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In this study, a novel active film was developed by employing ε‐polylysine (ε‐PL) as a filler in pullulan/curdlan (P/CD) composite film (P/CD/ε‐PL). The results showed that the structure of P/CD films was more uniform and denser compared to pullulan films, due to the good compatibility and intermolecular interaction between them. Among P/CD films, P/CD 6:1 film showed improved hydrophobicity, mechanical and barrier properties, and thermal stability, thereby selecting it for further use. Thereafter, the addition of ε‐PL further enhanced the structural and physicochemical properties of prepared P/CD/ε‐PL composite films, especially for P/CD/2.5%ε‐PL composite film. It exhibited improved ultraviolet barrier (about 80% at 200–400 nm), antibacterial activity (>90% against Staphylococcus aureus and Escherichia coli), and anti‐fog properties (clearly visible and transparent background). Furthermore, P/CD/2.5%ε‐PL composite film exerted its preservation effect on fresh‐cut peppers and kiwis during storage, delaying the softening, consumption of soluble solids, and deterioration. Therefore, the developed P/CD/2.5%ε‐PL composite film provided promising applications of active packing film. Practical Application: Fresh‐cut fruits and vegetables are prone to deteriorate during storage, and active packaging films play a crucial role in retaining their quality. This study was conducted to prepare a composite film by blending pullulan, curdlan, and ε‐PL and explore its structural, physicochemical, and functional properties, further verifying the preservation effect on fresh‐cut peppers and kiwis. Compared to polyethylene film, the P/CD/2.5%ε‐PL composite film delayed the softening, consumption of soluble solids, and deterioration of fresh‐cut peppers and kiwis during storage. It provides a new perspective on the preservation of fresh‐cut fruits and vegetables. [ABSTRACT FROM AUTHOR]

Curdlan's application is constrained by high gelation concentration, poor water solubility, and incompatibility with other polysaccharides. To address these limitations, this study investigated the effects of different concentrations (0.05–0.3%) of non-ionic polysaccharides (pullulan (PL), locust bean gum (LBG), guar gum (GG), and konjac gum (KGM)) on the heat-induced gelling properties of curdlan. PL with no branch showed 0.3% enhanced gel hardness. LBG with a small amount of galactose residue and KGM with an acetyl group had similar effects on hardness, while GG with a large amount of galactose residue slightly weakened the mixed gel. The rheological results showed that PL had little effect on curdlan, and LBG and KGM had a positive effect on curdlan unfolding, but 0.3% GG was significantly antagonistic to curdlan. The above results implied that non-ionic polysaccharides without side chains interacted weakly with the curdlan and hardly changed the properties of curdlan. Curdlan unfolding and stable suspension were favored if the structure contained galactose or acetyl side chains that interacted with curdlan through hydrogen bonding. These results suggested an effective way to modify curdlan by strengthening the interaction of curdlan with others and weakening the hydrogen bonding of curdlan to broaden its application in food colloids. [ABSTRACT FROM AUTHOR]

In this study, we grafted cholesterol with pullulan to synthesize hydrophobic pullulan(CHP). Three CHP polymers (CHP1, CHP2, and CHP3), with different degrees of substitution were designed by changing the feed ratio of cholesterol to pullulan. The 1H-NMR results showed that the hydrophobic substitutability of CHP1, CHP2, and CHP3 were calculated to be 8.26%, 5.67%, and 3.52%, respectively. The sizes of CHP1 NPs, CHP2 NPs, and CHP3 NPs were (118±7.9), (123±4.7) and (158±9.3) nm, respectively. The CHP NPs embedded with VCR and adsorbed Tween 80 (CHPT@VCR NPs). The results of microscale thermal imaging (MST) testing indicated the CHP-1 NPs with the highest degree of cholesterol substitution possessed the highest adsorption capacity for Tween 80. In vitro pharmacological studies were conducted in SJ-GBM2 cells, the results showed that the tumor cells inhibition rate and the cellular uptake rate of CHPT@VCR-1 NPs were the highest compared with CHPT@VCR-2 NPs and CHPT@VCR-3 NPs. [ABSTRACT FROM AUTHOR]

Summary: Black mulberry extract (BME) is rich in phenolics; however, their health benefits are restricted by their instability and poor absorption in the small intestine. Liposomal BME‐loaded pullulan/pectin nanofibers were developed to enhance the in vitro bioaccessibility of BME. The liposomes with BME (0.8%, w/v), were produced by the thin‐film hydration and ultrasonication method with a size of 76.41 ± 1.23 nm and encapsulated 79.40 ± 0.99%.of the BME. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) images showed that the uniform distribution of liposomes within the defect‐free fiber structure. Liposomal BME loading elevated the mucoadhesiveness of the nanofibers compared to free BME loading. Liposomal BME‐loaded nanofiber demonstrated a nearly two‐fold increase in the bioaccessibility of anthocyanins. The cellular release of all four different anthocyanins by Caco‐2 cells was significantly higher (3.92%–10.50%) in liposomal BME‐loaded nanofiber. Therefore, liposomal nanofibers show great potential as a method for delivering phenolics, specifically anthocyanins. [ABSTRACT FROM AUTHOR]

