The introduction of hydrophilic fillers in the matrix of hydrophobic thermoplastic polymers is a complicated issue, due to thermodynamic incompatibility of the components and poor adhesion properties. These complications are the most pronounced in the case of a hydrophilic polymer which cannot melt without decomposition (as polysaccharides) used as the filler. In this study, we have taken advantage of the solvent-free extrusion method both to modify the chitosan chemical structure in order to impart amphiphilic properties and to mix the obtained derivatives with polyethylene. The influence of the processes parameters, the presence of plasticizer, and the filler content on the thermal and mechanical properties of the composite film materials as well as their morphology has been investigated. It has been found that the introduction of hydrophobic fragments in the structure of chitosan insignificantly improved the mechanical properties of the materials in comparison with the pristine polysaccharide. A more significant effect has been caused by simultaneous introduction of the plasticizer, affording the materials with uniform morphology and improved plasticity.

Solid dispersions based on acyclovir and polysaccharides (starch and sodium carboxymethylcellulose) have been prepared by means of mechanochemistry. Mechanical co-processing of the drug and the polymers in a ball mill, an extruder, and a pulse mechanical action cell has led to amorphization of acyclovir, followed by its uniform distribution in the polymer matrix. A set of the IR and UV spectroscopy, DSC, and X-ray diffraction analysis data has revealed the presence of intermolecular interactions between the polysaccharide matrix and the drug. The obtained materials can be considered as potential system for further investigation as solid formulations of acyclovir with improved bioavailability.

Modification of the chitosan chemical structure by grafting hydrophobic fragments makes it possible to synthesize derivatives with amphiphilic properties. These derivatives were used as emulsifiers in the aqueous phase during the production of polylactide microparticles via the oil/water solvent evaporation technique. The application of the derivatives allows to achieve a high yield of the microparticles and to provide a hydrophilic coating on the surface of polylactide microparticle. The chitosan-coated polylactide microparticles were analyzed in terms of mean size, size distribution, surface, and internal morphology. The ability of the obtained microparticles to be used as a starting component for the fabrication of 3D materials through the surface-selective laser sintering was evaluated, and the optimal parameters for the process have been determined.

In the current study, novel matrices based on chitosan-g-oligo (L,L-/L,D-lactide) copolymers were fabricated. In particular, 2D films were prepared by solvent casting, while 3D macroporous hydrogels were obtained by lyophilization of copolymer solutions. Copolymers of chitosan (Chit) with semi-crystalline oligo (L,L-lactide) (Chit-LL) or amorphous oligo (L,D-lactide) (Chit-LD) were obtained by solid-state mechanochemical synthesis. The structure of the hydrogels was found to be a system of interconnected macropores with an average size of 150 μm. In vitro degradation of these copolymer-based matrices was shown to increase in the case of the Chit-LL-based hydrogel by 34% and decrease for the Chit-LD-based hydrogel by 23% compared to the parameter of the Chit sample. Localization and distribution of mouse fibroblast L929 cells and adipose tissue-derived mesenchymal stromal cells (MSCs) within the hydrogels was studied by confocal laser scanning microscopy (CLSM). Moreover, cellular response, namely cell adhesion, spreading, growth, proliferation, as well as cell differentiation in vitro were also evaluated in the hydrogels for 10–14 days. Both the Chit-LL and Chit-LD matrices were shown to support cell growth and proliferation, while they had improved swelling compared to the Chit matrix. Osteogenic MSCs differentiation on the copolymer-based films was studied by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Maximal expression levels of osteogenesis markers (alkaline phosphatase (ALPL), bone transcription factor (Runx2), and osteopontin (SPP1) were revealed for the Chit-LD films. Thus, osteodifferentiation was demonstrated to depend on the film composition. Both Chit-LL and Chit-LD copolymer-based matrices are promising for tissue engineering.

Taking into consideration the items of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this study reviews application of mechanochemical approaches to the modification of polysaccharides. The ability to avoid toxic solvents, initiators, or catalysts during processes is an important characteristic of the considered approach and is in line with current trends in the world. The mechanisms of chemical transformations in solid reactive systems during mechanical activation, the structure and physicochemical properties of the obtained products, their ability to dissolve and swell in different media, to form films and fibers, to self-organize in solution and stabilize nanodispersed inorganic particles and biologically active substances are considered using a number of polysaccharides and their derivatives as examples.

