Recent Developments and Applications of Microbial Levan, A Versatile Polysaccharide-Based Biopolymer.

Polysaccharides are essential components with diverse functions in living organisms and find widespread applications in various industries. They serve as food additives, stabilizers, thickeners, and fat substitutes in the food industry, while also contributing to dietary fiber for improved digestion and gut health. Plant-based polysaccharides are utilized in paper, textiles, wound dressings, biodegradable packaging, and tissue regeneration. Polysaccharides play a crucial role in medicine, pharmacy, and cosmetology, as well as in the production of biofuels and biomaterials. Among microbial biopolymers, microbial levan, a fructose polysaccharide, holds significant promise due to its high productivity and chemical diversity. Levan exhibits a wide range of properties, including film-forming ability, biodegradability, non-toxicity, self-aggregation, encapsulation, controlled release capacity, water retention, immunomodulatory and prebiotic activity, antimicrobial and anticancer activity, as well as high biocompatibility. These exceptional properties position levan as an attractive candidate for nature-based materials in food production, modern cosmetology, medicine, and pharmacy. Advancing the understanding of microbial polymers and reducing production costs is crucial to the future development of these fields. By further exploring the potential of microbial biopolymers, particularly levan, we can unlock new opportunities for sustainable materials and innovative applications that benefit various industries and contribute to advancements in healthcare, environmental conservation, and biotechnology.

Application of Levan-Rich Digestate Extract in the Production of Safe-to-Use and Functional Natural Body Wash Cosmetics.

The study focused on the evaluation of the possibility of using a levan-rich digestate extract in the production of safe and functional body wash cosmetics. Model shower gels were designed and formulated on the basis of raw materials of natural origin. Prepared prototypes contained various extract concentrations (16.7; 33; 50%). A gel without extract was used as a reference. The samples were evaluated for their safety in use and functionality. The results showed that the use of high-concentration levan-rich digestate extract in a shower gel resulted in a significant reduction in the negative impact on the skin. For example, the zein value decreased by over 50% in relation to the preparation without the extract. An over 40% reduction in the emulsifying capacity of hydrophobic substances was also demonstrated, which reduces skin dryness after the washing process. However, the presence of the extract did not significantly affect the parameters related to functionality. Overall, it was indicated that levan-rich digestate extract can be successfully used as a valuable ingredient in natural cleansing cosmetics.

Design and Engineering of "Green" Nanoemulsions for Enhanced Topical Delivery of Bakuchiol Achieved in a Sustainable Manner: A Novel Eco-Friendly Approach to Bioretinol.

In the present work, we establish novel "environmentally-friendly" oil-in-water nanoemulsions to enhance the transdermal delivery of bakuchiol, the so-called "bioretinol" obtained from powdered Psoralea corylifolia seeds via a sustainable process, i.e., using a supercritical fluid extraction approach with pure carbon dioxide (SC-CO2). According to Green Chemistry principles, five novel formulations were stabilized by "green" hybrid ionic surfactants such as coco-betaine-surfactin molecules obtained from coconut and fermented rapeseed meal. Preliminary optimization studies involving three dispersion stability tests, i.e., centrifugation, heating, and cooling cycles, indicated the most promising candidates for further physicochemical analysis. Finally, nanoemulsion colloidal characterization provided by scattering (dynamic and electrophoretic light scattering as well as backscattering), microscopic (transmission electron and confocal laser scanning microscopy), and spectroscopic (UV-Vis spectroscopy) methods revealed the most stable nanocarrier for transdermal biological investigation. In vitro, topical experiments provided on human skin cell line HaCaT keratinocytes and normal dermal NHDF fibroblasts indicated high cell viability upon treatment of the tested formulation with a final 0.02-0.2 mg/mL bakuchiol concentration. This excellent biocompatibility was confirmed by ex vivo and in vivo tests on animal and human skin tissue. The improved permeability and antiaging potential of the bakuchiol-encapsulated rich extract were observed, indicating that the obtained ecological nanoemulsions are competitive with commercial retinol formulations.

Antiradical Properties of N-Oxide Surfactants-Two in One.

Surfactants are molecules that lower surface or interfacial tension, and thus they are broadly used as detergents, wetting agents, emulsifiers, foaming agents, or dispersants. However, for modern applications, substances that can perform more than one function are desired. In this study we evaluated antioxidant properties of two homological series of N-oxide surfactants: monocephalic 3-(alkanoylamino)propyldimethylamine-N-oxides and dicephalic N,N-bis[3,3'-(dimethylamino)propyl]alkylamide di-N-oxides. Their antiradical properties were tested against stable radicals using electron paramagnetic resonance (EPR) and UV-vis spectroscopy. The experimental investigation was supported by theoretical density functional theory (DFT) and ab initio modeling of the X-H bonds dissociation enthalpies, ionization potentials, and Gibbs free energies for radical scavenging reactions. The evaluation was supplemented with a study of biological activity. We found that the mono- and di-N-oxides are capable of scavenging reactive radicals; however, the dicephalic surfactants are more efficient than their linear analogues.

