , Rustini  , Nastiti Christofori Maria Ratna Rini , Riswanto Florentinus Dika Octa , Benson Heather A. E. , Lucida Henny
Published: December 2022

If it can be effectively delivered to its site of action, α-mangostin has potential in development of novel cosmeceuticals due to its melanogenesis-blocking activity. The aim of this study was to develop an ultra-small unilamellar carrier system for α-mangostin and to evaluate its effect as an anti-age-spot serum on humans in vivo. The ultra-small unilamellar carrier bases were optimized using a 25 factorial design, with five factors (virgin coconut oil, soy lecithin, Tween 80, and stirring duration and speed) and two levels (low and high); response of droplet size was analyzed using Design Expert 12®. The anti-spot examination was conducted via capturing digital images of the human skin after topical application of an α-mangostin-loaded ultra-small unilamellar carrier at night for two consecutive weeks. The results thereof were analyzed using Motic Live Imaging 3.0 and a standard red, green, and blue score. The optimized serum formula was confirmed with a composition of 2.3% virgin coconut oil, 1% lecithin, and 28.3% Tween 80 (polysorbate 80) at a stirring speed of 1500 revolutions per minute for 15 min. Incorporation of 3% α-mangostin to the optimized base formula produced an ultra-small unilamellar carrier globule size of 16.5 nm, with zeta potential of −25.8 mV and a polydispersion index of 0.445. Physical characterization of an α-mangostin-loaded ultra-small unilamellar carrier comprised 90.94% transmittance, a pH value of 6.5, a viscosity of 38 cP, specific gravity of 1.042 g/mL and 72.46% entrapment efficiency. A transmission electron microscope confirmed spherical nanosized droplets in the system. Topical application of an α-mangostin-loaded ultra-small unilamellar carrier at night for 2 consecutive weeks demonstrated anti-age-spot activity shown through a significant reduction in intensity and area of spots in human volunteers (p < 0.05).
Lipid and Polymeric Nanoparticles: Successful Strategies for Nose-to-Brain Drug Delivery in the Treatment of Depression and Anxiety Disorders
Authors: Alberto Margarida , Paiva-Santos Ana Cláudia , Veiga Francisco , Pires Patrícia C.
Published: December 2022

Intranasal administration has gained an increasing interest for brain drug delivery since it allows direct transport through neuronal pathways, which can be quite advantageous for central nervous system disorders, such as depression and anxiety. Nanoparticles have been studied as possible alternatives to conventional formulations, with the objective of improving drug bioavailability. The present work aimed to analyze the potential of intranasal nanoparticle administration for the treatment of depression and anxiety, using the analysis of several studies already performed. From the carried-out analysis, it was concluded that the use of nanoparticles allows the drug’s protection from enzymatic degradation, and the modulation of its components allows controlled drug release and enhanced drug permeation. Furthermore, the results of in vivo studies further verified these systems’ potential, with the drug reaching the brain faster and leading to increased bioavailability and, consequently, therapeutic effect. Hence, in general, the intranasal administration of nanoparticles leads to a faster onset of action, with increased and prolonged brain drug concentrations and, consequently, therapeutic effects, presenting high potential as an alternative to the currently available therapies for the treatment of depression and anxiety.
Changes in Disposition of Ezetimibe and Its Active Metabolites Induced by Impaired Hepatic Function: The Influence of Enzyme and Transporter Activities
Authors: Xie Ningjie , Wang Hong , Qin Hua , Guo Zitao , Xue Hao , Hu Jiafeng , Chen Xiaoyan
Published: December 2022

Ezetimibe (EZE) is a selective cholesterol absorption inhibitor. Hepatic impairment significantly increases the systemic exposure of EZE and its main active phenolic glucuronide, EZE-Ph. Although changes in efflux transporter activity partly explain the changes in EZE-Ph pharmacokinetics, the causes of the changes to EZE and the effects of the administration route on EZE-Ph remain unclear. A carbon tetrachloride (CCl4)-induced hepatic failure rat model was combined with in vitro experiments to explore altered EZE and EZE-Ph disposition caused by hepatic impairment. The plasma exposure of EZE and EZE-Ph increased by 11.1- and 4.4-fold in CCl4-induced rats following an oral administration of 10 mg/kg EZE, and by 2.1- and 16.4-fold after an intravenous injection. The conversion of EZE to EZE-Ph decreased concentration-dependently in CCl4-induced rat liver S9 fractions, but no change was observed in the intestinal metabolism. EZE-Ph was a substrate for multiple efflux and uptake transporters, unlike EZE. In contrast to efflux transporters, no difference was seen in the hepatic uptake of EZE-Ph between control and CCl4-induced rats. However, bile acids that accumulated due to liver injury inhibited the uptake of EZE-Ph by organic anion transporting polypeptides (OATPs) (glycochenodeoxycholic acid and taurochenodeoxycholic acid had IC50 values of 15.1 and 7.94 μM in OATP1B3-overexpressed cells). In conclusion, the increased plasma exposure of the parent drug EZE during hepatic dysfunction was attributed to decreased hepatic glucuronide conjugation, whereas the increased exposure of the metabolite EZE-Ph was mainly related to transporter activity, particularly the inhibitory effects of bile acids on OATPs after oral administration.
Embedding Biomimetic Magnetic Nanoparticles Coupled with Peptide AS-48 into PLGA to Treat Intracellular Pathogens
Authors: Gaglio Salvatore Calogero , Jabalera Ylenia , Montalbán-López Manuel , Millán-Placer Ana Cristina , Lázaro-Callejón Marina , Maqueda Mercedes , Carrasco-Jimenez María Paz , Laso Alejandro , Aínsa José A. , Iglesias Guillermo R. , Perduca Massimiliano , López Concepción Jiménez
Published: December 2022