This study investigated the development of Pullulan/Collagen nanofiber scaffolds integrated with mesenchymal stem cells (MSCs) to enhance chronic wound healing. The combination of these biopolymers aims to optimize the scaffold properties for cell growth, viability, and tissue regeneration. Materials and Methods: Pullulan, Collagen, and Pullulan/Collagen composite nanofibers were fabricated using electrospinning. The fibers were characterized using scanning electron microscopy (SEM) to determine the fiber diameter, and Fourier-transform infrared spectroscopy (FTIR) was employed to assess the molecular interactions. Cell viability was evaluated using MSCs cultured on the scaffolds and apoptosis assays were conducted to assess cell health. Distilled water was used as the solvent to maximize biocompatibility. Results: SEM analysis revealed that Pullulan nanofibers exhibited a larger average diameter (274 ± 20 nm) compared to Collagen fibers (167.03 ± 40.04 nm), while the Pullulan/Collagen composite fibers averaged 280 ± 102 nm. FTIR confirmed the molecular interactions between Pullulan and Collagen. Regarding biocompatibility, the Pullulan/Collagen scaffold demonstrated superior cell viability at 99% compared to 91% for Pullulan alone. Apoptosis assays indicated significantly lower necrosis rates for the composite scaffold (1.29%) than for the Pullulan-only scaffolds (2.35%). Conclusion: The use of distilled water as a solvent played a critical role in increasing cell viability and facilitating healthy proliferation of MSCs without cellular damage. Additionally, the reduced platelet activation and macrophage activity (0.75-fold for both) further supported the biocompatibility of the Pullulan/Collagen scaffold, demonstrating its potential for tissue engineering and chronic wound healing applications. [ABSTRACT FROM AUTHOR]

Polysaccharide-based carriers as biomaterials for drug delivery have been inspiring scientists for years due to their exceptional characteristics, such as nontoxicity, biocompatibility, and degradability, as they are able to protect pharmaceutically active molecules and provide their controlled/modified release. This review focuses on selected drug delivery systems based on natural polymers, namely fucoidan, pullulan, dextran, and pectin, with the aim of highlighting published patent documents. The information contained in patents is very important because it is usually not published in any other document and is much less discussed as the state of the art in the scientific literature. The Espacenet—European Patent Office database and the International Patent Classification were used for the research to highlight the specific search procedure. The presented analysis of the innovative state of the art includes an overview from the first patent applications to the latest granted patents in this field. [ABSTRACT FROM AUTHOR]

Bone tissue engineering is a technique that simulates the bone tissue microenvironment by utilizing cells, tissue scaffolds, and growth factors. The collagen hydrogel is a three-dimensional network bionic material that has properties and structures comparable to those of the extracellular matrix (ECM), making it an ideal scaffold and drug delivery system for tissue engineering. The clinical applications of this material are restricted due to its low mechanical strength. In this investigation, a collagen-based gel (atelocollagen/glycerol/pullulan [Col/Gly/Pul] gel) that is moldable and injectable with high adhesive qualities was created by employing a straightforward technique that involved the introduction of Gly and Pul. This study aimed to characterize the internal morphology and chemical composition of the Col/Gly/Pul gel, as well as to verify its osteogenic properties through in vivo and in vitro experiments. When compared to a standard pure Col hydrogel, this material is more adaptable to the complexity of the local environment of bone defects and the apposition of irregularly shaped flaws due to its greater mechanical strength, injectability, and moldability. Overall, the Col/Gly/Pul gel is an implant that shows great potential for the treatment of complex bone defects and the enhancement of bone regeneration. [ABSTRACT FROM AUTHOR]

Pullulan is an extracellular polysaccharide produced via the fermentation of Aureobasidium pullulans. However, high sugar concentrations and hyperosmotic stress limit pullulan biosynthesis during the fermentation process. Therefore, we investigated the effects of proline supplementation on A. pullulans growth and pullulan biosynthesis under high sugar and hyperosmotic stress using physiological, biochemical, and transcriptomic analyses. High sugar concentrations significantly inhibited A. pullulans growth and pullulan biosynthesis. High sugar and hyperosmotic stress conditions significantly increased intracellular proline content in A. pullulans. However, treatment with proline (400 mg/L proline) significantly increased biomass and pullulan yield by 10.75% and 30.06% (174.8 g/L), respectively, compared with those in the control group. To further investigate the effect of proline on the fermentation process, we performed scanning electron microscopy and examined the activities of key fermentation enzymes. Proline treatment preserved cell integrity and upregulated the activities of key enzymes involved in pullulan biosynthesis. Transcriptome analysis revealed that most differentially expressed genes in the proline group were associated with metabolic pathways, including glycolysis/gluconeogenesis, pyruvate metabolism, and sulfur metabolism. Conclusively, proline supplementation protects A. pullulans against high sugar and hyperosmotic stress, providing a new theoretical basis and strategy for the efficient industrial production of pullulans. [ABSTRACT FROM AUTHOR]

