Content of blood cell components,inflammatory cytokines and growth factors in autologous platelet-rich plasma obtained by various methods

BACKGROUND The evaluation of the efficacy of platelet-rich plasma(PRP) in clinical practice yields conflicting results and raises numerous controversies. This may be due to different concentrations of biologically active components in PRP obtained with the use of different methods of gravity separation.AIM To compare the content, repeatability and correlations between biologically active components in PRP obtained with four different commercial systems.METHODS From a whole blood sample of each of 12 healthy male volunteers, 4 PRP samples were prepared using 4 different commercial kits [Arthrex Autologous Conditioned Plasma(ACP), Mini GPS Ⅲ, Xerthra, Dr. PRP] in accordance with the instructions provided by the manufacturers. A comparative analysis of blood cell components-13 selected inflammatory cytokines and 7 growth factors-in the obtained PRP samples was performed using the Kruskal-Wallis test by ranks. The repeatability of results in each method was evaluated by the estimation of the coefficient of variation. The Spearman correlation was used to estimate the relationship between blood cell content and cytokines.RESULTS Significantly higher concentrations of platelets(PLT), white blood cells(WBC) and red blood cells(RBC) were found in PRP obtained with the use of Mini GPS Ⅲ than in PRP obtained using other systems. Significant differences in the content of growth factors and cytokines in PRP were found. A positive correlation of the amount of PLT, RBC and WBC with the concentration of most of the growth factors was found but in only three inflammatory cytokines. The obtained correlations between blood cell components and cytokines differed between the systems in terms of statistical significance, which may be due to insufficient sample size. The repeatability of the obtained PLT concentration also varied between protocols with the lowest in Xerthra and the highest in Arthrex ACP.CONCLUSION Significant differences in the content of biologically active components and their repeatability were found in PRP obtained by various methods, providing new data for further research.

Prevascularized spongy-like hydrogels maintain their angiogenic potential after prolonged hypothermic storage

The chronic shortage of organs and tissues for transplantation represents a dramatic burden on healthcare systems worldwide.Tissue engineering offers a potential solution to address these shortages,but several challenges remain,with prevascularization being a critical factor for in vivo survival and integration of tissue engineering products.Concurrently,a different challenge hindering the clinical implementation of such products,regards their efficient preservation from the fabrication site to the bedside.Hypothermia has emerged as a potential solution for this issue due to its milder effects on biologic systems in comparison with other cold preservation methodologies.Its impact on prevascularization,however,has not been well studied.In this work,3D prevascularized constructs were fabricated using adipose-derived stromal vascular fraction cells and preserved at 4◦C using Hypothermosol or basal culture media(α-MEM).Hypothermosol efficiently preserved the structural and cellular integrity of prevascular networks as compared to constructs before preservation.In contrast,the use ofα-MEM led to a clear reduction in prevascular structures,with concurrent induction of high levels of apoptosis and autophagy at the cellular level.In vivo evaluation using a chorioallantoic membrane model demonstrated that,in opposition toα-MEM,Hypothermosol preservation retained the angiogenic potential of constructs before preservation by recruiting a similar number of blood vessels from the host and presenting similar integration with host tissue.These results emphasize the need of studying the impact of preservation techniques on key properties of tissue engineering constructs such as prevascularization,in order to validate and streamline their clinical application.