Among the strategies employed to overcome the development of multidrug-resistant bacteria, directed chemotherapy combined with local therapies (e.g., magnetic hyperthermia) has gained great interest. A nano-assembly coupling the antimicrobial peptide AS-48 to biomimetic magnetic nanoparticles (AS-48-BMNPs) was demonstrated to have potent bactericidal effects on both Gram-positive and Gram-negative bacteria when the antimicrobial activity of the peptide was combined with magnetic hyperthermia. Nevertheless, intracellular pathogens remain challenging due to the difficulty of the drug reaching the bacterium. Thus, improving the cellular uptake of the nanocarrier is crucial for the success of the treatment. In the present study, we demonstrate the embedding cellular uptake of the original nano-assembly into THP-1, reducing the toxicity of AS-48 toward healthy THP-1 cells. We optimized the design of PLGA[AS-48-BMNPs] in terms of size, colloidal stability, and hyperthermia activity (either magnetic or photothermal). The stability of the nano-formulation at physiological pH values was evaluated by studying the AS-48 release at this pH value. The influence of pH and hyperthermia on the AS-48 release from the nano-formulation was also studied. These results show a slower AS-48 release from PLGA[AS-48-BMNPs] compared to previous nano-formulations, which could make this new nano-formulation suitable for longer extended treatments of intracellular pathogens. PLGA[AS-48-BMNPs] are internalized in THP-1 cells where AS-48 is liberated slowly, which may be useful to treat diseases and prevent infection caused by intracellular pathogens. The treatment will be more efficient combined with hyperthermia or photothermia.
PAMAM-Calix-Dendrimers: Second Generation Synthesis, Fluorescent Properties and Catecholamines Binding
Authors: Mostovaya Olga , Shiabiev Igor , Pysin Dmitry , Stanavaya Alesia , Abashkin Viktar , Shcharbin Dzmitry , Padnya Pavel , Stoikov Ivan
Published: December 2022

A convenient method for the synthesis of the second generation of PAMAM dendrimers based on a p-tert-butylthiacalix[4]arene core in cone, partial cone and 1,3-alternate conformations was developed. Unusual fluorescence of the obtained PAMAM-calix-dendrimers has been found and explained. The binding ability of the synthesized dendrimers toward catecholamines (dopamine, L-adrenaline and L-noradrenaline) was shown by UV-Vis, fluorescence, 1D and 2D NMR spectroscopy and the binding constants (logKa 3.85–4.74) calculated. As was shown, the PAMAM-calix-dendrimers bind catecholamines by the internal cavities. All the studied hormones were most efficiently bound by the dendrimers bearing a macrocyclic core in 1,3-alternate conformation. The size of the formed supramolecular systems of dendrimer/catecholamine was established by the DLS method. A decrease in hemolytic activity of the PAMAM-calix-dendrimers with an increase in the generation number of a dendrimer was shown for the dendrimers with a core in 1,3-alternate conformation. The prospects for the use of the synthesized dendrimers with the macrocyclic core as drug delivery agents were discussed.
Topical Sustained Delivery of Miltefosine Via Drug-Eluting Contact Lenses to Treat Acanthamoeba Keratitis
Authors: Chen Lin , Kuang Liangju , Ross Amy E. , Farhat Wissam , Boychev Nikolay , Sharfi Sina , Kanu Levi N. , Liu Longqian , Kohane Daniel S. , Ciolino Joseph B.
Published: December 2022

This study aimed to develop a miltefosine-eluting contact lens (MLF-CL) device that would allow sustained and localized miltefosine release for the treatment of Acanthamoeba keratitis. MLF-CLs were produced in three different miltefosine doses by solvent-casting a thin miltefosine-polymer film around the periphery of a methafilcon hydrogel, which was then lathed into a contact lens. During seven days of in vitro testing, all three formulations demonstrated sustained release from the lens at theoretically therapeutic levels. Based on the physicochemical characterization of MLF-CLs, MLF-CL’s physical properties are not significantly different from commercial contact lenses in terms of light transmittance, water content and wettability. MLF-CLs possessed a slight reduction in compression modulus that was attributed to the inclusion of polymer-drug films but still remain within the optimal range of soft contact lenses. In cytotoxicity studies, MLF-CL indicated up to 91% viability, which decreased proportionally as miltefosine loading increased. A three-day biocompatibility test on New Zealand White rabbits revealed no impact of MLF-CLs on the corneal tissue. The MLF-CLs provided sustained in vitro release of miltefosine for a week while maintaining comparable physical features to a commercial contact lens. MLF-CL has a promising potential to be used as a successful treatment method for Acanthamoeba keratitis.
Extract of Calyces from Physalis peruviana Reduces Insulin Resistance and Oxidative Stress in Streptozotocin-Induced Diabetic Mice
Authors: Valderrama Ivonne Helena , Echeverry Sandra Milena , Rey Diana Patricia , Rodríguez Ingrid Andrea , Silva Fátima Regina Mena Barreto , Costa Geison M. , Ospina-Giraldo Luis Fernando , Aragón Diana Marcela
Published: December 2022

