State of the mineral component of rat bone tissue during hypokinesia and the recovery period

Experiments were conducted on young growing rats. Hypokinesia lasting from 20 to 200 days caused retarded gain in weight and volume of the femur and delayed development of the cortical layer of the diaphysis. In contrast, the density of the cortical layer of the femoral diaphysis increased due to elevation of the mineral saturation of the bone tissue microstructures. Incorporation of Ca into the bone tissue in hypokinesia had a tendency to reduce. Partial normalization of the bone tissue mineral component occurred during a 20 day recovery period following hypokinesia

Oxygen consumption of animals under conditions of hypokinesia

The influence of hypokinesia on the oxygen consumption of rats, dog, and squirrels was investigated. Three periods of gaseous exchange were revealed in rats under conditions of a limited motor activity. During the first 10-15 days O2 consumption displayed a sharp elevation; on the 20th-30th day, it became stabilized at a higher level (in comparison with control) and it sharply rose again on the 40th-100th day. In dogs, hypokinesia produced a reduction of O2 consumption and then a tendency to its elevation was seen. A short period of physical exercises in squirrels after hypokinesia led to increased oxygen consumption at rest

Effect of six-month hypokinesia in dogs on mineral component, reconstruction and mechanical properties of bone tissue

Ca45 incorporation into the bones of the limbs, particularly in the area of the muscle attachment increased in dogs as a result of 6 month hypokinesia. There were no phenomena of osteoporosis in the cortical layer of the diaphyses; however, changes in the form of osteons, an increase in the number of anastomoses between the channels and the thinning of the subperiosteal layer pointed to disturbances of the bone tissue reconstruction. Mineral saturation of the bone microstructures of the experimental dogs had a tendency to rise. No changes in the mechanical properties of the long bones occurred as a result of hypokinesia in dogs

Effects of factors of prolonged space flight on conditions of tortoise skeleton

After a 60-90 day space flight mild osteoporosis developed in the epiphyses and metaphyses of long tubular bones of tortoises, which was not attributed to reduced mineral saturation of the preserved bone tissue microstructures. The diminished strength of the cancellous bone of the epiphyses in tortoises after space flight was due to the reduced properties of its structure. The strength of the compact substance did not change under the effect of weightlessness

Biological activity comparative evaluation of the gene-Activated bone substitutes made of octacalcium phosphate and plasmid DNA carrying VEGF and SDF genes: Part 1 - in vitro

High need for effective bone substitutes and drawbacks of the materials approved for clinical use determine the increasing activity of biomedical research in this area. We have developed gene-Activated bone substitutes consisting of a scaffold based on octacalcium phosphate (OCP) and one of the two variants of plasmid DNA carrying either a gene for vascular endothelial growth factor (VEGF) or two genes encoding VEGF and stromal derived factor- 1α (SDF-1α). The aim of the study was to evaluate the cytotoxicity of the gene-Activated materials and their components, as well as biological activity in vitro. We found that both OCP and gene-Activated bone substitutes did not have any cytotoxicity, but reduced the proliferative activity of human bone marrow-derived multipotent mesenchymal stromal cells: material with doublegene construct decreased cell culture doubling rate of 24.3% more compared with the material carrying plasmid DNA encoding only VEGF. Both gene-Activated materials led to an increase in therapeutic genes mRNA levels, but the material with double-gene system enhanced VEGF protein production greater. Thus, the gene-Activated bone substitutes characterized by the absence of cytotoxic properties and possessed a specific activity increasing expression of the therapeutic genes. However, further studies are needed to detail the identified characteristics and assess the feasibility of the defined biological action in vivo

Biological activity comparative evaluation of the gene-Activated bone substitutes made of octacalcium phosphate and plasmid DNA carrying VEGF and SDF genes: Part 1 - in vitro

High need for effective bone substitutes and drawbacks of the materials approved for clinical use determine the increasing activity of biomedical research in this area. We have developed gene-Activated bone substitutes consisting of a scaffold based on octacalcium phosphate (OCP) and one of the two variants of plasmid DNA carrying either a gene for vascular endothelial growth factor (VEGF) or two genes encoding VEGF and stromal derived factor- 1α (SDF-1α). The aim of the study was to evaluate the cytotoxicity of the gene-Activated materials and their components, as well as biological activity in vitro. We found that both OCP and gene-Activated bone substitutes did not have any cytotoxicity, but reduced the proliferative activity of human bone marrow-derived multipotent mesenchymal stromal cells: material with doublegene construct decreased cell culture doubling rate of 24.3% more compared with the material carrying plasmid DNA encoding only VEGF. Both gene-Activated materials led to an increase in therapeutic genes mRNA levels, but the material with double-gene system enhanced VEGF protein production greater. Thus, the gene-Activated bone substitutes characterized by the absence of cytotoxic properties and possessed a specific activity increasing expression of the therapeutic genes. However, further studies are needed to detail the identified characteristics and assess the feasibility of the defined biological action in vivo

Biological activity comparative evaluation of the gene-Activated bone substitutes made of octacalcium phosphate and plasmid DNA carrying VEGF and SDF genes: Part 1 - in vitro

High need for effective bone substitutes and drawbacks of the materials approved for clinical use determine the increasing activity of biomedical research in this area. We have developed gene-Activated bone substitutes consisting of a scaffold based on octacalcium phosphate (OCP) and one of the two variants of plasmid DNA carrying either a gene for vascular endothelial growth factor (VEGF) or two genes encoding VEGF and stromal derived factor- 1α (SDF-1α). The aim of the study was to evaluate the cytotoxicity of the gene-Activated materials and their components, as well as biological activity in vitro. We found that both OCP and gene-Activated bone substitutes did not have any cytotoxicity, but reduced the proliferative activity of human bone marrow-derived multipotent mesenchymal stromal cells: material with doublegene construct decreased cell culture doubling rate of 24.3% more compared with the material carrying plasmid DNA encoding only VEGF. Both gene-Activated materials led to an increase in therapeutic genes mRNA levels, but the material with double-gene system enhanced VEGF protein production greater. Thus, the gene-Activated bone substitutes characterized by the absence of cytotoxic properties and possessed a specific activity increasing expression of the therapeutic genes. However, further studies are needed to detail the identified characteristics and assess the feasibility of the defined biological action in vivo

Biological activity comparative evaluation of the gene-Activated bone substitutes made of octacalcium phosphate and plasmid DNA carrying VEGF and SDF genes: Part 1 - in vitro

High need for effective bone substitutes and drawbacks of the materials approved for clinical use determine the increasing activity of biomedical research in this area. We have developed gene-Activated bone substitutes consisting of a scaffold based on octacalcium phosphate (OCP) and one of the two variants of plasmid DNA carrying either a gene for vascular endothelial growth factor (VEGF) or two genes encoding VEGF and stromal derived factor- 1α (SDF-1α). The aim of the study was to evaluate the cytotoxicity of the gene-Activated materials and their components, as well as biological activity in vitro. We found that both OCP and gene-Activated bone substitutes did not have any cytotoxicity, but reduced the proliferative activity of human bone marrow-derived multipotent mesenchymal stromal cells: material with doublegene construct decreased cell culture doubling rate of 24.3% more compared with the material carrying plasmid DNA encoding only VEGF. Both gene-Activated materials led to an increase in therapeutic genes mRNA levels, but the material with double-gene system enhanced VEGF protein production greater. Thus, the gene-Activated bone substitutes characterized by the absence of cytotoxic properties and possessed a specific activity increasing expression of the therapeutic genes. However, further studies are needed to detail the identified characteristics and assess the feasibility of the defined biological action in vivo