Macromol, Volume 4, Issue 3 (September 2024) – 16 articles

The interaction of poly(trimethylene carbonate) (PTMC) with hydroxyl group compounds was investigated as a model for polymer blending with polysaccharides. While 1-butanol, 2-butanol, ethylene glycol, and 1,2-cyclohexanediol showed almost no detectable interaction with PTMC in both solution states with the ¹H NMR and solid states with the FT-IR, glucose and cellobiose suggested a slight change in the spectral pattern in FT-IR analysis. The thermal properties of the blended samples of PTMC and these hydroxyl groups were also investigated. Although the blends of PTMC with 1-butanol and 2-butanol did not influence thermal degradation behaviors due to their low boiling points, the PTMC blend with a higher number of hydroxyl groups, especially glucose and cellobiose, tended to increase thermal resistance and glass transition temperature, hence showing the existence of an interaction through hydrogen bonding. Full article

A Leuconostoc mesenteroides strain (SJC113) isolated from cheese curd was found to produce large amounts of a mucoid exopolysaccharide (EPS). An analysis revealed the glucan nature of the EPS with 84.5% (1→6)-linked α-d-glucose units and 5.6% (1,3→6)-linked α-d-glucose units as branching points. The EPS showed 52% dextranase resistance and a yield of 7.4 ± 0.9 g/L from MRS medium supplemented with 10% sucrose within 48 h. Ln. mesenteroides SJC113 was also characterized and tested for the production of EPS as a fat substitute in fresh cheese. Strain SJC113 showed high tolerance to a wide range of NaCl concentrations (2, 5 and 10%), high β-galactosidase activity (2368 ± 24 Miller units), cholesterol-reducing ability (14.8 ± 4.1%), free radical scavenging activity (11.7 ± 0.7%) and hydroxyl scavenging activity (15.7 ± 0.4%). The strain had no virulence genes and was sensitive to clinically important antibiotics such as ampicillin, tetracycline and chloramphenicol. Ln. mesenteroides SJC113 produced highly viscous EPS during storage at 8 °C in skim milk with 5% sucrose. Therefore, these conditions were used for EPS production in skim milk before incorporation into fresh cheese. Four types of fresh cheese were produced: full-fat cheese (FF) made from pasteurized whole milk, non-fat cheese (NF) made from pasteurized skim milk, non-fat cheese made from skim milk fermented with Ln. mesenteroides without added sugar (NFLn0) and non-fat cheese made from skim milk fermented with Ln. mesenteroides with 5% sucrose (NFLn5). While the NF cheeses had the highest viscosity and hardness, the NFLn5 cheeses showed lower firmness and viscosity, higher water-holding capacity and lower weight loss during storage. Overall, the NFLn5 cheeses had similar rheological properties to full-fat cheeses with a low degree of syneresis. It was thus shown that the glucan-type EPS produced by Ln. mesenteroides SJC113 can successfully replace fat without altering the texture of fresh cheese. Full article

With the world population rising, wheat straw production is expected to reach 687–740 million tons per year by 2050. Its frequent application as a fuel source leads to air, water, and soil pollution. Limited literature exists on methods for separating components of residual wheat straw. Optimal conditions for organosolv pulping of hydrolyzed wheat straw include 3% FeCl₃·6H₂O as a catalyst, a biomass-to-solvent ratio of 1:15 (m/v), and 50% ethanol:water as cooking liquor at 200 °C for 30 min. Desilication conditions involve extraction with 7.5% Na₂CO₃ at a biomass-to-solvent ratio of 1:20 (m/v) treated at 115 °C for 60 min. Lignin from hydrolyzed wheat straw showed similar properties to organosolv lignin from untreated straw, with minimal lignin alteration during hydrolysis. Hydrolysis significantly degraded cellulose. A 41% lignin recovery rate with 95% purity was achieved from pre-extracted hydrolyzed straw. Recovered cellulose after silica removal had 2% ash and 87% purity. The innovation of this process lies in the development of a comprehensive, sustainable, efficient, and economically viable biorefinery process that efficiently separates key components of wheat straw, i.e., xylose, lignin, cellulose, and silica, while addressing environmental pollution associated with its traditional use as fuel. Full article

