[PERIFOCAL TISSUE REACTIONS TO IMPLANTATION OF THE SAMPLES OF HYDROGEL MATERIAL BASED ON POLYACRYLAMIDE WITH THE ADDITION OF THE CELLULOSE (AN EXPERIMENTAL STUDY)].

Tissue reactions to the grafting of samples of composite hydrogel based on polyacrylamide and cellulose of different origin (plant and bacterial) were studied in 48 laboratory outbred rats and 24 rabbits of chinchilla breed. The observations were carried out on Days 5, 14, 45 and 90 after placement of implants in the muscle, joint cavity, deep defects of the articular cartilage and subchondral bone. The study has revealed no migration and degradation of the samples. On Day 90, the signs of their biointegration (regardless of their nature) were detected in the muscles and in one case (the sample containing bacterial cellulose) in the cavity of the knee joint of the rat. The materials had good biocompatibility with muscle, cartilage and bone tissues, did not cause perifocal inflammation and effectively functioned as a prosthetic articular cartilage until the end of the study period.

Anisotropic swelling and mechanical behavior of composite bacterial cellulose-poly(acrylamide or acrylamide-sodium acrylate) hydrogels.

Bacterial cellulose-polyacrylamide (BC-PAAm) composite hydrogels are prepared by synthesis of PAAm networks inside the BC matrices. The behavior of these gels and of the ionic ones obtained via partial hydrolysis of BC-PAAm gels is studied under swelling and compressive deformation conditions. The dependences of the hydrogels' properties on the BC matrix preparation conditions, gel synthesis conditions and the BC content in the hydrogel compositions are studied. Two types of BC gel pellicle are used in the hydrogel synthesis, namely matrix pellicles subjected to pre-pressing (samples of series A) and those not subjected to any mechanical actions before synthesis (series B samples) containing about 99% water. The effect of anisotropic swelling of type A hydrogels is detected. The type B specimens swell isotropically. Both types of hydrogel exhibit substantial anisotropy of their mechanical properties, apparent in different shapes of compression stress-strain curves of samples cut out from the gel plates in various directions. Composite hydrogels show superb mechanical properties, including compression strength up to 10 MPa and the ability to withstand long-term cyclic stresses (up to 2000-6000 cycles) without substantial reduction of mechanical properties.

Effects of new wound dressings on healing of thermal burns of the skin in acute radiation disease.

Effects of new wound dressing bacterial cellulose impregnated with SOD and poviargol (Procel-Super and Procel-PA) and Inerpan hydrogel dressing on the reparative processes in deep dermal burns (IIIa-IIIb degree) in rats exposed to total even irradiation in a dose of 4 Gy were studied. Inerpan and Procel-Super dressings proved to be the most effective under these conditions: they accelerated healing of burn wounds by 17.0 and 5.5%, respectively.