Electrostatic self-assembly of polysaccharides into nanofibers

One-Step Fast Fabrication of Electrospun Fiber Membranes for Efficient Particulate Matter Removal

Rapid social and industrial development has resulted in an increasing demand for fossil fuel energy, which increases particulate matter (PM) pollution. In this study, we employed a simple one-step electrospinning technique to fabricate polysulfone (PSF) fiber membranes for PM filtration. A 0.3 g/mL polymer solution with an N,N-dimethylformamide:tetrahydrofuran volume ratio of 3:1 yielded uniform and bead-free PSF fibers with a diameter of approximately 1.17 μm. The PSF fiber membrane exhibited excellent hydrophobicity and mechanical properties, including a tensile strength of 1.14 MPa and an elongation at break of 116.6%. Finally, the PM filtration performance of the PSF fiber membrane was evaluated. The filtration efficiencies of the membrane for PM2.5 and PM1.0 were approximately 99.6% and 99.2%, respectively. The pressure drops were 65.0 and 65.2 Pa, which were significantly lower than those of commercial air filters. Using this technique, PSF fiber membrane filters can be easily fabricated over a large area, which is promising for numerous air filtration systems.

Classification and design strategies of polysaccharide-based nano-nutrient delivery systems for enhanced bioactivity and targeted delivery: A review

Since many nutrients are highly sensitive, they cannot be absorbed and utilized efficiently by the body. Using nano-delivery systems to encapsulate nutrients is an effective method of solving the problems associated with the application of nutrients at this stage. Polysaccharides, as natural biomaterials, have a unique chemical structure, ideal biocompatibility, biodegradability and low immunogenicity. This makes polysaccharides powerful carriers that can enhance the biological activity of nutrients. However, the true role of polysaccharide-based delivery systems requires an in-depth understanding of the structural and physicochemical characteristics of polysaccharide-based nanodelivery systems, as well as effective modulation of the intestinal delivery mechanism and the latest advances in nano-encapsulation. This review provides an overview of polysaccharide-based nano-delivery systems dependent on different carrier types, emphasizing recent advances in the application of polysaccharides, a biocomposite material designed for nutrient delivery systems. Strategies for polysaccharide-based nano-delivery systems to enhance the bioavailability of orally administered nutrients from the perspective of the intestinal absorption barrier are presented. Characterization methods for polysaccharide-based nano-delivery systems are presented as well as an explanation of the formation mechanisms behind nano-delivery systems from the perspective of molecular forces. Finally, we discussed the challenges currently facing polysaccharide-based nano-delivery systems as well as possible future directions for the future.

Nanofiber Carriers of Therapeutic Load: Current Trends

The fast advancement in nanotechnology has prompted the improvement of numerous methods for the creation of various nanoscale composites of which nanofibers have gotten extensive consideration. Nanofibers are polymeric/composite fibers which have a nanoscale diameter. They vary in porous structure and have an extensive area. Material choice is of crucial importance for the assembly of nanofibers and their function as efficient drug and biomedicine carriers. A broad scope of active pharmaceutical ingredients can be incorporated within the nanofibers or bound to their surface. The ability to deliver small molecular drugs such as antibiotics or anticancer medications, proteins, peptides, cells, DNA and RNAs has led to the biomedical application in disease therapy and tissue engineering. Although nanofibers have shown incredible potential for drug and biomedicine applications, there are still difficulties which should be resolved before they can be utilized in clinical practice. This review intends to give an outline of the recent advances in nanofibers, contemplating the preparation methods, the therapeutic loading and release and the various therapeutic applications.