Diabetes mellitus is a metabolic disorder mainly characterized by obesity, hyperglycemia, altered lipid profile, oxidative stress, and vascular compromise. Physalis peruviana is a plant used in traditional Colombian medicine for its known activities of glucose regulation. This study aimed to evaluate the anti-diabetic activity of the butanol fraction from an extract of Physalis peruviana calyces in two doses (50 mg/kg and 100 mg/kg) in induced type 2 diabetic mice. Blood glucose levels were evaluated once a week, demonstrating that a dose of 100 mg/kg resulted in greater regulation of blood glucose levels in mice throughout the experiment. The same overall result was found for the oral glucose tolerance test (OGTT) and the homeostatic model assessment for insulin resistance (HOMA- IR). The lipid profile exhibited improvement compared to the non-treated group, a dose of 100 mg/kg having greater protection against oxidative stress (catalase, superoxide dismutase, and malondialdehyde levels). Histopathological findings in several tissues showed structure preservation in most of the animals treated. The butanol fraction from Physalis peruviana at 100 mg/kg showed beneficial results in improving hyperglycemia, lipidemia, and oxidative stress status, and can therefore be considered a beneficial coadjuvant in the therapy of diabetes mellitus.
Animist Phytofilm: Plants in Amazonian Indigenous Filmmaking
Authors: Vieira Patrícia Isabel Lontro
Published: December 2022

Early films about plants offer a glimpse into the behavior of vegetal life, which had hitherto remained hidden from humans. Critics have praised this animistic capacity of cinema, allowing audiences to see the movement of beings that appeared to be inert and lifeless. With these reflections as a starting point, this article examines the notion of animist cinema. I argue that early movies still remained beholden to the goal of showing the multiple ways in which plants resemble humans, a tendency we often still find today in work on critical plant studies. I discuss the concept of animism in the context of Amazonian Indigenous societies as a springboard into an analysis of movies by Indigenous filmmakers from the region that highlight the plantness of human beings. I end the essay with an analysis of Ika Muru Huni Kuin’s film Shuku Shukuwe as an example of animist phytocinema.
EXPLANATION: Exoplanet and Transient Event Investigation Project—Optical Facilities and Solutions
Authors: Valyavin Gennady , Beskin Grigory , Valeev Azamat , Galazutdinov Gazinur , Fabrika Sergei , Romanyuk Iosif , Aitov Vitaly , Yakovlev Oleg , Ivanova Anastasia , Baluev Roman , Vlasyuk Valery , Han Inwoo , Karpov Sergei , Sasyuk Vyacheslav , Perkov Alexei , Bondar Sergei , Musaev Faig , Emelianov Eduard , Fatkhullin Timur , Drabek Sergei , Shergin Vladimir , Lee Byeong-Cheol , Mitiani Guram , Burlakova Tatiana , Yushkin Maksim , Sendzikas Eugene , Gadelshin Damir , Chmyreva Lisa , Beskakotov Anatoly , Dyachenko Vladimir , Rastegaev Denis , Mitrofanova Arina , Yakunin Ilia , Antonyuk Kirill , Plokhotnichenko Vladimir , Gutaev Alexei , Lyapsina Nadezhda , Chernenkov Vladimir , Biryukov Anton , Ivanov Evgenij , Katkova Elena , Belinski Alexander , Sokov Eugene , Tavrov Alexander , Korablev Oleg , Park Myeong-Gu , Stolyarov Vladislav , Bychkov Victor , Gorda Stanislav , Popov A. A. , Sobolev A. M.
Published: December 2022

Over the past decades, the achievements in astronomical instrumentation have given rise to a number of novel advanced studies related to the analysis of large arrays of observational data. One of the most famous of these studies is a study of transient events in the near and far space and a search for exoplanets. The main requirements for such kinds of projects are a simultaneous coverage of the largest possible field of view with the highest possible detection limits and temporal resolution. In this study, we present a similar project aimed at creating an extensive, continuously updated survey of transient events and exoplanets. To date, the core of the project incorporates several 0.07–2.5 m optical telescopes and the 6-m BTA telescope of the Special Astrophysical Observatory of RAS (Russia), a number of other Russian observatories and the Bonhyunsan observatory of the Korea Astronomy and Space Science Institute (South Korea). Our attention is mainly focused on the description of two groups of small, wide-angle optical telescopes for primary detection. All the telescopes are originally designed for the goals of the project and may be of interest to the scientific community. A description is also given for a new, high-precision optical spectrograph for the Doppler studies of transient and exoplanet events detected within the project. We present here the philosophy, expectations and first results obtained during the first year of running the project.
Key Space Enhanced Correlated Random Bit Generation Based on Synchronized Electro-Optic Self-Feedback Loops with Mach–Zehnder Modulators
Authors: Huang Chuyun , Gao Xulin , Wu Sile , Gu Wenfu , Su Biao , Wang Yuncai , Qin Yuwen , Gao Zhensen
Published: December 2022

