bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondrial Dysfunction: Pathophysiology and Mitochondria-Targeted Drug Delivery Approaches
Authors: Khan Tanzeel , Waseem Rashid , Zehra Zainy , Aiman Ayesha , Bhardwaj Priyanka , Ansari Jaoud , Hassan Md. Imtaiyaz , Islam Asimul
Published: November 2022

Mitochondria are implicated in a wide range of functions apart from ATP generation, and, therefore, constitute one of the most important organelles of cell. Since healthy mitochondria are essential for proper cellular functioning and survival, mitochondrial dysfunction may lead to various pathologies. Mitochondria are considered a novel and promising therapeutic target for the diagnosis, treatment, and prevention of various human diseases including metabolic disorders, cancer, and neurodegenerative diseases. For mitochondria-targeted therapy, there is a need to develop an effective drug delivery approach, owing to the mitochondrial special bilayer structure through which therapeutic molecules undergo multiple difficulties in reaching the core. In recent years, various nanoformulations have been designed such as polymeric nanoparticles, liposomes, inorganic nanoparticles conjugate with mitochondriotropic moieties such as mitochondria-penetrating peptides (MPPs), triphenylphosphonium (TPP), dequalinium (DQA), and mitochondrial protein import machinery for overcoming barriers involved in targeting mitochondria. The current approaches used for mitochondria-targeted drug delivery have provided promising ways to overcome the challenges associated with targeted-drug delivery. Herein, we review the research from past years to the current scenario that has identified mitochondrial dysfunction as a major contributor to the pathophysiology of various diseases. Furthermore, we discuss the recent advancements in mitochondria-targeted drug delivery strategies for the pathologies associated with mitochondrial dysfunction.
Lignin-Based Nanoparticles as Both Structural and Active Elements in Self-Assembling and Self-Healing Multifunctional Hydrogels for Chronic Wound Management
Authors: Morena A. Gala , Pérez-Rafael Sílvia , Tzanov Tzanko
Published: November 2022

Efficient wound healing is feasible when the dressing materials simultaneously target multiple factors causing wound chronicity, such as deleterious proteolytic and oxidative enzymes and bacterial infection. Herein, entirely bio-based multifunctional self-assembled hydrogels for wound healing were developed by simply mixing two biopolymers, thiolated hyaluronic acid (HA-SH) and silk fibroin (SF), with lignin-based nanoparticles (NPs) as both structural and functional elements. Sono-enzymatic lignin modification with natural phenolic compounds results in antibacterial and antioxidant phenolated lignin nanoparticles (PLN) capable of establishing multiple interactions with both polymers. These strong and dynamic polymer-NP interactions endow the hydrogels with self-healing and shear-thinning properties, and pH-responsive NP release is triggered at neutral to alkaline pH (7–9). Despite being a physically crosslinked hydrogel, the material was stable for at least 7 days, and its mechanical and functional properties can be tuned depending on the polymer and NP concentration. Furthermore, human skin cells in contact with the nanocomposite hydrogels for 7 days showed more than 93% viability, while the viability of clinically relevant Staphylococcus aureus and Pseudomonas aeruginosa was reduced by 99.7 and 99.0%, respectively. The hydrogels inhibited up to 52% of the activity of myeloperoxidase and matrix metalloproteinases, responsible for wound chronicity, and showed a strong antioxidant effect, which are crucial features promoting wound healing.
PLLA Composites Combined with Delivery System of Bioactive Agents for Anti-Inflammation and Re-Endothelialization
Authors: Baek Seung-Woon , Kim Da-Seul , Song Duck Hyun , Lee Semi , Lee Jun-Kyu , Park So-Yeon , Kim Jun Hyuk , Kim Tae-Hyung , Park Chun Gwon , Han Dong Keun
Published: November 2022

The development of a biodegradable vascular scaffold (BVS) for the treatment of cardiovascular diseases (CVDs) still requires some improvement. Among them, re-endothelialization and anti-inflammation are clinically important to restore vascular function. In this study, we proposed a coating system to deliver hydrophilic bioactive agents to BVS using nanoemulsion and drop-casting methods. The poly(L-lactide) (PLLA) scaffold containing magnesium hydroxide (MH) was coated on the surface with bioactive molecules such as polydeoxyribonucleotide (PDRN), L-arginine (Arg, R), and mesenchymal stem cell-derived extracellular vesicles (EVs). PDRN upregulates the expression of VEGF as one of the A2A receptor agonists; and Arg, synthesized into nitric oxide by intracellular eNOS, induces endothelialization. In particular, EVs, which are composed of a lipid bilayer and transfer bioactive materials such as protein and nucleic acid, regulate homeostasis in blood vessels. Such a bioactive agent coating system and its PLLA composite suggest a new platform for the treatment of cardiovascular dysfunction.
Effect of Ciprofloxacin-Loaded Niosomes on Escherichia coli and Staphylococcus aureus Biofilm Formation
Authors: Maurizi Linda , Forte Jacopo , Ammendolia Maria Grazia , Hanieh Patrizia Nadia , Conte Antonietta Lucia , Relucenti Michela , Donfrancesco Orlando , Ricci Caterina , Rinaldi Federica , Marianecci Carlotta , Carafa Maria , Longhi Catia
Published: November 2022