Polysaccharide-based nanofibers for pharmaceutical and biomedical applications: A review

Nanofibers are fibrous nanocarriers that can be synthesized from natural polymers, synthetic polymers, semiconducting materials, composite materials, and carbon-based materials. Recently, natural polysaccharides-based nanofibers are gaining attention in the field of pharmaceuticals and biomedical as these are biocompatible, biodegradable, non-toxic, and economic. Nanofibers can deliver a significant amount of drug to the targeted site and provide effective interaction of therapeutic agent at the site of action due to a larger surface area. Other important advantages of nanofibers are low density, high porosity, small pore size, high mechanical strength, and low cost. In this review, natural polysaccharides such as alginate, pullulan, hyaluronic acid, dextran, cellulose, chondroitin sulfate, chitosan, xanthan gum, and gellan gum are discussed for their characteristics, pharmaceutical utility, and biomedical applications. The authors have given particular emphasis to the several fabrication processes that utilize these polysaccharides to form nanofibers, and their recent updates in pharmaceutical applications such as drug delivery, tissue engineering, skin disorders, wound-healing dressings, cancer therapy, bioactive molecules delivery, anti-infectives, and solubility enhancement. Despite these many advantages, nanofibers have been explored less for their scale-up and applications in advanced therapeutic delivery.

Development and Characterization of Natural Product Derived Macromolecules Based Interpenetrating Polymer Network for Therapeutic Drug Targeting

Interpenetrating polymer network (IPN)-based bead formulations were exploited by cross-linking different hydrophilic polymers in different combinations and at different ratios. Polyvinyl alcohol, xanthan gum, guar gum, gellan gum, and sodium alginate (Na-alginate) were used in this work as hydrophilic polymers to enhance the solubility of diclofenac sodium and also to target the delivery at preferred locations. IPN beads based on polysaccharides were prepared by the ionic gelation method. Differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy data showed that the IPN microbeads solubilized and encapsulated the drug within the network. We found over 83% encapsulation efficiency of the drug delivery system for the drug, and this efficiency increased with the concentration of the polymer. Ex vivo experiments using the goat intestine revealed that the IPN microbeads were able to adhere to the intestinal epithelium, a mucoadhesive behavior that could be beneficial to the drug pharmacokinetics, while in vitro experiments in phosphate buffer showed that the IPN enabled significant drug release. We believe that these IPN microbeads are an excellent drug delivery system to solubilize drug molecules and ensure adhesion to the intestinal wall, thereby localizing the drug release to enhance bioavailability of poorly soluble drugs.

Microbial production and recovery of hybrid biopolymers from wastes for industrial applications- a review

Agro-industrial wastes to be a global concern since agriculture and industrial processes are growing exponentially with the fast increase of the world population. Biopolymers are complex molecules produced by living organisms, but also found in many wastes or derived from wastes. The main drawbacks for the use of polymers are the high costs of the polymer purification processes from waste and the scale-up in the case of biopolymer production by microorganisms. However, the use of biopolymers at industrial scale for the development of products with high added value, such as food or biomedical products, not only can compensate the primary costs of biopolymer production, but also improve local economies and environmental sustainability. The present review describes some of the most relevant aspects related to the synthesis of hybrid materials and nanocomposites based on biopolymers for the development of products with high-added value.

Self-assembly of multiscale anisotropic hydrogels through interfacial polyionic complexation

Polysaccharides are explored for various tissue engineering applications due to their inherent cytocompatibility and ability to form bulk hydrogels. However, bulk hydrogels offer poor control over their microarchitecture and multiscale hierarchy, parameters important to recreate extracellular matrix-mimetic microenvironment. Here, we developed a versatile platform technology to self-assemble oppositely charged polysaccharides into multiscale fibrous hydrogels with controlled anisotropic microarchitecture. We employed polyionic complexation through microfluidic flow of positively charged polysaccharide, chitosan, along with one of the three negatively charged polysaccharides: alginate, gellan gum, and kappa carrageenan. These hydrogels were composed of microscale fibers, which in turn were made of submicron fibrils confirming multiscale hierarchy. Fibrous hydrogels showed strong tensile mechanical properties, which were further modulated by encapsulation of shape-specific antioxidant cerium oxide nanoparticles (CNPs). Specifically, hydrogels with chitosan and gellan gum showed more than eight times higher tensile strength compared to the other two pairs. Incorporation of sphere-shaped cerium oxide nanoparticles in chitosan and gellan gum further reinforced fibrous hydrogels and increased their tensile strength by 40%. Altogether, our automated hydrogel fabrication platform allows fabrication of bioinspired biomaterials with scope for one-step encapsulation of small molecules and nanoparticles without chemical modification or use of chemical crosslinkers.