With the widespread application of big data, the amount of data transmitted through optical networks has been increasing dramatically. Correlated random bit generation (CRBG) is one of the key technologies in secure communication systems to ensure security performance and transmission efficiency. We propose and demonstrate a CRBG scheme based on a Mach–Zehnder modulator (MZM) electro-optic feedback loop to improve the security and speed of communication systems. In this scheme, common-signal-induced synchronization is accomplished to generate wideband complex physical entropy sources, and a private hardware module is employed to perform post-processing and nonlinear transformation of the synchronized signal. The simulation results show that the effective bandwidth of the output chaotic signal is significantly increased to 27.76 GHz, and high-quality synchronization with a correlation coefficient of over 0.98 is reached. A high-rate CRBG of up to 5.3 Gb/s is successfully achieved between two synchronized wideband physical entropy sources, and the hardware key space is enhanced to ∼242, which greatly improves the privacy of physical entropy sources. The proposed scheme provides a promising approach for high-speed private CRBG, which is expected to be used in high-speed secure key distribution and optical communication systems.
Analysis of Genetic Diversity and Resistance to Foliar Pathogens Based on Genotyping-by-Sequencing of a Para Rubber Diversity Panel and Progeny of an Interspecific Cross
Authors: Roy C. Bindu , Goonetilleke Shashi N. , Joseph Limiya , Krishnan Anu , Saha Thakurdas , Kilian Andrzej , Mather Diane E.
Published: December 2022

Para rubber trees (Hevea brasiliensis) are the largest major source of natural rubber in the world. Its major pathogens are Phytophthora spp., Corynespora cassiicola, and Colletotrichum spp. A rubber diversity panel of 116 clones using over 12,000 single nucleotide polymorphisms (SNPs) from DArTSeq genotyping revealed clear phylogenetic differences in clones that originated from different geographical regions of the world. An integrated linkage map constructed with an F1 progeny of 86 from an interspecific cross between H. brasiliensis and H. benthamiana using 23,978 markers [10,323 SNPs and 13,655 SilicoDArTs] spanned 3947.83 cM with 0.83 cM average marker-interval. The genome scaffolds that were anchored to the linkage map, covering 1.44 Gb of H. brasiliensis reference genome, revealed a high level of collinearity between the genetic map and reference genome. Association analysis identified 12 SNPs significantly associated with the resistance against Phytophthora, Corynespora, and Colletotrichum in six linkage groups: 2, 6, 12, 14, 17, and 18. Kompetitive Allele-Specific PCR marker assays were developed for those 12 SNPs, screened with 178 individuals, and detected clear separation between two genotypes. Within the proximity to those SNPs, 41 potentially key genes that have previously been reported to associate with plant disease resistance were predicted with high confidence.
Differentiation and Propagation Potential of Arnica montana L. Achenes as a Consequence of the Morphological Diversity of Flowers and the Position of Flower Heads on the Plant
Authors: Sugier Piotr , Rysiak Anna , Sugier Danuta , Winiarczyk Krystyna , Wołkowycki Dan , Kołos Aleksander
Published: December 2022

Arnica montana L. is a very important medicinal plant and simultaneously a European endemic endangered plant species. The morphological features and details of seed development and achene variability are poorly recognized. The aim of this study was to determine the impact of the achene position in the infructescence and the location of the inflorescence on the plant on the (i) morphological characteristics and germination ability of achenes, and (ii) recruitment of seedlings and their biometric features. Infructescences containing fully ripe achenes were randomly collected from A. montana individuals for the measurements and the germination experiment. Scanning electron microscopy, fluorescence microscopy, and light microscopy were used for characterization of flowers and achenes. The morphological traits of achenes and reproductive characteristics of A. montana were determined by the position of the achenes in the infructescence and the location of the inflorescence on the plant. The surface of arnica achenes is equipped with non-glandular and glandular trichomes, which is very rarely presented in species of the family Asteraceae. It is possible that the fluid-containing glandular trichomes are a source of essential oils. The peripherally located achenes were longer, thinner, and lighter. They were characterized by lower embryo weight, lower embryo/achene weight ratio, and lower germination capacity in comparison to the centrally located ones. The results presented in this article fill the gap in the knowledge of the morphology of achenes and the biology of the species, and provide information that can help in breeding programs, active protection, and field cultivation.
Rootstocks with Different Tolerance Grade to Citrus Tristeza Virus Induce Dissimilar Volatile Profile in Citrus sinensis and Avoidance Response in the Vector Aphis gossypii Glover
Authors: Guarino Salvatore , Mercati Francesco , Fatta Del Bosco Sergio , Motisi Antonio , Abbate Loredana
Published: December 2022

The citrus tristeza virus (CTV) is an agent of devastating epidemics of the citrus plant grafted on Citrus aurantium, one of the main rootstocks still used in the Mediterranean area. Consequently, CTV-tolerant alternative citrus rootstocks are considered necessary to manage this disease and/or its vector; that in Mediterranean countries is the aphid Aphis gossypii. In this study, we analyzed the VOCs emitted from Citrus sinensis plants grafted on the CTV-susceptible C. aurantium and on the CTV-tolerant Volkamer lemon, Forner-Alcaide no. 5, and Carrizo citrange. Furthermore, the aphid preference/avoidance response toward these combinations was evaluated in a semi-field experiment. The VOC profiles recorded on the leaves of C. sinensis grafted on the four rootstocks listed above showed significant differences in the abundances and ratios of the compounds emitted. The behavioral experiments indicated that A. gossypii prefers to orient and establish on the C. sinensis plants grafted on C. aurantium rather than on that grafted on the three CTV-tolerant varieties. The possibility that this avoidance mechanism is triggered by the different profile of the VOC emitted by the different combinations and the consequent susceptibility/tolerance shown toward CTV is discussed.
Effect of Normal and Rubberized Concrete Properties on the Behavior of RC Columns Strengthened with EB CFRP Laminates and Welded Wire Mesh under Static Axial Loading
Authors: Sharaky Ibrahim A. , Elamary Ahmed S. , Alharthi Yasir M. , Abdo Ayman
Published: December 2022