The combination of different wood-modification technologies to obtain improved performance is increasingly receiving attention in research. In this study, Scots pine (Pinus sylvestris) sapwood was impregnated with furfuryl alcohol (FFA) in pure aqueous 20, 40, and 60% solution strength without adding any catalyst. In a second step, the FFA was polymerized while simultaneously performing thermal modification in a closed system at 130, 150, or 180 °C. After leaching and ageing tests, the nine different combinations were tested in use class 4 applications (in contact with or very close to the ground and frequently wet) according to CEN/TS 15083-2 (2005) decay laboratory test. It was noted that even the minimum-intensity combination of 20% FFA at 130 °C resulted in maximum durability class (DC) 1 performance. On the contrary, DC 4 was assigned to thermally modified control samples, even at the maximum intensity of thermal modification. Similarly, for FFA modifications, previous research has suggested that an uptake of 35% solution strength is required to obtain an adequate durability performance in use class 4 applications. High levels of resistance against termites were also noted by corresponding termite lab tests. Moisture studies showed the combined treatments resulted in improved stability and reduced moisture uptakes. Thus, the results obtained by this study revealed synergistic performance effects, which originate from the combined thermo-chemical modification approach, and which were higher than simple accumulation of the individual performance of purely thermally or chemically modified wood. Thus, the presented findings have provided positive implications for industrial applications of thermo-chemical modification techniques and offers an array of new research opportunities. Full article

Although there are numerous available immunomodulators, those of natural origin would be preferable based on their safety profile and effectiveness. The research and clinical interest in immunomodulators have increased in the last decades, especially in the immunomodulatory properties of plant-based therapies. Innovative technologies and extensive study on immunomodulatory natural products, botanicals, extracts, and active moieties with immunomodulatory potential could provide us with valuable entities to develop as novel immunomodulatory medicines to enhance current chemotherapies. This review focuses on plant-based immunomodulatory drugs that are currently in clinical studies. However, further studies in this area are of utmost importance to obtain complete information about the positive effects of medicinal plants and their chemical components and molecules as an alternative to combatting various diseases and/or prevention. Full article

This study explores the potential of cold atmospheric plasma (CAP) to facilitate the delivery of large-molecule drugs to the brain. The blood–brain barrier (BBB) restricts the passage of most drugs, hindering treatment for neurological disorders. CAP generates reactive oxygen and nitrogen species (RONS) that may disrupt the BBB’s tight junctions, potentially increasing drug permeability. An in vitro BBB model and an immortalized cell line (bEND.3) were used in this experiment. Fluorescein isothiocyanate dextran (FD-4), a model drug, was added to the cells to determine drug permeability. Custom microplasma was used to produce reactive oxygen species (ROS). Trans-endothelial electrical resistance (TEER) measurements assessed the integrity of the BBB after the CAP treatment. A decrease in TEER was observed in the CAP-treated group compared to the controls, suggesting increased permeability. Additionally, fluorescence intensity measurements from the basal side of the trans-well plate indicated higher drug passage in the CAP-treated group. Moreover, the higher presence of ROS in the plasma-treated cells confirmed the potential of CAP in drug delivery. These findings suggest that CAP may be a promising approach for enhancing brain drug delivery. Full article

Microalgae are a substantial group of unicellular prokaryotic and eukaryotic marine organisms. Due to their high protein content of 50–70%, microalgae have the potential to become a sustainable alternative protein source, as well as aiding in the development of bioactive peptide-based nutraceuticals. A series of major steps are involved in the production of peptides from microalgae, which include the disruption of the microalgal cell wall, the hydrolysis of proteins, and the extraction or isolation of peptides derived from hydrolysis. Physical methods of cell wall disruptions are favored due to the ability to obtain high-quality protein fractions for peptide production. Bioactive peptides are protein fragments of two to twenty amino acid residues that have a beneficial impact on the physiological functions or conditions of human health. Strong scientific evidence exists for the in vitro antioxidant, antihypertensive, and anti-atherosclerotic properties of microalgal peptides. This review is aimed at summarizing the methods of producing microalgal peptides, and their role and mechanisms in improving cardiovascular health. The review reveals that the validation of the physiological benefits of the microalgal peptides in relation to cardiovascular disease, using human clinical trials, is required. Full article

The inadequate disposal of tires poses a significant threat to human health and requires effective recycling solutions. The crosslinked structure of rubber, formed through sulfur bridges during vulcanization, presents a major challenge for recycling because it prevents the rubber scraps from being reshaped thermoplastically. Reclaiming or devulcanization aims to reverse this crosslinking, allowing waste rubber to be transformed into products that can be reprocessed and revulcanized, thereby saving costs and preserving resources. Microwave technology shows promise for devulcanization due to its ability to break sulfur crosslinks. In this study, we investigate the devulcanization of ground tire rubber (GTR) through a combined process applied to samples from both car and truck tires subjected to varying periods of microwave irradiation (0, 3, 5 and 10 min). The devulcanized GTR was then blended with natural rubber (NR) and underwent a new vulcanization process, simulating recycling for novel applications. The GTR was mixed with NR in proportions of 0, 10, 30 and 50 parts per hundred rubber (phr). This study also examines the differences between the GTR from car tires and GTR from truck tires. The results showed that the treatment effectively breaks the crosslinks in the GTR, creating double bonds (C=C) and improving the mechanical properties of the revulcanized samples. The crosslinking density and related properties of the samples increased with treatment time, reaching a maximum at 5 min of microwave treatment, followed by a decrease at 10 min. Additionally, the incorporation of GTR enhanced the thermal stability of the resulting materials. Full article