Infections caused by bacterial biofilms represent a global health problem, causing considerable patient morbidity and mortality in addition to an economic burden. Escherichia coli, Staphylococcus aureus, and other medically relevant bacterial strains colonize clinical surfaces and medical devices via biofilm in which bacterial cells are protected from the action of the immune system, disinfectants, and antibiotics. Several approaches have been investigated to inhibit and disperse bacterial biofilms, and the use of drug delivery could represent a fascinating strategy. Ciprofloxacin (CIP), which belongs to the class of fluoroquinolones, has been extensively used against various bacterial infections, and its loading in nanocarriers, such as niosomes, could support the CIP antibiofilm activity. Niosomes, composed of two surfactants (Tween 85 and Span 80) without the presence of cholesterol, are prepared and characterized considering the following features: hydrodynamic diameter, ζ-potential, morphology, vesicle bilayer characteristics, physical-chemical stability, and biological efficacy. The obtained results suggest that: (i) niosomes by surfactants in the absence of cholesterol are formed, can entrap CIP, and are stable over time and in artificial biological media; (ii) the CIP inclusion in nanocarriers increase its stability, with respect to free drug; (iii) niosomes preparations were able to induce a relevant inhibition of biofilm formation.
Oral Pharmacokinetics of Hydroxycinnamic Acids: An Updated Review
Authors: Veras Kleyton Santos , Fachel Flávia Nathiely Silveira , de Araújo Bibiana Verlindo , Teixeira Helder Ferreira , Koester Letícia Scherer
Published: November 2022

Hydroxycinnamic acids (HCAs) such as caffeic acid (CA), chlorogenic acid (CGA), coumaric acid (COA) isomers, ferulic acid (FA) and rosmarinic acid (RA) are natural phenolic acids with widespread distribution in vegetal foods and well-documented pharmacological activities. However, the low bioavailability of HCAs impairs their administration by the oral route. The present review addresses new findings and important factors/obstacles for their oral administration, which were unexplored in the reviews published a decade ago concerning the bioavailability of phenolic acids. Based on this, the article aims to perform an updated review of the water solubility and gastrointestinal stability of HCAs, as well as describe their oral absorption, distribution, metabolism and excretion (ADME) processes by in vitro, ex vivo, in situ and in vivo methods.
Dissolution and Absorption of Inhaled Drug Particles in the Lungs
Authors: Eedara Basanth Babu , Bastola Rakesh , Das Shyamal C.
Published: November 2022

Dry powder inhalation therapy has been effective in treating localized lung diseases such asthma, chronic obstructive pulmonary diseases (COPD), cystic fibrosis and lung infections. In vitro characterization of dry powder formulations includes the determination of physicochemical nature and aerosol performance of powder particles. The relationship between particle properties (size, shape, surface morphology, porosity, solid state nature, and surface hydrophobicity) and aerosol performance of an inhalable dry powder formulation has been well established. However, unlike oral formulations, there is no standard dissolution method for evaluating the dissolution behavior of the inhalable dry powder particles in the lungs. This review focuses on various dissolution systems and absorption models, which have been developed to evaluate dry powder formulations. It covers a summary of airway epithelium, hurdles to developing an in vitro dissolution method for the inhaled dry powder particles, fine particle dose collection methods, various in vitro dissolution testing methods developed for dry powder particles, and models commonly used to study absorption of inhaled drug.
Dual-Enhanced Pluronic Nanoformulated Methotrexate-Based Treatment Approach for Breast Cancer: Development and Evaluation of In Vitro and In Vivo Efficiency
Authors: Mansour Amira , Mahmoud Mohamed Y. , Bakr Alaa F. , Ghoniem Monira G. , Adam Fatima A. , El-Sherbiny Ibrahim M.
Published: November 2022

Breast cancer is a prevalent tumor and causes deadly metastatic complications. Myriad cancer types, including breast cancer, are effectively treated by methotrexate (MTX). However, MTX hydrophobicity, adverse effects and the development of resistance have inspired a search for new effective strategies to overcome these challenges. These may include the addition of a bioenhancer and/or encapsulation into appropriate nano-based carriers. In the present study, the anticancer effect of MTX was fortified through dual approaches. First, the concomitant use of piperine (PIP) as a bioenhancer with MTX, which was investigated in the MCF-7 cell line. The results depicted significantly lower IC50 values for the combination (PIP/MTX) than for MTX. Second, PIP and MTX were individually nanoformulated into F-127 pluronic nanomicelles (PIP-NMs) and F-127/P-105 mixed pluronic nanomicelles (MTX-MNMs), respectively, validated by several characterization techniques, and the re-investigated cytotoxicity of PIP-NMs and MTX-MNMs was fortified. Besides, the PIP-NMs/MTX-MNMs demonstrated further cytotoxicity enhancement. The PIP-NMs/MTX-MNMs combination was analyzed by flow cytometry to understand the cell death mechanism. Moreover, the in vivo assessment of PIP-NMs/MTX-MNMs was adopted through the Ehrlich ascites model, which revealed a significant reduction of the tumor weight. However, some results of the tumor markers showed that the addition of PIP-NMs to MTX-MNMs did not significantly enhance the antitumor effect.
Synthesis and Electrochemical Evaluation of MSNs-PbAE Nanocontainers for the Controlled Release of Caffeine as a Corrosion Inhibitor
Authors: Aguirre-Pulido Martín , González-Sánchez Jorge A. , Dzib-Pérez Luis R. , Soria-Castro Montserrat , Ávila-Ortega Alejandro , Talavera-Pech William A.
Published: November 2022

