Cell Immunity in Implant-Associated Infections Caused by Biofilm-Forming Microorganisms.

High biofilm-forming capacity of Staphylococcus spp. strains isolated from biomaterial of patients with infectious complications after primary knee replacement developed within 6-12 months after surgery was experimentally demonstrated. Differential leukocyte counts and some indicators of cell immunity in these patients were compared with those in patients without purulent complications and healthy volunteers. In patients with implant-associated infection, the relative numbers of T cells (both T-helpers and T-suppressors) B cells were significantly (p<0.05) reduced, while the number of NK cells was significantly increased in comparison with the corresponding parameters in other groups. The revealed changes attest to cell immunity failure in biofilm infection.

Particularities of Bone Regeneration in Rats after Implantation of Polycaprolactone Scaffold Mineralized with Vaterite with Adsorbed Tannic Acid.

We studied the particularities of osteo- and angiogenesis in albino rats after implantation of polycaprolactone scaffolds mineralized with vaterite with adsorbed tannic acid in the femoral bone defect. It was found that the processes of angio- and osteogenesis in the bone tissue after scaffolds implantation depend on their biocompatibility. Implantation of non-biocompatible scaffolds was followed by activation of angio- and osteogenesis aimed at separation of these scaffold from surrounding tissues. Implantation of polycaprolactone/vaterite scaffolds containing tannic acid stimulated angio- and osteogenesis leading to vascularization and bone tissue formation in the matrix. This demonstrate prospects of clinical approbation of these scaffolds for stimulation of bone regeneration in traumatological and orthopedic patients.

Hybrid PCL/CaCO3 scaffolds with capabilities of carrying biologically active molecules: Synthesis, loading and in vivo applications.

Designing advanced biomaterials for tissue regeneration with drug delivery and release functionalities remains a challenge in regenerative medicine. In this research, we have developed novel composite scaffolds based on polymeric polycaprolactone fibers coated with porous calcium carbonate structures (PCL/CaCO3) for tissue engineering and have shown their drug delivery and release in rats. In vivo biocompatibility tests of PCL/CaCO3 scaffolds were complemented with in vivo drug release study, where tannic acid (TA) was used as a model drug. Release of TA from the scaffolds was realized by recrystallization of the porous vaterite phase of calcium carbonate into the crystalline calcite. Cell colonization and tissue vascularization as well as transplantability of developed PCL/CaCO3+TA scaffolds were observed. Detailed study of scaffold transformations during 21-day implantation period was followed by scanning electron microscopy and X-ray diffraction studies before and after in vivo implantation. The presented results demonstrate that PCL/CaCO3 scaffolds are attractive candidates for implants in bone regeneration and tissue engineering with a possibility of loading biologically active molecules and controlled release.

Application of Preparations Containing Copper Nanoparticles for the Treatment of Experimental Septic Wounds.

Regenerative activity of locally applied drugs based on copper nanoparticles was compared on white male rats with an experimental purulent wound infected with clinical polyantibiotic resistant strains of Staphylococcus aureus. The use of a suspension of copper nanoparticles and complex drugs based on chitosan and starch with copper nanoparticles led to a rapid reduction of the wound area and elimination of the wound-contaminating agent, which confirmed high antibacterial and regenerative activity of copper nanoparticles in the composition of the studied drugs.

Soft Tissue Regeneration under the Effect of Wound Coating Based on Chitosan (Natural Biopolymer).

We developed wound coating based on natural biopolymer chitosan with additional components (ceruloplasmin, L-asparaginic acid, and glycerol). Experiments on albino male rats demonstrated its regeneratory, antioxidant, and antibacterial effects on wounds involving all layers of the skin. Due to chemical composition and buffer component, the biodegraded wound coating optimizes all phases of the wound process, accelerates by 22-28% the reparative regeneration, and leads to anatomic and functional restoration of injured sites. High absorption capacity recommends its use in the treatment of wounds with profuse exudation.

[IN VIVO EVALUATION OF POLYCAPROLACTONE-HYDROXYAPATITE SCAFFOLD BIOCOMPATIBILITY].

Biocompatibility is one of the main and very important properties for scaffolds. The aim of the present study was to investigate cells population dynamics in vivo in the process of original polycaprolactone-hydroxyapatite scaffold colonization, as well as tissue reactions to the implantation to assess the biocompatibility of the matrix. It has been found that tissue reactive changes in white rats subside completely up to the 21st day after subcutaneous polycaprolactone-hydroxyapatite scaffold implantation. Matrix was actively colonized by connective tissue cells in the period from the 7th to the 21st day of the experiment. However, intensive scaffold vascularization started from the 14th day after implantation. These findings suggest a high degree of the polycaprolactone-hydroxyapatite scaffold biocompatiblilitye.

[The effect of the biopolymer chondroitin sulfate on reparative regeneration of connective tissue].

The research objective is a study of an intra-articular method of introduction of the preparation "mukosat" for stimulation of reparative regeneration of connective tissue of knee joints in rabbits with an experimental arthritis. It is ascertained that intra-articular maintenance of chondroitin sulfate (the preparation "mukosat") acts as a stimulus for reparative regeneration of connective tissue thus showing up positive changes in the status of connective tissue elements of joints: decrease in glycosaminoglycan content in blood serum and normalization of the composition of glycosaminoglycan carbohydrate component. It probably depends on stimulation of biosynthesis of autologous normal glycosaminoglycans in tissues of animal knee joints.

[Vascular endothelial Barrier Function].