Pullulan is a high-value biopolymer synthesized by Aureobasidium pullulans through the fermentation of starch and sugars. It finds extensive applications in food, packaging, biomedicine, and other sectors. However, the high production costs significantly limit the development and application of pullulan. Consequently, there is an urgent need to identify high-quality fermentation substrates. In recent years, the rapid growth of Huangjiu industry has led to the generation of waste Huangjiu lees, which not only contribute to environmental pollution but also represent a significant waste of resources. As a result, the resource utilization of Huangjiu lees has garnered considerable attention. In this study, Huangjiu lees were employed as raw materials for fermentation to produce pullulan. Following fermentation of Huangjiu lees powder with the primary strain Aureobasidium pullulans LL1, the yield of pullulan was notably reduced. Through adaptive evolution, an evolved strain, Aureobasidium pullulans AP9, was isolated, demonstrating enhanced efficiency in producing pullulan from Huangjiu lees. The impact of Huangjiu lees on pullulan biosynthesis was elucidated via transcriptome analysis. Fermentation conditions were optimized using a single-factor approach, and a multi-strain staged fermentation strategy involving Aspergillus niger and Aureobasidium pullulans was employed to further enhance pullulan yield. Under optimal conditions, the pullulan yield reached 22.06 g/L, with a molecular weight of 1.04 × 106 Da. This study underscores the significant potential of utilizing Huangjiu lees for pullulan production and offers valuable insights for the resource utilization of this byproduct. [ABSTRACT FROM AUTHOR]

Pullulan is a high-value polysaccharide produced through the fermentation of Aureobasidium pullulans. It has significant applications in the fields of food, medicine, environmental science, and packaging. However, the yield, molecular weight, and other characteristics of pullulan can vary depending on the fermentation substrate used. Therefore, it is crucial to analyze the underlying causes of these variations at the molecular level. In this study, we first investigated the morphological differences in A. pullulans YQ65 when cultured in YPD and PDA media. The results indicated that different culture media significantly influence the primary cell morphology of A. pullulans YQ65, which in turn affects the synthesis of secondary metabolites. Subsequently, we employed different culture media to ferment pullulan and examined the variations in pullulan yield, molecular weight, and biomass. Moreover, FTIR and thermodynamic stability tests were conducted to analyze the differences among pullulans across different culture media. Finally, transcriptome analysis revealed that A. pullulans YQ65, when cultured in YPD and PDA media, regulates its growth and metabolism through the expression of key genes that are involved in pathways such as the proteasome, oxidative phosphorylation, metabolism of various secondary metabolites, fatty acid anabolism, carbon metabolism, and amino acid metabolism. The transcriptome results were further validated by assessing the expression of specific genes. This study enhances the understanding of the fermentation differences observed with different substrates in A. pullulans and provides valuable insights for optimizing culture substrates. Additionally, it offers guidance for utilizing agricultural and forestry processing waste, as well as food processing by-products, to produce pullulan cost-effectively in the future. [ABSTRACT FROM AUTHOR]

Bio‐based active food packaging materials have a high market demand. We use coaxial electrospinning technology to prepare core–shell structured nanofibers with sustained antibacterial and antioxidant properties. The fiber core layer was composed of gelatin and tea polyphenols, whereas tea polyphenols provide antibacterial and antioxidant properties; the fiber sheath was composed of pullulan polysaccharides with antioxidant properties. By using a scanning electron microscope, it can be seen that the diameter distribution of the prepared nanofibers was uniform and the surface is smooth; using a transmission electron microscope, it can be clearly seen that the nanofibers have a core–shell structure; Fourier Transform Infrared and X‐ray diffraction analysis indicate that the nanofibers have an amorphous structure; the 2,2‐diphenyl‐1‐picrylhydrazyl free radical scavenging shows that nanofibers have higher antioxidant properties with the addition of tea polyphenols; antibacterial test showed that nanofibers had obvious inhibitory effect on the growth of Staphylococcus aureus and Escherichia coli; and the nanofiber film dissolution test shows that nanofibers can be used as fast soluble active packaging. Finally, core–sheath‐structured nanofibers can serve as active packaging for instant food, possessing both rapid water solubility and excellent antibacterial and antioxidant activity, making water‐soluble nanofibers interesting applications in the field of food packaging. [ABSTRACT FROM AUTHOR]

Background: Alpha mangostin (AM) has demonstrated significant potential as an anticancer agent, owing to its potent bioactivity. However, its clinical application is limited by poor solubility, which hampers its bioavailability and effectiveness. Amorphous solid dispersion (ASD) presents a promising technique to enhance the solubility and stability of AM. Molecular dynamics simulation offers a rapid, efficient, and precise method to evaluate and optimize ASD formulations before production. Aim of Study: In this study, we conducted molecular dynamics simulations to explore the ASD development of AM with poloxamer and pullulan. Result: Our results revealed that AM–poloxamer complexes exhibit superior interaction characteristics compared to AM–pullulan, with a 1:5 ratio of AM to poloxamer and a cooling rate of 1 °C/ns demonstrating the most favorable outcomes. This combination showed enhanced hydrogen bonding, a more compact molecular structure, and higher stability, making it the optimal choice for ASD formulation. Conclusion: The integration of molecular dynamics simulation into ASD development significantly accelerates the formulation process and provides critical insights into achieving a stable and effective AM dispersion. The AM–poloxamer complex, particularly at a 1:5 ratio with a 1 °C/ns cooling rate, offers the best potential for improving AM solubility and therapeutic efficacy. [ABSTRACT FROM AUTHOR]