In this paper, a controlled-release system of caffeine as a corrosion inhibitor was obtained by encapsulating it in MCM-41 silica nanoparticles coated with a poly(β-amino ester) (PbAE), a pH-sensible polymer. Encapsulation was verified using Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA). The release of caffeine from the nanocontainers was analyzed in electrolytes with pH values of 4, 5, and 7 using UV–Vis, showing a 21% higher release in acidic electrolytes than in neutral electrolytes, corroborating its pH sensitivity. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization were used to determine the inhibition mode and efficiency of the encapsulated and free caffeine. The caffeine released from the nanocontainers showed the highest efficiency, which was 85.19%. These results indicate that these nanocontainers could have potential use in smart anticorrosion coating applications.
Long-Term Evaluation of Changes in Kidney Function after Switching from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in Patients Living with HIV
Authors: Gilbert Jared M. , Vest Kirsten , Kish Troy D.
Published: November 2022

Tenofovir is one of the most widely used medications for HIV treatment and is administered as either tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF). Use of TAF is preferred as it is associated with fewer negative impacts on renal function; however, long-term follow-up beyond 96 weeks is limited. A retrospective chart review of patients ≥18 years who received TDF-containing anti-retroviral therapy (ART) for ≥6 months and then switched to a TAF-containing regimen between 1 December 2015 and 1 January 2020 is presented. The primary objective was to evaluate changes in kidney function as measured by eGFR and Scr. The secondary objective was to evaluate changes in lipids. Among the 142 patients identified, the median age was 66 years old with a median follow-up of 3.6 years. The change in kidney function was a median increase in Scr of 0.1 mg/dL and a decrease in eGFR of −8 mL/min/1.73 m2. The change in lipid panels at the end of the medication use evaluation endpoint was a decrease in total cholesterol, LDL, HDL, and triglycerides of −2.5, −0.1, −0.6, and −9 mmol/L, respectively. There was no clinically meaningful difference in kidney function as measured by eGFR or Scr, nor was there any clinically meaningful difference in lipid panels in patients switched from TDF to TAF-containing ART. Our observations suggest that the favorable impact of TAF on kidney function is sustained for at least 44 months after conversion from TDF.
Compressive Bidirectional Reflection Distribution Function-Based Feature Extraction Method for Camouflaged Object Segmentation
Authors: Chen Xueqi , Xu Yunkai , Shao Ajun , Kong Xiaofang , Chen Qian , Gu Guohua , Wan Minjie
Published: November 2022

Camouflaged target segmentation has been widely used in both civil and military applications, such as wildlife behaviour monitoring, crop pest control, and battle reconnaissance. However, it is difficult to distinguish camouflaged objects and natural backgrounds using traditional grey-level feature extraction. In this paper, a compressive bidirectional reflection distribution function-based feature extraction method is proposed for effective camouflaged object segmentation. First, multidimensional grey-level features are extracted from multiple images with different illumination angles in the same scene. Then, the multidimensional grey-level features are expanded based on Chebyshev polynomials. Next, the first several coefficients are integrated as a new optical feature, which is named the compressive bidirectional reflection distribution function feature. Finally, the camouflaged object can be effectively segmented from the background by compressive feature clustering. Both qualitative and quantitative experimental results prove that our method has remarkable advantages over conventional single-angle or multi-angle grey-level feature-based methods in terms of segmentation precision and running speed.
Proteomic Analysis of Barley (Hordeum vulgare L.) Leaves in Response to Date Palm Waste Compost Application
Authors: Ghouili Emna , Abid Ghassen , Jebara Moez , Nefissi Ouertani Rim , de Oliveira Ana Caroline , El Ayed Mohamed , Muhovski Yordan
Published: November 2022

Composts are an emerging biofertilizers used in agronomy that can improve crop performance, but much less is known regarding their modes of action. The current study aimed to investigate the differentially abundant proteins (DAPs) in barley leaves associated with growth promotion induced by application of date palm waste compost. Morphophysiological measurements revealed that compost induced a significant increase in plant height, chlorophyll content, gas exchange parameters and plant biomass. LC-MS/MS analyses indicate that compost induced global changes in the proteome of barley leaves. A total of 62 DAPs (26 upregulated and 36 downregulated) among a total of 2233 proteins were identified in response to compost application. The expression of DAPs was further validated based on qRT-PCR. Compost application showed altered abundance of several proteins related to abiotic stress, plant defense, redox homeostasis, transport, tricarboxylic acid cycle, carbohydrate, amino acid, energy and protein metabolism. Furthermore, proteins related to metabolic processes of phytohormone, DNA methylation and secondary metabolites were induced. These results indicate that barley responds to compost application by complex metabolism pathways and may result in a positive alteration in a physiological and metabolic barley plant state which consequently could lead to improved growth and stress adaptation observed in compost-treated plants.
Differential Effects of Ammonium (NH4+) and Potassium (K+) Nutrition on Photoassimilate Partitioning and Growth of Tobacco Seedlings
Authors: Aluko Oluwaseun Olayemi , Li Chuanzong , Yuan Guang , Nong Tongjia , Xiang Haiying , Wang Qian , Li Xuemei , Liu Haobao
Published: November 2022

