In Vitro Models of Spinal Cord Injury

Living organisms are extremely complex functional systems. At present, there are many in vivo models of spinal cord injury (SCI) that allow the modeling of any type of central nervous system (CNS) injury, however, with some disadvantages. The production of injury models can be a highly invasive and time‐consuming process and requires high technical requirements, and costly financial issues should also be taken into account. Of course, a large number of animals have been used to obtain the relevant data of statistical significance. All of these aspects can be reduced by carrying out experiments in in vitro conditions. The primary advantage of in vitro method is that it simplifies the system under study. There are two major groups of in vitro model in use: cell culture and organotypic slice (OTS) culture. OTS is an intermediate system of the screening of in vitro cell culture and animal models and represents the in vitro system preserving the basic tissue architecture that able to closely mimic the cellular and physiological characteristics in vivo. In vitro models are the preferred methods for the study of acute or subacute pathophysiology after a trauma stimulus, enabling precise control on the extracellular environment, easy and repeatable access to the cells

Characterization of Tetracalcium Phosphate/Monetite Biocement Modified by Magnesium Pyrophosphate

Magnesium pyrophosphate modified tetracalcium phosphate/monetite cement mixtures (MgTTCPM) were prepared by simple mechanical homogenization of compounds in a ball mill. The MgP2O7 was chosen due to the suitable setting properties of the final cements, in contrast to cements with the addition of amorphous (Ca, Mg) CO3 or newberite, which significantly extended the setting time even in small amounts (corresponding ~to 1 wt% of Mg in final cements). The results showed the gradual dissolution of the same amount of Mg2P2O7 phase, regardless of its content in the cement mixtures, and the refinement of formed HAP nanoparticles, which were joined into weakly and mutually bound spherical agglomerates. The compressive strength of composite cements was reduced to 14 MPa and the setting time was 5–10 min depending on the composition. Cytotoxicity of cements or their extracts was not detected and increased proliferative activity of mesenchymal stem cells with upregulation of osteopontin and osteonectin genes was verified in cells cultured for 7 and 15 days in cement extracts. The above facts, including insignificant changes in the pH of simulated body fluid solution and mechanical strength close to cancellous bone, indicate that MgTTCPM cement mixtures could be suitable biomaterials for use in the treatment of bone defects