The huge amounts of old and damaged tires spread worldwide has caused many complex environmental risks. The old tires have been converted to crumb rubber (CR) and tire recycled steel fiber (RSF) to facilitate their use. This study used CR to partially replace natural sand in reinforced (RC) columns. Externally bonded (EB) carbon-fiber-reinforced polymer (CFRP) laminates, welded wire mesh (WWM), and RSF were used to enhance the axial behavior of the tested columns to overcome the concrete deficiencies resulting from the inclusion of the CR instead of natural sand. Eighteen columns were prepared and tested to discuss the effects of strengthening type, CR content, RSF, and strengthening area on the axial behavior of the RC columns. Certain columns were internally reinforced with WWM, while others were externally strengthened with EB CFRP laminates. Partially or fully EB CFRP laminates were used to strengthen the columns. Moreover, one column was cast with NC and 0.2% RSF to investigate the role of RSF in confining the column. The results demonstrated a concrete strength reduction for the rubberized concrete (CRC) as the CR content increased. Conversely, the strengthened columns experienced higher load capacities than the corresponding un-strengthened ones cast with the same concrete mix. Moreover, adding 2% RSF to the NC mix could enhance the column capacity, although it decreased the concrete strength. Furthermore, using two CFRP layers increased the load capacity and ductility of the strengthened columns. The strengthened column cast with 50% CR showed the highest load efficiency (334.3% compared to the un-strengthened one).
Possibilities of Integrated Fabrication of Insulation Systems in Electric Drives by Injection Molding of Thermosets
Authors: Rösel Uta , Kneidl Maximilian , Drummer Dietmar , Franke Jörg
Published: December 2022

Due to the increasing demand for electro mobility and specifically for electrified vehicles, the demand for electric drive technology is expanding significantly with changing requirements in terms of the process and the application. The electrical insulation system of the stator is an essential part of the fabrication process with a high impact on the application properties. Due to limitations—for example, in terms of suitable materials for the stator insulation—a new technology of integrated fabrication by injection molding of thermosets has been founded. In this study, two epoxy (EP) types with different fillers were investigated to prove their suitability in terms of the material properties in the fabrication process and the application. A general realization of the integrated fabrication of insulation systems in electrical engineering by injection molding was proved. Further, the differences regarding the suitability of the two materials are portrayed. It was demonstrated that mainly the filler material influences the fabrication process and the properties in the application, leading to differing suitability in terms of the EP 3162 EMG within the fabrication process and in terms of XW 6640-1 within the application properties of the thermal conductivity and the thermal linear expansion. It was further shown that the filler within the material system is required to increase the thermal conductivity needed for the application. The inclusion of the filler influences the reaction kinetics and the viscosity behavior. A fabrication of the material with fillers is however still possible.
Loose Semirigid Aromatic Polyester Bottle Brushes at Poly(2-isopropyl-2-oxazoline) Side Chains of Various Lengths: Behavior in Solutions and Thermoresponsiveness
Authors: Tarabukina Elena , Krasova Anna , Kurlykin Mikhail , Tenkovtsev Andrey , Filippov Alexander
Published: December 2022

A polycondensation aromatic polyester with an oxygen spacer was synthesized and used as a macroinitiator for the grafting of linear poly(2-isopropyl-2-oxazoline) (PiPrOx) by the cationic polymerization method. The length of the thermosensitive side chains was varied by the initiator:monomer ratio. Using methods of molecular hydrodynamics, light scattering and turbidimetry, the copolymers were studied in organic solvents and in water. The molecular characteristics of the main chain and graft copolymers, the polymerization degree of side chains and their grafting density have been determined. The equilibrium rigidity of the macroinitiator and the conformations of grafted macromolecules were evaluated. In selective solvents, they take on a star-like conformation or aggregate depending on the degree of shielding of the main chain by side chains. The thermoresponsiveness of graft copolymers in aqueous solutions was studied, and their LCST were estimated. The results are compared with data for graft copolymers composed of PiPrOx side chains and flexible or rigid chain backbones of aromatic polyester type.
Analysis of PLA/PHB Biopolymer Material with Admixture of Hydroxyapatite and Tricalcium Phosphate for Clinical Use
Authors: Kohan Miroslav , Lancoš Samuel , Schnitzer Marek , Živčák Jozef , Hudák Radovan
Published: December 2022