ABSTRACT Kiwifruit stands out as a globally favored fruit owing to its palatable flavor and nutritional benefits. However, it continues to ripen after harvest, and this trait makes it more susceptible to fungal infections. Diaporthe spp. has garnered attention for causing postharvest soft rot in kiwifruit; consequently, effective prevention and treatment strategies for soft rot are crucial for managing postharvest diseases in kiwifruit. We found that pullulan treatment greatly decreased both the incidence of disease and lesion diameter following Diaporthe nobilis inoculation in kiwifruit. Pullulan at the concentrations (1%, 3%, and 5%) markedly reduced the disease incidence of the soft rot in kiwifruit after 3 days of inoculation with D. nobilis by 19.16%, 31.66%, and 48.33%, respectively, and lesion diameter of 5% pullulan treated kiwifruit was 38.1% lower than that of the control 3 days after treatment. Importantly, pullulan treatment maintained and reduced the accumulation of superoxide anion (O2−), hydrogen peroxide (H2O2), and the peroxidation of membrane lipids; maintained high levels of ascorbic acid (AsA) and glutathione (GSH); and stimulated the buildup of total phenolic. Additionally, pullulan treatment markedly increased the activities of defense‐related enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), phenylalanine ammonialyase (PAL), chitinase (CHI), and β‐1,3 glucanase (GLU). Furthermore, pullulan treatment was found to activate expressions of defense‐related genes. Overall, our data confirm the application of pullulan treatment for controlling postharvest soft rot in kiwifruit, potentially offering a valuable strategy for enhancing the storage stability and shelf life of this economically significant fruit.

Trehalose (TRE) was used to improve the gastrointestinal tolerance of Lactobacillus plantarum embedded with whey protein concentrate/pullulan (WPC/PUL) hydrogel and the embedded L. plantarum was applied to juice. The study indicated that 5% TRE significantly increased the viable counts of L. plantarum embedded in WPC/PUL hydrogel from (8.83 ± 0.03) to (9.14 ± 0.04) (lg (CFU/g)) in simulated gastric juice (SGJ) and from (9.13 ± 0.04) to (9.38 ± 0.04) (lg (CFU/g)) in simulated intestinal juice, respectively. The addition of TRE improved the glass transition temperature of WPC/PUL hydrogel and decreased the hardness and its solubility in SGJ, which may be responsible for the improved protection of WPC/PUL hydrogels on L. plantarum. In addition, TRE increased the viable counts of L. plantarum in WPC/PUL probiotic microcapsule juice at low pH and high temperature during storage.

In order to improve the water-resistance and ultraviolet (UV) barrier properties of pullulan (PL) film, edible composite films were prepared by solution casting based on PL and shellac (SH). The physical properties, thermal stability, mechanical properties, water vapor permeability and UV barrier of the composite films were characterized. The analysis of the functional properties revealed that the composite films had good compatibility, water-resistance (33.50˚–60.15˚), and strong UV-blocking properties (84.60%–0.00%). The addition of SH improved the water-resistance and mechanical properties of the films, but the thermal stability was slightly reduced. These films can be used as an edible coating on Chinese cherries. According to the characteristics of weight loss, decay incidence and other indicators of cherries, the PL-SH composite films can keep Chinese cherries fresh at room temperature at least for 7 days. Therefore, PL-SH composite films may be an environmentally friendly packaging material with application prospects in the fruit preservation industry.

Purpose: The objective was to encapsulate the standard peptide mixture (SPM) into a green electrospun Pull-NaAlg-CaCl2 composite with high encapsulation efficiency (EE). The morphology and stability of the fibers and the effects of feed solutions with different compositions on electrospinnability were investigated. Methods: To evaluate the morphology and stability of the fibers, scanning electron microscopy (SEM) and zeta potential measurements were performed. The effects of solution properties on electrospinnability evaluated by the conductivity, surface tension, dielectric constant and viscosity measurments. To obtain the EE of the SMP, their amount in the nanofibers was determined via high-performance liquid chromatography (HPLC). Results: The Pull-NaAlg-CaCl2 solution containing the SPM was successfully electrospun at a flow rate of 0.50 mL/h, an applied voltage of 12 kV, and a distance of 12 cm to the collector plate. The high conductivity and low surface tension induced electrospinnability, whereas SEM analyses revealed that the SPM-loaded electrospun fibers had fine, uniform and bead-free nanostructures with a mean diameter of 88.7 ± 10.85 nm. The zeta potential of the nanofiber dispersions indicated instability and a tendency toward aggregation. The encapsulation efficiency (EE) of the SPM by uniaxial electrospinning was 77.97 ± 1.65% in terms of the total peptide content. Conclusion: The combined effects of the applied voltage, concentration and feed rate of the feed solution and the dielectric constant on the zeta potential, stability of the nanofibers and desired EE need to be investigated. Our results indicate that the proposed technique is suitable for the green encapsulation of bioactive peptides and has potential use for nutraceutical, pharmaceutical and cosmetic purposes. [ABSTRACT FROM AUTHOR]