Guanine-rich sequences of nucleic acids, including DNA and RNA, are known to fold into non-canonical structures named G-quadruplexes (G4s). Such arrangements of these macromolecular polymers are mainly located in telomeres and in promoter regions of oncogenes and, for this reason, they represent a potential target for compounds with therapeutic applications. In fact, the ligand-mediated stabilization of G4s inhibits telomerase and the activity of transcriptional machinery and counteracts cancer cell immortalization. Flavonoids, along with other classes of small molecules, have been previously tested for their ability to stabilize G4s, but the mechanism of their interaction has not been fully elucidated. In the current work, we report a multi-technique investigation on the binding of tosylated isoflavones obtained by the B-ring modification of compounds from Maclura pomifera to a telomeric DNA sequence. Our study demonstrates that such derivatization leads to compounds showing lower binding affinity but with an increased selectivity toward G4 with respect to double-stranded DNA. The binding mode to the macromolecular target G4 was studied by combining results from electrospray mass spectrometry binding studies, nuclear magnetic resonance experiments and computational simulations. Overall, our findings show that tosylation influences the selectivity toward the macromolecular target by affecting the interaction mode with the nucleic acid. Full article

We attempted to perform surface microfabrication of the bioabsorbable material lactic acid–glycolic acid copolymer (LG-80) using a micro-imprint lithography technique with a gas-permeable porous mold at less than 5 °C. As a result, high-resolution surface micromachining with a height of 1.26 μm and a pitch of 2.97 μm was achieved using a convex sapphire mold with a height of 1.3 μm and a pitch of 3 μm. After processing, the LG-80 exhibited high water repellency, and FT-IR analysis of the surface showed no significant change in its chemical structure, confirming that the surface microfabrication was successful, while retaining the properties of the material. This demonstrated new possibilities for surface microfabrication technology for bioabsorbable materials, which are expected to be applied in the medical and life science fields in products such as surgical implants, tissue regeneration materials, and cell culture scaffold materials. In particular, the use of micro-imprint lithography enables low-cost and high-precision processing, which will be a major step toward the practical application of bioabsorbable materials. Full article

This study investigated the potential of annealed Bambara starch as a locally sourced stabilizer for ice cream, aimed at addressing the high cost of imported stabilizers. Annealed Bambara starch, modified at various temperatures (45, 50, 55, and 60 °C), was incorporated into ice cream formulations and compared with ice cream stabilized using xanthan gum and guar gum. The ice creams exhibited variations in percentage overrun (77.03–124.61%), foam stability (90.88–96.61%), viscosity (24.87–33.26%), and melting resistance. Conventionally stabilized ice cream outperformed in overrun, foam stability, viscosity, and melting rate properties. Descriptive sensory tests showed high intensity scores for color, aroma, taste, mouthfeel, and body attributes across all samples, with no weak intensity scores. Considering the performance of conventionally stabilized ice cream, those stabilized with Bambara starch annealed at 45 and 50 °C were recommended as potential alternatives, highlighting the potential of annealed Bambara starch as a cost-effective and locally sourced stabilizer for ice cream. Further studies should investigate the impact of annealing at different temperatures on the structural changes of Bambara starch to gain more insights into its effects on ice cream structure, facilitating its use in other food systems. Full article

Coagulation/Flocculation (C/F) process aims to efficiently eliminate turbidity, TSS, COD, BOD, toxic metals, phosphates, and UV_254nm from wastewater. Both natural and synthetic coagulants, used alone or in conjunction with flocculants, play crucial roles in this treatment. This review summarizes recent trends in coagulants for wastewater treatment, highlighting a wide array of inorganic and organic coagulants that have demonstrated significant efficacy based on reviewed studies. Notably, Crab Shell Bio-Coagulant (CS) excels in turbidity remov5al, achieving a remarkable 98.91% removal rate, while oak leaves protein shows superior performance in TSS and COD removal. Synthetic inorganic coagulants like PALS, PSiFAC_1.5:10:15, and PAPEFAC_1.5-10-15 demonstrate outstanding turbidity removal rates, over 96%. POFC-2 coagulant stands out for efficiently removing TSS and COD from domestic wastewater, achieving up to 93% removal for TSS and 89% for COD. Moreover, the utilization of FeCl₃ as an inorganic coagulant alongside chitosan as an organic flocculant shows promise in reducing turbidity, COD, and polyphenols in wastewater from vegetable oil refineries. PE-2, a novel organic coagulant, demonstrates exceptional efficacy in eliminating turbidity, TSS, COD, and BOD from sugar industry wastewater. Chitosan shows effectiveness in removing TOC and orthophosphates in brewery wastewater. Additionally, CTAB shows high efficiency in removing various toxic metal ions from wastewater. The hybrid coagulants: PAAP_0.1,0.5 and PPAZF accomplish exceptional turbidity removal rates, approximately 98%. Full article