Targeted Hybrid Nanocarriers as a System Enhancing the Skin Structure.

The skin is constantly exposed to external and internal factors that disturb its function. In this work, two nanosystems-levan nanoparticles and a surfactin-stabilized nanoemulsion were preserved (tested for microbial growth) and characterized (size, polydispersity, Zeta potential, and stability). The nanosystems were introduced in the model formulations-cream, tonic, and gel, and confirmed by TEM. The analysis showed that nanoemulsion has a spherical morphology and size 220-300 nm, while levan nanoparticles had irregular shapes independently of the use of matrix and with particle size (130-260 nm). Additionally, we examined the antiradical effect of levan nanoparticles and nanoemulsion in the prototype of formulations by scavenging DPPH (2,2-diphenyl-1-picrylhydrazyl; EPR spectroscopy). The model cream with both nanosystems and the whole range of products with nanosystems were evaluated in vivo for hydration, elasticity, smoothness, wrinkles and vascular lesions, discoloration, respectively. The cream improved skin condition in all tested parameters in at least 50% of volunteers. The use of more comprehensive care, additionally consisting of a tonic and gel, reduced the previously existing skin discoloration to 10.42 ± 0.58%. The presented prototype formulations are promising in improving skin conditions.

Nanoemulsion Stabilized by Safe Surfactin from Bacillus Subtilis as a Multifunctional, Custom-Designed Smart Delivery System.

The developing field of bio-nanotechnology aims to advance colloidal research via the introduction of multifunctional nanoparticles to augment the dermal effectiveness of active substances. Self-emulsifying drug delivery systems (SEDDS)-isotropic mixtures of oils, surfactants, solvents and co-solvents or surfactants-are attracting interest in the cosmeceutical field. As part of this study, SEDDS systems containing vitamin C or vitamin E and curcumin were developed, whereby the bioavailability of the active compounds increased by enhancing their permeability to deeper layers of the skin. A composition consisting of 50% surfactin from Bacillus subtilis, 30% Transcutol and 20% oil phase was designed to encapsulate the active substances, i.e., vitamin C or vitamin E and curcumin, contained in the oil phase. The developed carriers were characterized by average particle sizes of 69-183 nm. The formulations with the vitamins were found to be physically and chemically stable for 6 months. Transdermal tests were carried out, showing that the carriers enable the transport of active substances deep into the skin, stopping at the dermis border. The formulations with vitamin C and vitamin E reduced the discoloration, the vascular lesions, and the depth of the wrinkles on the tested skin, which can be useful in cosmetics in the treatment of problem skin, including capillary and sensitive skin.

Biotransformation of rapeseed meal leading to production of polymers, biosurfactants, and fodder.

After extracting the oil from rapeseed, the remaining meal byproduct is used in animal feed, particularly for cattle, and represents an effective, high-protein substitute for soybean meal. The biotransformation of rapeseed meal using Generally Recognized as Safe (GRAS) bacteria increases its nutritional value and enriches it with a variety of additives including polymers, biosurfactants, and enzymes. Polymers produced in SSF process with rapeseed meal (e.g., levan) have probiotic prosperities and can even serve as alternatives to antibiotics, which are banned from animal feed by law. Due to their moisturizing properties, these polymers are also incorporated into cosmetics. The biosurfactants produced by bacteria and yeast confer their strong antimicrobial effects to preserve the feed. In turn, the many enzymes produced during the biotransformation of rapeseed meal increase its nutritional value by reducing fibers, detrimental substances (e.g., tannins, erucic acid, phytic acid), and mycotoxins. Taken together, rapeseed meal biotransformation results in numerous benefits, for the animal and industry alike.

Fermentation parameters and conditions affecting levan production and its potential applications in cosmetics.

Levan is a polysaccharide composed of fructose units with ß-2,6-glycoside bonds. Microorganisms synthesize levan by levansucrase as a mixture of low- and high-molecular-weight fractions. Due to its properties, it has a wide range of applications in cosmetics, pharmaceuticals, food and medicine; it appears that the molecular weight of levan might impact its industrial use. To obtain one fraction of levan after biotransformation, ethanol precipitation with an increasing volume of alcohol was conducted. This precipitation process was also optimized. Several types of analyses were used. Low-molecular-weight levan was evaluated for toxicity in a normal human dermal fibroblast cell line and hemolytic potential on human erythrocytes. Levan was found to be non-cytotoxic and non-hemolytic in concentrations ranging from 0.01 to 1.00 mg/ml. Moreover, levan demonstrated antioxidant potential expressed as an ability to inhibit of oil/water emulsion oxidation and DPPH radical scavenging.