Purpose: The objective was to encapsulate the standard peptide mixture (SPM) into a green electrospun Pull-NaAlg-CaCl2 composite with high encapsulation efficiency (EE). The morphology and stability of the fibers and the effects of feed solutions with different compositions on electrospinnability were investigated. Methods: To evaluate the morphology and stability of the fibers, scanning electron microscopy (SEM) and zeta potential measurements were performed. The effects of solution properties on electrospinnability evaluated by the conductivity, surface tension, dielectric constant and viscosity measurments. To obtain the EE of the SMP, their amount in the nanofibers was determined via high-performance liquid chromatography (HPLC). Results: The Pull-NaAlg-CaCl2 solution containing the SPM was successfully electrospun at a flow rate of 0.50 mL/h, an applied voltage of 12 kV, and a distance of 12 cm to the collector plate. The high conductivity and low surface tension induced electrospinnability, whereas SEM analyses revealed that the SPM-loaded electrospun fibers had fine, uniform and bead-free nanostructures with a mean diameter of 88.7 ± 10.85 nm. The zeta potential of the nanofiber dispersions indicated instability and a tendency toward aggregation. The encapsulation efficiency (EE) of the SPM by uniaxial electrospinning was 77.97 ± 1.65% in terms of the total peptide content. Conclusion: The combined effects of the applied voltage, concentration and feed rate of the feed solution and the dielectric constant on the zeta potential, stability of the nanofibers and desired EE need to be investigated. Our results indicate that the proposed technique is suitable for the green encapsulation of bioactive peptides and has potential use for nutraceutical, pharmaceutical and cosmetic purposes. [ABSTRACT FROM AUTHOR]

Innovative electrospun pullulan/hemp protein isolate nanofibers (PUL/HP) with lecithin were successfully formulated for the delivery of phenylethanoid glycosides (PGs) from Teucrium montanum extract, at PUL to HP ratios of 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70, based on total polymer mass (w/w). A higher HP content led to a more elastic behavior, which was stimulated by a stronger entanglement between polymer and polypeptide chains. The biopolymers used showed favorable compatibility with the investigated PGs, achieving an encapsulation efficiency of over 80 %. The increased elastic behavior led to the formation of a bead-on-string morphology and a higher average diameter. The thermal stability of the loaded nanofibers was diminished by the presence of incorporated polyphenolic extract. Under simulated gastrointestinal conditions, a sustained release of total phenolic content from the delivery systems was achieved. According to the FTIR spectra, this is mainly due to the efficient interplay of hydrogen and hydrophobic interactions with the polyphenols within the polysaccharide-phospholipid-polypeptide structure. The circular dichroism spectra showed that the polyphenol extract was involved in the secondary HP structure, resulting in a rather random, uncoiled structure. These results provide a time- and cost-efficient approach to stabilize naturally immiscible biopolymers without crosslinking or emulsion preparation, while similarly altering the physicochemical properties of the drug delivery systems. [ABSTRACT FROM AUTHOR]

In this study, the gamma-cyclodextrin (γCD) inclusion complexes with essential oil (EO) compounds linalool and geraniol were encapsulated in pullulan nanofibers using an electrospinning technique. The nanofibers were produced with the initial EO content of ~ 11% (w/w) and ~ 74 to 77% of these volatile compounds could be preserved in pullulan/EO-γCD nanofibers due to inclusion complexation. On the other hand, only ~ 15 to 23% of EO could be kept in the case of pullulan/EO nanofibers in the absence of γCD. The EO-γCD inclusion complexation also ensured improved thermal stability for EO compounds, and their volatilization shifted from ~ 119–139 to ~ 239–292 °C ranges for pullulan/EO-γCD nanofibers. Moreover, pullulan/EO-γCD nanofibers displayed substantial long-term storage stability and, ~ 48 to 64% of EO content was still preserved even after 4 weeks, while this ratio was in the range of ~ 0.3 to 4.5% in the case of pullulan/EO nanofibers. The pullulan/geraniol-γCD nanofibers displayed an effective antibacterial activity against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria, and overwhelmingly better performance compared to pullulan/geraniol nanofibers due to the inclusion complexation. Briefly, EO-incorporated nanofibers were generated using GRAS γCD molecules and an edible pullulan polymer, and this approach can be a promising alternative to be effectively used in the food industry for the encapsulation and delivery of volatile EO compounds. [ABSTRACT FROM AUTHOR]