Plants utilize carbohydrates as the main energy source, but much focus has been on the impact of N and K on plant growth. Less is known about the combined impact of NH4+ and K+ nutrition on photoassimilate distribution among plant organs, and the resultant effect of such distribution on growth of tobacco seedlings, hence this study. Here, we investigated the synergetic effect of NH4+ and K+ nutrition on photoassimilate distribution, and their resultant effect on growth of tobacco seedlings. Soluble sugar and starch content peaks under moderate NH4+ and moderate K+ (2-2 mM), leading to improved plant growth, as evidenced by the increase in tobacco weight and root activity. Whereas, a drastic reduction in the above indicators was observed in plants under high NH4+ and low K+ (20-0.2 mM), due to low carbohydrate synthesis and poor photoassimilate distribution. A strong positive linear relationship also exists between carbohydrate (soluble sugar and starch) and the activities of these enzymes but not for invertase. Our findings demonstrated that NH4+ and K+-induced ion imbalance influences plant growth and is critical for photoassimilate distribution among organs of tobacco seedlings.
The Role of Carbonic Anhydrase αCA4 in Photosynthetic Reactions in Arabidopsis thaliana Studied, Using the Cas9 and T-DNA Induced Mutations in Its Gene
Authors: Rudenko Natalia N. , Permyakova Natalya V. , Ignatova Lyudmila K. , Nadeeva Elena M. , Zagorskaya Alla A. , Deineko Elena V. , Ivanov Boris N.
Published: November 2022

An homozygous mutant line of Arabidopsis thaliana with a knocked out At4g20990 gene encoding thylakoid carbonic anhydrase αCA4 was created using a CRISPR/Cas9 genome editing system. The effects of the mutation were compared with those in two mutant lines obtained by the T-DNA insertion method. In αCA4 knockouts of all three lines, non-photochemical quenching of chlorophyll a fluorescence was lower than in the wild type (WT) plants due to a decrease in its energy-dependent component. The αCA4 knockout also affected the level of expression of the genes encoding all proteins of the PSII light harvesting antennae, the genes encoding cytoplasmic and thylakoid CAs and the genes induced by plant immune signals. The production level of starch synthesis during the light period, as well as the level of its utilization during the darkness, were significantly higher in these mutants than in WT plants. These data confirm that the previously observed differences between insertional mutants and WT plants were not the result of the negative effects of T-DNA insertion transgenesis but the results of αCA4 gene knockout. Overall, the data indicate the involvement of αCA4 in the photosynthetic reactions in the thylakoid membrane, in particular in processes associated with the protection of higher plants’ photosynthetic apparatus from photoinhibition.
Eco-Geography and Phenology Are the Major Drivers of Reproductive Isolation in the Royal Irises, a Species Complex in the Course of Speciation
Authors: Osmolovsky Inna , Shifrin Mariana , Gamliel Inbal , Belmaker Jonathan , Sapir Yuval
Published: November 2022

The continuous nature of speciation implies that different species are found at different stages of divergence, from no- to complete reproductive isolation. This process and its underlying mechanisms are best viewed in incipient species. Moreover, the species complex can offer unique insight into how reproductive isolation (RI) has evolved. The royal irises (Iris section Oncocyclus) are a young group of species in the course of speciation, providing an ideal system for speciation study. We quantified pre- and post-zygotic reproductive barriers between the eight Israeli species of this complex and estimated the total RI among them. We tested for both pre-pollination and post-pollination reproductive barriers. Pre-pollination barriers, i.e., eco-geographic divergence and phenological differentiation were the major contributors to RI among the Iris species. On the other hand, post-pollination barriers, namely pollen–stigma interactions, fruit set, and seed viability had negligible contributions to total RI. The strength of RI was not uniform across the species complex, suggesting that species may have diverged at different rates. Overall, this study in a young, recently diverged group of species provides insight into the first steps of speciation, suggesting a crucial role of the pre-zygotic barriers.
Varietal Descriptors for the Distinction of Underutilized Varieties of Sechium edule (Jacq) Swartz
Authors: Cadena-Iñiguez Jorge , Avendaño-Arrazate Carlos Hugo , Arévalo-Galarza Ma. de Lourdes , Cisneros-Solano Víctor Manuel , Ruiz-Posadas Lucero del Mar , Aguirre-Medina Juan Francisco , Watanabe Kazuo , Machida-Hirano Ryoko , Barrera-Guzmán Luís Angel
Published: November 2022

Sechium edule (Jacq.) Sw. (Cucurbitaceae) is a species native to Mexico and Central America. The collection, characterization, and evaluation of accessions maintained in genebanks is essential for the conservation of this species. However, there are no specific varietal descriptors that differ from those used in a phenetic approach and are adapted to international registration guidelines to help distinguish, improve, cluster, and protect intraspecific variants of common use and those obtained by breeding. Therefore, 65 morphological descriptors (qualitative and quantitative) were evaluated in 133 accessions obtained from Mexico, Guatemala, and Costa Rica located in the National Germplasm Bank of S. edule in Mexico. These characteristics were observed to be phenetically stable for five generations under the same agroclimatic conditions. In addition, an analysis of amplified fragment length polymorphism (AFLP) was applied to 133 samples from a set of 245 accessions. According to the multivariate analysis, 26 of the 65 descriptors evaluated (qualitative and quantitative) enabled differentiation of varieties of S. edule. The AFLP analysis showed a high level of polymorphism and genetic distance between cultivated accessions and their corresponding wild ancestor. The variations in S. edule suggest that the morphological characteristics have differentiated from an essentially derived initial edible variety (ancestral original variety), but unlike other cucurbits, there is no evidence of the ancestral edible for Sechium since the seed is unorthodox and there are no relicts.
Properties in Langmuir Monolayers and Langmuir-Blodgett Films of a Block Copolymer Based on N-Isopropylacrylamide and 2,2,3,3-Tetrafluropropyl Methacrylate
Authors: Zamyshlyayeva Olga , Shaliagina Zarina , Simonova Maria , Filippov Alexander , Baten’kin Maxim
Published: November 2022

