Carbohydrate Polymer Technologies and Applications最新文献

Natural polymers have attracted considerable attention in recent decades among scientists due to their potential therapeutic uses, particularly as antimicrobial and antitumor agents. In this research, novel EPSs were extracted from garlic rhizosphere bacteria. The antibacterial and antitumor activities of the polymer were evaluated through biological assays. The antibacterial activity was tested against gram-positive microorganisms (such as Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus) and gram-negative organisms (such as Shigella sonnei and Escherichia coli). The most significant inhibition zone was observed with Listeria monocytogenes and S. typhi, measuring 35 mm, while the most miniature antibacterial effect was seen with Staphylococcus aureus at 23.67 mm.

Furthermore, the inhibitory effect of the crude polymer was assessed using a broth medium with two strains of E. coli and Bacillus cereus. Electron microscope images displayed varying degrees of damage to bacterial cells in the treated broth. The antitumor activity was determined using the MTT test on colon carcinoma cells (HCT-116), hepatocellular carcinoma cells (HepG-2), and CaCO₂ (intestinal carcinoma cells), with IC50 values of 188.86±6.17 µg/mL, 221.66±8.02 µg/mL, and 203.65±7.43 µg/mL, respectively, after 48 h. The bacteria responsible for polymer production were isolated from garlic plant rhizospheres and identified as Erwinia gerundensis CCASU-2024–69 through 16S rRNA sequencing. FTIR and NMR techniques determined the crude EPS's main components and functional groups, including carbonyl, carboxylic, methylene, and silanol. GC–MS analysis revealed 34 bioactive compounds, while HPLC analysis indicated that the EPS was a hetero-monosaccharide consisting of d-xylose, d-glucose, l-arabinose, ribose, and d-mannose. This research study represents the initial exploration into the exopolysaccharide derived from Erwinia gerundensis. To assess the interaction between the exopolysaccharide and the active sites of Bacillus cereus and E. coli, molecular docking experiments were conducted using five monosaccharides: d-xylose, d-glucose, l-arabinose, ribose, and d-mannose. The data obtained from the molecular docking analysis strongly correlates with the findings from biological studies.

Furthermore, these highly active compounds exhibit a favorable proposed ADMET profile. This particular exopolysaccharide shows potential as a natural antibiotic and holds promise in treating gastrointestinal cancer. A comprehensive assessment of laboratory animals is essential before its potential use as a prebiotic in nutrition.

The therapeutic capabilities of autologous stem cells can be fully exploited if their survival after implantation is improved.

For the first time, we compared three hydrogels, with different chemical structure, morphology, and viscoelastic properties, where the same differentiation factors were immobilized and spheroids from adipose stem cells (SASCs) were incorporated. The aim is to understand if hydrogel characteristics could influence the viability of the embedded stem cells. Specifically, hydrogels of partially degalactosylated xyloglucan (dXG), sodium alginate (Alg) and k-carrageenan (kC) were produced. The structure of the networks was probed by swelling/erosion measurements, rheological and morphological analysis. Cell viability was measured after 7 and 21 days. When SASCs were incubated under stemness conditions, dXG and kC hydrogels provide the optimal environment for cell viability. When incubated in the chondrogenic or osteogenic medium, a clear correlation was found between the storage and loss moduli and cell viability. Hydrogels with the lowest shear stiffness promote stem-cell differentiation and proliferation. The systems, particularly dXG, seem more similar to natural ECM and able to recreate niches, that colonized with stem cells could represent a real support in regenerative therapies. The injectability of formulations was evaluated to determine if they could be used for minimally invasive regenerative medicine interventions.

Nano-fibrillated bacterial cellulose (NFBC) can be prepared by cultivating a cellulose-producing bacterium in a medium containing a dispersant under agitating and aerobic conditions. Although NFBCs have various applications, their detailed structure and physical properties have not been clarified. Therefore, in this study, we performed detailed structural and physical property analyses of NFBCs to advance their potential applications. Atomic force microscopy and image analysis showed that the average fiber length of NFBCs was approximately 17 µm and fiber widths were 10–15 nm; the aspect ratios of NFBCs were > 1000, which are >10-fold higher than that of 2,2,6,6-tetramethylpioeridine-1-oxyl-oxidized cellulose nanofiber. Shear viscosity measurements showed that the NFBCs exhibited shear-thinning flow behavior even at low concentrations (0.01 wt%). Frequency sweep measurements showed that the storage modulus values were greater than the loss modulus values in the measured frequency range, indicating that the NFBCs were in a stable gel state. Thus, the NFBCs exhibited significantly longer fiber lengths, larger aspect ratios, and excellent viscoelastic properties based on these unique structural features. Our findings will help develop novel applications utilizing the ultrahigh aspect ratio unique to NFBC and its viscoelastic properties.