This study investigated the development of Pullulan/Collagen nanofiber scaffolds integrated with mesenchymal stem cells (MSCs) to enhance chronic wound healing. The combination of these biopolymers aims to optimize the scaffold properties for cell growth, viability, and tissue regeneration. Materials and Methods: Pullulan, Collagen, and Pullulan/Collagen composite nanofibers were fabricated using electrospinning. The fibers were characterized using scanning electron microscopy (SEM) to determine the fiber diameter, and Fourier-transform infrared spectroscopy (FTIR) was employed to assess the molecular interactions. Cell viability was evaluated using MSCs cultured on the scaffolds and apoptosis assays were conducted to assess cell health. Distilled water was used as the solvent to maximize biocompatibility. Results: SEM analysis revealed that Pullulan nanofibers exhibited a larger average diameter (274 ± 20 nm) compared to Collagen fibers (167.03 ± 40.04 nm), while the Pullulan/Collagen composite fibers averaged 280 ± 102 nm. FTIR confirmed the molecular interactions between Pullulan and Collagen. Regarding biocompatibility, the Pullulan/Collagen scaffold demonstrated superior cell viability at 99% compared to 91% for Pullulan alone. Apoptosis assays indicated significantly lower necrosis rates for the composite scaffold (1.29%) than for the Pullulan-only scaffolds (2.35%). Conclusion: The use of distilled water as a solvent played a critical role in increasing cell viability and facilitating healthy proliferation of MSCs without cellular damage. Additionally, the reduced platelet activation and macrophage activity (0.75-fold for both) further supported the biocompatibility of the Pullulan/Collagen scaffold, demonstrating its potential for tissue engineering and chronic wound healing applications.

Abstract Wastewater is a by-product of numerous industrial processes that have been demonstrated to have adverse effects on human and natural health due to the pollutants it contains. The pollutants in these substances are organic or inorganic molecules and heavy metal ions that significantly harm the environment and human health. A variety of techniques have been devised for the removal of heavy metal ions from wastewater. The adsorption process has attracted significant attention due to its straightforward implementation, cost-effectiveness, and the environmentally friendly production of adsorbent materials using biocompatible substances. In this study, the removal of Cu2+ ions from wastewater was conducted using chitosan pullulan, a biocompatible and biodegradable polymer. In addition to chitosan and pullulan, waste refractory materials from a furnace used in iron and steel production were added to these polymer materials to increase the adsorption capacity. The initial step involved grinding the waste refractory brick material. Subsequently, chitosan was dissolved in acetic acid. After that, the refractory material was suspended in this solution, facilitating the formation of hydrogel beads using a NaOH solution. The obtained hydrogels were coated with pullulan to produce polyelectrolyte gel. Pullulan was oxidized to 6-carboxypullulan by the TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl) oxidation method and the negatively charged groups in its structure interacted with the positively charged groups in the chitosan structure to produce a complex gel. The chemical structure, morphological analysis, thermal analysis, and water release analysis of the produced waste refractory brick material added chitosan/oxidized pullulan complex gels were examined. The impact of the 6-carboxypullulan coating on the gels’ properties was elucidated. Furthermore, the adsorption of Cu2⁺ was conducted using solutions containing 100, 500, and 1000 ppm Cu2⁺ ions. It has been observed that the material can clean water with over 98% efficiency, even in solutions that exceed the standards set for wastewater. The material’s efficacy in cleaning solutions with concentrations above the standard for wastewater cleaning is evidence of its high performance. Furthermore, the kinetics and isotherm of the adsorption reaction were examined. The kinetics were determined to be consistent with the Pseudo Second Order (chemical reaction controlled) and aligned with the Langmuir and Freundlich Isotherm (mixed adsorption occurred on homogeneous and heterogeneous surfaces).

Abstract One major limitation of effective vaccine delivery is its dependency on a robust cold chain infrastructure. While Vesicular stomatitis virus (VSV) has been demonstrated to be an effective viral vaccine vector for diseases including Ebola, its −70 °C storage requirement is a significant limitation for accessing disadvantaged locations and populations. Previous work has shown thermal stabilization of viral vaccines with a combination of pullulan and trehalose (PT) dried films. To improve the thermal stability of VSV, we optimized PT formulation concentrations and components, as well as drying methodology with enhanced vacuum drying. When formulated in PT films, VSV can be stored for 32 weeks at 4 °C with less than 2 log PFU loss, at 25 °C with 2.5 log PFU loss, and at 37 °C with 3.1 log PFU loss. These results demonstrate a significant advancement in VSV thermal stabilization, decreasing the cold chain requirements for VSV vectored vaccines.

Abstract Objectives The ascomycotic yeast-like fungus Aureobasidium exhibits the natural ability to synthesize several secondary metabolites, like polymalic acid, pullulan, or polyol lipids, with potential biotechnological applications. Combined with its polyextremotolerance, these properties make Aureobasidium a promising production host candidate. Hence, plenty of genomes of Aureobasidia have been sequenced recently. Here, we provide the annotated draft genome sequence of the polyol lipid-producing strain A. pullulans NRRL 62042. Data description The genome of A. pullulans NRRL 62042 was sequenced using Illumina NovaSeq 6000. Genome assembly revealed a genome size of 24.2 Mb divided into 39 scaffolds with a GC content of 50.1%. Genome annotation using Genemark v4.68 and GenDBE yielded 9,596 genes.