One trend in tissue engineering and regenerative medicine is the development of degradable composite polymers. The aim of this study was the comprehensive analysis of Polylactic acid (PLA)/Polyhydroxybutyrate (PHB) + Hydroxyapatite (HA)/Tricalcium phosphate (TCP) material from filament production to mechanical testing of samples with different infills and the production of an implant replacement for an intervertebral disc. Filament Maker—Composer 450 (3devo; Netherlands) was used to produce filaments. Experimental samples and the implant for the intervertebral disc were made using FDM technology using a DeltiQ2 3D printer (Trilab, Czech Republic). Mechanical testing of experimental samples was performed on an Inspekt TABLE 5 kN (Hegewald & Peschke, Nossen, Germany). Microscopic analysis, cytotoxicity test, and filament diameter analysis using descriptive statistics were also part of the focus. The results of the analysis of the diameter of the filament show that the filament meets the prescribed standard. The cytotoxicity test for PLA/PHB + HA/TCP material showed no toxicity. Microscopic analysis showed an even distribution of the ceramic component in the composite polymer. Mechanical testing showed a reduction in mechanical properties with 75% and 50% of the filling of experimental samples. All experimental samples subjected to mechanical testing showed higher tensile and compressive strength values compared to the values of the mechanical properties of vertebral trabecular bones, as reported in the literature. It can therefore be concluded that the material under investigation, PLA/PHB + HA/TCP appears to be a suitable candidate for hard tissue replacement.
Study of Morphology, Rheology, and Dynamic Properties toward Unveiling the Partial Miscibility in Poly(lactic acid)—Poly(hydroxybutyrate-co-hydroxyvalerate) Blends
Authors: Qiao Hu , Maazouz Abderrahim , Lamnawar Khalid
Published: December 2022

The purpose of the present work was to gain a fundamental understanding of how the composition and physico-chemical properties affect the rheology, morphology, miscibility, and thermal stability of poly(lactic acid) (PLA)—poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) biopolymer blends obtained by melt mixing. First, restricted processing conditions were chosen, due to the inherent thermal degradation of PHBV, as proven by rheological dynamic time sweep (DTS) measurements and size-exclusion chromatography (SEC). Based on this, the composition dependence of the blends was investigated using small-amplitude oscillatory shear rheology (SAOS), and the results were confirmed by scanning electron microscopy (SEM) analysis. Subsequently, the changes in glass transition temperatures (Tgs) from the molten to the solid state, as observed by DMA and DSC, were verified by coupling SAOS to dielectric relaxation spectroscopy (DRS). Herein, the thermo-rheological complexity of PLA/PHBV blends in the melt was revealed, especially for PLA-rich blends. Irregularly structured morphologies, caused by highly mismatched viscoelastic properties, illustrated the degree of partial miscibility. Moreover, the thermo-rheological complexity appeared in the molten state of the asymmetric PLA-rich phases could be correlated to the crystal-amorphous interfacial MWS polarization, because of the locally-induced phase separation and heterogeneity, and owing to the differences in their crystallization properties during cooling. The miscibility also suffered from the lower thermal stability of PLA and the even more unstable PHBV. Nevertheless, the melt-induced degradation process of the PLA/PHBV blends seemed to be responsible for some of the in situ self-compatibilization and plasticization mechanisms. As a result, the miscibility and thermo-rheological simplicity were improved for the intermediate and PHBV-rich compositions at low temperatures, since their properties were, to a large extent, governed by the significant degradation of PHBV. The present findings should increase the understanding of morphological changes in PLA/PHBV blends and help control their micro/nanostructure.
Functionalized Soybean Oil- and Vanillin-Based Dual Cure Photopolymerizable System for Light-Based 3D Structuring
Authors: Sereikaite Vilte , Navaruckiene Aukse , Jaras Justinas , Skliutas Edvinas , Ladika Dimitra , Gray David , Malinauskas Mangirdas , Talacka Vaidas , Ostrauskaite Jolita
Published: December 2022

A novel dual cure photopolymerizable system was developed by combining two plant-derived acrylic monomers, acrylated epoxidized soybean oil and vanillin dimethacrylate, as well as the thiol monomer pentaerythritol tetrakis (3-mercaptopropionate). Carefully selected resin composition allowed the researchers to overcome earlier stability/premature polymerization problems and to obtain stable (up to six months at 4 °C) and selectively-polymerizable resin. The resin demonstrated rapid photocuring without an induction period and reached a rigidity of 317.66 MPa, which was more than 20 times higher than that of the other vanillin-based polymers. Improved mechanical properties and thermal stability of the resulting cross-linked photopolymer were obtained compared to similar homo- and copolymers: Young’s modulus reached 4753 MPa, the compression modulus reached 1634 MPa, and the temperature of 10% weight loss was 373 °C. The developed photocurable system was successfully applied in stereolithography and characterized with femtosecond pulsed two-beam initiation threshold measurement for the first time. The polymerization threshold of the investigated polymer was determined to be controlled by the sample temperature, making the footprint of the workstations cheaper, faster, and more reliable.
Electrospun Polycaprolactone/ZnO Nanocomposite Membranes with High Antipathogen Activity
Authors: Permyakova Elizaveta S. , Manakhov Anton M. , Kiryukhantsev-Korneev Philipp V. , Leybo Denis V. , Konopatsky Anton S. , Makarets Yulia A. , Filippovich Svetlana Yu. , Ignatov Sergey G. , Shtansky Dmitry V.
Published: December 2022