The amphiphilic block copolymer poly(N-isopropylacrylamide)–Ge(C6F5)2–poly(2,2,3,3-tetrafluoropropyl methacrylate) was prepared by the reaction of chain transfer to bis-(pentafluorophenyl)germane during the polymerization of N-isopropylacrylamide and the subsequent postpolymerization of isolated functional polymers in 2,2,3,3–tetrafluoropropyl methacrylate. The conversion of the block copolymer was 68% and the molecular weight of the sample was 490,000 g/mol. The colloidal chemical properties of Langmuir monolayers and Langmuir-Blodgett films of synthesized block copolymer have been studied. For comparison, a functional polymer, namely, poly-N-isopropylacrylamide with terminal –Ge(C6F5)2H group, was synthesized and studied. The concentrations of spreading solutions were selected and the effect of subphase acidity on the formation of monolayers of macromolecules of the block copolymer was studied. It was found that regardless of the acidity of the subphase, high pressure of fracture of films are characteristic of monolayers of collapse pressures πmax = (48–61) mN/m. The morphology of the Langmuir-Blodgett films of functional polymer exhibit isolated elongated micelles with high densities in the form of “octopus” on the periphery of which there are terminal hydrophobic groups. For the Langmuir-Blodgett film of block copolymer, a comb-like structure is observed with characteristic protrusions.
Production and Characterization of Active Bacterial Cellulose Films Obtained from the Fermentation of Wine Bagasse and Discarded Potatoes by Komagateibacter xylinus
Authors: Cazón Patricia , Puertas Gema , Vázquez Manuel
Published: November 2022

Potato waste, such as peels, broken or spoiled potatoes and grape bagasse residues from the winery industry, can be used for the biotechnological production of high-value products. In this study, green, sustainable and highly productive technology was developed for the production of antioxidant bacterial cellulose (BC). The aim of this work was to evaluate the feasibility of a low-cost culture medium based on wine bagasse and potato waste to synthesize BC. Results show that the production of BC by Komagateibacter xylinus in the GP culture medium was five-fold higher than that in the control culture medium, reaching 4.0 g/L BC in 6 days. The compounds of the GP culture medium improved BC production yield. The mechanical, permeability, swelling capacity, antioxidant capacity and optical properties of the BC films from the GP medium were determined. The values obtained for the tensile and puncture properties were 22.77 MPa for tensile strength, 1.65% for elongation at break, 910.46 MPa for Young’s modulus, 159.31 g for burst strength and 0.70 mm for distance to burst. The obtained films showed lower permeability values (3.40 × 10−12 g/m·s·Pa) than those of other polysaccharide-based films. The BC samples showed an outstanding antioxidant capacity (0.31–1.32 mg GAE/g dried film for total phenolic content, %DPPH• 57.24–78.00% and %ABTS•+ 89.49–86.94%) and excellent UV-barrier capacity with a transmittance range of 0.02–0.38%. Therefore, a new process for the production of BC films with antioxidant properties was successfully developed.
Synthesis and Characterization of Chitosan-Containing ZnS/ZrO2/Graphene Oxide Nanocomposites and Their Application in Wound Dressing
Authors: Alghuwainem Yousef A. A. , Gouda Mohamed , Khalaf Mai M. , Elmushyakhi Abraham , Abou Taleb Manal F. , El-Lateef Hany M. Abd
Published: November 2022

The development of scaffold-based nanofilms for the acceleration of wound healing and for maintaining the high level of the healthcare system is still a challenge. The use of naturally sourced polymers as binders to deliver nanoparticles to sites of injury has been highly suggested. To this end, chitosan (CS) was embedded with different nanoparticles and examined for its potential usage in wound dressing. In detail, chitosan (CS)-containing zinc sulfide (ZnS)/zirconium dioxide (ZrO2)/graphene oxide (GO) nanocomposite films were successfully fabricated with the aim of achieving promising biological behavior in the wound healing process. Morphological examination by SEM showed the formation of porous films with a good scattering of ZnS and ZrO2 nanograins, especially amongst ZnS/ZrO2/GO@CS film. In addition, ZnS/ZrO2/GO@CS displayed the lowest contact angle of 67.1 ± 0.9°. Optically, the absorption edge records 2.35 eV for pure chitosan, while it declines to 1.8:1.9 scope with the addition of ZnS, ZrO2, and GO. Normal lung cell (WI-38) proliferation inspection demonstrated that the usage of 2.4 µg/mL ZnS/ZrO2/GO@CS led to a cell viability % of 142.79%, while the usage of 5000 µg/ mL led to a viability of 113.82%. However, the fibroblast malignant cell line exposed to 2.4 µg/mL ZnS/ZrO2/GO@CS showed a viability % of 92.81%, while this percentage showed a steep decline with the usage of 5000 µg/ mL and 2500 µg/mL, reaching 23.28% and 27.81%, respectively. Further biological assessment should be executed with a three-dimensional film scaffold by choosing surrounding media characteristics (normal/malignant) that enhance the selectivity potential. The fabricated scaffolds show promising selective performance, biologically.
Removal of Heavy Metal Ions from Wastewater with Poly-ε-Caprolactone-Reinforced Chitosan Composite
Authors: Martínez Manuel E. , Rangel-Méndez José René , Gimeno Miquel , Tecante Alberto , Lapidus Gretchen T. , Shirai Keiko
Published: November 2022

