Composite materials of various compositions based on chitosan and polylactide were obtained in the form of films or porous bulk samples. Preliminarily, poly-d,l-lactide was synthesized by ring-opening polymerization of lactide in the presence of Ti(OⁱPr)₄. Polylactide obtained at components molar ratio [lactide]:[Ti(OⁱPr)₄] = 3:1 had the best molecular weight characteristics at a high product yield. Film composition with the weight ratio chitosan-polylactide 50:50 wt. % was characterized by high mechanical properties. The value of the tensile strength of the film was 72 MPa with a deformation of 10% and an elastic modulus of 40 GPa, which is higher than the tensile strength of native chitosan by ~three times. The observed effect is a consequence of the fact that the chitosan-polylactide composite has an amorphous structure in contrast to the native chitosan, which is proved by X-ray phase analysis. An increase in the elastic modulus of the composite in the range of 20–60 °C in contrast to polylactide was found by dynamic mechanical analysis. The observed effect is apparently caused by the formation of hydrogen bonds between functional groups of chitosan and polylactide which is possible through an increase in polylactide segments mobility when its glass transition temperature is reached. The composite material is biocompatible and characterized by high cellular adhesion of fibroblasts (line hTERT BJ-5ta). Their growth on the composite surface was 2.4 times more active than on native chitosan. Bulk porous samples of the composition with the weight ratio chitosan-polylactide 50:50 wt. % were synthesized by original method in ammonium bicarbonate presence. Samples were characterized by a porosity of 82.4% and an average pore size of 100 microns. The biodegradability of such material and absence of inflammatory processes were proven in vivo by the blood parameters of experimental animals. Thus, materials with the weight ratio chitosan-polylactide 50:50 wt. % are promising for potential use in regenerative medicine.

The development of materials based on chitosan and polyesters that possess thermoplastic, biocompatible, and biodegradable properties is a perspective for additive technologies in biomedicine. Research on obtaining such compositions is constrained because the polysaccharide content does not exceed 5 wt.%, which cannot ensure effective tissue regeneration. Herein, we propose a method for obtaining thermoplastic block copolymers based on chitosan and poly(ε-caprolactone) by ultrasonic irradiation of a homogeneous solution of a homopolymer mixture in dimethyl sulfoxide as a common solvent, achieving a yield of 99%. The distinctive feature of the method is the interaction between the components at the molecular level and provides obtaining copolymers at any component ratio. SEM images revealed a homogeneous structure without structural defects in both solvent-cast films and extruded filaments. The block copolymers were characterized by high mechanical property tensile strength of up to 60–70 MPa and elasticity of up to 35% for films and 25–40 MPa and elasticity of up to 50% for filaments. Cell adhesion of composition investigated on fibroblast cells (hTERT BJ-5TA) is at the level of chitosan and demonstrated the absence of cytotoxicity.

Chitosan is a natural polysaccharide with excellent biocompatibility and biodegradability, which makes it a promising biomaterial for various biomedical applications. However, its mediocre mechanical characteristics and non-thermoplasticity limit its wider use, since it cannot be melted, which means it cannot be used in 3D printing. In this study, we sought to overcome this limitation by successfully synthesizing a grafted copolymer of chitosan and L-lactide through a ring-opening polymerization. The resulting copolymer showed melting ability with a melt index of 5 and satisfactory mechanical properties with a tensile strength of 68.3 MPa, which indicates the potential of the copolymer for structural applications. The thermal properties of the copolymer were studied by the by the differential scanning calorimetry method. In vitro studies have shown that the copolymer is non-toxic to cells and promotes adhesion and proliferation of fibroblasts. The wettability of the copolymer surface was also improved compared to pure polylactide, which increased its cell adhesion for fibroblasts. Overall, this study demonstrates the potential of the grafted chitosan/polylactide copolymer as a biomaterial for biomedical applications.

Chitosan is a natural polysaccharide with excellent biocompatibility and biodegradability, which makes it a promising biomaterial for various biomedical applications. However, its mediocre mechanical characteristics and non-thermoplasticity limit its wider use, since it cannot be melted, which means it cannot be used in 3D printing. In this study, the focus was to overcome this limitation by successfully synthesizing a grafted copolymer of chitosan and L-lactide through a ring-opening polymerization. The resulting copolymer showed melting ability with a melt index of 5 and satisfactory mechanical properties with a tensile strength of 68.3 MPa, which indicates the potential of the copolymer for structural applications. The thermal properties of the copolymer were studied by the differential scanning calorimetry method. In vitro studies indicate that the copolymer is non-toxic to cells and promotes adhesion and proliferation of fibroblasts. The wettability of the copolymer surface was also improved compared to pure polylactide, which increased its cell adhesion for fibroblasts. Overall, this study demonstrates the potential of the grafted chitosan/polylactide copolymer as a biomaterial for biomedical applications.