Curcumin (Cur) has shown potential anticancer effects against various cancers, including colorectal and breast cancers. The aim of this study was to develop nanocarriers (NCs) bioconjugated with trastuzumab (Tras) using click reactions. Chitosan-maleimide (CHI-Mal) and thiolated alginate (SH-ALG) were synthesized to prepare CS-Mal/SH-ALG NCs, which were then conjugated with Tras as a receptor-targeting ligand via click chemistry. The characteristics of the NCs, including Cur loading and release profiles, were examined. Biocompatibility, anticancer effects, targetability, and cell death analysis were conducted on HER2-positive breast cancer cell line (SK-BR-3). The developed NCs exhibited a nano-scaled size, relatively spherical shape, and positive surface charge. The 7-day release of Cur from the Cur-loaded CHI-Mal/SH-ALG NCs (Cur-NCs) was significantly higher in the cancer environment (pH 5.5; 98%) compared to body fluid (pH 7.4; 57%). Tras-conjugated Cur-NCs (Tras-Cur-NCs) demonstrated superior anticancer effects, receptor-targeting efficiency, and cellular uptake compared to free Cur and non-targeted Cur-NCs. Additionally, Tras-Cur-NCs enhanced apoptotic cell death, indicating a non-inflammatory cell death with strong anticancer effect against HER2-positive SK-BR-3 cells. The spontaneous click reaction successfully formed pH-responsive Tras-conjugated NCs for targeted Cur delivery to HER2-positive breast cancer cells.

Herein, chitosan films obtained by different approaches were functionalized with essential oils, i.e. mentha, clove, and cinnamon, by Supercritical Solvent Impregnation method to impart antioxidant and antimicrobial activity. The films were prepared from solutions with two different polymer concentrations (1 and 2.5 wt%) following three methodologies: casting and then drying at air (25 °C, 39 % relative humidity), casting and drying at 60 °C in humid conditions (82 % relativity humidity) and casting and water elimination by a freeze-drying process. The films were, then, characterized by scanning electron microscopy and X-ray diffraction, proving that the thickness, porosity, and crystallinity of the films are highly dependent on the preparation method. These structural variations affected the impregnation of essential oils by supercritical fluids, in terms of the amount and composition of the active compounds. Subsequently, yellowness, antioxidant and antimicrobial properties of the impregnated films were evaluated. The results demonstrated that the impregnated films retained high concentration of essential oils, especially the films impregnated with clove and produced by the freeze-drying process due to their higher porosity and lower crystallinity. These films also exhibited superior antimicrobial activity against Gram-positive and Gram-negative bacteria in comparison with the other two analyzed preparation methods.

As the global population grows, the demand for safe food security aligned with sustainable development objectives becomes increasingly critical. This review delves into the innovative design techniques of stimuli-responsive smart alginate nanomaterials. It focuses on smart alginate hybrid nanomaterials and their nanocomposites that react to external stimuli. pH-responsive smart alginate hybrid nanomaterials are effectively utilized for the targeted delivery of bioactive components. Conversely, pH, temperature, specific analytes, and ionic strength-responsive smart alginate nanocomposites have food preservation, packaging, safety, and waste upcycling applications. This paper provides an in-depth examination of recent advancements in pH-responsive smart alginate hybrid nanomaterials, emphasizing targeted distribution systems, including nanoparticles, nanoliposome complexes, high internal phase Pickering emulsions, emulgels, nanogels, nanobioaerogels, and electrospun nanofibers. Moreover, the review highlights how smart alginate nanocomposites contribute to sustainable food preservation and upcycling of food waste, enhancing food safety. Detailed discussions on commercialization regulations underscore the importance of regulatory compliance and safety in deploying these advanced materials.

Unhealthy aging causes the development of various diseases, which makes intervening in key targets an important breakthrough in the development of new drugs to delay aging and prevent age-related diseases. Regulating gut microbiota has become a potential intervention pathway for anti-aging. Modern studies have shown that polysaccharides, the main active ingredients of traditional Chinese medicine (TCM), have multi-target advantages in the mechanisms of action of anti-aging. Non-starch polysaccharides are degraded by the gut microbiota in vivo to produce short-chain fatty acids to enable the local and systemic physiological functions have also been confirmed, but the researches on how TCM polysaccharides can exert anti-aging by the regulation of the gut microbiota and its metabolites lack systematic review. This review describes changes in the gut microbiota with age, and how it causes the pathogenesis of age-related diseases. It summarizes the effects of TCM polysaccharides in interfering with aging, the process of regulating gut microbiota to exert anti-ageing activity through the mediation of AMPK, Nrf2, and NF-κB signaling pathways and other potential intervention pathways. Finally, this review summarizes laws that changes in molecular weight and monosaccharide composition affect the role of polysaccharides in the intestinal microenvironment thereby altering the function of gut microbiota.

Chitosan is promising for wound care solutions owing to its high biocompatibility, biodegradability, hemostasis, antimicrobial activity, and promotion of tissue regeneration. However, its antibacterial property is insufficient for some infected wounds and local conditions. Given the high antibacterial activity of copper, this work focused on synthesizing chitosan-copper complexes with 1, 3, 6, 12, 24, and 48 % copper to chitosan's amine groups, followed by electrospinning them with polyvinyl alcohol. The mats exhibited promising vapor transition rates ranging from 2800 ± 33 to 3201 ± 48 g/m2.day and a dual-phase release of copper, with an initial burst followed by a sustained release over 7 days. Superior fibroblast cell cytocompatibility was observed up to 12 % copper, with accelerated re-epithelialization and cell migration to 6 % copper. Antibacterial efficacy against both gram-positive Staphylococcus aureus)S. aureus(and gram-negative Escherichia coli (E. coli) bacteria was effective beyond 3 % copper. Typically, the optimal concentration of copper was identified at 6 %, exhibiting a balance of antibacterial activity and biocompatibility, with the ability to cover 98.0 ± 0.8 % of the wound area in only 24 h and increase cell proliferation by 189 ± 11 % within 5 days.