A wider application of naturally derived polysaccharides is of great interest as materials for food packaging industry. Biocompatibility and biodegradability of polysaccharide-based films and coatings ally with a shift from application of non-biodegradable petrochemical polymers to the more environmentally friendly ones. Due to a range of inherent features in chemical structure and bioactivity, the polysaccharide materials could bring additional functionality to food packaging. The chelating ability of the polysaccharides provides also their application as carriers of additional active components, such as nanoparticles, essential oils and polyphenols. The improved physicochemical, antibacterial and antioxidant properties of the filled films allows to consider the edible polysaccharide-based films as functional food products. This review is aimed at analysis of evolution of polysaccharide-based food packaging materials from inert one starting from cellophane to recent research works on development of multicomponent polysaccharide-based functional food films and coatings.

Surface-selective laser sintering (SSLS) is a specific version of selective laser sintering, which allows one to fabricate 3D structures with well-defined architectonic via selective melting of microparticle surface without alteration of their core. This mode of laser sintering requires a well-designed surface properties of the microparticles to adsorb laser irradiation. Water was chosen as safer sensitive absorber of laser radiation with a wavelength of 1.9 μm, i.e. one with low absorption coefficient by polymeric core. Biodegradable polylactide microparticles were fabricated via oil/water emulsion solvent evaporation technique using tailored-made chitosan-based macromolecules, which provided the effective interface stabilization during the microparticle fabrication and well balanced microparticle surface hydrophilicity to adsorb water. Especially build SSLS set-up was designed in order to monitor the effectiveness of the 3D scaffold fabrication from the obtained microparticles and to adapt the optimal laser radiation parameters with a wavelength of 1.9 μm (e.g. speed, line density, power).

Biodegradable polymeric fibrous non-woven materials are widely used type of scaffolds for tissue engineering. Their morphology and properties could be controlled by composition and fabrication technology. This work is aimed at development of fibrous scaffolds from a multicomponent polymeric system containing biodegradable synthetic (polylactide, polycaprolactone) and natural (gelatin, chitosan) components using different methods of non-woven mats fabrication: electrospinning and electro-assisted solution blow spinning. The effect of the fabrication technique of the fibrous materials onto their morphology and properties, including the ability to support adhesion and growth of cells, was evaluated. The mats fabricated using electrospinning technology consist of randomly oriented monofilament fibers, while application of solution blow spinning gave a rise to chaotically arranged multifilament fibers. Cytocompatibility of all fabricated fibrous mats was confirmed using in vitro analysis of metabolic activity, proliferative capacity and morphology of NIH 3T3 cell line. Live/Dead assay revealed the formation of the highest number of cell–cell contacts in the case of multifilament sample formed by electro-assisted solution blow spinning technology.

Materials in the form of thermally crosslinked films and macroporous hydrogels based on graft copolymers of chitosan with lactide oligomers of various stereochemical compositions synthesized by solid-state reactive extrusion are obtained and studied. It is shown that the chemical structure of the copolymers and the molecular weight of the initial chitosan significantly affect the morphology and properties of the materials. The heterogeneous morphology of materials based on the semicrystalline lactide oligomer leads to a decrease in the efficiency of crosslinking of the materials during heat treatment and a higher degree of moisture absorption of macroporous hydrogels.

The process of forming hybrid microparticles from a biodegradable polyester, that is, polylactide, and hydroxyapatite nanoparticles, which can be promising as cellular microcarriers or starting materials for obtaining three-dimensional scaffolds for bone tissue regeneration, has been investigated. A method has been developed for fabricating hybrid microparticles by evaporation of solvents from oil/water emulsions without the use of additional emulsifiers in a dispersion phase. It is shown that hydroxyapatite nanoparticles can effectively stabilize the interface during the preparation of microparticles. The effect of the concentration of hydroxyapatite nanoparticles and their preliminary dispersion using ultrasonic treatment on the yield of microparticles, their size distribution and morphology was evaluated.