An Overview of Biopolymeric Electrospun Nanofibers Based on Polysaccharides for Wound Healing Management

Currently, despite the thoroughgoing scientific research carried out in the area of wound healing management, the treatment of skin injuries, regardless of etiology remains a big provocation for health care professionals. An optimal wound dressing should be nontoxic, non-adherent, non-allergenic, should also maintain a humid medium at the wound interfacing, and be easily removed without trauma. For the development of functional and bioactive dressings, they must meet different conditions such as: The ability to remove excess exudates, to allow gaseous interchange, to behave as a barrier to microbes and to external physical or chemical aggressions, and at the same time to have the capacity of promoting the process of healing by stimulating other intricate processes such as differentiation, cell adhesion, and proliferation. Over the past several years, various types of wound dressings including hydrogels, hydrocolloids, films, foams, sponges, and micro/nanofibers have been formulated, and among them, the electrospun nanofibrous mats received an increased interest from researchers due to the numerous advantages and their intrinsic properties. The drug-embedded nanofibers are the potential candidates for wound dressing application by virtue of: Superior surface area-to volume ratio, enormous porosity (can allow oxy-permeability) or reticular nano-porosity (can inhibit the microorganisms'adhesion), structural similitude to the skin extracellular matrix, and progressive electrospinning methodology, which promotes a prolonged drug release. The reason that we chose to review the formulation of electrospun nanofibers based on polysaccharides as dressings useful in wound healing was based on the ever-growing research in this field, research that highlighted many advantages of the nanofibrillary network, but also a marked versatility in terms of numerous active substances that can be incorporated for rapid and infection-free tissue regeneration. In this review, we have extensively discussed the recent advancements performed on electrospun nanofibers (eNFs) formulation methodology as wound dressings, and we focused as well on the entrapment of different active biomolecules that have been incorporated on polysaccharides-based nanofibers, highlighting those bioagents capable of improving the healing process. In addition, in vivo tests performed to support their increased efficacy were also listed, and the advantages of the polysaccharide nanofiber-based wound dressings compared to the traditional ones were emphasized.

Genetically Engineered Flagella Form Collagen-like Ordered Structures for Inducing Stem Cell Differentiation

Bacteria use flagella, the protein nanofibers on their surface, as a molecular machine to swim. Flagella are polymerized from monomers, flagellins, which can display a peptide by genetic means. However, flagella as genetically modifiable nanofibers have not been used in building bone extracellular matrix-like structures for inducing stem cell differentiation in non-osteogenic medium. Here we discovered that interactions between Ca2+ ions and flagella (displaying a collagen-like peptide (GPP)8 on every flagellin) resulted in ordered bundle-like structures, which were further mineralized with hydroxyapatite to form ordered fibrous matrix. The resultant matrix significantly induced the osteogenic differentiation of stem cells, much more efficiently than wild-type flagella and type I collagen. This work shows that flagella can be used as protein building blocks in generating biomimetic materials.

Tree gum-based renewable materials: Sustainable applications in nanotechnology, biomedical and environmental fields

The prospective uses of tree gum polysaccharides and their nanostructures in various aspects of food, water, energy, biotechnology, environment and medicine industries, have garnered a great deal of attention recently. In addition to extensive applications of tree gums in food, there are substantial non-food applications of these commercial gums, which have gained widespread attention due to their availability, structural diversity and remarkable properties as 'green' bio-based renewable materials. Tree gums are obtainable as natural polysaccharides from various tree genera possessing exceptional properties, including their renewable, biocompatible, biodegradable, and non-toxic nature and their ability to undergo easy chemical modifications. This review focuses on non-food applications of several important commercially available gums (arabic, karaya, tragacanth, ghatti and kondagogu) for the greener synthesis and stabilization of metal/metal oxide NPs, production of electrospun fibers, environmental bioremediation, bio-catalysis, biosensors, coordination complexes of metal-hydrogels, and for antimicrobial and biomedical applications. Furthermore, polysaccharides acquired from botanical, seaweed, animal, and microbial origins are briefly compared with the characteristics of tree gum exudates.