Biopolymers最新文献

This study focused on the development of wound dressings. Plant active ingredients such as clover, chickweed, chamomile, garlic, liverwort, bitter melon, pine resin, marigold (Calendula officinalis), and St. John's Wort (Hypericum perforatum L.) were reinforced with polyethylene oxide (PEO) and polyvinyl alcohol (PVA) polymers, and nanofiber membranes were produced by electrospinning. As a result of the analyses, FTIR confirmed the presence of polymer and active ingredient functional groups in the composite membranes; softening and shifting were observed in the peaks. In the FEGSEM analysis, a thin and regular nanofiber structure was obtained in the S12 membrane in the range of 150–500 nm. In the tensile test, the tensile strength of the S12 sample was measured as 25.89 MPa, and this strength was associated with the homogeneous distribution and thinning of the fibers. In the mesenchymal stem cell analysis, cell viability was determined as 98%, and cell death was determined as 2% for the S12 membrane at the end of 72 h. The results show that the S12 composite membrane can be used as a biomaterial with ideal properties in wound healing applications.

One way to contribute to sustainable food systems is to develop ecological processes to prepare ingredients that deliver bioactive compounds. In this study, we used cold plasma (CP) and ultrasound (US) as alternative methods to produce inclusion complexes (ICs) of β-cyclodextrin (β-CD) with orange and clove essential oils. Further, the performance of starch-based active edible coatings containing ICs on perishable foods like mushrooms was assessed. CP and US treatments allowed the essential oil molecules to enter the hydrophobic cavity of the β-CD, leading to rhomboidal particles and clusters. The addition of ICs decreases the amount of moisture in starch-based active edible coatings, promoting high barrier property against water vapor (from 3.5 E-05 to 2.18 E-05 g/m s Pa) and low moisture content in their monolayer (Xm) (from 4.40 to 10.124 g water/100 g.d.s) since the hydrophobic components (terpenes and phenolics) of essential oil decreased the number of active sites to bind water molecules. These coatings reduce the weight loss of mushrooms (from 72% to 53%) under storage conditions. Further investigation through life cycle assessment and eco-efficiency analysis will be useful in determining whether cold plasma and ultrasound are green technologies for obtaining cost-effective ICs for coating production. The results could be of interest to those who are looking to develop ICs by CP and US to enhance edible coatings functionality for the food packaging field.

Based on the combination of poly (urea-formaldehyde) (UF), Sulfate of Potash-Magnesia (Sul-Po-Mag) fertilizer (2MgSO₄·K₂SO₄), and Date Kernel Seed (DS), a novel slow-release fertilizer in the form of granules called UF/DS/Sul-Po-Mag composite was introduced. The IR, DSC, TG, and X-ray spectra were used to characterize the synthesized composite. Characterizations revealed that the new fertilizer had good compatibility and strong hydrogen-bond interactions with improved mechanical and slow-release properties. An aqueous medium and soil incubation studies (up to 70 days) were used to examine the slow-release behavior. Over time, the accessible SO4⁻², K⁺, and Mg⁺² contents showed significantly lower SO4⁻², K⁺, and Mg⁺² losses than conventional fertilizer, even for low-polymerized materials. The fertilizer composite proved significant antimicrobial activity against all tested pathogens using the broth dilution technique. The minimum inhibition concentration (MIC) for tested bacteria and yeasts was 20 mg, while the maximum inhibition concentration (MAC) ranges from 40 to 60 mg. On the other hand, MIC for tested filamentous fungi was 100 mg, while MAC was 200–500 mg. These antimicrobial properties against harmful microbes and nutritional contents would enhance the growth of beneficial microorganisms and maintain good equilibrium in the microbial community.

Antimicrobial peptides (AMPs), produced in various organisms, including plants, as a first line of defense, are potent, functionally versatile, fast-acting small peptides with a net charge and diverse structures. Most AMPs demonstrate potent antibacterial activity, and AMPs with multimodal actions can potentially delay the development of antimicrobial resistance (AMR), one of the top 10 global public health challenges categorized by the WHO. Notably, the FDA has already approved several AMPs (Mol. Wt. ≤ 2 kDa) as antibiotics; however, there are not enough new-age antibiotics in the current pipeline to combat the looming problem of AMR in the clinic. Nevertheless, despite their potential, natural AMPs have their fair share of shortcomings for straightforward therapeutic applications. Therefore, extensive research on developing designer synthetic AMPs with broad-spectrum antimicrobial activity is currently being undertaken to mitigate the AMR challenge. In this context, we recently demonstrated a short synthetic designer AMP (SR17: ≤ 16 aa, mol. Wt. ≤ 2 kDa) that exhibits broad-spectrum bacteriostatic and bactericidal action against both gram-negative (Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii) and gram-positive (Staphylococcus aureus) bacteria. Interestingly, in gram-negative bacteria, the outer membrane proteins (OMPs) play a key role in transporting nutrients like iron from their surroundings through siderophores, which play a crucial role in various biochemical processes essential for their survival and growth. In the current study, the ability of SR17 to target the iron-transporting OMPs acting as the siderophore uptake system is investigated through computational techniques. A series of docking and molecular dynamics (MD) simulation studies involving iron transporters of various gram-negative bacteria indicate that SR17 can occupy the binding pocket in the OMPs necessary for binding of the iron-chelated siderophores, which is likely to prevent the further uptake of siderophores, affecting the growth and survival of the bacteria. Additionally, SR17 may potentially reach the bacterial cytoplasm by utilizing the siderophore uptake system and disrupt essential cytoplasmic processes, leading to the death of the bacteria, as observed in experimental studies.