The spread of bacterial, fungal, and viral diseases by airborne aerosol flows poses a serious threat to human health, so the development of highly effective antibacterial, antifungal and antiviral filters to protect the respiratory system is in great demand. In this study, we developed ZnO-modified polycaprolactone nanofibers (PCL-ZnO) by treating the nanofiber surface with plasma in a gaseous mixture of Ar/CO2/C2H4 followed by the deposition of ZnO nanoparticles (NPs). The structure and chemical composition of the composite fibers were characterized by SEM, TEM, EDX, FTIR, and XPS methods. We demonstrated high material stability. The mats were tested against Gram-positive and Gram-negative pathogenic bacteria and pathogenic fungi and demonstrated high antibacterial and antifungal activity.
Bioanalytical System for Determining the Phenol Index Based on Pseudomonas putida BS394(pBS216) Bacteria Immobilized in a Redox-Active Biocompatible Composite Polymer “Bovine Serum Albumin–Ferrocene–Carbon Nanotubes”
Authors: Perchikov Roman N. , Provotorova Daria V. , Kharkova Anna S. , Arlyapov Vyacheslav A. , Medvedeva Anastasia S. , Machulin Andrey V. , Filonov Andrey E. , Reshetilov Anatoly N.
Published: December 2022

The possibility of using the microorganisms Pseudomonas sp. 7p-81, Pseudomonas putida BS394(pBS216), Rhodococcus erythropolis s67, Rhodococcus pyridinivorans 5Ap, Rhodococcus erythropolis X5, Rhodococcus pyridinivorans F5 and Pseudomonas veronii DSM 11331T as the basis of a biosensor for the phenol index to assess water environments was studied. The adaptation of microorganisms to phenol during growth was carried out to increase the selectivity of the analytical system. The most promising microorganisms for biosensor formation were the bacteria P. putida BS394(pBS216). Cells were immobilized in redox-active polymers based on bovine serum albumin modified by ferrocenecarboxaldehyde and based on a composite with a carbon nanotube to increase sensitivity. The rate constants of the interaction of the redox-active polymer and the composite based on it with the biomaterial were 193.8 and 502.8 dm3/(g·s) respectively. For the biosensor created using hydrogel bovine serum albumin-ferrocene-carbon nanotubes, the lower limit of the determined phenol concentrations was 1 × 10−3 mg/dm3, the sensitivity coefficient was (5.8 ± 0.2)∙10−3 μA·dm3/mg, Michaelis constant KM = 230 mg/dm3, the maximum rate of the enzymatic reaction Rmax = 217 µA and the long-term stability of the bioanalyzer was 11 days. As a result of approbation, it was found that the urban water phenol content differed insignificantly, measured by creating a biosensor and using the standard photometric method.
The Effect of the Extrusion Method on Processing and Selected Properties of Poly(3-hydroxybutyric-co-3-hydroxyvaleric Acid)-Based Biocomposites with Flax and Hemp Fibers
Authors: Janowski Grzegorz , Frącz Wiesław , Bąk Łukasz , Trzepieciński Tomasz
Published: December 2022

The paper presents a comparative analysis of two extrusion methods of biocomposites with a poly(3-hydroxybutyrate-co-3-hydroxyvalerate acid) (PHBV) matrix filled with flax and hemp fibers in terms of biopolymer production, its processing in the further injection process, and an evaluation of the mechanical and functional properties of the products. Biocomposites containing 15% by weight of the filler were produced using single- and twin-screw extruders. The biocomposites were then processed by injection molding and then, among other things, the pressures in the mold cavity during processing were analyzed. The produced samples were tested by means of the following tests: uniaxial tensile strength, hardness, and impact tensile strength. The biocomposite’s microstructure was also analyzed using scanning electron microscopy (SEM), as were the shrinkage and water absorption of the manufactured products. In addition, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests were performed. It was found that the extrusion method changed significantly the geometry of the filler fibers and the processing capabilities of the manufactured materials. Significant differences in the mechanical and functional properties of the obtained biocomposite products were also found. On their basis, the advantages and disadvantages of both extrusion methods were discussed. Most of the obtained properties of injection products indicate the choice of single-screw extrusion. The products were characterized by slightly better mechanical properties and lower processing shrinkage. In turn, composites obtained by the screw method were characterized by lower water absorption and lower viscosity of the composite during injection molding.
Biopolymer-Based Wound Dressings with Biochemical Cues for Cell-Instructive Wound Repair
Authors: Singh Variksha , Marimuthu Thashree , Makatini Maya M. , Choonara Yahya E.
Published: December 2022

Regenerative medicine is an active research sphere that focuses on the repair, regeneration, and replacement of damaged tissues and organs. A plethora of innovative wound dressings and skin substitutes have been developed to treat cutaneous wounds and are aimed at reducing the length or need for a hospital stay. The inception of biomaterials with the ability to interact with cells and direct them toward desired lineages has brought about innovative designs in wound healing and tissue engineering. This cellular engagement is achieved by cell cues that can be biochemical or biophysical in nature. In effect, these cues seep into innate repair pathways, cause downstream cell behaviours and, ultimately, lead to advantageous healing. This review will focus on biomolecules with encoded biomimetic, instructive prompts that elicit desired cellular domino effects to achieve advanced wound repair. The wound healing dressings covered in this review are based on functionalized biopolymeric materials. While both biophysical and biochemical cues are vital for advanced wound healing applications, focus will be placed on biochemical cues and in vivo or clinical trial applications. The biochemical cues aforementioned will include peptide therapy, collagen matrices, cell-based therapy, decellularized matrices, platelet-rich plasma, and biometals.
Analysis of Bonding Mechanisms of Various Implants and Adhesives in Laminated Oak-Wood Elements
Authors: Novosel Andrija , Sedlar Tomislav , Miklečić Josip , Turkulin Hrvoje , Lučić Luka , Mihulja Goran , Živković Vjekoslav
Published: December 2022