Currently, the requirements for adsorbent materials are based on their environmentally friendly production and biodegradability. However, they are also related to the design of materials to sustain many cycles in pursuit of low cost and profitable devices for water treatments. In this regard, a chitosan reinforced with poly-ε-caprolactone thermoplastic composite was prepared and characterized by scanning electron microscopy; Fourier transforms infrared spectroscopy, X-ray diffraction analysis, mechanical properties, as well as erosion and swelling assays. The isotherm and kinetic data were fitted with Freundlich and pseudo-second-order models, respectively. The adsorption equilibrium capacities at pH 6 of Zn(II), Cu(II), Fe(II), and Al(III) were 165.59 ± 3.41 mg/g, 3.91 ± 0.02 mg/g, 10.72 ± 0.11 mg/g, and 1.99 ± 0.22 mg/g, respectively. The adsorbent material lost approximately 6% of the initial mass in the adsorption-desorption processes.
Cellulose Nanocrystals (CNCs) and Its Modified Form from Durian Rind as Dexamethasone Carrier
Authors: Putro Jindrayani Nyoo , Edi Soetaredjo Felycia , Irawaty Wenny , Budi Hartono Sandy , Santoso Shella Permatasari , Lie Jenni , Yuliana Maria , Widyarani  , Shuwanto Hardy , Wijaya Christian Julius , Gunarto Chintya , Puspitasari Nathania , Ismadji Suryadi
Published: November 2022

In this study, CNCs were extracted from durian rind. Modification to CNCs with saponin was conducted at 50 °C for one h. CNCs and CNCs-saponin were employed as dexamethasone carriers. Modification to CNCs using saponin did not change the relative crystallinity of CNCs. CNCs’ molecular structure and surface chemistry did not alter significantly after modification. Both nanoparticles have surface charges independently of pH. Dexamethasone-released kinetics were studied at two different pH (7.4 and 5.8). Higuchi, Ritger–Peppas, first-order kinetic and sigmoidal equations were used to represent the released kinetic data. The sigmoidal equation was found to be superior to other models. The CNCs and CNCs-saponin showed burst release at 30 min. The study indicated that cell viability decreased by 30% after modification with saponin.
Use of Fourier Series in X-ray Diffraction (XRD) Analysis and Fourier-Transform Infrared Spectroscopy (FTIR) for Estimation of Crystallinity in Cellulose from Different Sources
Authors: Montoya-Escobar Nicolás , Ospina-Acero Daniel , Velásquez-Cock Jorge Andrés , Gómez-Hoyos Catalina , Serpa Guerra Angélica , Gañan Rojo Piedad Felisinda , Vélez Acosta Lina Maria , Escobar Juan Pablo , Correa-Hincapié Natalia , Triana-Chávez Omar , Zuluaga Gallego Robin , Stefani Pablo M.
Published: November 2022

Cellulose crystallinity can be described according to the crystal size and the crystallinity index (CI). In this research, using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods, we studied the crystallinity of three different types of cellulose: banana rachis (BR), commercial cellulose (CS), and bacterial cellulose (BC). For each type of cellulose, we analyzed three different crystallization grades. These variations were obtained using three milling conditions: 6.5 h, 10 min, and unmilled (films). We developed a code in MATLAB software to perform deconvolution of the XRD data to estimate CI and full width at half-maximum (FWHM). For deconvolution, crystalline peaks were represented with Voigt functions, and a Fourier series fitted to the amorphous profile was used as the amorphous contribution, which allowed the contribution of the amorphous profile to be more effectively modeled. Comparisons based on the FTIR spectra and XRD results showed there were no compositional differences between the amorphous samples. However, changes associated with crystallinity were observed when the milling time was 10 min. The obtained CI (%) values show agreement with values reported in the literature and confirm the effectiveness of the method used in this work in predicting the crystallization aspects of cellulose samples.
Parametric Study on Low-Velocity Impact (LVI) Damage and Compression after Impact (CAI) Strength of Composite Laminates
Authors: Guo Shuangxi , Li Xueqin , Liu Tianwei , Bu Guangyu , Bai Jiangbo
Published: November 2022

A full-scale model for predicting low-velocity impact (LVI) damage and compression after impact (CAI) strength was established based on a subroutine of the material constitutive relationship and the cohesive elements. The dynamic responses of the laminate under impact load and damage propagation under a compressive load were presented. The influences of impact energy and ply thickness on the impact damage and the CAI strength were predicted. The predicted results were compared with the experimental ones. It is shown that the predicted value of the CAI strength is in good agreement with the experimental result. As the impact energy reaches a certain value, the CAI strength no longer decreases with the increase in the impact energy. Decreasing the ply thickness can effectively improve the damage resistance and CAI strength.
Valorisation of Underutilized Grass Fibre (Stem) as a Potential Material for Paper Production
Authors: Lee Chuan Li , Chin Kit Ling , H’ng Paik San , Hafizuddin Mohd Sahfani , Khoo Pui San
Published: November 2022