Endothelium is an important regulator of selective permeability of the vascular wall for different molecules and cells. This review summarizes current data on endothelial barrier function. Endothelial glycocalyx structure, its function and role in the molecular transport and leukocytes migration across the endothelial barrier are discussed. The mechanisms of transcellular transport of macromolecules and cell migration through endothelial cells are reviewed. Special section of this article addresses the structure and function of tight and adherens endothelial junction, as well as their importance for the regulation of paracellular transport across the endothelial barrier. Particular attention is paid to the signaling mechanism of endothelial barrier function regulation and the factors that influence on the vascular permeability.

[Reparative regeneration of connective tissue structures of mammals under antioxidant therapy conditions].

The influence of administration of the antioxidant complexes consisting of nonenzymatic antioxidants (alpha-tocopherol acetate preparation) and enzymatic antioxidants (ceruloplasmin) has been studied in rabbits with experimental arthritis. The introduction of alpha-tocopherol acetate (at a daily dose of 4 mg) improved metabolic processes in the organism (decreased in the rate of erythrocyte precipitation, total leukocytes and their stub and segmental forms; increased in erythrocyte count; reduced the glycosaminoglycan content as determined from uronic acid and hexose level; decreased ceruloplasmin activity and malonic dialdehyde level ion blood serum, all at p < 0.05), thus favoring reduction in the total activity of the inflammatory process as judged from hematological and biochemical data. Intra-articular introduction of ceruloplasmin (1.5 mg/kg, once per week) positively influenced the state of joint structures in damaged knee joints of the animals: decreased the activity of ceruloplasmin (from 5.28 ± 0.06 to 3.94 ± 0.01 AU), and malonic dialdehyde level (0.18 ± 0.02 to 0.08 ± 0.01 µM) in the articular fluid (all at p < 0.05). These effects are probably related to the elimination of inefficiency of the antioxidant system in the synovial medium, thus preventing inflammatory destruction of articular tissues, hindering the development of pannus, and assisting the activation of reparative regeneration of connective tissue structures.

[THE STATE AND PERSPECTIVES OF DEVELOPMENT OF TRAUMATOLOGICAL ORTHOPEDIC OUT-PATIENT CARE TO POPULATION OF THE PRIVOLJSKII FEDERAL OKRUG].

The article presents the results of analysis ofmanpower support of specialized out-patient traumatological orthopedic care in the Privoljskii federal okrug. The manpower deficiency of traumatologist-orthopedist at the out-patient stage was established especially especially in rural area. This is cause of low indicators ofdispensary monitoring of patients with consequences of traumas and diseases of musculo-skeletal system and factual unavailability of rehabilitation care to patients of given profile. The experience oftraining and re-training of traumatologist-orthopedist is presented. The organization of hospital-substituting forms of medical service of profile patients in the Saratovskaia oblast. The directions of development of organization of specialized out-patient care to population of the region.

[The correlation analysis of content of α-defensins of neutrophils 1-3 and cytokines in blood plasma of patients in acute and early periods of traumatic disease of spinal cord.]

The technique of enzyme-linked immunosorbent assay was implemented to analyze in acute and early period of traumatic disease of spinal cord the content of human α-defensins of neutrophils 1-3 and pro- and anti-inflammatory cytokines in blood of 40 patients with complicated damages of cervical spine. The implemented comparative analysis established new correlations, characterizing systemic inflammatory response during post-traumatic period.

[Modern aspects of pathogenesis of the trauma of the spinal cord and trunks of peripheral nerves].

In pathogenesis of the traumatic disease of the spinal cord, two mechanisms of the injuries of its neuronal apparatus are defined: primary (necrosis) and secondary (apoptosis). In the work a participation of a number of internal causes in the progression of apoptosis in injury of the spinal cord and peripheral nerve trunks, the role of those remains little-studied up to date, is discussed.

[Structural and functional characteristics of bone tissue and blood cytokines in health and disease of the joints].

Change of structural and functional state of bone in patients with primary osteoarthrosis of the hip joint compared to healthy individuals is characterized by decreased bone formation with a relative predominance of resorption. Osteopenic syndrome develops in the background of evident imbalance of a blood cytokine profile with increasing the level of proinflammatory and the variability of the level of anti-inflammatory cytokines.

[Endothelial cell adhesion molecules].

The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

[The biological kinetics of biofilms of clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa separated from patients with bronchopulmonary complications under traumatic disease of spinal cord].

The capacity and intensity of formation of microbial biofilms was analyzed in 24 strains of Staphylococcus aureus and Pseudomonas aeruginosa in static conditions of cultivation during 24, 48, 72 and 96 yours. The microorganisms were separated from patients with bronchopulmonary infectious complications in acute and early periods of traumatic disease of spinal cord.

[The possibilities and perspectives of using scaffold technology for bone regeneration].

The article deals with the one of the topical problem of tissue engineering--the design and implementation of biomaterials that could replace and repair bone defects. This review presents the recent studies of the potential of scaffold technology in bone tissue regeneration. This article contains information about the basic parameters and properties of modern scaffold systems. The results of experimental in vitro and in vivo studies on the use of matrices made of various materials are shown. Advantages and disadvantages of various materials used for the production of scaffolds are discussed. Attention is paid to the advantages combinations of different materials to achieve the desired structural and functional properties. Particular attention is paid to technologies and systems of targeted delivery and controlled release of factors that stimulate bone tissue regeneration. Different strategies for modulating tissue reactions and immune responses that take place during scaffold implantation are presented.