This study analysed the bonding mechanisms and strength between wood and non-wood implants in producing laminated oak-wood beams. The suitability of different types of adhesives, namely for load-bearing and general purpose, was also analysed. Three different types of non-wood implants—carbon fibres, glass fibres, and aluminium were glued with epoxy resin (ER), thermoplastic 1-k polyurethane adhesives (PUR), structural polyurethane adhesives (PUR 2 and PUR 3), and polyvinyl acetate (PVAc) adhesives and bonds were tested for shear strength (SS) according to ISO 6238:2018. Results of the bond quality expressed as the ultimate load to failure and displacement were recorded using the universal mechanical testing machine in combination with the digital image correlation (DIC) method. Before the shear test, all the samples were conditioned in dry and wet climatic conditions. Test results indicated that the application of PUR adhesives for bonding carbon and glass fibres with oak wood could sufficiently replace two-component ER, which is generally recommended for such purposes but is very challenging to utilise in industrial conditions. PVAc adhesives proved efficient only for combination with AL implants and in dry conditions. Aluminium sheets were shown to require surface pre-treatment, such as sanding and degreasing or a different type of adhesive to achieve sufficient adhesion.
Local Piezoelectric Response of Polymer/Ceramic Nanocomposite Fibers
Authors: Magnani Aurora , Capaccioli Simone , Azimi Bahareh , Danti Serena , Labardi Massimiliano
Published: December 2022

Effective converse piezoelectric coefficient (d33,eff) mapping of poly(vinylidene fluoride) (PVDF) nanofibers with ceramic BaTiO3 nanoparticle inclusions obtained by electrospinning was carried out by piezoresponse force microscopy (PFM) in a peculiar dynamic mode, namely constant-excitation frequency-modulation (CE-FM), particularly suitable for the analysis of compliant materials. Mapping of single nanocomposite fibers was carried out to demonstrate the ability of CE-FM-PFM to investigate the nanostructure of semicrystalline polymers well above their glass transition temperature, such as PVDF, by revealing the distribution of piezoelectric activity of the nanofiber, as well as of the embedded nanoparticles employed. A decreased piezoelectric activity at the nanoparticle site compared to the polymeric fiber was found. This evidence can be rationalized in terms of a tradeoff between the dielectric constants and piezoelectric coefficients of the component materials, as well as on the mutual orientation of polar axes.
Biodegradable Interpolycomplexes for Anti-Erosion Stabilization of Soil and Sand
Authors: Novoskoltseva Olga A. , Belov Andrey A. , Loiko Nataliya G. , Nikolaev Yury A. , Panova Irina G. , Yaroslavov Alexander A.
Published: December 2022

A linear anionic polysaccharide, sodium alginate, electrostatically interacts with a cationic polysaccharide, quaternized hydroxyethyl cellulose ethoxylate, in aqueous solution, thus giving an interpolyelectrolyte complex. Aqueous solutions of the initial polysaccharides and polycomplexes with an excess of the cationic or anionic polymers were used for the stabilization of soil and sand against water erosion. Physicochemical, mechanical and biological properties of the polymers and coatings were characterized by gravimetric analysis, viscosimetry, mechanical strength assessment, cell viability, and cell-mediated degradation with the following main conclusions. (a) Non-stoichiometric polycomplexes with an excess of cationic or anionic units (“cationic” and “anionic” polycomplexes, respectively) form transparent solutions or stable-in-time dispersions. (b) The complexation results in a decrease in the viscosity of polymer solutions. (c) A complete dissociation of polycomplexes to the initial components is achieved in a 0.2 M NaCl solution. (d) Soil/sand treatment with 1 wt% aqueous solutions of polymers or polycomplexes and further drying lead to the formation of strong composite coatings from polymer(s) and soil/sand particles. (e) Cationic polycomplexes form stronger coatings in comparison with anionic polycomplexes. (f) The polymer–soil coatings are stable towards re-watering, while the polymer–sand coatings show a much lower resistance to water. (g) The individual polysaccharides demonstrate a negligible toxicity to Gram-negative and Gram-positive bacteria and yeast. (h) The addition of Bacillus subtilis culture initiates the degradation of the polysaccharides and polycomplexes. (i) Films from polysaccharides and polycomplexes decompose down to small fragments after being in soil for 6 weeks. The results of the work are of importance for constructing water-resistant, low toxicity and biodegradable protective coatings for soil and sand.
Plants Utilize Suberin Biopolymers as a Vector for Transmitting Visible Light through Their Roots
Authors: Waller Spenser , Wilder Stacy L. , Schueller Michael J. , Ferrieri Richard A.
Published: December 2022

Plants conduct light from their aboveground tissues belowground to their root system. This phenomenon may influence root growth and perhaps serve to stimulate natural biological functions of the microorganisms associating with them. Here we show that light transmission in maize roots largely occurs within the endodermis, a region rich in suberin polyester biopolymers. Using cork as a natural resource rich in suberin polymers, we extracted, depolymerized, and examined light transmission in the visible and infrared regions. Suberin co-monomers dissolved in toluene showed no evidence of enhanced light transmission over that of the pure solvent in the visible light region and reduced light transmission in the infrared region. However, when these co-monomers were catalytically repolymerized using Bi(OTf)3, light transmission through suspended polymers significantly increased 1.3-fold in the visible light region over that in pure toluene, but was reduced in the infrared region.