This study aimed to evaluate the synergistic action of electron beam irradiated chitosan and Ampelomyces quisqualis for the management of powdery mildew, the most significant disease incited by the obligate fungus Erysiphe necator Schw. (Formerly known as Uncinula necator (Schw.) Burr.) that causes substantial losses in grapes. In vivo field trials conducted during 2020-21 and 2021-22, the evaluation of irradiated chitosan and bioagent and fungicide for the efficient in managing the grape powdery mildew disease. The fungicide sulfur 80% WDG was determined to be the most efficient. However, it was followed by a friendly combination of irradiated chitosan (150 ppm) with A. quisqualis (0.5%). Eco-friendly molecules, that is irradiated chitosan 150 ppm with A. quisqualis (0.5%), were found to be the best alternative for chemical molecules to achieve the disease control 63.60% and were identified alternative to chemical treatments to manage the powdery mildew disease of grapes. Irradiated chitosan and biocontrol agents showed synergistic action for the management of powdery mildew in grapevines.

Silk fibroin (SF), a biodegradable and biocompatible material with excellent mechanical properties, is widely utilized in food packaging and medical applications. However, regenerated SF is inherently brittle, necessitating the addition of polyethylene glycol (PEG), a nontoxic and biocompatible plasticizer, to enhance its flexibility. In this study, SF-PEG films were fabricated using two solvent systems: a single solvent (1-butyl-3-methylimidazolium chloride, BMIM Cl) and a binary solvent system (BMIM Cl and dimethyl sulfoxide, DMSO). SL-PEG films were prepared using the single solvent, while SM-PEG films were produced with the binary solvent system. The structural, mechanical, and morphological properties of the films were compared. Results showed that the SM-PEG films exhibited excellent mechanical performance, with a tensile strength of 6.9 ± 0.7 MPa, a Young's modulus of 367.0 ± 42.9 MPa, and an elongation at break of 42.6% ± 4.0%, significantly outperforming the SL-PEG films. The enhanced performance of SM-PEG films was attributed to the improved dispersion of PEG within the SF matrix, facilitated by the binary solvent system. In conclusion, the binary solvent system effectively improved the flexibility and ductility of SF-PEG films, making them better suited for applications requiring robust and adaptable biomaterials, such as in food packaging and medical applications.

This study investigated the effects of different solvent systems on the microstructure, roughness, and secondary structure of soluble eggshell membrane proteins (SEPs). The solvent system of CaCl₂/C₂H₅OH/H₂O produced tiny holes on the surface of SEP, and LiBr resulted in the formation of long holes. The saline solution increased the diameter of the protein fiber, the particle size of the solution, and the surface roughness of regenerated SEP films, mainly due to the enhanced intermolecular aggregation and precipitation. Zeta potential measurements indicated salts decreased the negative values and reduced the stability of the SEP solution. The different solutions showed similar circular dichroism waveforms. The peak intensity decreased at the positive and negative peaks, indicating that the triple helix structure of collagen was denatured to different degrees. Besides, the addition of salts decreased the content of α-helices and the β-turns and increased the content of β-sheets and random coils, indicating an increase in the disordered structure of the protein. This study contributes to a deeper understanding of the structural and functional relationships of eggshell membrane proteins, providing a vital basis for developing novel, eco-friendly, and multifunctional protein materials.

The study aims to evaluate the effects of different contents of quercetin (1%–3%) on structural and morphological characteristics of soy protein isolate (SPI) based films fabricated by the solution casting method. Prior to the preparation of the modified SPI film, quercetin incorporated SPI suspension was characterised for molecular weight distribution, particle size, and zeta potential. Addition of quercetin affected the charge distribution on the surface of protein and made it a more stable entity, as evident from more negative ζ- potential values. The as-prepared film was structurally and thermally characterised by x-ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The results revealed the changes in the secondary conformation of the protein structure with a simultaneous decrease in the crystallinity of the conjugated films and an increase in the thermal stability of quercetin incorporated SPI films. Quercetin incorporated SPI film was also subjected to morphological, antioxidant, and biodegradation studies. The antioxidant activity of the modified films in terms of scavenging free radicals like 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) increased significantly due to the native antioxidative ability of quercetin. The initial phase of biodegradation was rapid, followed by a slower rate of degradation phase. FTIR studies were used to structurally characterise biodegraded samples, and the results revealed the formation of carboxyl dimer during fragmentation and disruption of peptide bonds.

Inflammation processes can cause mild to severe damage in the human body and can lead to a large number of inflammation-related diseases (IRD) such as cancer, neural, vascular, and pulmonary diseases. Limitations of anti-inflammatory drugs (AID) application are reflected in high therapeutic doses, toxicity, low bioavailability and solubility, side effects, etc. Polymeric nanosystems (PS) have been recognized as a safe and effective technology that is able to overcome these limitations by AID encapsulation and is able to answer to the specific demands of the IRD treatment. PS are attracting great attention due to their versatility, biocompatibility, low toxicity, fine-tuned properties, functionality, and ability for precise delivery of anti-inflammatory drugs to the targeted sites in the human body. This article offers an overview of three classes of polymeric nanosystems: a) dendrimers, b) polymeric micelles and polymeric nanoparticles, and c) polymeric filomicelles, as well as their properties, preparation, and application in IRD treatment. In the future, the number of PS formulations in clinical practice will certainly increase.