Treatments of fragmentary fractures in case of loss regenerative potential of bone tissue require usingdiff erent composite materials. Among all of them, ceramics based on synthetic hydroxyapatite and tricalcium phosphate are considered promising. The reparative osteogenesis in spongy and compact rabbit’s bone tissueusing 3 composite materials with diff erent physicochemical propertieswas studied. A reparative osteogenesiscontrolled by monitoring clinical, radiologic and macromorphologic parameters. Composite materials infl uence on the organism was studied by determining the dynamics of hematological parameters throughout the study period. To realize this scheme was formed a 3 experimental groups and one control group of rabbits. The created defects of animals of fi rst experimental group were fi lled out with GT + α-TKF-500, thedefects of second oneanimals group fi lled out with GTlKl-2, and defects ofthird oneanimals group fi lled out with GTlKg-700. The GTlKl-700materials were doped with silicon. In control animals, bone defects were allowed to heal under a blood clot. During the studies, all animals were located in the same environment conditions. A blood samples for hematological investigation was taken from the external jugular vein before anesthesia and at the 3rd, 7th, 14th, 21st and 42nd day after surgery. X-ray examination was performed on 14th, 21st, and 42nddays.The animals were removed from the experiment on 21stand 42nd days. The samples were examined by macromorphologic method. By radiologic examination was found that composite materials had osteoconductive properties except the silicondoped example which hadosteoinductive properties. The samples of compact bone tissue of 1st and 3rd experimental groups characterized by formation of punctate osteosclerosis with a compacted contour of the periosteumon the 42nd day. But the bone samples of 2nd experimental group had compacted contours of the periosteum only. However, in the cancellous bone tissue on the 42nd day in the animals of the 1st experimental group developed point osteosclerosis, which visualized as individual granules of the composite.But in the animals of 2nd group thewhite spot which was outlined shape and homogeneous structure at the defect was found. The bone samples of 3rd animals group shoved a clearly limited point osteosclerosisforming were was found ceramic granules. In case using ofGT + α-TKF-500, a strong connection of granules from the formed bone tissue and without any periosteal growthswas noted. Using GTlKl-2 places of defects were identical to not injured sites of radial bones. Using GTlKg-700 shows that bone defect is fi lled to the level of the plane of the bone surface and covered with a periosteum without visible growths. The granules of the composite are evenly distributed in the regenerate and associated with bone tissue. The analysis of hematological parameters did not reveal any fundamental diff erences, but the use of hydroxyapatite implants is not accompanied, in contrast to spontaneous reparative osteogenesis, the development of leukocytosis, which indicates a moderate course of its infl ammatory reaction. But the latter is accompanied by a platelet reaction, the most pronounced when using implants, which is probably due to the infl uence of platelet factors and is indirect evidence of early osteoblastic reaction. Key words: fractures, rabbits, erythrocytes, leukocytes, platelets, hemoglobin.
Bone regeneration is one of the most complex and unique types of tissue regeneration, although quite long in time, comparatively, for example, with soft tissues, but provides the complete identity of the damaged site with normal bone. The most complex fractures are fragmentation, which can be occurs within wide range - 25-60% of the total number of all fractures. In such cases, due to the loss of contact with soft tissues, the fragments lose blood supply and regeneration, which leads to different bone size defect. This condition cause limitation of the main mechanisms of bone consolidation – endoostal and intramembrane ossification. In this regard, a strategic medical treatment is the replacement of bone defect with biological or synthetic material, which creates a site for the processes of reparative osteogenesis. The most widespread combined biocompatible materials in the various combinations of β-tricalcium phosphate and hydroxyapatite ("Maxresorb®", "Perossal®", "calc-i-oss®CRYSTAL", "easy-graft®CRYSTAL"), or composite composites based on bioactive and biogenic materials: hydroxylapatite + collagen (Biostite, Collagraft, Avitene, Collola, Hapkol, Collapan, MP Composite); hydroxylapatite + tricalcium phosphate + collagen ("Hydroxyapol", "Collapolum"); hydroxylapatite + collagen + sulfated glycosaminoglycans ("Biomatrix", "Osteomatrix", "Bioimplant"). Unfortunately, in veterinary medicine osteotropic materials developed for humane medicine are used only. Recently, a separate group of biocompatible composites based on the combination of hydroxyapatite with β-tricalcium phosphate, doped with magnesium, sodium, potassium, zinc, copper, aluminum, strontium, silicon, germanium, in order to provide them with specific properties - antibacterial, osteoinductive, antitumor, immunomodulating, etc. However, the spectrum of biological effects of these ions on bone metabolism is extremely diverse, and therefore the use of composite ceramics doped with microelement ions requires a comprehensive clinical and experimental justification. The purpose of the study is to evaluate the osteointegration and osteoinductive properties of ceramics based on hydroxyapatite and β-tricalcium phosphate doped with silicon for model fractures of the femur in rabbits. The work is done on rabbits of Californian breed at the age of 3 months. and a weight of about 2.5 kg. To substantiate the ceramics GTlKg-2, 2 groups of 10 rabbits were formed in each, in which model bone defects were formed in the distal parts of the hip dysthymia. Animals of the experimental group defects filled with granules of ceramics. In the rabbits of the control group, the defect was left to heal under a blood clot. Animals were extracted from the experiment at the 21st and 42nd day. X-ray and histomorphological studies were performed. On the 21st day of reparative osteogenesis, rabbits of all groups fully rested on the injured limb, signs of inflammatory reaction were absent in the experimental group, and the control marked the pronounced seal of the periosteum across the entire surface of the femur. It should be noted that hydroxyapatite ceramics does not possess x-ray contrast properties. On the 42nd day of regeneration of rabbits both groups fully rested on injured limb, signs of inflammatory reaction of soft tissues in the area of injury were absent. Radiologically, in animals of the experimental group in the place of bone defect, spot osteosclerosis was detected in the form of a clearly defined white heel, opposite to which the contour of the periosteum was sealed. At the same time, on the control X-rays, along with a well-defined, but more elongated septum of the periodontal, revealed a bone marrow panossus at the site of the injury, with a clearly defined extension of the eclipse. Substantially complemented macromorphological picture of bone biopsy. In particular, in the case of replacement of bone defect GTlKg-2, at the 21st day in the traumatic areas a limited and moderate periosteal reaction was noted. Along with this, in control animals, in this period, it was not completely replaced by fibrous cartilaginous tissue, as evidenced by its craterial appearance. Histologically, in the control animals, the bone defect formed a cartilage tissue along the periphery, and the bone beams, which were at a certain distance from the place of the defect, were at the stage of resorption. In the case of its replacement granules GTlKg-2 formed bone-ceramic regenerate, that is, the intervals between the granules are filled with bone tissue. The obtained results give grounds to consider that GTlKg-2 contributes to the formation of bone tissue due to its osteointegration and osteoinductive properties. Key words: reparative osteogenesis, osteointegration, osteocytes, osteoblasts, hydroxyapatite composite with β-tricalcium phosphate, doped with silicon.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.