An integrated and feasible approach was proposed using the underutilized grass fibre (stem) derived from Napier grass and sugarcane for paper production in this study. To enhance paper strength, pre-hydrolysis and beating techniques have been used to improve the chemical pulps and mechanical pulping process, respectively. Napier grass and sugarcane are promising non-wood sources for pulp production, owing to their high cellulose and low lignin and extractive content. With the additional mild alkaline pre-treatment to the mechanical pulping process, the lignin content was greatly reduced. The results reveal that the mechanical pulping with alkaline pre-treatment may indeed potentially replace the most prevalent pulping process (chemical pulping). As evidenced by the paper strength properties, mechanical pulping is far more suitable for grass-type biomass, particularly Napier grass, which had a folding endurance capability five times greater than chemical pulping. Furthermore, the remaining high hemicellulose content from mechanical pulping contributed to a high pulp yield, while also facilitating the fibrillation on the sugarcane’s laboratory paper handsheet. The findings also demonstrated that the additional beating process from chemical pulping causes the fibres to be drawn toward each other, resulting in a more robust fibre network that contributes to good paper strength. Consequently, this work sheds new light on the development of advanced paper derived from grass fibre.
Seismic Performance of Recycled Aggregate Geopolymer Concrete-Filled Double Skin Tubular Columns with Internal Steel and External FRP Tube
Authors: Alashker Yasser , Raza Ali
Published: November 2022

The large production of cement is resulting in a high-carbon footprint, which is essential to minimize for sustainable concrete construction. Moreover, the large quantity of recycled coarse aggregate (RCA) from the demolition of old concrete structures is creating problems for landfill and disposal. The primary goal of this study is to investigate the seismic efficiency of innovative fiber-reinforced polymer (FRP)-recycled aggregate geopolymer concrete (RAGC) steel-tubed columns (FGSTCs) with an internal steel tube (STT), an external glass-FRP tube (GLT), and RAGC located between the two-tubed components to develop a serviceable structural element. To study their seismic functioning under axial load and lateral repeated load, five FGSTC specimens were manufactured and analyzed under quasi-static loads. The influence of three variables on the performance of FGSTC specimens, consisting of STT reinforcing ratio, compression ratio, and recycled coarse aggregate (RCA) replacement ratio, was investigated in this investigation. The produced specimens’ ductility, hysteretic loops, strain distribution, skeleton curves, stiffness functioning, energy capacity dissipation, damaging functioning, and strength loss were all assessed and discussed. The results of this investigation revealed that percentage substitution of RCA had a minor impact on the seismic functioning of FGSTCs; however, the compression-load ratio depicted a substantial impact. The energy loss of the FGSTCs was 24.5% higher than that of their natural aggregate equivalents. FGSTCs may have a 16.9% lower cumulative failure rate than their natural aggregate counterparts.
Effect of Processing Time of Steam-Explosion for the Extraction of Cellulose Fibers from Phoenix canariensis Palm Leaves as Potential Renewable Feedstock for Materials
Authors: Pérez-Limiñana Maria Angeles , Pérez-Aguilar Henoc , Ruzafa-Silvestre Carlos , Orgilés-Calpena Elena , Arán-Ais Francisca
Published: November 2022

This paper briefly discusses the utilization of pruning wastes as a lignocellulosic source of cellulose fibers, which could be of potential use in the development of valuable materials such as sustainable textiles and fillers for footwear components including uppers and soles. Phoenix canariensis palm leaves, one of the most common plants found in the local environment of the Alicante region (Spain), was used as a biomass raw material. Determining appropriate processing parameters and their desired range of maximum cellulose extraction states is key to improving yields. Therefore, this study aimed at determining the effect of processing conditions on cellulose extraction by optimizing the hydrothermal process, as a part of overall combined processes involving several steps. Specifically, the time of the steam-explosion stage was varied between 15 and 33 min in order to maximize the cellulose extraction yield. The composition of both the extracted fibers and the resulting by-product solutions generated during the different steps were determined by FTIR and TGA in order to analyze the effectiveness of removing hemicellulose, lignin and extractives as well as the removed substances at each stage for their further valorization. Additionally, the morphology of cellulosic fibers was evaluated by SEM and their crystallinity by XRD. Crystalline cellulose fibers were successfully extracted from pruning biomass wastes, achieving more efficient removal of hemicellulose and lignin when the hydrothermal process was assessed over 25–33 min. This resulted in finer and smoother fibers, but the crystallinity of α-cellulose decreased as the time of steam-explosion increased to 33 min. The characterization of waste solutions generated after the different extraction steps confirmed that the most effective treatments to remove lignin and hemicellulose from the cell wall are alkaline pretreatment and a hydrothermal process.
Novel Metallo-Supramolecular Polymers with 1-Thioxophosphole Main-Chain Units and Remarkable Photoinduced Changes in Their Resonance Raman Spectra
Authors: Šloufová Ivana , Urválková Tereza , Hissler Muriel , Vohlídal Jiří
Published: November 2022