The article focuses on the pharmaceutical applications of pullulan, a biopolymer derived from the Aureobasidium species, highlighting its biocompatibility, biodegradability, and versatility as a polymer. It explores pullulan's role in drug delivery systems, including applications such as orodispersible films, capsule formulation, controlled drug release, tumor and cancer cell targeting, gene delivery, and tissue engineering.

In this study, a pullulan hydrogel is grafted by poly(N-vinylimidazole) (PNVI) in a heterogeneous acidic medium under a nitrogen atmosphere for Methyl Orange (MO) and Acid Green 25 (AG25) dye removal application. The effect of monomer concentration as a significant parameter for grafting yield is investigated thoroughly, and it is demonstrated that 189% grafting yield of PNVI grafted onto epichlorohydrin crosslinked pullulan (pullulan-ECH-graft-PNVI) can be obtained under proper conditions. Equilibrium water absorption capacity values reveal the pH-responsivity of pullulan-ECH-graft-PNVI hydrogels (6000%) as compared to the epichlorohydrin crosslinked pullulan (pullulan-ECH) hydrogel (1000%) counterpart. Further characterization of the samples was performed by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Adsorption of MO and AG25 on pullulan-ECH-graft-PNVI samples was studied at various pH, dye concentration, and time. The optimal adsorption pH value was measured at pH 3.0 with an adsorption capacity of 36.6 mg MO/g adsorbent and 5.72 mg AG25/g adsorbent. Isotherms and kinetic studies describe the adsorption profiles of the samples. The adsorption trends of the samples best fit the Freundlich model, which supports heterolayer dye adsorption and surface heterogeneity. Adsorption kinetic results indicate a pseudo-second-order kinetic model, which shows chemisorption. [ABSTRACT FROM AUTHOR]

Melanin is a high value bioproduct generated through the fermentation of Aureobasidium pullulans, playing a crucial role in various fields, including food, medicine, environmental protection, and materials science. However, its high production costs and low synthetic yields significantly limit its applications. Therefore, it is essential to identify high-yield strains, reduce production costs, and optimize fermentation strategies. In this study, a high melanin-yielding Aureobasidium pullulans 53LC7 was screened and identified, and the fermentation process was optimized based on melanin yield, color value, and pullulan yield. The results indicated that the melanin yield peaked at an initial pH of 6.0, temperature of 27 °C, fermentation time of 6.5 d, and inoculation quantity of 2.5%, achieving a melanin yield of 16.33 g/L. Subsequently, huangjiu lees, a byproduct of huangjiu production, was incorporated into the fermentation medium, resulting in a melanin yield of 5.91 g/L. This suggests that the Aureobasidium pullulans was not effectively utilizing huangjiu lees. To address this, we employed an adaptive evolution strategy, which increased the melanin yield to 8.72 g/L. The enhanced production was correlated with the expression of key genes, including FKS, PKS, and Cmr1. Finally, cellulase was utilized to convert the crude fibers in huangjiu lees, which were difficult to utilize, into usable substrates, while pullulanase was employed to minimize byproduct formation in the fermentation system, resulting in a melanin yield of 19.07 g/L. This study not only provides promising strains for further research but also offers valuable insights for resource production technologies. [ABSTRACT FROM AUTHOR]

Restoring the structures and functions of tissues along with organs in human bodies is a topic gathering attention nowadays. These issues are widely discussed in the context of regenerative medicine. Excipients/delivery systems play a key role in this topic, guaranteeing a positive impact on the effectiveness of the drugs or therapeutic substances supplied. Advances in materials engineering, particularly in the development of hydrogel biomaterials, have influenced the idea of creating an innovative material that could serve as a carrier for active substances while ensuring biocompatibility and meeting all the stringent requirements imposed on medical materials. This work presents the preparation of a natural polymeric material based on pullulan modified with silymarin, which belongs to the group of flavonoids and derives from a plant called Silybum marianum. Under UV light, matrices with a previously prepared composition were crosslinked. Before proceeding to the next stage of the research, the purity of the composition of the matrices was checked using Fourier-transform infrared (FT-IR) spectroscopy. Incubation tests lasting 19 days were carried out using incubation fluids such as simulated body fluid (SBF), Ringer's solution, and artificial saliva. Changes in pH, electrolytic conductivity, and weight were observed and then used to determine the sorption capacity. During incubation, SBF proved to be the most stable fluid, with a pH level of 7.6–7.8. Sorption tests showed a high sorption capacity of samples incubated in both Ringer's solution and artificial saliva (approximately 350%) and SBF (approximately 300%). After incubation, the surface morphology was analyzed using an optical microscope for samples demonstrating the greatest changes over time. The active substance, silymarin, was released using a water bath, and then the antioxidant capacity was determined using the Folin–Ciocâlteu test. The tests carried out proved that the material produced is active and harmless, which was shown by the incubation analysis. The continuous release of the active ingredient increases the biological value of the biomaterial. The material requires further research, including a more detailed assessment of its balance; however, it demonstrates promising potential for further experiments. [ABSTRACT FROM AUTHOR]