Drug delivery is essential to provide correct treatments in many ways. The critical points in any drug delivery method are patient compliance, maximum efficacy in therapy, minimum toxicity, and enabling new medical treatments. Pulmonary drug delivery is one way of delivering therapeutics locally and systemically. The lung microenvironment and mechanical and biological barriers must be surpassed for successful drug delivery. This makes the delivery challenging. Formulations that can be delivered through the lung and have a responsive character are of great interest since they can hold the key to the successful delivery of therapeutics. This review has gathered fundamental studies related to materials (polymeric, lipidic, inorganic, and biomolecules) that are responsive to pH, enzymes, ROS, magnetism, and other variables, and it shows the advances and applications in pulmonary drug delivery for different diseases in vitro as well as in vivo. Full article

Thermoplastic starch (TPS) has gained considerable attention during the last few years in developing starch-based biodegradable food packaging materials or edible coatings due to its high availability and low cost. TPS is manufactured from starch plasticized with food-grade plasticizers, making it suitable for food contact applications. In addition, TPS is bio-based and biodegradable, which, from an environmental perspective, closes the circle of the circular economy. However, the industrial application of TPS is somewhat limited due to its poor mechanical performance and low water resistance. However, the low water resistance could increase the water sensitivity of TPS, which could be advantageous for coating application or food encapsulation. The present work aims to tailor the water sensitivity of TPS by adding peach gum polysaccharide to obtain water-soluble films. With this aim, peach gum polysaccharide (PGP) was extracted from peach gum (PG) using the thermal hydrolysis method. Films of TPS-PG and TPS-PGP were prepared and characterized by their water sensitivity and mechanical, microstructural, and thermal properties. The results show that PGP allows the obtaining of films with water sensitivities higher than 70% but also improves TPS elongation at break, making the material more suitable for application as film. Full article

The integration of the biocompatibility of collagen and the remote-control ability of magnetic elements serves as both a cell scaffold and an actuator. We studied the preparation, characterization, and potential applications of collagen–magnetic particle composite microbeads (CMPMBs). The interplay among collagen concentration, particle size, and surface roughness was found to influence cell adhesion and proliferation. Adsorption and desorption tests showed the reversible attachment of the particles to magnetic sheets, enabling precise spatial control and targeted cell delivery. The particles demonstrated their utility as cell carriers, supporting cell migration and proliferation. These findings showcase the potential of CMPMBs as a promising platform for advanced cell delivery and tissue regeneration applications. The ability to fine-tune particle properties and manipulate them using magnetic fields offers new possibilities for creating complex tissue constructs and controlling cellular behavior, which could contribute to the development of more effective regenerative therapies and tissue engineering approaches. Full article

The utility of brewery spent grain (BSG), a byproduct of the beer production process, for the synthesis of polyhydroxyalkanoates (PHAs), is a significant advancement towards sustainable and cost-effective biopolymer production. This paper reviews the upcycling potential of BSG as a substrate for PHA production, utilizing various biotechnological approaches to convert this abundant waste material into high-value biodegradable polymers. Through a comprehensive review of recent studies, we highlight the biochemical composition of BSG and its suitability for microbial fermentation processes. This research delves into different methodologies for PHA production from BSG, including the use of mixed microbial cultures (MMCs) for the synthesis of volatile fatty acids (VFAs), a critical precursor in PHA production, and solid-state fermentation (SSF) techniques. We also examine the optimization of process parameters such as pH, temperature, and microbial concentration through the application of the Doehlert design, revealing the intricate relationships between these factors and their impact on VFA profiles and PHA yields. Additionally, this paper discusses challenges and future perspectives for enhancing the efficiency and economic viability of PHA production from BSG. By harnessing the untapped potential of BSG, this research contributes to the development of a circular economy model, emphasizing waste valorization and the creation of sustainable alternatives to conventional plastics. Full article