New low-bandgap unimers, with the central thiophene-(1-thioxophosphole)-thiophene (TPT) ring sequence and 2,2′:6′,2″-terpyridin-4′-yl (tpy) end groups connected to the central unit via conjugated linkers of different size, are prepared and assembled with Zn(II) and Fe(II) ions to metallo-supramolecular polymers (MSPs) that are studied regarding their properties. The most interesting feature of Zn-MSPs is the luminescence extended deep into the NIR region. Fe-MSPs not only show the metal-to-ligand charge transfer (MLCT) manifested by the MLCT band (an expected feature) but also an as-yet-undescribed remarkable phenomenon: specific damping of the bands of the TPT sequence in the resonance Raman spectra taken from solid Fe-MSPs using the excitation to the MLCT band (532 nm). The damping is highly reversible at the low laser power of 0.1 mW but gradually becomes irreversible as the power reaches ca. 5 mW. The revealed phenomenon is not shown by the same Fe-MSPs in solutions, nor by Fe-MSPs containing no phosphole units. A hypothesis is proposed that explains this phenomenon and its dependence on the irradiation intensity as a result of the interplay of three factors: (i) enhancement of the MLCT process by excitation radiation, (ii) the electron-acceptor character of the 1-thioxophosphole ring, and (iii) morphological changes of the lattice and their dependence on the population of new structures in the lattice.
Emerging Trends in Porogens toward Material Fabrication: Recent Progresses and Challenges
Authors: Lakshmi D. Shanthana , K. S. Radha , Castro-Muñoz Roberto , Tańczyk Marek
Published: November 2022

Fabrication of tailor-made materials requires meticulous planning, use of technical equipments, major components and suitable additives that influence the end application. Most of the processes of separation/transport/adsorption have environmental applications that demands a material to be with measurable porous nature, stability (mechanical, thermal) and morphology. Researchers say that a vital role is played by porogens in this regard. Porogens (i.e., synthetic, natural, mixed) and their qualitative and quantitative influence on the substrate material (polymers (bio, synthetic), ceramic, metals, etc.) and their fabrication processes are summarized. In most cases, porogens critically influence the morphology, performance, surface and cross-section, which are directly linked to material efficiency, stability, reusability potential and its applications. However, currently there are no review articles exclusively focused on the porogen pores’ role in material fabrication in general. Accordingly, this article comprises a review of the literature on various types of porogens, their efficiency in different host materials (organic, inorganic, etc.), pore size distribution (macro, micro and nano), their advantages and limitations, to a certain extent, and their critical applications. These include separation, transport of pollutants, stability improvement and much more. The progress made and the remaining challenges in porogens’ role in the material fabrication process need to be summarized for researcher’s attention.
Improvement in Migration Resistance of Hydroxyl-Terminated Polybutadiene (HTPB) Liners by Using Graphene Barriers
Authors: Zhang Yanan , Tian Yu , Zhang Yulong , Fu Xuelong , Li Hao , Lu Zhehong , Zhang Tengyue , Hu Yubing
Published: November 2022

The excessive migration of plasticizers leads to debonding and cracking of a liner, which can compromise the safety of a solid propellant. Graphene oxide (GO), with a laminar structure as a filler, can effectively reduce the migration of plasticizers. In this study, we modified GO using toluene diisocyanate (TDI). The cross-link density of the substrate was increased by grafting isocyanate groups to obtain a denser liner for the purpose of preventing plasticizer migration. We also used octadecylamine (ODA) to modify GO by grafting negatively charged amide groups on the GO surface. The electrostatic repulsive effect of the amide group on the plasticizer molecules was used to prevent plasticizer migration. Two modified GOs were filled into the hydroxyl-terminated polybutadiene to prepare two composite liners. We then investigated the migration resistance and migration kinetics of each modified liner using the dipping method. In addition, we explored the mechanical properties of each modified liner. Compared with the original liner, the anti-migration and mechanical properties of the modified composite liners were significantly improved. Among them, the TDI-modified liner had the most obvious improvement in migration resistance, while the ODA-modified liner had the greatest improvement in bonding properties. All types of liners met the requirements of the current propellant systems. This study provides an effective reference for improving the migration resistance and bonding properties of the composite liner.
Macroscopic Properties and Pore Structure Fractal Characteristics of Alkali-Activated Metakaolin–Slag Composite Cementitious Materials
Authors: Zhan Jianghuai , Fu Bo , Cheng Zhenyun
Published: November 2022

To investigate the effects of slag and Na2O content on the macroscopic properties and pore structure characteristics of alkali-activated metakaolin–slag (AAMS) composite cementitious materials, this study used X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM-EDS), and mercury-pressure (MIP) tests for characterization and analyzed the hydration product compositions, microstructures, and pore structure characteristics of AAMS composite cementitious materials. The relationships between the fractal dimension and the pore structure parameters, compressive strengths, and drying shrinkage rates of AAMS composite cementitious materials were investigated with the thermodynamic fractal model. The results showed that at the age of 28 d, the compressive strength and drying shrinkage of the AAMS composite binder increased by 20.57% and 215.11%, respectively, when the slag content increased from 0 to 50%. When the Na2O content increased from 8% to 12%, the compressive strength and drying shrinkage of the AAMS composite increased by 24.37% and 129.40%, respectively. The compressive strengths of AAMS composite cementitious materials increased with increasing slag content and Na2O content, but the drying shrinkage of the system increased, and the volume stability worsened. Microscopic analyses showed that with increases in the slag and Na2O contents, the hydration products of AAMS composite cementitious materials increased, and C-A-S-H and N-A-S-H filled each other so that the internal structures of AAMS composite cementitious materials were denser, and the porosities were significantly reduced. By comparing and analyzing the Menger sponge model and the fractal model based on the thermodynamic relationships, it was found that the fractal model based on the thermodynamic relationship better reflected the pore size distribution over the whole pore size determination range, and the correlation coefficients R2 were above 0.99, indicating that the fractal dimension calculated by the fractal model based on the thermodynamic relationship provided a comprehensive evaluation index for the pore structure characteristics of AAMS composite cementitious materials, and the fractal dimension correlated well with the pore structure parameters, compressive strengths, and drying shrinkage rates of cementitious materials.