Open fractures can be divided into three degrees (1, 2, 3), based on diversity of tissue damage and infections. First- and second- degree open wounds within 6-8 hours may be treated by primary intention using conventional osteosynthesis techniques. In contrast, treatments for the third- degree fractures include to remove the necrotic tissue and to eliminate infection. The open fractures are most common reason for osteomyelitis in small animals. Open fractures may also form sequesters because of infection bone fragments in the fracture zone. Soft- tissue wounds and fractures bones in open fractures of long bones in dogs have significant pathogenetic influence not only in the pathological zone, but also in overall animal organism. Open fractures can also be life - threatening, because it can cause to complications such as pseudoarthrosis, purulent osteomyelitis, and sepsis, so the treatment of open fractures of the bones of the extremities must combine antiseptic and stimulating therapy.

Achievements of nanotechnology since 2007, began intensively implementing in veterinary - medical practice. However, are most rational to use nanoaquahelats of metals because of its high antibacterial properties and considerable regenerative activity. The nanoaquahelate therapy of open fractures in dogs it is necessary to complement the robust immobilization damaged segment and immobilization of proximal and distal joints. As expressed in an open fracture the whole system reacts connective tissue, the determination of its response and reparative capacity has important theoretical and practical significance.

The purpose of this study was to investigate the changes in connective tissue and regenerate hard time forming callus in wound healing of open fractures of long bones in dogs under the influence of nanoaquahelats metals: Ag, Cu, Zn, Mg, Co.

Experiments were performed on two groups of dogs - analogs with open fractures of radial and tibial bones. Following the treatment, animals were housed under identical experimental conditions and on standard diet. We carried out a debridement, osteosynthesis of bone fragments, topical antiseptic and imposed fenestrated bandage hardens. Through the cannula was introduced in the wound: for the control animals Clamoxyl solution (prolonged broad-spectrum antibiotic) at a dose of 0,1 ml/kg body weight once a day; for test animals – complex nanoaquahelats of metals (Ag, Cu, Zn, Mg, Co) at a dose of 10 ml, in a concentration of 70–100 mg/l (50–70 nm, nanosize).The experiment lasted 40 days. During the experiment conducted regularly measuring body temperature, heart rate and breathing. In the serum of animals the level of glycoproteins, glycosaminoglycans and sialic acids was determined. Small fragments were obtained from different parts of the fracture gap radius and tibia economical method trepanobiopsy from 10 days to 25 minutes, with an interval of 5 days. Bioethical standards have been met. There were a total of 10 dogs in the study with fractures of the forearm and lower leg. The fragments were fixed in 10% neutral formalin and decalcified in 7 % nitric acid. Were prepared, frozen and paraffin sections. Sections were stained with hematoxylin and eosin, Van Gieson. Study of pathogenetic mechanisms of the reaction of connective-tissue in the open bone fractures, include accounting for changes in specific markers of connective tissue metabolites in serum blood (glycoproteins, proteoglycans, sialic acids).

The examination of the status of metabolism connective tissue showed a significant increase in the level of the destruction markers in control dogs throughout the experiment. The destruction of connective tissue caused by wound healing and regenerate connective-tissue restructuring processes in dogs of the experimental group was less pronounced, that is leaking more favorably.

A zone of fracture, on the background dystrophic and necrobiotic changes in end portions of the wreckages, characterized by abundant infiltration of neutrophils, monocytes and lymphocytes, that in the control after 16–20 days was changing of expressions proliferation of fibroblasts, followed accompanied by the production of a base material (matrix) of the connective tissue.

In the experiment, the corresponding changes were accelerated by 3–5 days, after which the fracture gap noted intense proliferation of fibrous mesh fibers.

Appropriate changes were accelerated by 3–5 days in the experiment, after which the fracture gap noted intense proliferation of fibrous mesh fibers.

The formation well structured callus tissue with vascular constriction channels were observed in the control after 22–25 days. A callus fracture is painted paler hematoxylin and eosin due to pronounced sclerosis and hyalinosis.

A callus fracture appeared as a dense bone on the 19–20th day of the experiment and its density is much higher than the density of all bone fragments that it is firmly connected to each other, which marked the formation Callus durum.

Application of metal nanoparticles in open fractures in dogs reduces the time adjustment regenerate connective-tissue due to less severe destruction of connective tissue.

Slow recovery of the histopathological characteristics of callus fracture bone tissue in the diaphyseal radius and tibia observed in control animals. Meanwhile, in dogs used nanoaqahelate therapy normalization observed histopathological indicators much earlier: as a rule, by 19–20 per day.

Application of nanoparticles of metals: Ag, Cu, Zn, Mg, Co; with open fractures in dogs reduces the time adjustment regenerate connective-tissue due to less severe degradation of connective tissue restores the histopathological characteristics of solid callus at an earlier date.

Key words: nanoaquahelats of metals, open fractures of long bones, connective-tissue of regenerate, hard callus, dog.