This review explores the production of the fungal polysaccharide pullulan by mutants and natural isolates of Aureobasidium species using strain improvement. Pullulan is a neutral polysaccharide gum whose structure is a maltotriose-containing glucan. This polysaccharide gum has applications in the fields of food, pharmaceuticals, biomedical and wastewater treatment. The strain improvement of Aureobasidium species has focused on the pullulan production process, including the isolation of strains exhibiting reduced pigmentation, polysaccharide overproduction, the production of pullulan with variable molecular weight, and increased osmotolerant strains promoting pullulan production at high carbon source concentrations and pullulan production on hemicellulosic substrates. The majority of studies have emphasized the isolation of reduced pigmentation and pullulan hyperproducer strains since the goal of large-scale commercial pullulan production is to synthesize non-pigmented polysaccharides. A promising area of strain improvement is the isolation of strains that synthesize authentic pullulan from hemicellulosic substrates. If strain improvement in this area is successful, the goal of commercially producing pullulan at a competitive cost will eventually be achieved. [ABSTRACT FROM AUTHOR]

The floatability of fluorite and calcite exhibit similar properties, rendering their flotation separation challenging. Macromolecular polysaccharide reagents containing the polyhydroxyl group have shown broad promising application. The selectivity of polysaccharide is relatively low. In this study, the introduction of Fe3+ was employed to enhance the selective adsorption capacity of Pullulan polysaccharide towards fluorite and calcite minerals, thereby achieving effective flotation separation. Furthermore, the mechanism underlying intramolecular interactions was elucidated. The DFT calculation and XPS analysis revealed that the adsorption of Fe3+ on the calcite surface was more favorable, leading to the formation of a Ca-O-Fe structure. The MD simulation, XPS analysis, and Zeta potential analysis revealed that the Fe-OH groups on the surface of calcite reacted with the -OH groups in Pullulan and formed bonds, resulting in the formation of a Calcite-Fe-Pullulan structure. This facilitated the attachment of a significant number of Pullulan molecules to the calcite surface. The formation of a hydrophilic layer on the outer surface of calcite by Pullulan, in contrast to the absence of such layer on fluorite's surface, results in an increased disparity in surface floatability between these two minerals, thereby enhancing the efficiency of flotation separation. [ABSTRACT FROM AUTHOR]

Pullulan is a microbial exopolysaccharide produced by Aureobasidium spp. with excellent physical and chemical properties, resulting in great application value. In this study, a novel strain RM1603 of Aureobasidium pullulans with high pullulan production of 51.0 ± 1.0 g·L− 1 isolated from rhizosphere soil was subjected to atmospheric and room temperature plasma (ARTP) mutagenesis, followed by selection of mutants to obtain pullulan high-producing strains. Finally, two mutants Mu0816 and Mu1519 were obtained, with polysaccharide productions of 58.7 ± 0.8 and 60.0 ± 0.8 g∙L− 1 after 72-h fermentation, representing 15.1 and 17.6% increases compared with the original strain, respectively. Transcriptome analysis of the two mutants and the original strain revealed that the high expression of α/β-hydrolase (ABHD), α-amylase (AMY1), and sugar porter family MFS transporters (SPF-MFS) in the mutants may be related to the synthesis and secretion of pullulan. These results demonstrated the effectiveness of ARTP mutagenesis in A. pullulans, providing a basis for the investigation of genes related to pullulan synthesis and secretion. [ABSTRACT FROM AUTHOR]

Pullulan is a biopolymer produced by various strains of the fungi Aureobasidium pullulans. It is made up of maltotriose units consisting of α-(1,6) and α-(1,4) glycosidic bonds. Pullulan was discovered by Bauer in 1938, characterized by Bernier in 1958 and named as 'pullulan' by Bender in 1959. Submerged fermentation is widely employed for pullulan production followed by downstream processing for recovery of pullulan. Factors such as nutrients, minerals, pH, temperature, surfactants, light intensity, and melanin intermediate affect its production. Various optimization methods such as Plackett Burman design, response surface methodology, and artificial neural networks have been utilised for enhancing the yield of pullulan. Pullulan yield as high as 62.52 g/L can be achieved using a 5 L fermenter under optimised conditions. It can be characterized by techniques such as nuclear magnetic resonance, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy. The biopolymer has remarkable properties which makes it an ideal candidate to be used in various applications such as the biomedical and pharmaceutical sectors, cosmetics, food, and wastewater treatment. Pullulan's applications can be expanded by chemically modifying to obtain grafted pullulan, polymer blends, nanocomposites and hydrogels which have been gaining importance in recent years. Over the years, many patents using pullulan have been granted for different applications worldwide. This review sheds light on all these aspects of pullulan including its future scope. [ABSTRACT FROM AUTHOR]