Исследовано влияние обработки в плазме низкочастотного тлеющего разряда при пониженном давлении на растворимость пленок на основе хитозана или его сополимера с олиголактидом и коллагеном в водных средах. Изучен вклад различных факторов, в т. ч. пониженного давления, УФ-излучения, взаимодействия активных компонентов плазмы с поверхностью полимеров, на потерю растворимости. Установлено, что образование нерастворимой в воде фракции хитозансодержащих пленочных образцов после обработки в плазме связано в основном с воздействием УФ-излучения, однако определенную роль играет воздействие электронов и ионов, а также пониженное давление.

Biodegradable polymeric microparticles are widely used in drug delivery systems with prolonged-release profiles and/or cell microcarriers. Their fabrication via the oil/water emulsion solvent evaporation technique has normally required emulsifiers in the aqueous phase. The present work aims to evaluate the effectiveness of various polysaccharides, such as chitosan, hyaluronic acid, cellulose, arabinogalactan, guar and their derivatives, as an alternative to synthetic surfactants for polylactide microparticle stabilization during their fabrication. Targeted modification of the biopolymer’s chemical structure was also tested as a tool to enhance polysaccharides’ emulsifying ability. The transformation of biomacromolecules into a form of nanoparticle via bottom-up or top-down methods and their subsequent application for microparticle fabrication via the Pickering emulsion solvent evaporation technique was useful as a one-step approach towards the preparation of core/shell microparticles. The effect of polysaccharides’ chemical structure and the form of their application on the polylactide microparticles’ total yield, size distribution and morphology was evaluated. The application of polysaccharides has great potential in terms of the development of green chemistry and the biocompatibility of the formed microparticles, which is especially important in biomedicine application.

Hydrophobic derivatives of polysaccharides possess an amphiphilic behavior and are widely used as rheological modifiers, selective sorbents, and stabilizers for compositions intended for various applications. In this work, we studied the mechanochemical reactions of chitosan alkylation when interacting with docosylglycidyl and hexadecylglycidyl ethers in the absence of solvents at shear deformation in a pilot twin-screw extruder. The chemical structure and physical properties of the obtained derivatives were characterized by elemental analysis, FT-IR spectroscopy, dynamic light scattering, scanning electron microscopy, and mechanical tests. According to calculations for products soluble in aqueous media, it was possible to introduce about 5–12 hydrophobic fragments per chitosan macromolecule with a degree of polymerization of 500–2000. The length of the carbon chain of the alkyl substituent significantly affects its reactivity under the chosen conditions of mechanochemical synthesis. It was shown that modification disturbs the packing ability of the macromolecules, resulting in an increase of plasticity and drop in the elastic modulus of the film made from the hydrophobically modified chitosan samples.

Solid-state mechanochemical approach to copolymer synthesis is a promising way to produce macromolecules combining properties and advantages of polymers of different nature. In addition to high efficiency and ecological benefits this synthetic route allows producing a relatively high amount of copolymers, which makes fabrication of the copolymer-based materials reasonable. Synthesis of amphiphilic natural/synthetic copolymers is especially promising in terms of their further use for formation of advanced materials for various applications, especially for biomedicine. This study highlights an effect of hydrophilic-hydrophobic balance of complex protein-contained chitosan-g-oligo-/polylactide copolymers on possibility to apply a range of material fabrication methods.

Graft-copolymers based on bioresorbable synthetic (oligo-/polylactide) and natural (chitosan and collagen/gelatin) components were synthesized through solid-state reactive co-extrusion and used for fabrication of fibrous non-woven mats via the electrospinning technique. The effect of the macromolecular features of the initial components on the copolymer characteristics was evaluated using FTIR-spectroscopy, differential scanning calorimetry and elemental analysis. Dynamic light scattering analysis showed that the copolymers have a tendency to form stable ultra-fine dispersions with a mean size of macromolecular aggregates of 150 nm within chlorinated solvents. The copolymer-containing non-woven fibrous mats were fabricated via an electrospinning procedure using chloroform as a solvent. An effect of the copolymer composition on the casting solution's viscosity, conductivity and surface tension was evaluated. Scanning electron microscopy showed that the obtained mats consist of randomly distributed fibers with a mean size of ∼5 μm and a more complex morphology than mats fabricated from neat polylactide. The proposed mechanochemical approach to obtain hybrid copolymeric compositions differs from typical liquid-phase methods in terms of high efficiency, simplicity and cleanness.